diff options
Diffstat (limited to 'libgo/go/encoding/gob')
-rw-r--r-- | libgo/go/encoding/gob/codec_test.go | 1406 | ||||
-rw-r--r-- | libgo/go/encoding/gob/debug.go | 687 | ||||
-rw-r--r-- | libgo/go/encoding/gob/decode.go | 1279 | ||||
-rw-r--r-- | libgo/go/encoding/gob/decoder.go | 214 | ||||
-rw-r--r-- | libgo/go/encoding/gob/doc.go | 366 | ||||
-rw-r--r-- | libgo/go/encoding/gob/dump.go | 22 | ||||
-rw-r--r-- | libgo/go/encoding/gob/encode.go | 717 | ||||
-rw-r--r-- | libgo/go/encoding/gob/encoder.go | 251 | ||||
-rw-r--r-- | libgo/go/encoding/gob/encoder_test.go | 664 | ||||
-rw-r--r-- | libgo/go/encoding/gob/error.go | 39 | ||||
-rw-r--r-- | libgo/go/encoding/gob/gobencdec_test.go | 528 | ||||
-rw-r--r-- | libgo/go/encoding/gob/timing_test.go | 94 | ||||
-rw-r--r-- | libgo/go/encoding/gob/type.go | 788 | ||||
-rw-r--r-- | libgo/go/encoding/gob/type_test.go | 161 |
14 files changed, 7216 insertions, 0 deletions
diff --git a/libgo/go/encoding/gob/codec_test.go b/libgo/go/encoding/gob/codec_test.go new file mode 100644 index 0000000..dc0e007 --- /dev/null +++ b/libgo/go/encoding/gob/codec_test.go @@ -0,0 +1,1406 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bytes" + "errors" + "math" + "reflect" + "strings" + "testing" + "unsafe" +) + +// Guarantee encoding format by comparing some encodings to hand-written values +type EncodeT struct { + x uint64 + b []byte +} + +var encodeT = []EncodeT{ + {0x00, []byte{0x00}}, + {0x0F, []byte{0x0F}}, + {0xFF, []byte{0xFF, 0xFF}}, + {0xFFFF, []byte{0xFE, 0xFF, 0xFF}}, + {0xFFFFFF, []byte{0xFD, 0xFF, 0xFF, 0xFF}}, + {0xFFFFFFFF, []byte{0xFC, 0xFF, 0xFF, 0xFF, 0xFF}}, + {0xFFFFFFFFFF, []byte{0xFB, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}}, + {0xFFFFFFFFFFFF, []byte{0xFA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}}, + {0xFFFFFFFFFFFFFF, []byte{0xF9, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}}, + {0xFFFFFFFFFFFFFFFF, []byte{0xF8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF}}, + {0x1111, []byte{0xFE, 0x11, 0x11}}, + {0x1111111111111111, []byte{0xF8, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11}}, + {0x8888888888888888, []byte{0xF8, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88}}, + {1 << 63, []byte{0xF8, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}}, +} + +// testError is meant to be used as a deferred function to turn a panic(gobError) into a +// plain test.Error call. +func testError(t *testing.T) { + if e := recover(); e != nil { + t.Error(e.(gobError).err) // Will re-panic if not one of our errors, such as a runtime error. + } + return +} + +// Test basic encode/decode routines for unsigned integers +func TestUintCodec(t *testing.T) { + defer testError(t) + b := new(bytes.Buffer) + encState := newEncoderState(b) + for _, tt := range encodeT { + b.Reset() + encState.encodeUint(tt.x) + if !bytes.Equal(tt.b, b.Bytes()) { + t.Errorf("encodeUint: %#x encode: expected % x got % x", tt.x, tt.b, b.Bytes()) + } + } + decState := newDecodeState(b) + for u := uint64(0); ; u = (u + 1) * 7 { + b.Reset() + encState.encodeUint(u) + v := decState.decodeUint() + if u != v { + t.Errorf("Encode/Decode: sent %#x received %#x", u, v) + } + if u&(1<<63) != 0 { + break + } + } +} + +func verifyInt(i int64, t *testing.T) { + defer testError(t) + var b = new(bytes.Buffer) + encState := newEncoderState(b) + encState.encodeInt(i) + decState := newDecodeState(b) + decState.buf = make([]byte, 8) + j := decState.decodeInt() + if i != j { + t.Errorf("Encode/Decode: sent %#x received %#x", uint64(i), uint64(j)) + } +} + +// Test basic encode/decode routines for signed integers +func TestIntCodec(t *testing.T) { + for u := uint64(0); ; u = (u + 1) * 7 { + // Do positive and negative values + i := int64(u) + verifyInt(i, t) + verifyInt(-i, t) + verifyInt(^i, t) + if u&(1<<63) != 0 { + break + } + } + verifyInt(-1<<63, t) // a tricky case +} + +// The result of encoding a true boolean with field number 7 +var boolResult = []byte{0x07, 0x01} +// The result of encoding a number 17 with field number 7 +var signedResult = []byte{0x07, 2 * 17} +var unsignedResult = []byte{0x07, 17} +var floatResult = []byte{0x07, 0xFE, 0x31, 0x40} +// The result of encoding a number 17+19i with field number 7 +var complexResult = []byte{0x07, 0xFE, 0x31, 0x40, 0xFE, 0x33, 0x40} +// The result of encoding "hello" with field number 7 +var bytesResult = []byte{0x07, 0x05, 'h', 'e', 'l', 'l', 'o'} + +func newDecodeState(buf *bytes.Buffer) *decoderState { + d := new(decoderState) + d.b = buf + d.buf = make([]byte, uint64Size) + return d +} + +func newEncoderState(b *bytes.Buffer) *encoderState { + b.Reset() + state := &encoderState{enc: nil, b: b} + state.fieldnum = -1 + return state +} + +// Test instruction execution for encoding. +// Do not run the machine yet; instead do individual instructions crafted by hand. +func TestScalarEncInstructions(t *testing.T) { + var b = new(bytes.Buffer) + + // bool + { + data := struct{ a bool }{true} + instr := &encInstr{encBool, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(boolResult, b.Bytes()) { + t.Errorf("bool enc instructions: expected % x got % x", boolResult, b.Bytes()) + } + } + + // int + { + b.Reset() + data := struct{ a int }{17} + instr := &encInstr{encInt, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(signedResult, b.Bytes()) { + t.Errorf("int enc instructions: expected % x got % x", signedResult, b.Bytes()) + } + } + + // uint + { + b.Reset() + data := struct{ a uint }{17} + instr := &encInstr{encUint, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(unsignedResult, b.Bytes()) { + t.Errorf("uint enc instructions: expected % x got % x", unsignedResult, b.Bytes()) + } + } + + // int8 + { + b.Reset() + data := struct{ a int8 }{17} + instr := &encInstr{encInt8, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(signedResult, b.Bytes()) { + t.Errorf("int8 enc instructions: expected % x got % x", signedResult, b.Bytes()) + } + } + + // uint8 + { + b.Reset() + data := struct{ a uint8 }{17} + instr := &encInstr{encUint8, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(unsignedResult, b.Bytes()) { + t.Errorf("uint8 enc instructions: expected % x got % x", unsignedResult, b.Bytes()) + } + } + + // int16 + { + b.Reset() + data := struct{ a int16 }{17} + instr := &encInstr{encInt16, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(signedResult, b.Bytes()) { + t.Errorf("int16 enc instructions: expected % x got % x", signedResult, b.Bytes()) + } + } + + // uint16 + { + b.Reset() + data := struct{ a uint16 }{17} + instr := &encInstr{encUint16, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(unsignedResult, b.Bytes()) { + t.Errorf("uint16 enc instructions: expected % x got % x", unsignedResult, b.Bytes()) + } + } + + // int32 + { + b.Reset() + data := struct{ a int32 }{17} + instr := &encInstr{encInt32, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(signedResult, b.Bytes()) { + t.Errorf("int32 enc instructions: expected % x got % x", signedResult, b.Bytes()) + } + } + + // uint32 + { + b.Reset() + data := struct{ a uint32 }{17} + instr := &encInstr{encUint32, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(unsignedResult, b.Bytes()) { + t.Errorf("uint32 enc instructions: expected % x got % x", unsignedResult, b.Bytes()) + } + } + + // int64 + { + b.Reset() + data := struct{ a int64 }{17} + instr := &encInstr{encInt64, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(signedResult, b.Bytes()) { + t.Errorf("int64 enc instructions: expected % x got % x", signedResult, b.Bytes()) + } + } + + // uint64 + { + b.Reset() + data := struct{ a uint64 }{17} + instr := &encInstr{encUint64, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(unsignedResult, b.Bytes()) { + t.Errorf("uint64 enc instructions: expected % x got % x", unsignedResult, b.Bytes()) + } + } + + // float32 + { + b.Reset() + data := struct{ a float32 }{17} + instr := &encInstr{encFloat32, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(floatResult, b.Bytes()) { + t.Errorf("float32 enc instructions: expected % x got % x", floatResult, b.Bytes()) + } + } + + // float64 + { + b.Reset() + data := struct{ a float64 }{17} + instr := &encInstr{encFloat64, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(floatResult, b.Bytes()) { + t.Errorf("float64 enc instructions: expected % x got % x", floatResult, b.Bytes()) + } + } + + // bytes == []uint8 + { + b.Reset() + data := struct{ a []byte }{[]byte("hello")} + instr := &encInstr{encUint8Array, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(bytesResult, b.Bytes()) { + t.Errorf("bytes enc instructions: expected % x got % x", bytesResult, b.Bytes()) + } + } + + // string + { + b.Reset() + data := struct{ a string }{"hello"} + instr := &encInstr{encString, 6, 0, 0} + state := newEncoderState(b) + instr.op(instr, state, unsafe.Pointer(&data)) + if !bytes.Equal(bytesResult, b.Bytes()) { + t.Errorf("string enc instructions: expected % x got % x", bytesResult, b.Bytes()) + } + } +} + +func execDec(typ string, instr *decInstr, state *decoderState, t *testing.T, p unsafe.Pointer) { + defer testError(t) + v := int(state.decodeUint()) + if v+state.fieldnum != 6 { + t.Fatalf("decoding field number %d, got %d", 6, v+state.fieldnum) + } + instr.op(instr, state, decIndirect(p, instr.indir)) + state.fieldnum = 6 +} + +func newDecodeStateFromData(data []byte) *decoderState { + b := bytes.NewBuffer(data) + state := newDecodeState(b) + state.fieldnum = -1 + return state +} + +// Test instruction execution for decoding. +// Do not run the machine yet; instead do individual instructions crafted by hand. +func TestScalarDecInstructions(t *testing.T) { + ovfl := errors.New("overflow") + + // bool + { + var data struct { + a bool + } + instr := &decInstr{decBool, 6, 0, 0, ovfl} + state := newDecodeStateFromData(boolResult) + execDec("bool", instr, state, t, unsafe.Pointer(&data)) + if data.a != true { + t.Errorf("bool a = %v not true", data.a) + } + } + // int + { + var data struct { + a int + } + instr := &decInstr{decOpTable[reflect.Int], 6, 0, 0, ovfl} + state := newDecodeStateFromData(signedResult) + execDec("int", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("int a = %v not 17", data.a) + } + } + + // uint + { + var data struct { + a uint + } + instr := &decInstr{decOpTable[reflect.Uint], 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uint", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uint a = %v not 17", data.a) + } + } + + // int8 + { + var data struct { + a int8 + } + instr := &decInstr{decInt8, 6, 0, 0, ovfl} + state := newDecodeStateFromData(signedResult) + execDec("int8", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("int8 a = %v not 17", data.a) + } + } + + // uint8 + { + var data struct { + a uint8 + } + instr := &decInstr{decUint8, 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uint8", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uint8 a = %v not 17", data.a) + } + } + + // int16 + { + var data struct { + a int16 + } + instr := &decInstr{decInt16, 6, 0, 0, ovfl} + state := newDecodeStateFromData(signedResult) + execDec("int16", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("int16 a = %v not 17", data.a) + } + } + + // uint16 + { + var data struct { + a uint16 + } + instr := &decInstr{decUint16, 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uint16", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uint16 a = %v not 17", data.a) + } + } + + // int32 + { + var data struct { + a int32 + } + instr := &decInstr{decInt32, 6, 0, 0, ovfl} + state := newDecodeStateFromData(signedResult) + execDec("int32", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("int32 a = %v not 17", data.a) + } + } + + // uint32 + { + var data struct { + a uint32 + } + instr := &decInstr{decUint32, 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uint32", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uint32 a = %v not 17", data.a) + } + } + + // uintptr + { + var data struct { + a uintptr + } + instr := &decInstr{decOpTable[reflect.Uintptr], 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uintptr", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uintptr a = %v not 17", data.a) + } + } + + // int64 + { + var data struct { + a int64 + } + instr := &decInstr{decInt64, 6, 0, 0, ovfl} + state := newDecodeStateFromData(signedResult) + execDec("int64", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("int64 a = %v not 17", data.a) + } + } + + // uint64 + { + var data struct { + a uint64 + } + instr := &decInstr{decUint64, 6, 0, 0, ovfl} + state := newDecodeStateFromData(unsignedResult) + execDec("uint64", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("uint64 a = %v not 17", data.a) + } + } + + // float32 + { + var data struct { + a float32 + } + instr := &decInstr{decFloat32, 6, 0, 0, ovfl} + state := newDecodeStateFromData(floatResult) + execDec("float32", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("float32 a = %v not 17", data.a) + } + } + + // float64 + { + var data struct { + a float64 + } + instr := &decInstr{decFloat64, 6, 0, 0, ovfl} + state := newDecodeStateFromData(floatResult) + execDec("float64", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17 { + t.Errorf("float64 a = %v not 17", data.a) + } + } + + // complex64 + { + var data struct { + a complex64 + } + instr := &decInstr{decOpTable[reflect.Complex64], 6, 0, 0, ovfl} + state := newDecodeStateFromData(complexResult) + execDec("complex", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17+19i { + t.Errorf("complex a = %v not 17+19i", data.a) + } + } + + // complex128 + { + var data struct { + a complex128 + } + instr := &decInstr{decOpTable[reflect.Complex128], 6, 0, 0, ovfl} + state := newDecodeStateFromData(complexResult) + execDec("complex", instr, state, t, unsafe.Pointer(&data)) + if data.a != 17+19i { + t.Errorf("complex a = %v not 17+19i", data.a) + } + } + + // bytes == []uint8 + { + var data struct { + a []byte + } + instr := &decInstr{decUint8Slice, 6, 0, 0, ovfl} + state := newDecodeStateFromData(bytesResult) + execDec("bytes", instr, state, t, unsafe.Pointer(&data)) + if string(data.a) != "hello" { + t.Errorf(`bytes a = %q not "hello"`, string(data.a)) + } + } + + // string + { + var data struct { + a string + } + instr := &decInstr{decString, 6, 0, 0, ovfl} + state := newDecodeStateFromData(bytesResult) + execDec("bytes", instr, state, t, unsafe.Pointer(&data)) + if data.a != "hello" { + t.Errorf(`bytes a = %q not "hello"`, data.a) + } + } +} + +func TestEndToEnd(t *testing.T) { + type T2 struct { + T string + } + s1 := "string1" + s2 := "string2" + type T1 struct { + A, B, C int + M map[string]*float64 + EmptyMap map[string]int // to check that we receive a non-nil map. + N *[3]float64 + Strs *[2]string + Int64s *[]int64 + RI complex64 + S string + Y []byte + T *T2 + } + pi := 3.14159 + e := 2.71828 + t1 := &T1{ + A: 17, + B: 18, + C: -5, + M: map[string]*float64{"pi": &pi, "e": &e}, + EmptyMap: make(map[string]int), + N: &[3]float64{1.5, 2.5, 3.5}, + Strs: &[2]string{s1, s2}, + Int64s: &[]int64{77, 89, 123412342134}, + RI: 17 - 23i, + S: "Now is the time", + Y: []byte("hello, sailor"), + T: &T2{"this is T2"}, + } + b := new(bytes.Buffer) + err := NewEncoder(b).Encode(t1) + if err != nil { + t.Error("encode:", err) + } + var _t1 T1 + err = NewDecoder(b).Decode(&_t1) + if err != nil { + t.Fatal("decode:", err) + } + if !reflect.DeepEqual(t1, &_t1) { + t.Errorf("encode expected %v got %v", *t1, _t1) + } + // Be absolutely sure the received map is non-nil. + if t1.EmptyMap == nil { + t.Errorf("nil map sent") + } + if _t1.EmptyMap == nil { + t.Errorf("nil map received") + } +} + +func TestOverflow(t *testing.T) { + type inputT struct { + Maxi int64 + Mini int64 + Maxu uint64 + Maxf float64 + Minf float64 + Maxc complex128 + Minc complex128 + } + var it inputT + var err error + b := new(bytes.Buffer) + enc := NewEncoder(b) + dec := NewDecoder(b) + + // int8 + b.Reset() + it = inputT{ + Maxi: math.MaxInt8 + 1, + } + type outi8 struct { + Maxi int8 + Mini int8 + } + var o1 outi8 + enc.Encode(it) + err = dec.Decode(&o1) + if err == nil || err.Error() != `value for "Maxi" out of range` { + t.Error("wrong overflow error for int8:", err) + } + it = inputT{ + Mini: math.MinInt8 - 1, + } + b.Reset() + enc.Encode(it) + err = dec.Decode(&o1) + if err == nil || err.Error() != `value for "Mini" out of range` { + t.Error("wrong underflow error for int8:", err) + } + + // int16 + b.Reset() + it = inputT{ + Maxi: math.MaxInt16 + 1, + } + type outi16 struct { + Maxi int16 + Mini int16 + } + var o2 outi16 + enc.Encode(it) + err = dec.Decode(&o2) + if err == nil || err.Error() != `value for "Maxi" out of range` { + t.Error("wrong overflow error for int16:", err) + } + it = inputT{ + Mini: math.MinInt16 - 1, + } + b.Reset() + enc.Encode(it) + err = dec.Decode(&o2) + if err == nil || err.Error() != `value for "Mini" out of range` { + t.Error("wrong underflow error for int16:", err) + } + + // int32 + b.Reset() + it = inputT{ + Maxi: math.MaxInt32 + 1, + } + type outi32 struct { + Maxi int32 + Mini int32 + } + var o3 outi32 + enc.Encode(it) + err = dec.Decode(&o3) + if err == nil || err.Error() != `value for "Maxi" out of range` { + t.Error("wrong overflow error for int32:", err) + } + it = inputT{ + Mini: math.MinInt32 - 1, + } + b.Reset() + enc.Encode(it) + err = dec.Decode(&o3) + if err == nil || err.Error() != `value for "Mini" out of range` { + t.Error("wrong underflow error for int32:", err) + } + + // uint8 + b.Reset() + it = inputT{ + Maxu: math.MaxUint8 + 1, + } + type outu8 struct { + Maxu uint8 + } + var o4 outu8 + enc.Encode(it) + err = dec.Decode(&o4) + if err == nil || err.Error() != `value for "Maxu" out of range` { + t.Error("wrong overflow error for uint8:", err) + } + + // uint16 + b.Reset() + it = inputT{ + Maxu: math.MaxUint16 + 1, + } + type outu16 struct { + Maxu uint16 + } + var o5 outu16 + enc.Encode(it) + err = dec.Decode(&o5) + if err == nil || err.Error() != `value for "Maxu" out of range` { + t.Error("wrong overflow error for uint16:", err) + } + + // uint32 + b.Reset() + it = inputT{ + Maxu: math.MaxUint32 + 1, + } + type outu32 struct { + Maxu uint32 + } + var o6 outu32 + enc.Encode(it) + err = dec.Decode(&o6) + if err == nil || err.Error() != `value for "Maxu" out of range` { + t.Error("wrong overflow error for uint32:", err) + } + + // float32 + b.Reset() + it = inputT{ + Maxf: math.MaxFloat32 * 2, + } + type outf32 struct { + Maxf float32 + Minf float32 + } + var o7 outf32 + enc.Encode(it) + err = dec.Decode(&o7) + if err == nil || err.Error() != `value for "Maxf" out of range` { + t.Error("wrong overflow error for float32:", err) + } + + // complex64 + b.Reset() + it = inputT{ + Maxc: complex(math.MaxFloat32*2, math.MaxFloat32*2), + } + type outc64 struct { + Maxc complex64 + Minc complex64 + } + var o8 outc64 + enc.Encode(it) + err = dec.Decode(&o8) + if err == nil || err.Error() != `value for "Maxc" out of range` { + t.Error("wrong overflow error for complex64:", err) + } +} + +func TestNesting(t *testing.T) { + type RT struct { + A string + Next *RT + } + rt := new(RT) + rt.A = "level1" + rt.Next = new(RT) + rt.Next.A = "level2" + b := new(bytes.Buffer) + NewEncoder(b).Encode(rt) + var drt RT + dec := NewDecoder(b) + err := dec.Decode(&drt) + if err != nil { + t.Fatal("decoder error:", err) + } + if drt.A != rt.A { + t.Errorf("nesting: encode expected %v got %v", *rt, drt) + } + if drt.Next == nil { + t.Errorf("nesting: recursion failed") + } + if drt.Next.A != rt.Next.A { + t.Errorf("nesting: encode expected %v got %v", *rt.Next, *drt.Next) + } +} + +// These three structures have the same data with different indirections +type T0 struct { + A int + B int + C int + D int +} +type T1 struct { + A int + B *int + C **int + D ***int +} +type T2 struct { + A ***int + B **int + C *int + D int +} + +func TestAutoIndirection(t *testing.T) { + // First transfer t1 into t0 + var t1 T1 + t1.A = 17 + t1.B = new(int) + *t1.B = 177 + t1.C = new(*int) + *t1.C = new(int) + **t1.C = 1777 + t1.D = new(**int) + *t1.D = new(*int) + **t1.D = new(int) + ***t1.D = 17777 + b := new(bytes.Buffer) + enc := NewEncoder(b) + enc.Encode(t1) + dec := NewDecoder(b) + var t0 T0 + dec.Decode(&t0) + if t0.A != 17 || t0.B != 177 || t0.C != 1777 || t0.D != 17777 { + t.Errorf("t1->t0: expected {17 177 1777 17777}; got %v", t0) + } + + // Now transfer t2 into t0 + var t2 T2 + t2.D = 17777 + t2.C = new(int) + *t2.C = 1777 + t2.B = new(*int) + *t2.B = new(int) + **t2.B = 177 + t2.A = new(**int) + *t2.A = new(*int) + **t2.A = new(int) + ***t2.A = 17 + b.Reset() + enc.Encode(t2) + t0 = T0{} + dec.Decode(&t0) + if t0.A != 17 || t0.B != 177 || t0.C != 1777 || t0.D != 17777 { + t.Errorf("t2->t0 expected {17 177 1777 17777}; got %v", t0) + } + + // Now transfer t0 into t1 + t0 = T0{17, 177, 1777, 17777} + b.Reset() + enc.Encode(t0) + t1 = T1{} + dec.Decode(&t1) + if t1.A != 17 || *t1.B != 177 || **t1.C != 1777 || ***t1.D != 17777 { + t.Errorf("t0->t1 expected {17 177 1777 17777}; got {%d %d %d %d}", t1.A, *t1.B, **t1.C, ***t1.D) + } + + // Now transfer t0 into t2 + b.Reset() + enc.Encode(t0) + t2 = T2{} + dec.Decode(&t2) + if ***t2.A != 17 || **t2.B != 177 || *t2.C != 1777 || t2.D != 17777 { + t.Errorf("t0->t2 expected {17 177 1777 17777}; got {%d %d %d %d}", ***t2.A, **t2.B, *t2.C, t2.D) + } + + // Now do t2 again but without pre-allocated pointers. + b.Reset() + enc.Encode(t0) + ***t2.A = 0 + **t2.B = 0 + *t2.C = 0 + t2.D = 0 + dec.Decode(&t2) + if ***t2.A != 17 || **t2.B != 177 || *t2.C != 1777 || t2.D != 17777 { + t.Errorf("t0->t2 expected {17 177 1777 17777}; got {%d %d %d %d}", ***t2.A, **t2.B, *t2.C, t2.D) + } +} + +type RT0 struct { + A int + B string + C float64 +} +type RT1 struct { + C float64 + B string + A int + NotSet string +} + +func TestReorderedFields(t *testing.T) { + var rt0 RT0 + rt0.A = 17 + rt0.B = "hello" + rt0.C = 3.14159 + b := new(bytes.Buffer) + NewEncoder(b).Encode(rt0) + dec := NewDecoder(b) + var rt1 RT1 + // Wire type is RT0, local type is RT1. + err := dec.Decode(&rt1) + if err != nil { + t.Fatal("decode error:", err) + } + if rt0.A != rt1.A || rt0.B != rt1.B || rt0.C != rt1.C { + t.Errorf("rt1->rt0: expected %v; got %v", rt0, rt1) + } +} + +// Like an RT0 but with fields we'll ignore on the decode side. +type IT0 struct { + A int64 + B string + Ignore_d []int + Ignore_e [3]float64 + Ignore_f bool + Ignore_g string + Ignore_h []byte + Ignore_i *RT1 + Ignore_m map[string]int + C float64 +} + +func TestIgnoredFields(t *testing.T) { + var it0 IT0 + it0.A = 17 + it0.B = "hello" + it0.C = 3.14159 + it0.Ignore_d = []int{1, 2, 3} + it0.Ignore_e[0] = 1.0 + it0.Ignore_e[1] = 2.0 + it0.Ignore_e[2] = 3.0 + it0.Ignore_f = true + it0.Ignore_g = "pay no attention" + it0.Ignore_h = []byte("to the curtain") + it0.Ignore_i = &RT1{3.1, "hi", 7, "hello"} + it0.Ignore_m = map[string]int{"one": 1, "two": 2} + + b := new(bytes.Buffer) + NewEncoder(b).Encode(it0) + dec := NewDecoder(b) + var rt1 RT1 + // Wire type is IT0, local type is RT1. + err := dec.Decode(&rt1) + if err != nil { + t.Error("error: ", err) + } + if int(it0.A) != rt1.A || it0.B != rt1.B || it0.C != rt1.C { + t.Errorf("rt0->rt1: expected %v; got %v", it0, rt1) + } +} + +func TestBadRecursiveType(t *testing.T) { + type Rec ***Rec + var rec Rec + b := new(bytes.Buffer) + err := NewEncoder(b).Encode(&rec) + if err == nil { + t.Error("expected error; got none") + } else if strings.Index(err.Error(), "recursive") < 0 { + t.Error("expected recursive type error; got", err) + } + // Can't test decode easily because we can't encode one, so we can't pass one to a Decoder. +} + +type Bad0 struct { + CH chan int + C float64 +} + +func TestInvalidField(t *testing.T) { + var bad0 Bad0 + bad0.CH = make(chan int) + b := new(bytes.Buffer) + dummyEncoder := new(Encoder) // sufficient for this purpose. + dummyEncoder.encode(b, reflect.ValueOf(&bad0), userType(reflect.TypeOf(&bad0))) + if err := dummyEncoder.err; err == nil { + t.Error("expected error; got none") + } else if strings.Index(err.Error(), "type") < 0 { + t.Error("expected type error; got", err) + } +} + +type Indirect struct { + A ***[3]int + S ***[]int + M ****map[string]int +} + +type Direct struct { + A [3]int + S []int + M map[string]int +} + +func TestIndirectSliceMapArray(t *testing.T) { + // Marshal indirect, unmarshal to direct. + i := new(Indirect) + i.A = new(**[3]int) + *i.A = new(*[3]int) + **i.A = new([3]int) + ***i.A = [3]int{1, 2, 3} + i.S = new(**[]int) + *i.S = new(*[]int) + **i.S = new([]int) + ***i.S = []int{4, 5, 6} + i.M = new(***map[string]int) + *i.M = new(**map[string]int) + **i.M = new(*map[string]int) + ***i.M = new(map[string]int) + ****i.M = map[string]int{"one": 1, "two": 2, "three": 3} + b := new(bytes.Buffer) + NewEncoder(b).Encode(i) + dec := NewDecoder(b) + var d Direct + err := dec.Decode(&d) + if err != nil { + t.Error("error: ", err) + } + if len(d.A) != 3 || d.A[0] != 1 || d.A[1] != 2 || d.A[2] != 3 { + t.Errorf("indirect to direct: d.A is %v not %v", d.A, ***i.A) + } + if len(d.S) != 3 || d.S[0] != 4 || d.S[1] != 5 || d.S[2] != 6 { + t.Errorf("indirect to direct: d.S is %v not %v", d.S, ***i.S) + } + if len(d.M) != 3 || d.M["one"] != 1 || d.M["two"] != 2 || d.M["three"] != 3 { + t.Errorf("indirect to direct: d.M is %v not %v", d.M, ***i.M) + } + // Marshal direct, unmarshal to indirect. + d.A = [3]int{11, 22, 33} + d.S = []int{44, 55, 66} + d.M = map[string]int{"four": 4, "five": 5, "six": 6} + i = new(Indirect) + b.Reset() + NewEncoder(b).Encode(d) + dec = NewDecoder(b) + err = dec.Decode(&i) + if err != nil { + t.Fatal("error: ", err) + } + if len(***i.A) != 3 || (***i.A)[0] != 11 || (***i.A)[1] != 22 || (***i.A)[2] != 33 { + t.Errorf("direct to indirect: ***i.A is %v not %v", ***i.A, d.A) + } + if len(***i.S) != 3 || (***i.S)[0] != 44 || (***i.S)[1] != 55 || (***i.S)[2] != 66 { + t.Errorf("direct to indirect: ***i.S is %v not %v", ***i.S, ***i.S) + } + if len(****i.M) != 3 || (****i.M)["four"] != 4 || (****i.M)["five"] != 5 || (****i.M)["six"] != 6 { + t.Errorf("direct to indirect: ****i.M is %v not %v", ****i.M, d.M) + } +} + +// An interface with several implementations +type Squarer interface { + Square() int +} + +type Int int + +func (i Int) Square() int { + return int(i * i) +} + +type Float float64 + +func (f Float) Square() int { + return int(f * f) +} + +type Vector []int + +func (v Vector) Square() int { + sum := 0 + for _, x := range v { + sum += x * x + } + return sum +} + +type Point struct { + X, Y int +} + +func (p Point) Square() int { + return p.X*p.X + p.Y*p.Y +} + +// A struct with interfaces in it. +type InterfaceItem struct { + I int + Sq1, Sq2, Sq3 Squarer + F float64 + Sq []Squarer +} + +// The same struct without interfaces +type NoInterfaceItem struct { + I int + F float64 +} + +func TestInterface(t *testing.T) { + iVal := Int(3) + fVal := Float(5) + // Sending a Vector will require that the receiver define a type in the middle of + // receiving the value for item2. + vVal := Vector{1, 2, 3} + b := new(bytes.Buffer) + item1 := &InterfaceItem{1, iVal, fVal, vVal, 11.5, []Squarer{iVal, fVal, nil, vVal}} + // Register the types. + Register(Int(0)) + Register(Float(0)) + Register(Vector{}) + err := NewEncoder(b).Encode(item1) + if err != nil { + t.Error("expected no encode error; got", err) + } + + item2 := InterfaceItem{} + err = NewDecoder(b).Decode(&item2) + if err != nil { + t.Fatal("decode:", err) + } + if item2.I != item1.I { + t.Error("normal int did not decode correctly") + } + if item2.Sq1 == nil || item2.Sq1.Square() != iVal.Square() { + t.Error("Int did not decode correctly") + } + if item2.Sq2 == nil || item2.Sq2.Square() != fVal.Square() { + t.Error("Float did not decode correctly") + } + if item2.Sq3 == nil || item2.Sq3.Square() != vVal.Square() { + t.Error("Vector did not decode correctly") + } + if item2.F != item1.F { + t.Error("normal float did not decode correctly") + } + // Now check that we received a slice of Squarers correctly, including a nil element + if len(item1.Sq) != len(item2.Sq) { + t.Fatalf("[]Squarer length wrong: got %d; expected %d", len(item2.Sq), len(item1.Sq)) + } + for i, v1 := range item1.Sq { + v2 := item2.Sq[i] + if v1 == nil || v2 == nil { + if v1 != nil || v2 != nil { + t.Errorf("item %d inconsistent nils", i) + } + continue + if v1.Square() != v2.Square() { + t.Errorf("item %d inconsistent values: %v %v", i, v1, v2) + } + } + } +} + +// A struct with all basic types, stored in interfaces. +type BasicInterfaceItem struct { + Int, Int8, Int16, Int32, Int64 interface{} + Uint, Uint8, Uint16, Uint32, Uint64 interface{} + Float32, Float64 interface{} + Complex64, Complex128 interface{} + Bool interface{} + String interface{} + Bytes interface{} +} + +func TestInterfaceBasic(t *testing.T) { + b := new(bytes.Buffer) + item1 := &BasicInterfaceItem{ + int(1), int8(1), int16(1), int32(1), int64(1), + uint(1), uint8(1), uint16(1), uint32(1), uint64(1), + float32(1), 1.0, + complex64(1i), complex128(1i), + true, + "hello", + []byte("sailor"), + } + err := NewEncoder(b).Encode(item1) + if err != nil { + t.Error("expected no encode error; got", err) + } + + item2 := &BasicInterfaceItem{} + err = NewDecoder(b).Decode(&item2) + if err != nil { + t.Fatal("decode:", err) + } + if !reflect.DeepEqual(item1, item2) { + t.Errorf("encode expected %v got %v", item1, item2) + } + // Hand check a couple for correct types. + if v, ok := item2.Bool.(bool); !ok || !v { + t.Error("boolean should be true") + } + if v, ok := item2.String.(string); !ok || v != item1.String.(string) { + t.Errorf("string should be %v is %v", item1.String, v) + } +} + +type String string + +type PtrInterfaceItem struct { + Str1 interface{} // basic + Str2 interface{} // derived +} + +// We'll send pointers; should receive values. +// Also check that we can register T but send *T. +func TestInterfacePointer(t *testing.T) { + b := new(bytes.Buffer) + str1 := "howdy" + str2 := String("kiddo") + item1 := &PtrInterfaceItem{ + &str1, + &str2, + } + // Register the type. + Register(str2) + err := NewEncoder(b).Encode(item1) + if err != nil { + t.Error("expected no encode error; got", err) + } + + item2 := &PtrInterfaceItem{} + err = NewDecoder(b).Decode(&item2) + if err != nil { + t.Fatal("decode:", err) + } + // Hand test for correct types and values. + if v, ok := item2.Str1.(string); !ok || v != str1 { + t.Errorf("basic string failed: %q should be %q", v, str1) + } + if v, ok := item2.Str2.(String); !ok || v != str2 { + t.Errorf("derived type String failed: %q should be %q", v, str2) + } +} + +func TestIgnoreInterface(t *testing.T) { + iVal := Int(3) + fVal := Float(5) + // Sending a Point will require that the receiver define a type in the middle of + // receiving the value for item2. + pVal := Point{2, 3} + b := new(bytes.Buffer) + item1 := &InterfaceItem{1, iVal, fVal, pVal, 11.5, nil} + // Register the types. + Register(Int(0)) + Register(Float(0)) + Register(Point{}) + err := NewEncoder(b).Encode(item1) + if err != nil { + t.Error("expected no encode error; got", err) + } + + item2 := NoInterfaceItem{} + err = NewDecoder(b).Decode(&item2) + if err != nil { + t.Fatal("decode:", err) + } + if item2.I != item1.I { + t.Error("normal int did not decode correctly") + } + if item2.F != item2.F { + t.Error("normal float did not decode correctly") + } +} + +type U struct { + A int + B string + c float64 + D uint +} + +func TestUnexportedFields(t *testing.T) { + var u0 U + u0.A = 17 + u0.B = "hello" + u0.c = 3.14159 + u0.D = 23 + b := new(bytes.Buffer) + NewEncoder(b).Encode(u0) + dec := NewDecoder(b) + var u1 U + u1.c = 1234. + err := dec.Decode(&u1) + if err != nil { + t.Fatal("decode error:", err) + } + if u0.A != u0.A || u0.B != u1.B || u0.D != u1.D { + t.Errorf("u1->u0: expected %v; got %v", u0, u1) + } + if u1.c != 1234. { + t.Error("u1.c modified") + } +} + +var singletons = []interface{}{ + true, + 7, + 3.2, + "hello", + [3]int{11, 22, 33}, + []float32{0.5, 0.25, 0.125}, + map[string]int{"one": 1, "two": 2}, +} + +func TestDebugSingleton(t *testing.T) { + if debugFunc == nil { + return + } + b := new(bytes.Buffer) + // Accumulate a number of values and print them out all at once. + for _, x := range singletons { + err := NewEncoder(b).Encode(x) + if err != nil { + t.Fatal("encode:", err) + } + } + debugFunc(b) +} + +// A type that won't be defined in the gob until we send it in an interface value. +type OnTheFly struct { + A int +} + +type DT struct { + // X OnTheFly + A int + B string + C float64 + I interface{} + J interface{} + I_nil interface{} + M map[string]int + T [3]int + S []string +} + +func TestDebugStruct(t *testing.T) { + if debugFunc == nil { + return + } + Register(OnTheFly{}) + var dt DT + dt.A = 17 + dt.B = "hello" + dt.C = 3.14159 + dt.I = 271828 + dt.J = OnTheFly{3} + dt.I_nil = nil + dt.M = map[string]int{"one": 1, "two": 2} + dt.T = [3]int{11, 22, 33} + dt.S = []string{"hi", "joe"} + b := new(bytes.Buffer) + err := NewEncoder(b).Encode(dt) + if err != nil { + t.Fatal("encode:", err) + } + debugBuffer := bytes.NewBuffer(b.Bytes()) + dt2 := &DT{} + err = NewDecoder(b).Decode(&dt2) + if err != nil { + t.Error("decode:", err) + } + debugFunc(debugBuffer) +} diff --git a/libgo/go/encoding/gob/debug.go b/libgo/go/encoding/gob/debug.go new file mode 100644 index 0000000..b21c7fa --- /dev/null +++ b/libgo/go/encoding/gob/debug.go @@ -0,0 +1,687 @@ +package gob + +// This file is not normally included in the gob package. Used only for debugging the package itself. +// Add debug.go to the files listed in the Makefile to add Debug to the gob package. +// Except for reading uints, it is an implementation of a reader that is independent of +// the one implemented by Decoder. + +import ( + "bytes" + "fmt" + "io" + "os" + "strings" + "sync" +) + +var dumpBytes = false // If true, print the remaining bytes in the input buffer at each item. + +// Init installs the debugging facility. If this file is not compiled in the +// package, the tests in codec_test.go are no-ops. +func init() { + debugFunc = Debug +} + +var ( + blanks = bytes.Repeat([]byte{' '}, 3*10) + empty = []byte(": <empty>\n") + tabs = strings.Repeat("\t", 100) +) + +// tab indents itself when printed. +type tab int + +func (t tab) String() string { + n := int(t) + if n > len(tabs) { + n = len(tabs) + } + return tabs[0:n] +} + +func (t tab) print() { + fmt.Fprint(os.Stderr, t) +} + +// A peekReader wraps an io.Reader, allowing one to peek ahead to see +// what's coming without stealing the data from the client of the Reader. +type peekReader struct { + r io.Reader + data []byte // read-ahead data +} + +// newPeekReader returns a peekReader that wraps r. +func newPeekReader(r io.Reader) *peekReader { + return &peekReader{r: r} +} + +// Read is the usual method. It will first take data that has been read ahead. +func (p *peekReader) Read(b []byte) (n int, err error) { + if len(p.data) == 0 { + return p.r.Read(b) + } + // Satisfy what's possible from the read-ahead data. + n = copy(b, p.data) + // Move data down to beginning of slice, to avoid endless growth + copy(p.data, p.data[n:]) + p.data = p.data[:len(p.data)-n] + return +} + +// peek returns as many bytes as possible from the unread +// portion of the stream, up to the length of b. +func (p *peekReader) peek(b []byte) (n int, err error) { + if len(p.data) > 0 { + n = copy(b, p.data) + if n == len(b) { + return + } + b = b[n:] + } + if len(b) == 0 { + return + } + m, e := io.ReadFull(p.r, b) + if m > 0 { + p.data = append(p.data, b[:m]...) + } + n += m + if e == io.ErrUnexpectedEOF { + // That means m > 0 but we reached EOF. If we got data + // we won't complain about not being able to peek enough. + if n > 0 { + e = nil + } else { + e = io.EOF + } + } + return n, e +} + +type debugger struct { + mutex sync.Mutex + remain int // the number of bytes known to remain in the input + remainingKnown bool // the value of 'remain' is valid + r *peekReader + wireType map[typeId]*wireType + tmp []byte // scratch space for decoding uints. +} + +// dump prints the next nBytes of the input. +// It arranges to print the output aligned from call to +// call, to make it easy to see what has been consumed. +func (deb *debugger) dump(format string, args ...interface{}) { + if !dumpBytes { + return + } + fmt.Fprintf(os.Stderr, format+" ", args...) + if !deb.remainingKnown { + return + } + if deb.remain < 0 { + fmt.Fprintf(os.Stderr, "remaining byte count is negative! %d\n", deb.remain) + return + } + data := make([]byte, deb.remain) + n, _ := deb.r.peek(data) + if n == 0 { + os.Stderr.Write(empty) + return + } + b := new(bytes.Buffer) + fmt.Fprintf(b, "[%d]{\n", deb.remain) + // Blanks until first byte + lineLength := 0 + if n := len(data); n%10 != 0 { + lineLength = 10 - n%10 + fmt.Fprintf(b, "\t%s", blanks[:lineLength*3]) + } + // 10 bytes per line + for len(data) > 0 { + if lineLength == 0 { + fmt.Fprint(b, "\t") + } + m := 10 - lineLength + lineLength = 0 + if m > len(data) { + m = len(data) + } + fmt.Fprintf(b, "% x\n", data[:m]) + data = data[m:] + } + fmt.Fprint(b, "}\n") + os.Stderr.Write(b.Bytes()) +} + +// Debug prints a human-readable representation of the gob data read from r. +// It is a no-op unless debugging was enabled when the package was built. +func Debug(r io.Reader) { + err := debug(r) + if err != nil { + fmt.Fprintf(os.Stderr, "gob debug: %s\n", err) + } +} + +// debug implements Debug, but catches panics and returns +// them as errors to be printed by Debug. +func debug(r io.Reader) (err error) { + defer catchError(&err) + fmt.Fprintln(os.Stderr, "Start of debugging") + deb := &debugger{ + r: newPeekReader(r), + wireType: make(map[typeId]*wireType), + tmp: make([]byte, 16), + } + if b, ok := r.(*bytes.Buffer); ok { + deb.remain = b.Len() + deb.remainingKnown = true + } + deb.gobStream() + return +} + +// note that we've consumed some bytes +func (deb *debugger) consumed(n int) { + if deb.remainingKnown { + deb.remain -= n + } +} + +// int64 decodes and returns the next integer, which must be present. +// Don't call this if you could be at EOF. +func (deb *debugger) int64() int64 { + return toInt(deb.uint64()) +} + +// uint64 returns and decodes the next unsigned integer, which must be present. +// Don't call this if you could be at EOF. +// TODO: handle errors better. +func (deb *debugger) uint64() uint64 { + n, w, err := decodeUintReader(deb.r, deb.tmp) + if err != nil { + errorf("debug: read error: %s", err) + } + deb.consumed(w) + return n +} + +// GobStream: +// DelimitedMessage* (until EOF) +func (deb *debugger) gobStream() { + // Make sure we're single-threaded through here. + deb.mutex.Lock() + defer deb.mutex.Unlock() + + for deb.delimitedMessage(0) { + } +} + +// DelimitedMessage: +// uint(lengthOfMessage) Message +func (deb *debugger) delimitedMessage(indent tab) bool { + for { + n := deb.loadBlock(true) + if n < 0 { + return false + } + deb.dump("Delimited message of length %d", n) + deb.message(indent) + } + return true +} + +// loadBlock preps us to read a message +// of the length specified next in the input. It returns +// the length of the block. The argument tells whether +// an EOF is acceptable now. If it is and one is found, +// the return value is negative. +func (deb *debugger) loadBlock(eofOK bool) int { + n64, w, err := decodeUintReader(deb.r, deb.tmp) // deb.uint64 will error at EOF + if err != nil { + if eofOK && err == io.EOF { + return -1 + } + errorf("debug: unexpected error: %s", err) + } + deb.consumed(w) + n := int(n64) + if n < 0 { + errorf("huge value for message length: %d", n64) + } + return int(n) +} + +// Message: +// TypeSequence TypedValue +// TypeSequence +// (TypeDefinition DelimitedTypeDefinition*)? +// DelimitedTypeDefinition: +// uint(lengthOfTypeDefinition) TypeDefinition +// TypedValue: +// int(typeId) Value +func (deb *debugger) message(indent tab) bool { + for { + // Convert the uint64 to a signed integer typeId + uid := deb.int64() + id := typeId(uid) + deb.dump("type id=%d", id) + if id < 0 { + deb.typeDefinition(indent, -id) + n := deb.loadBlock(false) + deb.dump("Message of length %d", n) + continue + } else { + deb.value(indent, id) + break + } + } + return true +} + +// Helper methods to make it easy to scan a type descriptor. + +// common returns the CommonType at the input point. +func (deb *debugger) common() CommonType { + fieldNum := -1 + name := "" + id := typeId(0) + for { + delta := deb.delta(-1) + if delta == 0 { + break + } + fieldNum += delta + switch fieldNum { + case 0: + name = deb.string() + case 1: + // Id typeId + id = deb.typeId() + default: + errorf("corrupted CommonType") + } + } + return CommonType{name, id} +} + +// uint returns the unsigned int at the input point, as a uint (not uint64). +func (deb *debugger) uint() uint { + return uint(deb.uint64()) +} + +// int returns the signed int at the input point, as an int (not int64). +func (deb *debugger) int() int { + return int(deb.int64()) +} + +// typeId returns the type id at the input point. +func (deb *debugger) typeId() typeId { + return typeId(deb.int64()) +} + +// string returns the string at the input point. +func (deb *debugger) string() string { + x := int(deb.uint64()) + b := make([]byte, x) + nb, _ := deb.r.Read(b) + if nb != x { + errorf("corrupted type") + } + deb.consumed(nb) + return string(b) +} + +// delta returns the field delta at the input point. The expect argument, +// if non-negative, identifies what the value should be. +func (deb *debugger) delta(expect int) int { + delta := int(deb.uint64()) + if delta < 0 || (expect >= 0 && delta != expect) { + errorf("decode: corrupted type: delta %d expected %d", delta, expect) + } + return delta +} + +// TypeDefinition: +// [int(-typeId) (already read)] encodingOfWireType +func (deb *debugger) typeDefinition(indent tab, id typeId) { + deb.dump("type definition for id %d", id) + // Encoding is of a wireType. Decode the structure as usual + fieldNum := -1 + wire := new(wireType) + // A wireType defines a single field. + delta := deb.delta(-1) + fieldNum += delta + switch fieldNum { + case 0: // array type, one field of {{Common}, elem, length} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of elem + deb.delta(1) + id := deb.typeId() + // Field number 3 is length + deb.delta(1) + length := deb.int() + wire.ArrayT = &arrayType{com, id, length} + + case 1: // slice type, one field of {{Common}, elem} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of elem + deb.delta(1) + id := deb.typeId() + wire.SliceT = &sliceType{com, id} + + case 2: // struct type, one field of {{Common}, []fieldType} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is slice of FieldType + deb.delta(1) + numField := int(deb.uint()) + field := make([]*fieldType, numField) + for i := 0; i < numField; i++ { + field[i] = new(fieldType) + deb.delta(1) // field 0 of fieldType: name + field[i].Name = deb.string() + deb.delta(1) // field 1 of fieldType: id + field[i].Id = deb.typeId() + deb.delta(0) // end of fieldType + } + wire.StructT = &structType{com, field} + + case 3: // map type, one field of {{Common}, key, elem} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + // Field number 1 is type Id of key + deb.delta(1) + keyId := deb.typeId() + // Field number 2 is type Id of elem + deb.delta(1) + elemId := deb.typeId() + wire.MapT = &mapType{com, keyId, elemId} + case 4: // GobEncoder type, one field of {{Common}} + // Field number 0 is CommonType + deb.delta(1) + com := deb.common() + wire.GobEncoderT = &gobEncoderType{com} + default: + errorf("bad field in type %d", fieldNum) + } + deb.printWireType(indent, wire) + deb.delta(0) // end inner type (arrayType, etc.) + deb.delta(0) // end wireType + // Remember we've seen this type. + deb.wireType[id] = wire +} + +// Value: +// SingletonValue | StructValue +func (deb *debugger) value(indent tab, id typeId) { + wire, ok := deb.wireType[id] + if ok && wire.StructT != nil { + deb.structValue(indent, id) + } else { + deb.singletonValue(indent, id) + } +} + +// SingletonValue: +// uint(0) FieldValue +func (deb *debugger) singletonValue(indent tab, id typeId) { + deb.dump("Singleton value") + // is it a builtin type? + wire := deb.wireType[id] + _, ok := builtinIdToType[id] + if !ok && wire == nil { + errorf("type id %d not defined", id) + } + m := deb.uint64() + if m != 0 { + errorf("expected zero; got %d", m) + } + deb.fieldValue(indent, id) +} + +// InterfaceValue: +// NilInterfaceValue | NonNilInterfaceValue +func (deb *debugger) interfaceValue(indent tab) { + deb.dump("Start of interface value") + if nameLen := deb.uint64(); nameLen == 0 { + deb.nilInterfaceValue(indent) + } else { + deb.nonNilInterfaceValue(indent, int(nameLen)) + } +} + +// NilInterfaceValue: +// uint(0) [already read] +func (deb *debugger) nilInterfaceValue(indent tab) int { + fmt.Fprintf(os.Stderr, "%snil interface\n", indent) + return 0 +} + +// NonNilInterfaceValue: +// ConcreteTypeName TypeSequence InterfaceContents +// ConcreteTypeName: +// uint(lengthOfName) [already read=n] name +// InterfaceContents: +// int(concreteTypeId) DelimitedValue +// DelimitedValue: +// uint(length) Value +func (deb *debugger) nonNilInterfaceValue(indent tab, nameLen int) { + // ConcreteTypeName + b := make([]byte, nameLen) + deb.r.Read(b) // TODO: CHECK THESE READS!! + deb.consumed(nameLen) + name := string(b) + + for { + id := deb.typeId() + if id < 0 { + deb.typeDefinition(indent, -id) + n := deb.loadBlock(false) + deb.dump("Nested message of length %d", n) + } else { + // DelimitedValue + x := deb.uint64() // in case we want to ignore the value; we don't. + fmt.Fprintf(os.Stderr, "%sinterface value, type %q id=%d; valueLength %d\n", indent, name, id, x) + deb.value(indent, id) + break + } + } +} + +// printCommonType prints a common type; used by printWireType. +func (deb *debugger) printCommonType(indent tab, kind string, common *CommonType) { + indent.print() + fmt.Fprintf(os.Stderr, "%s %q id=%d\n", kind, common.Name, common.Id) +} + +// printWireType prints the contents of a wireType. +func (deb *debugger) printWireType(indent tab, wire *wireType) { + fmt.Fprintf(os.Stderr, "%stype definition {\n", indent) + indent++ + switch { + case wire.ArrayT != nil: + deb.printCommonType(indent, "array", &wire.ArrayT.CommonType) + fmt.Fprintf(os.Stderr, "%slen %d\n", indent+1, wire.ArrayT.Len) + fmt.Fprintf(os.Stderr, "%selemid %d\n", indent+1, wire.ArrayT.Elem) + case wire.MapT != nil: + deb.printCommonType(indent, "map", &wire.MapT.CommonType) + fmt.Fprintf(os.Stderr, "%skey id=%d\n", indent+1, wire.MapT.Key) + fmt.Fprintf(os.Stderr, "%selem id=%d\n", indent+1, wire.MapT.Elem) + case wire.SliceT != nil: + deb.printCommonType(indent, "slice", &wire.SliceT.CommonType) + fmt.Fprintf(os.Stderr, "%selem id=%d\n", indent+1, wire.SliceT.Elem) + case wire.StructT != nil: + deb.printCommonType(indent, "struct", &wire.StructT.CommonType) + for i, field := range wire.StructT.Field { + fmt.Fprintf(os.Stderr, "%sfield %d:\t%s\tid=%d\n", indent+1, i, field.Name, field.Id) + } + case wire.GobEncoderT != nil: + deb.printCommonType(indent, "GobEncoder", &wire.GobEncoderT.CommonType) + } + indent-- + fmt.Fprintf(os.Stderr, "%s}\n", indent) +} + +// fieldValue prints a value of any type, such as a struct field. +// FieldValue: +// builtinValue | ArrayValue | MapValue | SliceValue | StructValue | InterfaceValue +func (deb *debugger) fieldValue(indent tab, id typeId) { + _, ok := builtinIdToType[id] + if ok { + if id == tInterface { + deb.interfaceValue(indent) + } else { + deb.printBuiltin(indent, id) + } + return + } + wire, ok := deb.wireType[id] + if !ok { + errorf("type id %d not defined", id) + } + switch { + case wire.ArrayT != nil: + deb.arrayValue(indent, wire) + case wire.MapT != nil: + deb.mapValue(indent, wire) + case wire.SliceT != nil: + deb.sliceValue(indent, wire) + case wire.StructT != nil: + deb.structValue(indent, id) + case wire.GobEncoderT != nil: + deb.gobEncoderValue(indent, id) + default: + panic("bad wire type for field") + } +} + +// printBuiltin prints a value not of a fundamental type, that is, +// one whose type is known to gobs at bootstrap time. +func (deb *debugger) printBuiltin(indent tab, id typeId) { + switch id { + case tBool: + x := deb.int64() + if x == 0 { + fmt.Fprintf(os.Stderr, "%sfalse\n", indent) + } else { + fmt.Fprintf(os.Stderr, "%strue\n", indent) + } + case tInt: + x := deb.int64() + fmt.Fprintf(os.Stderr, "%s%d\n", indent, x) + case tUint: + x := deb.int64() + fmt.Fprintf(os.Stderr, "%s%d\n", indent, x) + case tFloat: + x := deb.uint64() + fmt.Fprintf(os.Stderr, "%s%g\n", indent, floatFromBits(x)) + case tComplex: + r := deb.uint64() + i := deb.uint64() + fmt.Fprintf(os.Stderr, "%s%g+%gi\n", indent, floatFromBits(r), floatFromBits(i)) + case tBytes: + x := int(deb.uint64()) + b := make([]byte, x) + deb.r.Read(b) + deb.consumed(x) + fmt.Fprintf(os.Stderr, "%s{% x}=%q\n", indent, b, b) + case tString: + x := int(deb.uint64()) + b := make([]byte, x) + deb.r.Read(b) + deb.consumed(x) + fmt.Fprintf(os.Stderr, "%s%q\n", indent, b) + default: + panic("unknown builtin") + } +} + +// ArrayValue: +// uint(n) FieldValue*n +func (deb *debugger) arrayValue(indent tab, wire *wireType) { + elemId := wire.ArrayT.Elem + u := deb.uint64() + length := int(u) + for i := 0; i < length; i++ { + deb.fieldValue(indent, elemId) + } + if length != wire.ArrayT.Len { + fmt.Fprintf(os.Stderr, "%s(wrong length for array: %d should be %d)\n", indent, length, wire.ArrayT.Len) + } +} + +// MapValue: +// uint(n) (FieldValue FieldValue)*n [n (key, value) pairs] +func (deb *debugger) mapValue(indent tab, wire *wireType) { + keyId := wire.MapT.Key + elemId := wire.MapT.Elem + u := deb.uint64() + length := int(u) + for i := 0; i < length; i++ { + deb.fieldValue(indent+1, keyId) + deb.fieldValue(indent+1, elemId) + } +} + +// SliceValue: +// uint(n) (n FieldValue) +func (deb *debugger) sliceValue(indent tab, wire *wireType) { + elemId := wire.SliceT.Elem + u := deb.uint64() + length := int(u) + deb.dump("Start of slice of length %d", length) + + for i := 0; i < length; i++ { + deb.fieldValue(indent, elemId) + } +} + +// StructValue: +// (uint(fieldDelta) FieldValue)* +func (deb *debugger) structValue(indent tab, id typeId) { + deb.dump("Start of struct value of %q id=%d\n<<\n", id.name(), id) + fmt.Fprintf(os.Stderr, "%s%s struct {\n", indent, id.name()) + wire, ok := deb.wireType[id] + if !ok { + errorf("type id %d not defined", id) + } + strct := wire.StructT + fieldNum := -1 + indent++ + for { + delta := deb.uint64() + if delta == 0 { // struct terminator is zero delta fieldnum + break + } + fieldNum += int(delta) + if fieldNum < 0 || fieldNum >= len(strct.Field) { + deb.dump("field number out of range: prevField=%d delta=%d", fieldNum-int(delta), delta) + break + } + fmt.Fprintf(os.Stderr, "%sfield %d:\t%s\n", indent, fieldNum, wire.StructT.Field[fieldNum].Name) + deb.fieldValue(indent+1, strct.Field[fieldNum].Id) + } + indent-- + fmt.Fprintf(os.Stderr, "%s} // end %s struct\n", indent, id.name()) + deb.dump(">> End of struct value of type %d %q", id, id.name()) +} + +// GobEncoderValue: +// uint(n) byte*n +func (deb *debugger) gobEncoderValue(indent tab, id typeId) { + len := deb.uint64() + deb.dump("GobEncoder value of %q id=%d, length %d\n", id.name(), id, len) + fmt.Fprintf(os.Stderr, "%s%s (implements GobEncoder)\n", indent, id.name()) + data := make([]byte, len) + _, err := deb.r.Read(data) + if err != nil { + errorf("gobEncoder data read: %s", err) + } + fmt.Fprintf(os.Stderr, "%s[% .2x]\n", indent+1, data) +} diff --git a/libgo/go/encoding/gob/decode.go b/libgo/go/encoding/gob/decode.go new file mode 100644 index 0000000..1515d12 --- /dev/null +++ b/libgo/go/encoding/gob/decode.go @@ -0,0 +1,1279 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +// TODO(rsc): When garbage collector changes, revisit +// the allocations in this file that use unsafe.Pointer. + +import ( + "bytes" + "errors" + "io" + "math" + "reflect" + "unsafe" +) + +var ( + errBadUint = errors.New("gob: encoded unsigned integer out of range") + errBadType = errors.New("gob: unknown type id or corrupted data") + errRange = errors.New("gob: bad data: field numbers out of bounds") +) + +// decoderState is the execution state of an instance of the decoder. A new state +// is created for nested objects. +type decoderState struct { + dec *Decoder + // The buffer is stored with an extra indirection because it may be replaced + // if we load a type during decode (when reading an interface value). + b *bytes.Buffer + fieldnum int // the last field number read. + buf []byte + next *decoderState // for free list +} + +// We pass the bytes.Buffer separately for easier testing of the infrastructure +// without requiring a full Decoder. +func (dec *Decoder) newDecoderState(buf *bytes.Buffer) *decoderState { + d := dec.freeList + if d == nil { + d = new(decoderState) + d.dec = dec + d.buf = make([]byte, uint64Size) + } else { + dec.freeList = d.next + } + d.b = buf + return d +} + +func (dec *Decoder) freeDecoderState(d *decoderState) { + d.next = dec.freeList + dec.freeList = d +} + +func overflow(name string) error { + return errors.New(`value for "` + name + `" out of range`) +} + +// decodeUintReader reads an encoded unsigned integer from an io.Reader. +// Used only by the Decoder to read the message length. +func decodeUintReader(r io.Reader, buf []byte) (x uint64, width int, err error) { + width = 1 + _, err = r.Read(buf[0:width]) + if err != nil { + return + } + b := buf[0] + if b <= 0x7f { + return uint64(b), width, nil + } + n := -int(int8(b)) + if n > uint64Size { + err = errBadUint + return + } + width, err = io.ReadFull(r, buf[0:n]) + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return + } + // Could check that the high byte is zero but it's not worth it. + for _, b := range buf[0:width] { + x = x<<8 | uint64(b) + } + width++ // +1 for length byte + return +} + +// decodeUint reads an encoded unsigned integer from state.r. +// Does not check for overflow. +func (state *decoderState) decodeUint() (x uint64) { + b, err := state.b.ReadByte() + if err != nil { + error_(err) + } + if b <= 0x7f { + return uint64(b) + } + n := -int(int8(b)) + if n > uint64Size { + error_(errBadUint) + } + width, err := state.b.Read(state.buf[0:n]) + if err != nil { + error_(err) + } + // Don't need to check error; it's safe to loop regardless. + // Could check that the high byte is zero but it's not worth it. + for _, b := range state.buf[0:width] { + x = x<<8 | uint64(b) + } + return x +} + +// decodeInt reads an encoded signed integer from state.r. +// Does not check for overflow. +func (state *decoderState) decodeInt() int64 { + x := state.decodeUint() + if x&1 != 0 { + return ^int64(x >> 1) + } + return int64(x >> 1) +} + +// decOp is the signature of a decoding operator for a given type. +type decOp func(i *decInstr, state *decoderState, p unsafe.Pointer) + +// The 'instructions' of the decoding machine +type decInstr struct { + op decOp + field int // field number of the wire type + indir int // how many pointer indirections to reach the value in the struct + offset uintptr // offset in the structure of the field to encode + ovfl error // error message for overflow/underflow (for arrays, of the elements) +} + +// Since the encoder writes no zeros, if we arrive at a decoder we have +// a value to extract and store. The field number has already been read +// (it's how we knew to call this decoder). +// Each decoder is responsible for handling any indirections associated +// with the data structure. If any pointer so reached is nil, allocation must +// be done. + +// Walk the pointer hierarchy, allocating if we find a nil. Stop one before the end. +func decIndirect(p unsafe.Pointer, indir int) unsafe.Pointer { + for ; indir > 1; indir-- { + if *(*unsafe.Pointer)(p) == nil { + // Allocation required + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(unsafe.Pointer)) + } + p = *(*unsafe.Pointer)(p) + } + return p +} + +// ignoreUint discards a uint value with no destination. +func ignoreUint(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.decodeUint() +} + +// ignoreTwoUints discards a uint value with no destination. It's used to skip +// complex values. +func ignoreTwoUints(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.decodeUint() + state.decodeUint() +} + +// decBool decodes a uint and stores it as a boolean through p. +func decBool(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(bool)) + } + p = *(*unsafe.Pointer)(p) + } + *(*bool)(p) = state.decodeUint() != 0 +} + +// decInt8 decodes an integer and stores it as an int8 through p. +func decInt8(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int8)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeInt() + if v < math.MinInt8 || math.MaxInt8 < v { + error_(i.ovfl) + } else { + *(*int8)(p) = int8(v) + } +} + +// decUint8 decodes an unsigned integer and stores it as a uint8 through p. +func decUint8(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint8)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeUint() + if math.MaxUint8 < v { + error_(i.ovfl) + } else { + *(*uint8)(p) = uint8(v) + } +} + +// decInt16 decodes an integer and stores it as an int16 through p. +func decInt16(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int16)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeInt() + if v < math.MinInt16 || math.MaxInt16 < v { + error_(i.ovfl) + } else { + *(*int16)(p) = int16(v) + } +} + +// decUint16 decodes an unsigned integer and stores it as a uint16 through p. +func decUint16(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint16)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeUint() + if math.MaxUint16 < v { + error_(i.ovfl) + } else { + *(*uint16)(p) = uint16(v) + } +} + +// decInt32 decodes an integer and stores it as an int32 through p. +func decInt32(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int32)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeInt() + if v < math.MinInt32 || math.MaxInt32 < v { + error_(i.ovfl) + } else { + *(*int32)(p) = int32(v) + } +} + +// decUint32 decodes an unsigned integer and stores it as a uint32 through p. +func decUint32(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint32)) + } + p = *(*unsafe.Pointer)(p) + } + v := state.decodeUint() + if math.MaxUint32 < v { + error_(i.ovfl) + } else { + *(*uint32)(p) = uint32(v) + } +} + +// decInt64 decodes an integer and stores it as an int64 through p. +func decInt64(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(int64)) + } + p = *(*unsafe.Pointer)(p) + } + *(*int64)(p) = int64(state.decodeInt()) +} + +// decUint64 decodes an unsigned integer and stores it as a uint64 through p. +func decUint64(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(uint64)) + } + p = *(*unsafe.Pointer)(p) + } + *(*uint64)(p) = uint64(state.decodeUint()) +} + +// Floating-point numbers are transmitted as uint64s holding the bits +// of the underlying representation. They are sent byte-reversed, with +// the exponent end coming out first, so integer floating point numbers +// (for example) transmit more compactly. This routine does the +// unswizzling. +func floatFromBits(u uint64) float64 { + var v uint64 + for i := 0; i < 8; i++ { + v <<= 8 + v |= u & 0xFF + u >>= 8 + } + return math.Float64frombits(v) +} + +// storeFloat32 decodes an unsigned integer, treats it as a 32-bit floating-point +// number, and stores it through p. It's a helper function for float32 and complex64. +func storeFloat32(i *decInstr, state *decoderState, p unsafe.Pointer) { + v := floatFromBits(state.decodeUint()) + av := v + if av < 0 { + av = -av + } + // +Inf is OK in both 32- and 64-bit floats. Underflow is always OK. + if math.MaxFloat32 < av && av <= math.MaxFloat64 { + error_(i.ovfl) + } else { + *(*float32)(p) = float32(v) + } +} + +// decFloat32 decodes an unsigned integer, treats it as a 32-bit floating-point +// number, and stores it through p. +func decFloat32(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(float32)) + } + p = *(*unsafe.Pointer)(p) + } + storeFloat32(i, state, p) +} + +// decFloat64 decodes an unsigned integer, treats it as a 64-bit floating-point +// number, and stores it through p. +func decFloat64(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(float64)) + } + p = *(*unsafe.Pointer)(p) + } + *(*float64)(p) = floatFromBits(uint64(state.decodeUint())) +} + +// decComplex64 decodes a pair of unsigned integers, treats them as a +// pair of floating point numbers, and stores them as a complex64 through p. +// The real part comes first. +func decComplex64(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(complex64)) + } + p = *(*unsafe.Pointer)(p) + } + storeFloat32(i, state, p) + storeFloat32(i, state, unsafe.Pointer(uintptr(p)+unsafe.Sizeof(float32(0)))) +} + +// decComplex128 decodes a pair of unsigned integers, treats them as a +// pair of floating point numbers, and stores them as a complex128 through p. +// The real part comes first. +func decComplex128(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(complex128)) + } + p = *(*unsafe.Pointer)(p) + } + real := floatFromBits(uint64(state.decodeUint())) + imag := floatFromBits(uint64(state.decodeUint())) + *(*complex128)(p) = complex(real, imag) +} + +// decUint8Slice decodes a byte slice and stores through p a slice header +// describing the data. +// uint8 slices are encoded as an unsigned count followed by the raw bytes. +func decUint8Slice(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new([]uint8)) + } + p = *(*unsafe.Pointer)(p) + } + n := int(state.decodeUint()) + if n < 0 { + errorf("negative length decoding []byte") + } + slice := (*[]uint8)(p) + if cap(*slice) < n { + *slice = make([]uint8, n) + } else { + *slice = (*slice)[0:n] + } + if _, err := state.b.Read(*slice); err != nil { + errorf("error decoding []byte: %s", err) + } +} + +// decString decodes byte array and stores through p a string header +// describing the data. +// Strings are encoded as an unsigned count followed by the raw bytes. +func decString(i *decInstr, state *decoderState, p unsafe.Pointer) { + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.Pointer(new(string)) + } + p = *(*unsafe.Pointer)(p) + } + b := make([]byte, state.decodeUint()) + state.b.Read(b) + // It would be a shame to do the obvious thing here, + // *(*string)(p) = string(b) + // because we've already allocated the storage and this would + // allocate again and copy. So we do this ugly hack, which is even + // even more unsafe than it looks as it depends the memory + // representation of a string matching the beginning of the memory + // representation of a byte slice (a byte slice is longer). + *(*string)(p) = *(*string)(unsafe.Pointer(&b)) +} + +// ignoreUint8Array skips over the data for a byte slice value with no destination. +func ignoreUint8Array(i *decInstr, state *decoderState, p unsafe.Pointer) { + b := make([]byte, state.decodeUint()) + state.b.Read(b) +} + +// Execution engine + +// The encoder engine is an array of instructions indexed by field number of the incoming +// decoder. It is executed with random access according to field number. +type decEngine struct { + instr []decInstr + numInstr int // the number of active instructions +} + +// allocate makes sure storage is available for an object of underlying type rtyp +// that is indir levels of indirection through p. +func allocate(rtyp reflect.Type, p uintptr, indir int) uintptr { + if indir == 0 { + return p + } + up := unsafe.Pointer(p) + if indir > 1 { + up = decIndirect(up, indir) + } + if *(*unsafe.Pointer)(up) == nil { + // Allocate object. + *(*unsafe.Pointer)(up) = unsafe.New(rtyp) + } + return *(*uintptr)(up) +} + +// decodeSingle decodes a top-level value that is not a struct and stores it through p. +// Such values are preceded by a zero, making them have the memory layout of a +// struct field (although with an illegal field number). +func (dec *Decoder) decodeSingle(engine *decEngine, ut *userTypeInfo, basep uintptr) (err error) { + state := dec.newDecoderState(&dec.buf) + state.fieldnum = singletonField + delta := int(state.decodeUint()) + if delta != 0 { + errorf("decode: corrupted data: non-zero delta for singleton") + } + instr := &engine.instr[singletonField] + if instr.indir != ut.indir { + return errors.New("gob: internal error: inconsistent indirection") + } + ptr := unsafe.Pointer(basep) // offset will be zero + if instr.indir > 1 { + ptr = decIndirect(ptr, instr.indir) + } + instr.op(instr, state, ptr) + dec.freeDecoderState(state) + return nil +} + +// decodeSingle decodes a top-level struct and stores it through p. +// Indir is for the value, not the type. At the time of the call it may +// differ from ut.indir, which was computed when the engine was built. +// This state cannot arise for decodeSingle, which is called directly +// from the user's value, not from the innards of an engine. +func (dec *Decoder) decodeStruct(engine *decEngine, ut *userTypeInfo, p uintptr, indir int) { + p = allocate(ut.base, p, indir) + state := dec.newDecoderState(&dec.buf) + state.fieldnum = -1 + basep := p + for state.b.Len() > 0 { + delta := int(state.decodeUint()) + if delta < 0 { + errorf("decode: corrupted data: negative delta") + } + if delta == 0 { // struct terminator is zero delta fieldnum + break + } + fieldnum := state.fieldnum + delta + if fieldnum >= len(engine.instr) { + error_(errRange) + break + } + instr := &engine.instr[fieldnum] + p := unsafe.Pointer(basep + instr.offset) + if instr.indir > 1 { + p = decIndirect(p, instr.indir) + } + instr.op(instr, state, p) + state.fieldnum = fieldnum + } + dec.freeDecoderState(state) +} + +// ignoreStruct discards the data for a struct with no destination. +func (dec *Decoder) ignoreStruct(engine *decEngine) { + state := dec.newDecoderState(&dec.buf) + state.fieldnum = -1 + for state.b.Len() > 0 { + delta := int(state.decodeUint()) + if delta < 0 { + errorf("ignore decode: corrupted data: negative delta") + } + if delta == 0 { // struct terminator is zero delta fieldnum + break + } + fieldnum := state.fieldnum + delta + if fieldnum >= len(engine.instr) { + error_(errRange) + } + instr := &engine.instr[fieldnum] + instr.op(instr, state, unsafe.Pointer(nil)) + state.fieldnum = fieldnum + } + dec.freeDecoderState(state) +} + +// ignoreSingle discards the data for a top-level non-struct value with no +// destination. It's used when calling Decode with a nil value. +func (dec *Decoder) ignoreSingle(engine *decEngine) { + state := dec.newDecoderState(&dec.buf) + state.fieldnum = singletonField + delta := int(state.decodeUint()) + if delta != 0 { + errorf("decode: corrupted data: non-zero delta for singleton") + } + instr := &engine.instr[singletonField] + instr.op(instr, state, unsafe.Pointer(nil)) + dec.freeDecoderState(state) +} + +// decodeArrayHelper does the work for decoding arrays and slices. +func (dec *Decoder) decodeArrayHelper(state *decoderState, p uintptr, elemOp decOp, elemWid uintptr, length, elemIndir int, ovfl error) { + instr := &decInstr{elemOp, 0, elemIndir, 0, ovfl} + for i := 0; i < length; i++ { + up := unsafe.Pointer(p) + if elemIndir > 1 { + up = decIndirect(up, elemIndir) + } + elemOp(instr, state, up) + p += uintptr(elemWid) + } +} + +// decodeArray decodes an array and stores it through p, that is, p points to the zeroth element. +// The length is an unsigned integer preceding the elements. Even though the length is redundant +// (it's part of the type), it's a useful check and is included in the encoding. +func (dec *Decoder) decodeArray(atyp reflect.Type, state *decoderState, p uintptr, elemOp decOp, elemWid uintptr, length, indir, elemIndir int, ovfl error) { + if indir > 0 { + p = allocate(atyp, p, 1) // All but the last level has been allocated by dec.Indirect + } + if n := state.decodeUint(); n != uint64(length) { + errorf("length mismatch in decodeArray") + } + dec.decodeArrayHelper(state, p, elemOp, elemWid, length, elemIndir, ovfl) +} + +// decodeIntoValue is a helper for map decoding. Since maps are decoded using reflection, +// unlike the other items we can't use a pointer directly. +func decodeIntoValue(state *decoderState, op decOp, indir int, v reflect.Value, ovfl error) reflect.Value { + instr := &decInstr{op, 0, indir, 0, ovfl} + up := unsafe.Pointer(unsafeAddr(v)) + if indir > 1 { + up = decIndirect(up, indir) + } + op(instr, state, up) + return v +} + +// decodeMap decodes a map and stores its header through p. +// Maps are encoded as a length followed by key:value pairs. +// Because the internals of maps are not visible to us, we must +// use reflection rather than pointer magic. +func (dec *Decoder) decodeMap(mtyp reflect.Type, state *decoderState, p uintptr, keyOp, elemOp decOp, indir, keyIndir, elemIndir int, ovfl error) { + if indir > 0 { + p = allocate(mtyp, p, 1) // All but the last level has been allocated by dec.Indirect + } + up := unsafe.Pointer(p) + if *(*unsafe.Pointer)(up) == nil { // maps are represented as a pointer in the runtime + // Allocate map. + *(*unsafe.Pointer)(up) = unsafe.Pointer(reflect.MakeMap(mtyp).Pointer()) + } + // Maps cannot be accessed by moving addresses around the way + // that slices etc. can. We must recover a full reflection value for + // the iteration. + v := reflect.ValueOf(unsafe.Unreflect(mtyp, unsafe.Pointer(p))) + n := int(state.decodeUint()) + for i := 0; i < n; i++ { + key := decodeIntoValue(state, keyOp, keyIndir, allocValue(mtyp.Key()), ovfl) + elem := decodeIntoValue(state, elemOp, elemIndir, allocValue(mtyp.Elem()), ovfl) + v.SetMapIndex(key, elem) + } +} + +// ignoreArrayHelper does the work for discarding arrays and slices. +func (dec *Decoder) ignoreArrayHelper(state *decoderState, elemOp decOp, length int) { + instr := &decInstr{elemOp, 0, 0, 0, errors.New("no error")} + for i := 0; i < length; i++ { + elemOp(instr, state, nil) + } +} + +// ignoreArray discards the data for an array value with no destination. +func (dec *Decoder) ignoreArray(state *decoderState, elemOp decOp, length int) { + if n := state.decodeUint(); n != uint64(length) { + errorf("length mismatch in ignoreArray") + } + dec.ignoreArrayHelper(state, elemOp, length) +} + +// ignoreMap discards the data for a map value with no destination. +func (dec *Decoder) ignoreMap(state *decoderState, keyOp, elemOp decOp) { + n := int(state.decodeUint()) + keyInstr := &decInstr{keyOp, 0, 0, 0, errors.New("no error")} + elemInstr := &decInstr{elemOp, 0, 0, 0, errors.New("no error")} + for i := 0; i < n; i++ { + keyOp(keyInstr, state, nil) + elemOp(elemInstr, state, nil) + } +} + +// decodeSlice decodes a slice and stores the slice header through p. +// Slices are encoded as an unsigned length followed by the elements. +func (dec *Decoder) decodeSlice(atyp reflect.Type, state *decoderState, p uintptr, elemOp decOp, elemWid uintptr, indir, elemIndir int, ovfl error) { + n := int(uintptr(state.decodeUint())) + if indir > 0 { + up := unsafe.Pointer(p) + if *(*unsafe.Pointer)(up) == nil { + // Allocate the slice header. + *(*unsafe.Pointer)(up) = unsafe.Pointer(new([]unsafe.Pointer)) + } + p = *(*uintptr)(up) + } + // Allocate storage for the slice elements, that is, the underlying array, + // if the existing slice does not have the capacity. + // Always write a header at p. + hdrp := (*reflect.SliceHeader)(unsafe.Pointer(p)) + if hdrp.Cap < n { + hdrp.Data = uintptr(unsafe.NewArray(atyp.Elem(), n)) + hdrp.Cap = n + } + hdrp.Len = n + dec.decodeArrayHelper(state, hdrp.Data, elemOp, elemWid, n, elemIndir, ovfl) +} + +// ignoreSlice skips over the data for a slice value with no destination. +func (dec *Decoder) ignoreSlice(state *decoderState, elemOp decOp) { + dec.ignoreArrayHelper(state, elemOp, int(state.decodeUint())) +} + +// setInterfaceValue sets an interface value to a concrete value, +// but first it checks that the assignment will succeed. +func setInterfaceValue(ivalue reflect.Value, value reflect.Value) { + if !value.Type().AssignableTo(ivalue.Type()) { + errorf("cannot assign value of type %s to %s", value.Type(), ivalue.Type()) + } + ivalue.Set(value) +} + +// decodeInterface decodes an interface value and stores it through p. +// Interfaces are encoded as the name of a concrete type followed by a value. +// If the name is empty, the value is nil and no value is sent. +func (dec *Decoder) decodeInterface(ityp reflect.Type, state *decoderState, p uintptr, indir int) { + // Create a writable interface reflect.Value. We need one even for the nil case. + ivalue := allocValue(ityp) + // Read the name of the concrete type. + b := make([]byte, state.decodeUint()) + state.b.Read(b) + name := string(b) + if name == "" { + // Copy the representation of the nil interface value to the target. + // This is horribly unsafe and special. + *(*[2]uintptr)(unsafe.Pointer(p)) = ivalue.InterfaceData() + return + } + // The concrete type must be registered. + typ, ok := nameToConcreteType[name] + if !ok { + errorf("name not registered for interface: %q", name) + } + // Read the type id of the concrete value. + concreteId := dec.decodeTypeSequence(true) + if concreteId < 0 { + error_(dec.err) + } + // Byte count of value is next; we don't care what it is (it's there + // in case we want to ignore the value by skipping it completely). + state.decodeUint() + // Read the concrete value. + value := allocValue(typ) + dec.decodeValue(concreteId, value) + if dec.err != nil { + error_(dec.err) + } + // Allocate the destination interface value. + if indir > 0 { + p = allocate(ityp, p, 1) // All but the last level has been allocated by dec.Indirect + } + // Assign the concrete value to the interface. + // Tread carefully; it might not satisfy the interface. + setInterfaceValue(ivalue, value) + // Copy the representation of the interface value to the target. + // This is horribly unsafe and special. + *(*[2]uintptr)(unsafe.Pointer(p)) = ivalue.InterfaceData() +} + +// ignoreInterface discards the data for an interface value with no destination. +func (dec *Decoder) ignoreInterface(state *decoderState) { + // Read the name of the concrete type. + b := make([]byte, state.decodeUint()) + _, err := state.b.Read(b) + if err != nil { + error_(err) + } + id := dec.decodeTypeSequence(true) + if id < 0 { + error_(dec.err) + } + // At this point, the decoder buffer contains a delimited value. Just toss it. + state.b.Next(int(state.decodeUint())) +} + +// decodeGobDecoder decodes something implementing the GobDecoder interface. +// The data is encoded as a byte slice. +func (dec *Decoder) decodeGobDecoder(state *decoderState, v reflect.Value) { + // Read the bytes for the value. + b := make([]byte, state.decodeUint()) + _, err := state.b.Read(b) + if err != nil { + error_(err) + } + // We know it's a GobDecoder, so just call the method directly. + err = v.Interface().(GobDecoder).GobDecode(b) + if err != nil { + error_(err) + } +} + +// ignoreGobDecoder discards the data for a GobDecoder value with no destination. +func (dec *Decoder) ignoreGobDecoder(state *decoderState) { + // Read the bytes for the value. + b := make([]byte, state.decodeUint()) + _, err := state.b.Read(b) + if err != nil { + error_(err) + } +} + +// Index by Go types. +var decOpTable = [...]decOp{ + reflect.Bool: decBool, + reflect.Int8: decInt8, + reflect.Int16: decInt16, + reflect.Int32: decInt32, + reflect.Int64: decInt64, + reflect.Uint8: decUint8, + reflect.Uint16: decUint16, + reflect.Uint32: decUint32, + reflect.Uint64: decUint64, + reflect.Float32: decFloat32, + reflect.Float64: decFloat64, + reflect.Complex64: decComplex64, + reflect.Complex128: decComplex128, + reflect.String: decString, +} + +// Indexed by gob types. tComplex will be added during type.init(). +var decIgnoreOpMap = map[typeId]decOp{ + tBool: ignoreUint, + tInt: ignoreUint, + tUint: ignoreUint, + tFloat: ignoreUint, + tBytes: ignoreUint8Array, + tString: ignoreUint8Array, + tComplex: ignoreTwoUints, +} + +// decOpFor returns the decoding op for the base type under rt and +// the indirection count to reach it. +func (dec *Decoder) decOpFor(wireId typeId, rt reflect.Type, name string, inProgress map[reflect.Type]*decOp) (*decOp, int) { + ut := userType(rt) + // If the type implements GobEncoder, we handle it without further processing. + if ut.isGobDecoder { + return dec.gobDecodeOpFor(ut) + } + // If this type is already in progress, it's a recursive type (e.g. map[string]*T). + // Return the pointer to the op we're already building. + if opPtr := inProgress[rt]; opPtr != nil { + return opPtr, ut.indir + } + typ := ut.base + indir := ut.indir + var op decOp + k := typ.Kind() + if int(k) < len(decOpTable) { + op = decOpTable[k] + } + if op == nil { + inProgress[rt] = &op + // Special cases + switch t := typ; t.Kind() { + case reflect.Array: + name = "element of " + name + elemId := dec.wireType[wireId].ArrayT.Elem + elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress) + ovfl := overflow(name) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.decodeArray(t, state, uintptr(p), *elemOp, t.Elem().Size(), t.Len(), i.indir, elemIndir, ovfl) + } + + case reflect.Map: + name = "element of " + name + keyId := dec.wireType[wireId].MapT.Key + elemId := dec.wireType[wireId].MapT.Elem + keyOp, keyIndir := dec.decOpFor(keyId, t.Key(), name, inProgress) + elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress) + ovfl := overflow(name) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + up := unsafe.Pointer(p) + state.dec.decodeMap(t, state, uintptr(up), *keyOp, *elemOp, i.indir, keyIndir, elemIndir, ovfl) + } + + case reflect.Slice: + name = "element of " + name + if t.Elem().Kind() == reflect.Uint8 { + op = decUint8Slice + break + } + var elemId typeId + if tt, ok := builtinIdToType[wireId]; ok { + elemId = tt.(*sliceType).Elem + } else { + elemId = dec.wireType[wireId].SliceT.Elem + } + elemOp, elemIndir := dec.decOpFor(elemId, t.Elem(), name, inProgress) + ovfl := overflow(name) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.decodeSlice(t, state, uintptr(p), *elemOp, t.Elem().Size(), i.indir, elemIndir, ovfl) + } + + case reflect.Struct: + // Generate a closure that calls out to the engine for the nested type. + enginePtr, err := dec.getDecEnginePtr(wireId, userType(typ)) + if err != nil { + error_(err) + } + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + // indirect through enginePtr to delay evaluation for recursive structs. + dec.decodeStruct(*enginePtr, userType(typ), uintptr(p), i.indir) + } + case reflect.Interface: + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.decodeInterface(t, state, uintptr(p), i.indir) + } + } + } + if op == nil { + errorf("decode can't handle type %s", rt) + } + return &op, indir +} + +// decIgnoreOpFor returns the decoding op for a field that has no destination. +func (dec *Decoder) decIgnoreOpFor(wireId typeId) decOp { + op, ok := decIgnoreOpMap[wireId] + if !ok { + if wireId == tInterface { + // Special case because it's a method: the ignored item might + // define types and we need to record their state in the decoder. + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.ignoreInterface(state) + } + return op + } + // Special cases + wire := dec.wireType[wireId] + switch { + case wire == nil: + errorf("bad data: undefined type %s", wireId.string()) + case wire.ArrayT != nil: + elemId := wire.ArrayT.Elem + elemOp := dec.decIgnoreOpFor(elemId) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.ignoreArray(state, elemOp, wire.ArrayT.Len) + } + + case wire.MapT != nil: + keyId := dec.wireType[wireId].MapT.Key + elemId := dec.wireType[wireId].MapT.Elem + keyOp := dec.decIgnoreOpFor(keyId) + elemOp := dec.decIgnoreOpFor(elemId) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.ignoreMap(state, keyOp, elemOp) + } + + case wire.SliceT != nil: + elemId := wire.SliceT.Elem + elemOp := dec.decIgnoreOpFor(elemId) + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.ignoreSlice(state, elemOp) + } + + case wire.StructT != nil: + // Generate a closure that calls out to the engine for the nested type. + enginePtr, err := dec.getIgnoreEnginePtr(wireId) + if err != nil { + error_(err) + } + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + // indirect through enginePtr to delay evaluation for recursive structs + state.dec.ignoreStruct(*enginePtr) + } + + case wire.GobEncoderT != nil: + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + state.dec.ignoreGobDecoder(state) + } + } + } + if op == nil { + errorf("bad data: ignore can't handle type %s", wireId.string()) + } + return op +} + +// gobDecodeOpFor returns the op for a type that is known to implement +// GobDecoder. +func (dec *Decoder) gobDecodeOpFor(ut *userTypeInfo) (*decOp, int) { + rcvrType := ut.user + if ut.decIndir == -1 { + rcvrType = reflect.PtrTo(rcvrType) + } else if ut.decIndir > 0 { + for i := int8(0); i < ut.decIndir; i++ { + rcvrType = rcvrType.Elem() + } + } + var op decOp + op = func(i *decInstr, state *decoderState, p unsafe.Pointer) { + // Caller has gotten us to within one indirection of our value. + if i.indir > 0 { + if *(*unsafe.Pointer)(p) == nil { + *(*unsafe.Pointer)(p) = unsafe.New(ut.base) + } + } + // Now p is a pointer to the base type. Do we need to climb out to + // get to the receiver type? + var v reflect.Value + if ut.decIndir == -1 { + v = reflect.ValueOf(unsafe.Unreflect(rcvrType, unsafe.Pointer(&p))) + } else { + v = reflect.ValueOf(unsafe.Unreflect(rcvrType, p)) + } + state.dec.decodeGobDecoder(state, v) + } + return &op, int(ut.indir) + +} + +// compatibleType asks: Are these two gob Types compatible? +// Answers the question for basic types, arrays, maps and slices, plus +// GobEncoder/Decoder pairs. +// Structs are considered ok; fields will be checked later. +func (dec *Decoder) compatibleType(fr reflect.Type, fw typeId, inProgress map[reflect.Type]typeId) bool { + if rhs, ok := inProgress[fr]; ok { + return rhs == fw + } + inProgress[fr] = fw + ut := userType(fr) + wire, ok := dec.wireType[fw] + // If fr is a GobDecoder, the wire type must be GobEncoder. + // And if fr is not a GobDecoder, the wire type must not be either. + if ut.isGobDecoder != (ok && wire.GobEncoderT != nil) { // the parentheses look odd but are correct. + return false + } + if ut.isGobDecoder { // This test trumps all others. + return true + } + switch t := ut.base; t.Kind() { + default: + // chan, etc: cannot handle. + return false + case reflect.Bool: + return fw == tBool + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return fw == tInt + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return fw == tUint + case reflect.Float32, reflect.Float64: + return fw == tFloat + case reflect.Complex64, reflect.Complex128: + return fw == tComplex + case reflect.String: + return fw == tString + case reflect.Interface: + return fw == tInterface + case reflect.Array: + if !ok || wire.ArrayT == nil { + return false + } + array := wire.ArrayT + return t.Len() == array.Len && dec.compatibleType(t.Elem(), array.Elem, inProgress) + case reflect.Map: + if !ok || wire.MapT == nil { + return false + } + MapType := wire.MapT + return dec.compatibleType(t.Key(), MapType.Key, inProgress) && dec.compatibleType(t.Elem(), MapType.Elem, inProgress) + case reflect.Slice: + // Is it an array of bytes? + if t.Elem().Kind() == reflect.Uint8 { + return fw == tBytes + } + // Extract and compare element types. + var sw *sliceType + if tt, ok := builtinIdToType[fw]; ok { + sw = tt.(*sliceType) + } else { + sw = dec.wireType[fw].SliceT + } + elem := userType(t.Elem()).base + return sw != nil && dec.compatibleType(elem, sw.Elem, inProgress) + case reflect.Struct: + return true + } + return true +} + +// typeString returns a human-readable description of the type identified by remoteId. +func (dec *Decoder) typeString(remoteId typeId) string { + if t := idToType[remoteId]; t != nil { + // globally known type. + return t.string() + } + return dec.wireType[remoteId].string() +} + +// compileSingle compiles the decoder engine for a non-struct top-level value, including +// GobDecoders. +func (dec *Decoder) compileSingle(remoteId typeId, ut *userTypeInfo) (engine *decEngine, err error) { + rt := ut.user + engine = new(decEngine) + engine.instr = make([]decInstr, 1) // one item + name := rt.String() // best we can do + if !dec.compatibleType(rt, remoteId, make(map[reflect.Type]typeId)) { + return nil, errors.New("gob: wrong type received for local value " + name + ": " + dec.typeString(remoteId)) + } + op, indir := dec.decOpFor(remoteId, rt, name, make(map[reflect.Type]*decOp)) + ovfl := errors.New(`value for "` + name + `" out of range`) + engine.instr[singletonField] = decInstr{*op, singletonField, indir, 0, ovfl} + engine.numInstr = 1 + return +} + +// compileIgnoreSingle compiles the decoder engine for a non-struct top-level value that will be discarded. +func (dec *Decoder) compileIgnoreSingle(remoteId typeId) (engine *decEngine, err error) { + engine = new(decEngine) + engine.instr = make([]decInstr, 1) // one item + op := dec.decIgnoreOpFor(remoteId) + ovfl := overflow(dec.typeString(remoteId)) + engine.instr[0] = decInstr{op, 0, 0, 0, ovfl} + engine.numInstr = 1 + return +} + +// compileDec compiles the decoder engine for a value. If the value is not a struct, +// it calls out to compileSingle. +func (dec *Decoder) compileDec(remoteId typeId, ut *userTypeInfo) (engine *decEngine, err error) { + rt := ut.base + srt := rt + if srt.Kind() != reflect.Struct || + ut.isGobDecoder { + return dec.compileSingle(remoteId, ut) + } + var wireStruct *structType + // Builtin types can come from global pool; the rest must be defined by the decoder. + // Also we know we're decoding a struct now, so the client must have sent one. + if t, ok := builtinIdToType[remoteId]; ok { + wireStruct, _ = t.(*structType) + } else { + wire := dec.wireType[remoteId] + if wire == nil { + error_(errBadType) + } + wireStruct = wire.StructT + } + if wireStruct == nil { + errorf("type mismatch in decoder: want struct type %s; got non-struct", rt) + } + engine = new(decEngine) + engine.instr = make([]decInstr, len(wireStruct.Field)) + seen := make(map[reflect.Type]*decOp) + // Loop over the fields of the wire type. + for fieldnum := 0; fieldnum < len(wireStruct.Field); fieldnum++ { + wireField := wireStruct.Field[fieldnum] + if wireField.Name == "" { + errorf("empty name for remote field of type %s", wireStruct.Name) + } + ovfl := overflow(wireField.Name) + // Find the field of the local type with the same name. + localField, present := srt.FieldByName(wireField.Name) + // TODO(r): anonymous names + if !present || !isExported(wireField.Name) { + op := dec.decIgnoreOpFor(wireField.Id) + engine.instr[fieldnum] = decInstr{op, fieldnum, 0, 0, ovfl} + continue + } + if !dec.compatibleType(localField.Type, wireField.Id, make(map[reflect.Type]typeId)) { + errorf("wrong type (%s) for received field %s.%s", localField.Type, wireStruct.Name, wireField.Name) + } + op, indir := dec.decOpFor(wireField.Id, localField.Type, localField.Name, seen) + engine.instr[fieldnum] = decInstr{*op, fieldnum, indir, uintptr(localField.Offset), ovfl} + engine.numInstr++ + } + return +} + +// getDecEnginePtr returns the engine for the specified type. +func (dec *Decoder) getDecEnginePtr(remoteId typeId, ut *userTypeInfo) (enginePtr **decEngine, err error) { + rt := ut.base + decoderMap, ok := dec.decoderCache[rt] + if !ok { + decoderMap = make(map[typeId]**decEngine) + dec.decoderCache[rt] = decoderMap + } + if enginePtr, ok = decoderMap[remoteId]; !ok { + // To handle recursive types, mark this engine as underway before compiling. + enginePtr = new(*decEngine) + decoderMap[remoteId] = enginePtr + *enginePtr, err = dec.compileDec(remoteId, ut) + if err != nil { + delete(decoderMap, remoteId) + } + } + return +} + +// emptyStruct is the type we compile into when ignoring a struct value. +type emptyStruct struct{} + +var emptyStructType = reflect.TypeOf(emptyStruct{}) + +// getDecEnginePtr returns the engine for the specified type when the value is to be discarded. +func (dec *Decoder) getIgnoreEnginePtr(wireId typeId) (enginePtr **decEngine, err error) { + var ok bool + if enginePtr, ok = dec.ignorerCache[wireId]; !ok { + // To handle recursive types, mark this engine as underway before compiling. + enginePtr = new(*decEngine) + dec.ignorerCache[wireId] = enginePtr + wire := dec.wireType[wireId] + if wire != nil && wire.StructT != nil { + *enginePtr, err = dec.compileDec(wireId, userType(emptyStructType)) + } else { + *enginePtr, err = dec.compileIgnoreSingle(wireId) + } + if err != nil { + delete(dec.ignorerCache, wireId) + } + } + return +} + +// decodeValue decodes the data stream representing a value and stores it in val. +func (dec *Decoder) decodeValue(wireId typeId, val reflect.Value) { + defer catchError(&dec.err) + // If the value is nil, it means we should just ignore this item. + if !val.IsValid() { + dec.decodeIgnoredValue(wireId) + return + } + // Dereference down to the underlying type. + ut := userType(val.Type()) + base := ut.base + var enginePtr **decEngine + enginePtr, dec.err = dec.getDecEnginePtr(wireId, ut) + if dec.err != nil { + return + } + engine := *enginePtr + if st := base; st.Kind() == reflect.Struct && !ut.isGobDecoder { + if engine.numInstr == 0 && st.NumField() > 0 && len(dec.wireType[wireId].StructT.Field) > 0 { + name := base.Name() + errorf("type mismatch: no fields matched compiling decoder for %s", name) + } + dec.decodeStruct(engine, ut, uintptr(unsafeAddr(val)), ut.indir) + } else { + dec.decodeSingle(engine, ut, uintptr(unsafeAddr(val))) + } +} + +// decodeIgnoredValue decodes the data stream representing a value of the specified type and discards it. +func (dec *Decoder) decodeIgnoredValue(wireId typeId) { + var enginePtr **decEngine + enginePtr, dec.err = dec.getIgnoreEnginePtr(wireId) + if dec.err != nil { + return + } + wire := dec.wireType[wireId] + if wire != nil && wire.StructT != nil { + dec.ignoreStruct(*enginePtr) + } else { + dec.ignoreSingle(*enginePtr) + } +} + +func init() { + var iop, uop decOp + switch reflect.TypeOf(int(0)).Bits() { + case 32: + iop = decInt32 + uop = decUint32 + case 64: + iop = decInt64 + uop = decUint64 + default: + panic("gob: unknown size of int/uint") + } + decOpTable[reflect.Int] = iop + decOpTable[reflect.Uint] = uop + + // Finally uintptr + switch reflect.TypeOf(uintptr(0)).Bits() { + case 32: + uop = decUint32 + case 64: + uop = decUint64 + default: + panic("gob: unknown size of uintptr") + } + decOpTable[reflect.Uintptr] = uop +} + +// Gob assumes it can call UnsafeAddr on any Value +// in order to get a pointer it can copy data from. +// Values that have just been created and do not point +// into existing structs or slices cannot be addressed, +// so simulate it by returning a pointer to a copy. +// Each call allocates once. +func unsafeAddr(v reflect.Value) uintptr { + if v.CanAddr() { + return v.UnsafeAddr() + } + x := reflect.New(v.Type()).Elem() + x.Set(v) + return x.UnsafeAddr() +} + +// Gob depends on being able to take the address +// of zeroed Values it creates, so use this wrapper instead +// of the standard reflect.Zero. +// Each call allocates once. +func allocValue(t reflect.Type) reflect.Value { + return reflect.New(t).Elem() +} diff --git a/libgo/go/encoding/gob/decoder.go b/libgo/go/encoding/gob/decoder.go new file mode 100644 index 0000000..5e684d3 --- /dev/null +++ b/libgo/go/encoding/gob/decoder.go @@ -0,0 +1,214 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bufio" + "bytes" + "errors" + "io" + "reflect" + "sync" +) + +// A Decoder manages the receipt of type and data information read from the +// remote side of a connection. +type Decoder struct { + mutex sync.Mutex // each item must be received atomically + r io.Reader // source of the data + buf bytes.Buffer // buffer for more efficient i/o from r + wireType map[typeId]*wireType // map from remote ID to local description + decoderCache map[reflect.Type]map[typeId]**decEngine // cache of compiled engines + ignorerCache map[typeId]**decEngine // ditto for ignored objects + freeList *decoderState // list of free decoderStates; avoids reallocation + countBuf []byte // used for decoding integers while parsing messages + tmp []byte // temporary storage for i/o; saves reallocating + err error +} + +// NewDecoder returns a new decoder that reads from the io.Reader. +// If r does not also implement io.ByteReader, it will be wrapped in a +// bufio.Reader. +func NewDecoder(r io.Reader) *Decoder { + dec := new(Decoder) + // We use the ability to read bytes as a plausible surrogate for buffering. + if _, ok := r.(io.ByteReader); !ok { + r = bufio.NewReader(r) + } + dec.r = r + dec.wireType = make(map[typeId]*wireType) + dec.decoderCache = make(map[reflect.Type]map[typeId]**decEngine) + dec.ignorerCache = make(map[typeId]**decEngine) + dec.countBuf = make([]byte, 9) // counts may be uint64s (unlikely!), require 9 bytes + + return dec +} + +// recvType loads the definition of a type. +func (dec *Decoder) recvType(id typeId) { + // Have we already seen this type? That's an error + if id < firstUserId || dec.wireType[id] != nil { + dec.err = errors.New("gob: duplicate type received") + return + } + + // Type: + wire := new(wireType) + dec.decodeValue(tWireType, reflect.ValueOf(wire)) + if dec.err != nil { + return + } + // Remember we've seen this type. + dec.wireType[id] = wire +} + +var errBadCount = errors.New("invalid message length") + +// recvMessage reads the next count-delimited item from the input. It is the converse +// of Encoder.writeMessage. It returns false on EOF or other error reading the message. +func (dec *Decoder) recvMessage() bool { + // Read a count. + nbytes, _, err := decodeUintReader(dec.r, dec.countBuf) + if err != nil { + dec.err = err + return false + } + if nbytes >= 1<<31 { + dec.err = errBadCount + return false + } + dec.readMessage(int(nbytes)) + return dec.err == nil +} + +// readMessage reads the next nbytes bytes from the input. +func (dec *Decoder) readMessage(nbytes int) { + // Allocate the buffer. + if cap(dec.tmp) < nbytes { + dec.tmp = make([]byte, nbytes+100) // room to grow + } + dec.tmp = dec.tmp[:nbytes] + + // Read the data + _, dec.err = io.ReadFull(dec.r, dec.tmp) + if dec.err != nil { + if dec.err == io.EOF { + dec.err = io.ErrUnexpectedEOF + } + return + } + dec.buf.Write(dec.tmp) +} + +// toInt turns an encoded uint64 into an int, according to the marshaling rules. +func toInt(x uint64) int64 { + i := int64(x >> 1) + if x&1 != 0 { + i = ^i + } + return i +} + +func (dec *Decoder) nextInt() int64 { + n, _, err := decodeUintReader(&dec.buf, dec.countBuf) + if err != nil { + dec.err = err + } + return toInt(n) +} + +func (dec *Decoder) nextUint() uint64 { + n, _, err := decodeUintReader(&dec.buf, dec.countBuf) + if err != nil { + dec.err = err + } + return n +} + +// decodeTypeSequence parses: +// TypeSequence +// (TypeDefinition DelimitedTypeDefinition*)? +// and returns the type id of the next value. It returns -1 at +// EOF. Upon return, the remainder of dec.buf is the value to be +// decoded. If this is an interface value, it can be ignored by +// simply resetting that buffer. +func (dec *Decoder) decodeTypeSequence(isInterface bool) typeId { + for dec.err == nil { + if dec.buf.Len() == 0 { + if !dec.recvMessage() { + break + } + } + // Receive a type id. + id := typeId(dec.nextInt()) + if id >= 0 { + // Value follows. + return id + } + // Type definition for (-id) follows. + dec.recvType(-id) + // When decoding an interface, after a type there may be a + // DelimitedValue still in the buffer. Skip its count. + // (Alternatively, the buffer is empty and the byte count + // will be absorbed by recvMessage.) + if dec.buf.Len() > 0 { + if !isInterface { + dec.err = errors.New("extra data in buffer") + break + } + dec.nextUint() + } + } + return -1 +} + +// Decode reads the next value from the connection and stores +// it in the data represented by the empty interface value. +// If e is nil, the value will be discarded. Otherwise, +// the value underlying e must be a pointer to the +// correct type for the next data item received. +func (dec *Decoder) Decode(e interface{}) error { + if e == nil { + return dec.DecodeValue(reflect.Value{}) + } + value := reflect.ValueOf(e) + // If e represents a value as opposed to a pointer, the answer won't + // get back to the caller. Make sure it's a pointer. + if value.Type().Kind() != reflect.Ptr { + dec.err = errors.New("gob: attempt to decode into a non-pointer") + return dec.err + } + return dec.DecodeValue(value) +} + +// DecodeValue reads the next value from the connection. +// If v is the zero reflect.Value (v.Kind() == Invalid), DecodeValue discards the value. +// Otherwise, it stores the value into v. In that case, v must represent +// a non-nil pointer to data or be an assignable reflect.Value (v.CanSet()) +func (dec *Decoder) DecodeValue(v reflect.Value) error { + if v.IsValid() { + if v.Kind() == reflect.Ptr && !v.IsNil() { + // That's okay, we'll store through the pointer. + } else if !v.CanSet() { + return errors.New("gob: DecodeValue of unassignable value") + } + } + // Make sure we're single-threaded through here. + dec.mutex.Lock() + defer dec.mutex.Unlock() + + dec.buf.Reset() // In case data lingers from previous invocation. + dec.err = nil + id := dec.decodeTypeSequence(false) + if dec.err == nil { + dec.decodeValue(id, v) + } + return dec.err +} + +// If debug.go is compiled into the program , debugFunc prints a human-readable +// representation of the gob data read from r by calling that file's Debug function. +// Otherwise it is nil. +var debugFunc func(io.Reader) diff --git a/libgo/go/encoding/gob/doc.go b/libgo/go/encoding/gob/doc.go new file mode 100644 index 0000000..05ebef1 --- /dev/null +++ b/libgo/go/encoding/gob/doc.go @@ -0,0 +1,366 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package gob manages streams of gobs - binary values exchanged between an +Encoder (transmitter) and a Decoder (receiver). A typical use is transporting +arguments and results of remote procedure calls (RPCs) such as those provided by +package "rpc". + +A stream of gobs is self-describing. Each data item in the stream is preceded by +a specification of its type, expressed in terms of a small set of predefined +types. Pointers are not transmitted, but the things they point to are +transmitted; that is, the values are flattened. Recursive types work fine, but +recursive values (data with cycles) are problematic. This may change. + +To use gobs, create an Encoder and present it with a series of data items as +values or addresses that can be dereferenced to values. The Encoder makes sure +all type information is sent before it is needed. At the receive side, a +Decoder retrieves values from the encoded stream and unpacks them into local +variables. + +The source and destination values/types need not correspond exactly. For structs, +fields (identified by name) that are in the source but absent from the receiving +variable will be ignored. Fields that are in the receiving variable but missing +from the transmitted type or value will be ignored in the destination. If a field +with the same name is present in both, their types must be compatible. Both the +receiver and transmitter will do all necessary indirection and dereferencing to +convert between gobs and actual Go values. For instance, a gob type that is +schematically, + + struct { A, B int } + +can be sent from or received into any of these Go types: + + struct { A, B int } // the same + *struct { A, B int } // extra indirection of the struct + struct { *A, **B int } // extra indirection of the fields + struct { A, B int64 } // different concrete value type; see below + +It may also be received into any of these: + + struct { A, B int } // the same + struct { B, A int } // ordering doesn't matter; matching is by name + struct { A, B, C int } // extra field (C) ignored + struct { B int } // missing field (A) ignored; data will be dropped + struct { B, C int } // missing field (A) ignored; extra field (C) ignored. + +Attempting to receive into these types will draw a decode error: + + struct { A int; B uint } // change of signedness for B + struct { A int; B float } // change of type for B + struct { } // no field names in common + struct { C, D int } // no field names in common + +Integers are transmitted two ways: arbitrary precision signed integers or +arbitrary precision unsigned integers. There is no int8, int16 etc. +discrimination in the gob format; there are only signed and unsigned integers. As +described below, the transmitter sends the value in a variable-length encoding; +the receiver accepts the value and stores it in the destination variable. +Floating-point numbers are always sent using IEEE-754 64-bit precision (see +below). + +Signed integers may be received into any signed integer variable: int, int16, etc.; +unsigned integers may be received into any unsigned integer variable; and floating +point values may be received into any floating point variable. However, +the destination variable must be able to represent the value or the decode +operation will fail. + +Structs, arrays and slices are also supported. Strings and arrays of bytes are +supported with a special, efficient representation (see below). When a slice is +decoded, if the existing slice has capacity the slice will be extended in place; +if not, a new array is allocated. Regardless, the length of the resuling slice +reports the number of elements decoded. + +Functions and channels cannot be sent in a gob. Attempting +to encode a value that contains one will fail. + +The rest of this comment documents the encoding, details that are not important +for most users. Details are presented bottom-up. + +An unsigned integer is sent one of two ways. If it is less than 128, it is sent +as a byte with that value. Otherwise it is sent as a minimal-length big-endian +(high byte first) byte stream holding the value, preceded by one byte holding the +byte count, negated. Thus 0 is transmitted as (00), 7 is transmitted as (07) and +256 is transmitted as (FE 01 00). + +A boolean is encoded within an unsigned integer: 0 for false, 1 for true. + +A signed integer, i, is encoded within an unsigned integer, u. Within u, bits 1 +upward contain the value; bit 0 says whether they should be complemented upon +receipt. The encode algorithm looks like this: + + uint u; + if i < 0 { + u = (^i << 1) | 1 // complement i, bit 0 is 1 + } else { + u = (i << 1) // do not complement i, bit 0 is 0 + } + encodeUnsigned(u) + +The low bit is therefore analogous to a sign bit, but making it the complement bit +instead guarantees that the largest negative integer is not a special case. For +example, -129=^128=(^256>>1) encodes as (FE 01 01). + +Floating-point numbers are always sent as a representation of a float64 value. +That value is converted to a uint64 using math.Float64bits. The uint64 is then +byte-reversed and sent as a regular unsigned integer. The byte-reversal means the +exponent and high-precision part of the mantissa go first. Since the low bits are +often zero, this can save encoding bytes. For instance, 17.0 is encoded in only +three bytes (FE 31 40). + +Strings and slices of bytes are sent as an unsigned count followed by that many +uninterpreted bytes of the value. + +All other slices and arrays are sent as an unsigned count followed by that many +elements using the standard gob encoding for their type, recursively. + +Maps are sent as an unsigned count followed by that man key, element +pairs. Empty but non-nil maps are sent, so if the sender has allocated +a map, the receiver will allocate a map even no elements are +transmitted. + +Structs are sent as a sequence of (field number, field value) pairs. The field +value is sent using the standard gob encoding for its type, recursively. If a +field has the zero value for its type, it is omitted from the transmission. The +field number is defined by the type of the encoded struct: the first field of the +encoded type is field 0, the second is field 1, etc. When encoding a value, the +field numbers are delta encoded for efficiency and the fields are always sent in +order of increasing field number; the deltas are therefore unsigned. The +initialization for the delta encoding sets the field number to -1, so an unsigned +integer field 0 with value 7 is transmitted as unsigned delta = 1, unsigned value += 7 or (01 07). Finally, after all the fields have been sent a terminating mark +denotes the end of the struct. That mark is a delta=0 value, which has +representation (00). + +Interface types are not checked for compatibility; all interface types are +treated, for transmission, as members of a single "interface" type, analogous to +int or []byte - in effect they're all treated as interface{}. Interface values +are transmitted as a string identifying the concrete type being sent (a name +that must be pre-defined by calling Register), followed by a byte count of the +length of the following data (so the value can be skipped if it cannot be +stored), followed by the usual encoding of concrete (dynamic) value stored in +the interface value. (A nil interface value is identified by the empty string +and transmits no value.) Upon receipt, the decoder verifies that the unpacked +concrete item satisfies the interface of the receiving variable. + +The representation of types is described below. When a type is defined on a given +connection between an Encoder and Decoder, it is assigned a signed integer type +id. When Encoder.Encode(v) is called, it makes sure there is an id assigned for +the type of v and all its elements and then it sends the pair (typeid, encoded-v) +where typeid is the type id of the encoded type of v and encoded-v is the gob +encoding of the value v. + +To define a type, the encoder chooses an unused, positive type id and sends the +pair (-type id, encoded-type) where encoded-type is the gob encoding of a wireType +description, constructed from these types: + + type wireType struct { + ArrayT *ArrayType + SliceT *SliceType + StructT *StructType + MapT *MapType + } + type ArrayType struct { + CommonType + Elem typeId + Len int + } + type CommonType struct { + Name string // the name of the struct type + Id int // the id of the type, repeated so it's inside the type + } + type SliceType struct { + CommonType + Elem typeId + } + type StructType struct { + CommonType + Field []*fieldType // the fields of the struct. + } + type FieldType struct { + Name string // the name of the field. + Id int // the type id of the field, which must be already defined + } + type MapType struct { + CommonType + Key typeId + Elem typeId + } + +If there are nested type ids, the types for all inner type ids must be defined +before the top-level type id is used to describe an encoded-v. + +For simplicity in setup, the connection is defined to understand these types a +priori, as well as the basic gob types int, uint, etc. Their ids are: + + bool 1 + int 2 + uint 3 + float 4 + []byte 5 + string 6 + complex 7 + interface 8 + // gap for reserved ids. + WireType 16 + ArrayType 17 + CommonType 18 + SliceType 19 + StructType 20 + FieldType 21 + // 22 is slice of fieldType. + MapType 23 + +Finally, each message created by a call to Encode is preceded by an encoded +unsigned integer count of the number of bytes remaining in the message. After +the initial type name, interface values are wrapped the same way; in effect, the +interface value acts like a recursive invocation of Encode. + +In summary, a gob stream looks like + + (byteCount (-type id, encoding of a wireType)* (type id, encoding of a value))* + +where * signifies zero or more repetitions and the type id of a value must +be predefined or be defined before the value in the stream. + +See "Gobs of data" for a design discussion of the gob wire format: +http://blog.golang.org/2011/03/gobs-of-data.html +*/ +package gob + +/* +Grammar: + +Tokens starting with a lower case letter are terminals; int(n) +and uint(n) represent the signed/unsigned encodings of the value n. + +GobStream: + DelimitedMessage* +DelimitedMessage: + uint(lengthOfMessage) Message +Message: + TypeSequence TypedValue +TypeSequence + (TypeDefinition DelimitedTypeDefinition*)? +DelimitedTypeDefinition: + uint(lengthOfTypeDefinition) TypeDefinition +TypedValue: + int(typeId) Value +TypeDefinition: + int(-typeId) encodingOfWireType +Value: + SingletonValue | StructValue +SingletonValue: + uint(0) FieldValue +FieldValue: + builtinValue | ArrayValue | MapValue | SliceValue | StructValue | InterfaceValue +InterfaceValue: + NilInterfaceValue | NonNilInterfaceValue +NilInterfaceValue: + uint(0) +NonNilInterfaceValue: + ConcreteTypeName TypeSequence InterfaceContents +ConcreteTypeName: + uint(lengthOfName) [already read=n] name +InterfaceContents: + int(concreteTypeId) DelimitedValue +DelimitedValue: + uint(length) Value +ArrayValue: + uint(n) FieldValue*n [n elements] +MapValue: + uint(n) (FieldValue FieldValue)*n [n (key, value) pairs] +SliceValue: + uint(n) FieldValue*n [n elements] +StructValue: + (uint(fieldDelta) FieldValue)* +*/ + +/* +For implementers and the curious, here is an encoded example. Given + type Point struct {X, Y int} +and the value + p := Point{22, 33} +the bytes transmitted that encode p will be: + 1f ff 81 03 01 01 05 50 6f 69 6e 74 01 ff 82 00 + 01 02 01 01 58 01 04 00 01 01 59 01 04 00 00 00 + 07 ff 82 01 2c 01 42 00 +They are determined as follows. + +Since this is the first transmission of type Point, the type descriptor +for Point itself must be sent before the value. This is the first type +we've sent on this Encoder, so it has type id 65 (0 through 64 are +reserved). + + 1f // This item (a type descriptor) is 31 bytes long. + ff 81 // The negative of the id for the type we're defining, -65. + // This is one byte (indicated by FF = -1) followed by + // ^-65<<1 | 1. The low 1 bit signals to complement the + // rest upon receipt. + + // Now we send a type descriptor, which is itself a struct (wireType). + // The type of wireType itself is known (it's built in, as is the type of + // all its components), so we just need to send a *value* of type wireType + // that represents type "Point". + // Here starts the encoding of that value. + // Set the field number implicitly to -1; this is done at the beginning + // of every struct, including nested structs. + 03 // Add 3 to field number; now 2 (wireType.structType; this is a struct). + // structType starts with an embedded commonType, which appears + // as a regular structure here too. + 01 // add 1 to field number (now 0); start of embedded commonType. + 01 // add 1 to field number (now 0, the name of the type) + 05 // string is (unsigned) 5 bytes long + 50 6f 69 6e 74 // wireType.structType.commonType.name = "Point" + 01 // add 1 to field number (now 1, the id of the type) + ff 82 // wireType.structType.commonType._id = 65 + 00 // end of embedded wiretype.structType.commonType struct + 01 // add 1 to field number (now 1, the field array in wireType.structType) + 02 // There are two fields in the type (len(structType.field)) + 01 // Start of first field structure; add 1 to get field number 0: field[0].name + 01 // 1 byte + 58 // structType.field[0].name = "X" + 01 // Add 1 to get field number 1: field[0].id + 04 // structType.field[0].typeId is 2 (signed int). + 00 // End of structType.field[0]; start structType.field[1]; set field number to -1. + 01 // Add 1 to get field number 0: field[1].name + 01 // 1 byte + 59 // structType.field[1].name = "Y" + 01 // Add 1 to get field number 1: field[0].id + 04 // struct.Type.field[1].typeId is 2 (signed int). + 00 // End of structType.field[1]; end of structType.field. + 00 // end of wireType.structType structure + 00 // end of wireType structure + +Now we can send the Point value. Again the field number resets to -1: + + 07 // this value is 7 bytes long + ff 82 // the type number, 65 (1 byte (-FF) followed by 65<<1) + 01 // add one to field number, yielding field 0 + 2c // encoding of signed "22" (0x22 = 44 = 22<<1); Point.x = 22 + 01 // add one to field number, yielding field 1 + 42 // encoding of signed "33" (0x42 = 66 = 33<<1); Point.y = 33 + 00 // end of structure + +The type encoding is long and fairly intricate but we send it only once. +If p is transmitted a second time, the type is already known so the +output will be just: + + 07 ff 82 01 2c 01 42 00 + +A single non-struct value at top level is transmitted like a field with +delta tag 0. For instance, a signed integer with value 3 presented as +the argument to Encode will emit: + + 03 04 00 06 + +Which represents: + + 03 // this value is 3 bytes long + 04 // the type number, 2, represents an integer + 00 // tag delta 0 + 06 // value 3 + +*/ diff --git a/libgo/go/encoding/gob/dump.go b/libgo/go/encoding/gob/dump.go new file mode 100644 index 0000000..0d0017c --- /dev/null +++ b/libgo/go/encoding/gob/dump.go @@ -0,0 +1,22 @@ +package main + +// Need to compile package gob with debug.go to build this program. + +import ( + "encoding/gob" + "fmt" + "os" +) + +func main() { + var err error + file := os.Stdin + if len(os.Args) > 1 { + file, err = os.Open(os.Args[1]) + if err != nil { + fmt.Fprintf(os.Stderr, "dump: %s\n", err) + os.Exit(1) + } + } + gob.Debug(file) +} diff --git a/libgo/go/encoding/gob/encode.go b/libgo/go/encoding/gob/encode.go new file mode 100644 index 0000000..c7e4823 --- /dev/null +++ b/libgo/go/encoding/gob/encode.go @@ -0,0 +1,717 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bytes" + "math" + "reflect" + "unsafe" +) + +const uint64Size = int(unsafe.Sizeof(uint64(0))) + +// encoderState is the global execution state of an instance of the encoder. +// Field numbers are delta encoded and always increase. The field +// number is initialized to -1 so 0 comes out as delta(1). A delta of +// 0 terminates the structure. +type encoderState struct { + enc *Encoder + b *bytes.Buffer + sendZero bool // encoding an array element or map key/value pair; send zero values + fieldnum int // the last field number written. + buf [1 + uint64Size]byte // buffer used by the encoder; here to avoid allocation. + next *encoderState // for free list +} + +func (enc *Encoder) newEncoderState(b *bytes.Buffer) *encoderState { + e := enc.freeList + if e == nil { + e = new(encoderState) + e.enc = enc + } else { + enc.freeList = e.next + } + e.sendZero = false + e.fieldnum = 0 + e.b = b + return e +} + +func (enc *Encoder) freeEncoderState(e *encoderState) { + e.next = enc.freeList + enc.freeList = e +} + +// Unsigned integers have a two-state encoding. If the number is less +// than 128 (0 through 0x7F), its value is written directly. +// Otherwise the value is written in big-endian byte order preceded +// by the byte length, negated. + +// encodeUint writes an encoded unsigned integer to state.b. +func (state *encoderState) encodeUint(x uint64) { + if x <= 0x7F { + err := state.b.WriteByte(uint8(x)) + if err != nil { + error_(err) + } + return + } + i := uint64Size + for x > 0 { + state.buf[i] = uint8(x) + x >>= 8 + i-- + } + state.buf[i] = uint8(i - uint64Size) // = loop count, negated + _, err := state.b.Write(state.buf[i : uint64Size+1]) + if err != nil { + error_(err) + } +} + +// encodeInt writes an encoded signed integer to state.w. +// The low bit of the encoding says whether to bit complement the (other bits of the) +// uint to recover the int. +func (state *encoderState) encodeInt(i int64) { + var x uint64 + if i < 0 { + x = uint64(^i<<1) | 1 + } else { + x = uint64(i << 1) + } + state.encodeUint(uint64(x)) +} + +// encOp is the signature of an encoding operator for a given type. +type encOp func(i *encInstr, state *encoderState, p unsafe.Pointer) + +// The 'instructions' of the encoding machine +type encInstr struct { + op encOp + field int // field number + indir int // how many pointer indirections to reach the value in the struct + offset uintptr // offset in the structure of the field to encode +} + +// update emits a field number and updates the state to record its value for delta encoding. +// If the instruction pointer is nil, it does nothing +func (state *encoderState) update(instr *encInstr) { + if instr != nil { + state.encodeUint(uint64(instr.field - state.fieldnum)) + state.fieldnum = instr.field + } +} + +// Each encoder for a composite is responsible for handling any +// indirections associated with the elements of the data structure. +// If any pointer so reached is nil, no bytes are written. If the +// data item is zero, no bytes are written. Single values - ints, +// strings etc. - are indirected before calling their encoders. +// Otherwise, the output (for a scalar) is the field number, as an +// encoded integer, followed by the field data in its appropriate +// format. + +// encIndirect dereferences p indir times and returns the result. +func encIndirect(p unsafe.Pointer, indir int) unsafe.Pointer { + for ; indir > 0; indir-- { + p = *(*unsafe.Pointer)(p) + if p == nil { + return unsafe.Pointer(nil) + } + } + return p +} + +// encBool encodes the bool with address p as an unsigned 0 or 1. +func encBool(i *encInstr, state *encoderState, p unsafe.Pointer) { + b := *(*bool)(p) + if b || state.sendZero { + state.update(i) + if b { + state.encodeUint(1) + } else { + state.encodeUint(0) + } + } +} + +// encInt encodes the int with address p. +func encInt(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := int64(*(*int)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeInt(v) + } +} + +// encUint encodes the uint with address p. +func encUint(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := uint64(*(*uint)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// encInt8 encodes the int8 with address p. +func encInt8(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := int64(*(*int8)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeInt(v) + } +} + +// encUint8 encodes the uint8 with address p. +func encUint8(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := uint64(*(*uint8)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// encInt16 encodes the int16 with address p. +func encInt16(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := int64(*(*int16)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeInt(v) + } +} + +// encUint16 encodes the uint16 with address p. +func encUint16(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := uint64(*(*uint16)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// encInt32 encodes the int32 with address p. +func encInt32(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := int64(*(*int32)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeInt(v) + } +} + +// encUint encodes the uint32 with address p. +func encUint32(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := uint64(*(*uint32)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// encInt64 encodes the int64 with address p. +func encInt64(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := *(*int64)(p) + if v != 0 || state.sendZero { + state.update(i) + state.encodeInt(v) + } +} + +// encInt64 encodes the uint64 with address p. +func encUint64(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := *(*uint64)(p) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// encUintptr encodes the uintptr with address p. +func encUintptr(i *encInstr, state *encoderState, p unsafe.Pointer) { + v := uint64(*(*uintptr)(p)) + if v != 0 || state.sendZero { + state.update(i) + state.encodeUint(v) + } +} + +// floatBits returns a uint64 holding the bits of a floating-point number. +// Floating-point numbers are transmitted as uint64s holding the bits +// of the underlying representation. They are sent byte-reversed, with +// the exponent end coming out first, so integer floating point numbers +// (for example) transmit more compactly. This routine does the +// swizzling. +func floatBits(f float64) uint64 { + u := math.Float64bits(f) + var v uint64 + for i := 0; i < 8; i++ { + v <<= 8 + v |= u & 0xFF + u >>= 8 + } + return v +} + +// encFloat32 encodes the float32 with address p. +func encFloat32(i *encInstr, state *encoderState, p unsafe.Pointer) { + f := *(*float32)(p) + if f != 0 || state.sendZero { + v := floatBits(float64(f)) + state.update(i) + state.encodeUint(v) + } +} + +// encFloat64 encodes the float64 with address p. +func encFloat64(i *encInstr, state *encoderState, p unsafe.Pointer) { + f := *(*float64)(p) + if f != 0 || state.sendZero { + state.update(i) + v := floatBits(f) + state.encodeUint(v) + } +} + +// encComplex64 encodes the complex64 with address p. +// Complex numbers are just a pair of floating-point numbers, real part first. +func encComplex64(i *encInstr, state *encoderState, p unsafe.Pointer) { + c := *(*complex64)(p) + if c != 0+0i || state.sendZero { + rpart := floatBits(float64(real(c))) + ipart := floatBits(float64(imag(c))) + state.update(i) + state.encodeUint(rpart) + state.encodeUint(ipart) + } +} + +// encComplex128 encodes the complex128 with address p. +func encComplex128(i *encInstr, state *encoderState, p unsafe.Pointer) { + c := *(*complex128)(p) + if c != 0+0i || state.sendZero { + rpart := floatBits(real(c)) + ipart := floatBits(imag(c)) + state.update(i) + state.encodeUint(rpart) + state.encodeUint(ipart) + } +} + +// encUint8Array encodes the byte slice whose header has address p. +// Byte arrays are encoded as an unsigned count followed by the raw bytes. +func encUint8Array(i *encInstr, state *encoderState, p unsafe.Pointer) { + b := *(*[]byte)(p) + if len(b) > 0 || state.sendZero { + state.update(i) + state.encodeUint(uint64(len(b))) + state.b.Write(b) + } +} + +// encString encodes the string whose header has address p. +// Strings are encoded as an unsigned count followed by the raw bytes. +func encString(i *encInstr, state *encoderState, p unsafe.Pointer) { + s := *(*string)(p) + if len(s) > 0 || state.sendZero { + state.update(i) + state.encodeUint(uint64(len(s))) + state.b.WriteString(s) + } +} + +// encStructTerminator encodes the end of an encoded struct +// as delta field number of 0. +func encStructTerminator(i *encInstr, state *encoderState, p unsafe.Pointer) { + state.encodeUint(0) +} + +// Execution engine + +// encEngine an array of instructions indexed by field number of the encoding +// data, typically a struct. It is executed top to bottom, walking the struct. +type encEngine struct { + instr []encInstr +} + +const singletonField = 0 + +// encodeSingle encodes a single top-level non-struct value. +func (enc *Encoder) encodeSingle(b *bytes.Buffer, engine *encEngine, basep uintptr) { + state := enc.newEncoderState(b) + state.fieldnum = singletonField + // There is no surrounding struct to frame the transmission, so we must + // generate data even if the item is zero. To do this, set sendZero. + state.sendZero = true + instr := &engine.instr[singletonField] + p := unsafe.Pointer(basep) // offset will be zero + if instr.indir > 0 { + if p = encIndirect(p, instr.indir); p == nil { + return + } + } + instr.op(instr, state, p) + enc.freeEncoderState(state) +} + +// encodeStruct encodes a single struct value. +func (enc *Encoder) encodeStruct(b *bytes.Buffer, engine *encEngine, basep uintptr) { + state := enc.newEncoderState(b) + state.fieldnum = -1 + for i := 0; i < len(engine.instr); i++ { + instr := &engine.instr[i] + p := unsafe.Pointer(basep + instr.offset) + if instr.indir > 0 { + if p = encIndirect(p, instr.indir); p == nil { + continue + } + } + instr.op(instr, state, p) + } + enc.freeEncoderState(state) +} + +// encodeArray encodes the array whose 0th element is at p. +func (enc *Encoder) encodeArray(b *bytes.Buffer, p uintptr, op encOp, elemWid uintptr, elemIndir int, length int) { + state := enc.newEncoderState(b) + state.fieldnum = -1 + state.sendZero = true + state.encodeUint(uint64(length)) + for i := 0; i < length; i++ { + elemp := p + up := unsafe.Pointer(elemp) + if elemIndir > 0 { + if up = encIndirect(up, elemIndir); up == nil { + errorf("encodeArray: nil element") + } + elemp = uintptr(up) + } + op(nil, state, unsafe.Pointer(elemp)) + p += uintptr(elemWid) + } + enc.freeEncoderState(state) +} + +// encodeReflectValue is a helper for maps. It encodes the value v. +func encodeReflectValue(state *encoderState, v reflect.Value, op encOp, indir int) { + for i := 0; i < indir && v.IsValid(); i++ { + v = reflect.Indirect(v) + } + if !v.IsValid() { + errorf("encodeReflectValue: nil element") + } + op(nil, state, unsafe.Pointer(unsafeAddr(v))) +} + +// encodeMap encodes a map as unsigned count followed by key:value pairs. +// Because map internals are not exposed, we must use reflection rather than +// addresses. +func (enc *Encoder) encodeMap(b *bytes.Buffer, mv reflect.Value, keyOp, elemOp encOp, keyIndir, elemIndir int) { + state := enc.newEncoderState(b) + state.fieldnum = -1 + state.sendZero = true + keys := mv.MapKeys() + state.encodeUint(uint64(len(keys))) + for _, key := range keys { + encodeReflectValue(state, key, keyOp, keyIndir) + encodeReflectValue(state, mv.MapIndex(key), elemOp, elemIndir) + } + enc.freeEncoderState(state) +} + +// encodeInterface encodes the interface value iv. +// To send an interface, we send a string identifying the concrete type, followed +// by the type identifier (which might require defining that type right now), followed +// by the concrete value. A nil value gets sent as the empty string for the name, +// followed by no value. +func (enc *Encoder) encodeInterface(b *bytes.Buffer, iv reflect.Value) { + state := enc.newEncoderState(b) + state.fieldnum = -1 + state.sendZero = true + if iv.IsNil() { + state.encodeUint(0) + return + } + + ut := userType(iv.Elem().Type()) + name, ok := concreteTypeToName[ut.base] + if !ok { + errorf("type not registered for interface: %s", ut.base) + } + // Send the name. + state.encodeUint(uint64(len(name))) + _, err := state.b.WriteString(name) + if err != nil { + error_(err) + } + // Define the type id if necessary. + enc.sendTypeDescriptor(enc.writer(), state, ut) + // Send the type id. + enc.sendTypeId(state, ut) + // Encode the value into a new buffer. Any nested type definitions + // should be written to b, before the encoded value. + enc.pushWriter(b) + data := new(bytes.Buffer) + data.Write(spaceForLength) + enc.encode(data, iv.Elem(), ut) + if enc.err != nil { + error_(enc.err) + } + enc.popWriter() + enc.writeMessage(b, data) + if enc.err != nil { + error_(err) + } + enc.freeEncoderState(state) +} + +// isZero returns whether the value is the zero of its type. +func isZero(val reflect.Value) bool { + switch val.Kind() { + case reflect.Array, reflect.Map, reflect.Slice, reflect.String: + return val.Len() == 0 + case reflect.Bool: + return !val.Bool() + case reflect.Complex64, reflect.Complex128: + return val.Complex() == 0 + case reflect.Chan, reflect.Func, reflect.Ptr: + return val.IsNil() + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return val.Int() == 0 + case reflect.Float32, reflect.Float64: + return val.Float() == 0 + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return val.Uint() == 0 + } + panic("unknown type in isZero " + val.Type().String()) +} + +// encGobEncoder encodes a value that implements the GobEncoder interface. +// The data is sent as a byte array. +func (enc *Encoder) encodeGobEncoder(b *bytes.Buffer, v reflect.Value) { + // TODO: should we catch panics from the called method? + // We know it's a GobEncoder, so just call the method directly. + data, err := v.Interface().(GobEncoder).GobEncode() + if err != nil { + error_(err) + } + state := enc.newEncoderState(b) + state.fieldnum = -1 + state.encodeUint(uint64(len(data))) + state.b.Write(data) + enc.freeEncoderState(state) +} + +var encOpTable = [...]encOp{ + reflect.Bool: encBool, + reflect.Int: encInt, + reflect.Int8: encInt8, + reflect.Int16: encInt16, + reflect.Int32: encInt32, + reflect.Int64: encInt64, + reflect.Uint: encUint, + reflect.Uint8: encUint8, + reflect.Uint16: encUint16, + reflect.Uint32: encUint32, + reflect.Uint64: encUint64, + reflect.Uintptr: encUintptr, + reflect.Float32: encFloat32, + reflect.Float64: encFloat64, + reflect.Complex64: encComplex64, + reflect.Complex128: encComplex128, + reflect.String: encString, +} + +// encOpFor returns (a pointer to) the encoding op for the base type under rt and +// the indirection count to reach it. +func (enc *Encoder) encOpFor(rt reflect.Type, inProgress map[reflect.Type]*encOp) (*encOp, int) { + ut := userType(rt) + // If the type implements GobEncoder, we handle it without further processing. + if ut.isGobEncoder { + return enc.gobEncodeOpFor(ut) + } + // If this type is already in progress, it's a recursive type (e.g. map[string]*T). + // Return the pointer to the op we're already building. + if opPtr := inProgress[rt]; opPtr != nil { + return opPtr, ut.indir + } + typ := ut.base + indir := ut.indir + k := typ.Kind() + var op encOp + if int(k) < len(encOpTable) { + op = encOpTable[k] + } + if op == nil { + inProgress[rt] = &op + // Special cases + switch t := typ; t.Kind() { + case reflect.Slice: + if t.Elem().Kind() == reflect.Uint8 { + op = encUint8Array + break + } + // Slices have a header; we decode it to find the underlying array. + elemOp, indir := enc.encOpFor(t.Elem(), inProgress) + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + slice := (*reflect.SliceHeader)(p) + if !state.sendZero && slice.Len == 0 { + return + } + state.update(i) + state.enc.encodeArray(state.b, slice.Data, *elemOp, t.Elem().Size(), indir, int(slice.Len)) + } + case reflect.Array: + // True arrays have size in the type. + elemOp, indir := enc.encOpFor(t.Elem(), inProgress) + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + state.update(i) + state.enc.encodeArray(state.b, uintptr(p), *elemOp, t.Elem().Size(), indir, t.Len()) + } + case reflect.Map: + keyOp, keyIndir := enc.encOpFor(t.Key(), inProgress) + elemOp, elemIndir := enc.encOpFor(t.Elem(), inProgress) + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + // Maps cannot be accessed by moving addresses around the way + // that slices etc. can. We must recover a full reflection value for + // the iteration. + v := reflect.ValueOf(unsafe.Unreflect(t, unsafe.Pointer(p))) + mv := reflect.Indirect(v) + // We send zero-length (but non-nil) maps because the + // receiver might want to use the map. (Maps don't use append.) + if !state.sendZero && mv.IsNil() { + return + } + state.update(i) + state.enc.encodeMap(state.b, mv, *keyOp, *elemOp, keyIndir, elemIndir) + } + case reflect.Struct: + // Generate a closure that calls out to the engine for the nested type. + enc.getEncEngine(userType(typ)) + info := mustGetTypeInfo(typ) + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + state.update(i) + // indirect through info to delay evaluation for recursive structs + state.enc.encodeStruct(state.b, info.encoder, uintptr(p)) + } + case reflect.Interface: + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + // Interfaces transmit the name and contents of the concrete + // value they contain. + v := reflect.ValueOf(unsafe.Unreflect(t, unsafe.Pointer(p))) + iv := reflect.Indirect(v) + if !state.sendZero && (!iv.IsValid() || iv.IsNil()) { + return + } + state.update(i) + state.enc.encodeInterface(state.b, iv) + } + } + } + if op == nil { + errorf("can't happen: encode type %s", rt) + } + return &op, indir +} + +// gobEncodeOpFor returns the op for a type that is known to implement +// GobEncoder. +func (enc *Encoder) gobEncodeOpFor(ut *userTypeInfo) (*encOp, int) { + rt := ut.user + if ut.encIndir == -1 { + rt = reflect.PtrTo(rt) + } else if ut.encIndir > 0 { + for i := int8(0); i < ut.encIndir; i++ { + rt = rt.Elem() + } + } + var op encOp + op = func(i *encInstr, state *encoderState, p unsafe.Pointer) { + var v reflect.Value + if ut.encIndir == -1 { + // Need to climb up one level to turn value into pointer. + v = reflect.ValueOf(unsafe.Unreflect(rt, unsafe.Pointer(&p))) + } else { + v = reflect.ValueOf(unsafe.Unreflect(rt, p)) + } + if !state.sendZero && isZero(v) { + return + } + state.update(i) + state.enc.encodeGobEncoder(state.b, v) + } + return &op, int(ut.encIndir) // encIndir: op will get called with p == address of receiver. +} + +// compileEnc returns the engine to compile the type. +func (enc *Encoder) compileEnc(ut *userTypeInfo) *encEngine { + srt := ut.base + engine := new(encEngine) + seen := make(map[reflect.Type]*encOp) + rt := ut.base + if ut.isGobEncoder { + rt = ut.user + } + if !ut.isGobEncoder && + srt.Kind() == reflect.Struct { + for fieldNum, wireFieldNum := 0, 0; fieldNum < srt.NumField(); fieldNum++ { + f := srt.Field(fieldNum) + if !isExported(f.Name) { + continue + } + op, indir := enc.encOpFor(f.Type, seen) + engine.instr = append(engine.instr, encInstr{*op, wireFieldNum, indir, uintptr(f.Offset)}) + wireFieldNum++ + } + if srt.NumField() > 0 && len(engine.instr) == 0 { + errorf("type %s has no exported fields", rt) + } + engine.instr = append(engine.instr, encInstr{encStructTerminator, 0, 0, 0}) + } else { + engine.instr = make([]encInstr, 1) + op, indir := enc.encOpFor(rt, seen) + engine.instr[0] = encInstr{*op, singletonField, indir, 0} // offset is zero + } + return engine +} + +// getEncEngine returns the engine to compile the type. +// typeLock must be held (or we're in initialization and guaranteed single-threaded). +func (enc *Encoder) getEncEngine(ut *userTypeInfo) *encEngine { + info, err1 := getTypeInfo(ut) + if err1 != nil { + error_(err1) + } + if info.encoder == nil { + // mark this engine as underway before compiling to handle recursive types. + info.encoder = new(encEngine) + info.encoder = enc.compileEnc(ut) + } + return info.encoder +} + +// lockAndGetEncEngine is a function that locks and compiles. +// This lets us hold the lock only while compiling, not when encoding. +func (enc *Encoder) lockAndGetEncEngine(ut *userTypeInfo) *encEngine { + typeLock.Lock() + defer typeLock.Unlock() + return enc.getEncEngine(ut) +} + +func (enc *Encoder) encode(b *bytes.Buffer, value reflect.Value, ut *userTypeInfo) { + defer catchError(&enc.err) + engine := enc.lockAndGetEncEngine(ut) + indir := ut.indir + if ut.isGobEncoder { + indir = int(ut.encIndir) + } + for i := 0; i < indir; i++ { + value = reflect.Indirect(value) + } + if !ut.isGobEncoder && value.Type().Kind() == reflect.Struct { + enc.encodeStruct(b, engine, unsafeAddr(value)) + } else { + enc.encodeSingle(b, engine, unsafeAddr(value)) + } +} diff --git a/libgo/go/encoding/gob/encoder.go b/libgo/go/encoding/gob/encoder.go new file mode 100644 index 0000000..e4a48df --- /dev/null +++ b/libgo/go/encoding/gob/encoder.go @@ -0,0 +1,251 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bytes" + "errors" + "io" + "reflect" + "sync" +) + +// An Encoder manages the transmission of type and data information to the +// other side of a connection. +type Encoder struct { + mutex sync.Mutex // each item must be sent atomically + w []io.Writer // where to send the data + sent map[reflect.Type]typeId // which types we've already sent + countState *encoderState // stage for writing counts + freeList *encoderState // list of free encoderStates; avoids reallocation + byteBuf bytes.Buffer // buffer for top-level encoderState + err error +} + +// Before we encode a message, we reserve space at the head of the +// buffer in which to encode its length. This means we can use the +// buffer to assemble the message without another allocation. +const maxLength = 9 // Maximum size of an encoded length. +var spaceForLength = make([]byte, maxLength) + +// NewEncoder returns a new encoder that will transmit on the io.Writer. +func NewEncoder(w io.Writer) *Encoder { + enc := new(Encoder) + enc.w = []io.Writer{w} + enc.sent = make(map[reflect.Type]typeId) + enc.countState = enc.newEncoderState(new(bytes.Buffer)) + return enc +} + +// writer() returns the innermost writer the encoder is using +func (enc *Encoder) writer() io.Writer { + return enc.w[len(enc.w)-1] +} + +// pushWriter adds a writer to the encoder. +func (enc *Encoder) pushWriter(w io.Writer) { + enc.w = append(enc.w, w) +} + +// popWriter pops the innermost writer. +func (enc *Encoder) popWriter() { + enc.w = enc.w[0 : len(enc.w)-1] +} + +func (enc *Encoder) badType(rt reflect.Type) { + enc.setError(errors.New("gob: can't encode type " + rt.String())) +} + +func (enc *Encoder) setError(err error) { + if enc.err == nil { // remember the first. + enc.err = err + } +} + +// writeMessage sends the data item preceded by a unsigned count of its length. +func (enc *Encoder) writeMessage(w io.Writer, b *bytes.Buffer) { + // Space has been reserved for the length at the head of the message. + // This is a little dirty: we grab the slice from the bytes.Buffer and massage + // it by hand. + message := b.Bytes() + messageLen := len(message) - maxLength + // Encode the length. + enc.countState.b.Reset() + enc.countState.encodeUint(uint64(messageLen)) + // Copy the length to be a prefix of the message. + offset := maxLength - enc.countState.b.Len() + copy(message[offset:], enc.countState.b.Bytes()) + // Write the data. + _, err := w.Write(message[offset:]) + // Drain the buffer and restore the space at the front for the count of the next message. + b.Reset() + b.Write(spaceForLength) + if err != nil { + enc.setError(err) + } +} + +// sendActualType sends the requested type, without further investigation, unless +// it's been sent before. +func (enc *Encoder) sendActualType(w io.Writer, state *encoderState, ut *userTypeInfo, actual reflect.Type) (sent bool) { + if _, alreadySent := enc.sent[actual]; alreadySent { + return false + } + typeLock.Lock() + info, err := getTypeInfo(ut) + typeLock.Unlock() + if err != nil { + enc.setError(err) + return + } + // Send the pair (-id, type) + // Id: + state.encodeInt(-int64(info.id)) + // Type: + enc.encode(state.b, reflect.ValueOf(info.wire), wireTypeUserInfo) + enc.writeMessage(w, state.b) + if enc.err != nil { + return + } + + // Remember we've sent this type, both what the user gave us and the base type. + enc.sent[ut.base] = info.id + if ut.user != ut.base { + enc.sent[ut.user] = info.id + } + // Now send the inner types + switch st := actual; st.Kind() { + case reflect.Struct: + for i := 0; i < st.NumField(); i++ { + enc.sendType(w, state, st.Field(i).Type) + } + case reflect.Array, reflect.Slice: + enc.sendType(w, state, st.Elem()) + case reflect.Map: + enc.sendType(w, state, st.Key()) + enc.sendType(w, state, st.Elem()) + } + return true +} + +// sendType sends the type info to the other side, if necessary. +func (enc *Encoder) sendType(w io.Writer, state *encoderState, origt reflect.Type) (sent bool) { + ut := userType(origt) + if ut.isGobEncoder { + // The rules are different: regardless of the underlying type's representation, + // we need to tell the other side that this exact type is a GobEncoder. + return enc.sendActualType(w, state, ut, ut.user) + } + + // It's a concrete value, so drill down to the base type. + switch rt := ut.base; rt.Kind() { + default: + // Basic types and interfaces do not need to be described. + return + case reflect.Slice: + // If it's []uint8, don't send; it's considered basic. + if rt.Elem().Kind() == reflect.Uint8 { + return + } + // Otherwise we do send. + break + case reflect.Array: + // arrays must be sent so we know their lengths and element types. + break + case reflect.Map: + // maps must be sent so we know their lengths and key/value types. + break + case reflect.Struct: + // structs must be sent so we know their fields. + break + case reflect.Chan, reflect.Func: + // Probably a bad field in a struct. + enc.badType(rt) + return + } + + return enc.sendActualType(w, state, ut, ut.base) +} + +// Encode transmits the data item represented by the empty interface value, +// guaranteeing that all necessary type information has been transmitted first. +func (enc *Encoder) Encode(e interface{}) error { + return enc.EncodeValue(reflect.ValueOf(e)) +} + +// sendTypeDescriptor makes sure the remote side knows about this type. +// It will send a descriptor if this is the first time the type has been +// sent. +func (enc *Encoder) sendTypeDescriptor(w io.Writer, state *encoderState, ut *userTypeInfo) { + // Make sure the type is known to the other side. + // First, have we already sent this type? + rt := ut.base + if ut.isGobEncoder { + rt = ut.user + } + if _, alreadySent := enc.sent[rt]; !alreadySent { + // No, so send it. + sent := enc.sendType(w, state, rt) + if enc.err != nil { + return + } + // If the type info has still not been transmitted, it means we have + // a singleton basic type (int, []byte etc.) at top level. We don't + // need to send the type info but we do need to update enc.sent. + if !sent { + typeLock.Lock() + info, err := getTypeInfo(ut) + typeLock.Unlock() + if err != nil { + enc.setError(err) + return + } + enc.sent[rt] = info.id + } + } +} + +// sendTypeId sends the id, which must have already been defined. +func (enc *Encoder) sendTypeId(state *encoderState, ut *userTypeInfo) { + // Identify the type of this top-level value. + state.encodeInt(int64(enc.sent[ut.base])) +} + +// EncodeValue transmits the data item represented by the reflection value, +// guaranteeing that all necessary type information has been transmitted first. +func (enc *Encoder) EncodeValue(value reflect.Value) error { + // Make sure we're single-threaded through here, so multiple + // goroutines can share an encoder. + enc.mutex.Lock() + defer enc.mutex.Unlock() + + // Remove any nested writers remaining due to previous errors. + enc.w = enc.w[0:1] + + ut, err := validUserType(value.Type()) + if err != nil { + return err + } + + enc.err = nil + enc.byteBuf.Reset() + enc.byteBuf.Write(spaceForLength) + state := enc.newEncoderState(&enc.byteBuf) + + enc.sendTypeDescriptor(enc.writer(), state, ut) + enc.sendTypeId(state, ut) + if enc.err != nil { + return enc.err + } + + // Encode the object. + enc.encode(state.b, value, ut) + if enc.err == nil { + enc.writeMessage(enc.writer(), state.b) + } + + enc.freeEncoderState(state) + return enc.err +} diff --git a/libgo/go/encoding/gob/encoder_test.go b/libgo/go/encoding/gob/encoder_test.go new file mode 100644 index 0000000..bc5af12 --- /dev/null +++ b/libgo/go/encoding/gob/encoder_test.go @@ -0,0 +1,664 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bytes" + "fmt" + "io" + "reflect" + "strings" + "testing" +) + +type ET2 struct { + X string +} + +type ET1 struct { + A int + Et2 *ET2 + Next *ET1 +} + +// Like ET1 but with a different name for a field +type ET3 struct { + A int + Et2 *ET2 + DifferentNext *ET1 +} + +// Like ET1 but with a different type for a field +type ET4 struct { + A int + Et2 float64 + Next int +} + +func TestEncoderDecoder(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + et1 := new(ET1) + et1.A = 7 + et1.Et2 = new(ET2) + err := enc.Encode(et1) + if err != nil { + t.Error("encoder fail:", err) + } + dec := NewDecoder(b) + newEt1 := new(ET1) + err = dec.Decode(newEt1) + if err != nil { + t.Fatal("error decoding ET1:", err) + } + + if !reflect.DeepEqual(et1, newEt1) { + t.Fatalf("invalid data for et1: expected %+v; got %+v", *et1, *newEt1) + } + if b.Len() != 0 { + t.Error("not at eof;", b.Len(), "bytes left") + } + + enc.Encode(et1) + newEt1 = new(ET1) + err = dec.Decode(newEt1) + if err != nil { + t.Fatal("round 2: error decoding ET1:", err) + } + if !reflect.DeepEqual(et1, newEt1) { + t.Fatalf("round 2: invalid data for et1: expected %+v; got %+v", *et1, *newEt1) + } + if b.Len() != 0 { + t.Error("round 2: not at eof;", b.Len(), "bytes left") + } + + // Now test with a running encoder/decoder pair that we recognize a type mismatch. + err = enc.Encode(et1) + if err != nil { + t.Error("round 3: encoder fail:", err) + } + newEt2 := new(ET2) + err = dec.Decode(newEt2) + if err == nil { + t.Fatal("round 3: expected `bad type' error decoding ET2") + } +} + +// Run one value through the encoder/decoder, but use the wrong type. +// Input is always an ET1; we compare it to whatever is under 'e'. +func badTypeCheck(e interface{}, shouldFail bool, msg string, t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + et1 := new(ET1) + et1.A = 7 + et1.Et2 = new(ET2) + err := enc.Encode(et1) + if err != nil { + t.Error("encoder fail:", err) + } + dec := NewDecoder(b) + err = dec.Decode(e) + if shouldFail && err == nil { + t.Error("expected error for", msg) + } + if !shouldFail && err != nil { + t.Error("unexpected error for", msg, err) + } +} + +// Test that we recognize a bad type the first time. +func TestWrongTypeDecoder(t *testing.T) { + badTypeCheck(new(ET2), true, "no fields in common", t) + badTypeCheck(new(ET3), false, "different name of field", t) + badTypeCheck(new(ET4), true, "different type of field", t) +} + +func corruptDataCheck(s string, err error, t *testing.T) { + b := bytes.NewBufferString(s) + dec := NewDecoder(b) + err1 := dec.Decode(new(ET2)) + if err1 != err { + t.Errorf("from %q expected error %s; got %s", s, err, err1) + } +} + +// Check that we survive bad data. +func TestBadData(t *testing.T) { + corruptDataCheck("", io.EOF, t) + corruptDataCheck("\x7Fhi", io.ErrUnexpectedEOF, t) + corruptDataCheck("\x03now is the time for all good men", errBadType, t) +} + +// Types not supported by the Encoder. +var unsupportedValues = []interface{}{ + make(chan int), + func(a int) bool { return true }, +} + +func TestUnsupported(t *testing.T) { + var b bytes.Buffer + enc := NewEncoder(&b) + for _, v := range unsupportedValues { + err := enc.Encode(v) + if err == nil { + t.Errorf("expected error for %T; got none", v) + } + } +} + +func encAndDec(in, out interface{}) error { + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(in) + if err != nil { + return err + } + dec := NewDecoder(b) + err = dec.Decode(out) + if err != nil { + return err + } + return nil +} + +func TestTypeToPtrType(t *testing.T) { + // Encode a T, decode a *T + type Type0 struct { + A int + } + t0 := Type0{7} + t0p := new(Type0) + if err := encAndDec(t0, t0p); err != nil { + t.Error(err) + } +} + +func TestPtrTypeToType(t *testing.T) { + // Encode a *T, decode a T + type Type1 struct { + A uint + } + t1p := &Type1{17} + var t1 Type1 + if err := encAndDec(t1, t1p); err != nil { + t.Error(err) + } +} + +func TestTypeToPtrPtrPtrPtrType(t *testing.T) { + type Type2 struct { + A ****float64 + } + t2 := Type2{} + t2.A = new(***float64) + *t2.A = new(**float64) + **t2.A = new(*float64) + ***t2.A = new(float64) + ****t2.A = 27.4 + t2pppp := new(***Type2) + if err := encAndDec(t2, t2pppp); err != nil { + t.Fatal(err) + } + if ****(****t2pppp).A != ****t2.A { + t.Errorf("wrong value after decode: %g not %g", ****(****t2pppp).A, ****t2.A) + } +} + +func TestSlice(t *testing.T) { + type Type3 struct { + A []string + } + t3p := &Type3{[]string{"hello", "world"}} + var t3 Type3 + if err := encAndDec(t3, t3p); err != nil { + t.Error(err) + } +} + +func TestValueError(t *testing.T) { + // Encode a *T, decode a T + type Type4 struct { + A int + } + t4p := &Type4{3} + var t4 Type4 // note: not a pointer. + if err := encAndDec(t4p, t4); err == nil || strings.Index(err.Error(), "pointer") < 0 { + t.Error("expected error about pointer; got", err) + } +} + +func TestArray(t *testing.T) { + type Type5 struct { + A [3]string + B [3]byte + } + type Type6 struct { + A [2]string // can't hold t5.a + } + t5 := Type5{[3]string{"hello", ",", "world"}, [3]byte{1, 2, 3}} + var t5p Type5 + if err := encAndDec(t5, &t5p); err != nil { + t.Error(err) + } + var t6 Type6 + if err := encAndDec(t5, &t6); err == nil { + t.Error("should fail with mismatched array sizes") + } +} + +func TestRecursiveMapType(t *testing.T) { + type recursiveMap map[string]recursiveMap + r1 := recursiveMap{"A": recursiveMap{"B": nil, "C": nil}, "D": nil} + r2 := make(recursiveMap) + if err := encAndDec(r1, &r2); err != nil { + t.Error(err) + } +} + +func TestRecursiveSliceType(t *testing.T) { + type recursiveSlice []recursiveSlice + r1 := recursiveSlice{0: recursiveSlice{0: nil}, 1: nil} + r2 := make(recursiveSlice, 0) + if err := encAndDec(r1, &r2); err != nil { + t.Error(err) + } +} + +// Regression test for bug: must send zero values inside arrays +func TestDefaultsInArray(t *testing.T) { + type Type7 struct { + B []bool + I []int + S []string + F []float64 + } + t7 := Type7{ + []bool{false, false, true}, + []int{0, 0, 1}, + []string{"hi", "", "there"}, + []float64{0, 0, 1}, + } + var t7p Type7 + if err := encAndDec(t7, &t7p); err != nil { + t.Error(err) + } +} + +var testInt int +var testFloat32 float32 +var testString string +var testSlice []string +var testMap map[string]int +var testArray [7]int + +type SingleTest struct { + in interface{} + out interface{} + err string +} + +var singleTests = []SingleTest{ + {17, &testInt, ""}, + {float32(17.5), &testFloat32, ""}, + {"bike shed", &testString, ""}, + {[]string{"bike", "shed", "paint", "color"}, &testSlice, ""}, + {map[string]int{"seven": 7, "twelve": 12}, &testMap, ""}, + {[7]int{4, 55, 0, 0, 0, 0, 0}, &testArray, ""}, // case that once triggered a bug + {[7]int{4, 55, 1, 44, 22, 66, 1234}, &testArray, ""}, + + // Decode errors + {172, &testFloat32, "wrong type"}, +} + +func TestSingletons(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + dec := NewDecoder(b) + for _, test := range singleTests { + b.Reset() + err := enc.Encode(test.in) + if err != nil { + t.Errorf("error encoding %v: %s", test.in, err) + continue + } + err = dec.Decode(test.out) + switch { + case err != nil && test.err == "": + t.Errorf("error decoding %v: %s", test.in, err) + continue + case err == nil && test.err != "": + t.Errorf("expected error decoding %v: %s", test.in, test.err) + continue + case err != nil && test.err != "": + if strings.Index(err.Error(), test.err) < 0 { + t.Errorf("wrong error decoding %v: wanted %s, got %v", test.in, test.err, err) + } + continue + } + // Get rid of the pointer in the rhs + val := reflect.ValueOf(test.out).Elem().Interface() + if !reflect.DeepEqual(test.in, val) { + t.Errorf("decoding singleton: expected %v got %v", test.in, val) + } + } +} + +func TestStructNonStruct(t *testing.T) { + type Struct struct { + A string + } + type NonStruct string + s := Struct{"hello"} + var sp Struct + if err := encAndDec(s, &sp); err != nil { + t.Error(err) + } + var ns NonStruct + if err := encAndDec(s, &ns); err == nil { + t.Error("should get error for struct/non-struct") + } else if strings.Index(err.Error(), "type") < 0 { + t.Error("for struct/non-struct expected type error; got", err) + } + // Now try the other way + var nsp NonStruct + if err := encAndDec(ns, &nsp); err != nil { + t.Error(err) + } + if err := encAndDec(ns, &s); err == nil { + t.Error("should get error for non-struct/struct") + } else if strings.Index(err.Error(), "type") < 0 { + t.Error("for non-struct/struct expected type error; got", err) + } +} + +type interfaceIndirectTestI interface { + F() bool +} + +type interfaceIndirectTestT struct{} + +func (this *interfaceIndirectTestT) F() bool { + return true +} + +// A version of a bug reported on golang-nuts. Also tests top-level +// slice of interfaces. The issue was registering *T caused T to be +// stored as the concrete type. +func TestInterfaceIndirect(t *testing.T) { + Register(&interfaceIndirectTestT{}) + b := new(bytes.Buffer) + w := []interfaceIndirectTestI{&interfaceIndirectTestT{}} + err := NewEncoder(b).Encode(w) + if err != nil { + t.Fatal("encode error:", err) + } + + var r []interfaceIndirectTestI + err = NewDecoder(b).Decode(&r) + if err != nil { + t.Fatal("decode error:", err) + } +} + +// Now follow various tests that decode into things that can't represent the +// encoded value, all of which should be legal. + +// Also, when the ignored object contains an interface value, it may define +// types. Make sure that skipping the value still defines the types by using +// the encoder/decoder pair to send a value afterwards. If an interface +// is sent, its type in the test is always NewType0, so this checks that the +// encoder and decoder don't skew with respect to type definitions. + +type Struct0 struct { + I interface{} +} + +type NewType0 struct { + S string +} + +type ignoreTest struct { + in, out interface{} +} + +var ignoreTests = []ignoreTest{ + // Decode normal struct into an empty struct + {&struct{ A int }{23}, &struct{}{}}, + // Decode normal struct into a nil. + {&struct{ A int }{23}, nil}, + // Decode singleton string into a nil. + {"hello, world", nil}, + // Decode singleton slice into a nil. + {[]int{1, 2, 3, 4}, nil}, + // Decode struct containing an interface into a nil. + {&Struct0{&NewType0{"value0"}}, nil}, + // Decode singleton slice of interfaces into a nil. + {[]interface{}{"hi", &NewType0{"value1"}, 23}, nil}, +} + +func TestDecodeIntoNothing(t *testing.T) { + Register(new(NewType0)) + for i, test := range ignoreTests { + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(test.in) + if err != nil { + t.Errorf("%d: encode error %s:", i, err) + continue + } + dec := NewDecoder(b) + err = dec.Decode(test.out) + if err != nil { + t.Errorf("%d: decode error: %s", i, err) + continue + } + // Now see if the encoder and decoder are in a consistent state. + str := fmt.Sprintf("Value %d", i) + err = enc.Encode(&NewType0{str}) + if err != nil { + t.Fatalf("%d: NewType0 encode error: %s", i, err) + } + ns := new(NewType0) + err = dec.Decode(ns) + if err != nil { + t.Fatalf("%d: NewType0 decode error: %s", i, err) + } + if ns.S != str { + t.Fatalf("%d: expected %q got %q", i, str, ns.S) + } + } +} + +// Another bug from golang-nuts, involving nested interfaces. +type Bug0Outer struct { + Bug0Field interface{} +} + +type Bug0Inner struct { + A int +} + +func TestNestedInterfaces(t *testing.T) { + var buf bytes.Buffer + e := NewEncoder(&buf) + d := NewDecoder(&buf) + Register(new(Bug0Outer)) + Register(new(Bug0Inner)) + f := &Bug0Outer{&Bug0Outer{&Bug0Inner{7}}} + var v interface{} = f + err := e.Encode(&v) + if err != nil { + t.Fatal("Encode:", err) + } + err = d.Decode(&v) + if err != nil { + t.Fatal("Decode:", err) + } + // Make sure it decoded correctly. + outer1, ok := v.(*Bug0Outer) + if !ok { + t.Fatalf("v not Bug0Outer: %T", v) + } + outer2, ok := outer1.Bug0Field.(*Bug0Outer) + if !ok { + t.Fatalf("v.Bug0Field not Bug0Outer: %T", outer1.Bug0Field) + } + inner, ok := outer2.Bug0Field.(*Bug0Inner) + if !ok { + t.Fatalf("v.Bug0Field.Bug0Field not Bug0Inner: %T", outer2.Bug0Field) + } + if inner.A != 7 { + t.Fatalf("final value %d; expected %d", inner.A, 7) + } +} + +// The bugs keep coming. We forgot to send map subtypes before the map. + +type Bug1Elem struct { + Name string + Id int +} + +type Bug1StructMap map[string]Bug1Elem + +func bug1EncDec(in Bug1StructMap, out *Bug1StructMap) error { + return nil +} + +func TestMapBug1(t *testing.T) { + in := make(Bug1StructMap) + in["val1"] = Bug1Elem{"elem1", 1} + in["val2"] = Bug1Elem{"elem2", 2} + + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(in) + if err != nil { + t.Fatal("encode:", err) + } + dec := NewDecoder(b) + out := make(Bug1StructMap) + err = dec.Decode(&out) + if err != nil { + t.Fatal("decode:", err) + } + if !reflect.DeepEqual(in, out) { + t.Errorf("mismatch: %v %v", in, out) + } +} + +func TestGobMapInterfaceEncode(t *testing.T) { + m := map[string]interface{}{ + "up": uintptr(0), + "i0": []int{-1}, + "i1": []int8{-1}, + "i2": []int16{-1}, + "i3": []int32{-1}, + "i4": []int64{-1}, + "u0": []uint{1}, + "u1": []uint8{1}, + "u2": []uint16{1}, + "u3": []uint32{1}, + "u4": []uint64{1}, + "f0": []float32{1}, + "f1": []float64{1}, + "c0": []complex64{complex(2, -2)}, + "c1": []complex128{complex(2, float64(-2))}, + "us": []uintptr{0}, + "bo": []bool{false}, + "st": []string{"s"}, + } + buf := bytes.NewBuffer(nil) + enc := NewEncoder(buf) + err := enc.Encode(m) + if err != nil { + t.Errorf("encode map: %s", err) + } +} + +func TestSliceReusesMemory(t *testing.T) { + buf := bytes.NewBuffer(nil) + // Bytes + { + x := []byte("abcd") + enc := NewEncoder(buf) + err := enc.Encode(x) + if err != nil { + t.Errorf("bytes: encode: %s", err) + } + // Decode into y, which is big enough. + y := []byte("ABCDE") + addr := &y[0] + dec := NewDecoder(buf) + err = dec.Decode(&y) + if err != nil { + t.Fatal("bytes: decode:", err) + } + if !bytes.Equal(x, y) { + t.Errorf("bytes: expected %q got %q\n", x, y) + } + if addr != &y[0] { + t.Errorf("bytes: unnecessary reallocation") + } + } + // general slice + { + x := []rune("abcd") + enc := NewEncoder(buf) + err := enc.Encode(x) + if err != nil { + t.Errorf("ints: encode: %s", err) + } + // Decode into y, which is big enough. + y := []rune("ABCDE") + addr := &y[0] + dec := NewDecoder(buf) + err = dec.Decode(&y) + if err != nil { + t.Fatal("ints: decode:", err) + } + if !reflect.DeepEqual(x, y) { + t.Errorf("ints: expected %q got %q\n", x, y) + } + if addr != &y[0] { + t.Errorf("ints: unnecessary reallocation") + } + } +} + +// Used to crash: negative count in recvMessage. +func TestBadCount(t *testing.T) { + b := []byte{0xfb, 0xa5, 0x82, 0x2f, 0xca, 0x1} + if err := NewDecoder(bytes.NewBuffer(b)).Decode(nil); err == nil { + t.Error("expected error from bad count") + } else if err.Error() != errBadCount.Error() { + t.Error("expected bad count error; got", err) + } +} + +// Verify that sequential Decoders built on a single input will +// succeed if the input implements ReadByte and there is no +// type information in the stream. +func TestSequentialDecoder(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + const count = 10 + for i := 0; i < count; i++ { + s := fmt.Sprintf("%d", i) + if err := enc.Encode(s); err != nil { + t.Error("encoder fail:", err) + } + } + for i := 0; i < count; i++ { + dec := NewDecoder(b) + var s string + if err := dec.Decode(&s); err != nil { + t.Fatal("decoder fail:", err) + } + if s != fmt.Sprintf("%d", i) { + t.Fatalf("decode expected %d got %s", i, s) + } + } +} diff --git a/libgo/go/encoding/gob/error.go b/libgo/go/encoding/gob/error.go new file mode 100644 index 0000000..fbae8b6 --- /dev/null +++ b/libgo/go/encoding/gob/error.go @@ -0,0 +1,39 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import "fmt" + +// Errors in decoding and encoding are handled using panic and recover. +// Panics caused by user error (that is, everything except run-time panics +// such as "index out of bounds" errors) do not leave the file that caused +// them, but are instead turned into plain error returns. Encoding and +// decoding functions and methods that do not return an error either use +// panic to report an error or are guaranteed error-free. + +// A gobError is used to distinguish errors (panics) generated in this package. +type gobError struct { + err error +} + +// errorf is like error_ but takes Printf-style arguments to construct an error. +// It always prefixes the message with "gob: ". +func errorf(format string, args ...interface{}) { + error_(fmt.Errorf("gob: "+format, args...)) +} + +// error wraps the argument error and uses it as the argument to panic. +func error_(err error) { + panic(gobError{err}) +} + +// catchError is meant to be used as a deferred function to turn a panic(gobError) into a +// plain error. It overwrites the error return of the function that deferred its call. +func catchError(err *error) { + if e := recover(); e != nil { + *err = e.(gobError).err // Will re-panic if not one of our errors, such as a runtime error. + } + return +} diff --git a/libgo/go/encoding/gob/gobencdec_test.go b/libgo/go/encoding/gob/gobencdec_test.go new file mode 100644 index 0000000..eacfd84 --- /dev/null +++ b/libgo/go/encoding/gob/gobencdec_test.go @@ -0,0 +1,528 @@ +// Copyright 20011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file contains tests of the GobEncoder/GobDecoder support. + +package gob + +import ( + "bytes" + "errors" + "fmt" + "io" + "strings" + "testing" +) + +// Types that implement the GobEncoder/Decoder interfaces. + +type ByteStruct struct { + a byte // not an exported field +} + +type StringStruct struct { + s string // not an exported field +} + +type ArrayStruct struct { + a [8192]byte // not an exported field +} + +type Gobber int + +type ValueGobber string // encodes with a value, decodes with a pointer. + +// The relevant methods + +func (g *ByteStruct) GobEncode() ([]byte, error) { + b := make([]byte, 3) + b[0] = g.a + b[1] = g.a + 1 + b[2] = g.a + 2 + return b, nil +} + +func (g *ByteStruct) GobDecode(data []byte) error { + if g == nil { + return errors.New("NIL RECEIVER") + } + // Expect N sequential-valued bytes. + if len(data) == 0 { + return io.EOF + } + g.a = data[0] + for i, c := range data { + if c != g.a+byte(i) { + return errors.New("invalid data sequence") + } + } + return nil +} + +func (g *StringStruct) GobEncode() ([]byte, error) { + return []byte(g.s), nil +} + +func (g *StringStruct) GobDecode(data []byte) error { + // Expect N sequential-valued bytes. + if len(data) == 0 { + return io.EOF + } + a := data[0] + for i, c := range data { + if c != a+byte(i) { + return errors.New("invalid data sequence") + } + } + g.s = string(data) + return nil +} + +func (a *ArrayStruct) GobEncode() ([]byte, error) { + return a.a[:], nil +} + +func (a *ArrayStruct) GobDecode(data []byte) error { + if len(data) != len(a.a) { + return errors.New("wrong length in array decode") + } + copy(a.a[:], data) + return nil +} + +func (g *Gobber) GobEncode() ([]byte, error) { + return []byte(fmt.Sprintf("VALUE=%d", *g)), nil +} + +func (g *Gobber) GobDecode(data []byte) error { + _, err := fmt.Sscanf(string(data), "VALUE=%d", (*int)(g)) + return err +} + +func (v ValueGobber) GobEncode() ([]byte, error) { + return []byte(fmt.Sprintf("VALUE=%s", v)), nil +} + +func (v *ValueGobber) GobDecode(data []byte) error { + _, err := fmt.Sscanf(string(data), "VALUE=%s", (*string)(v)) + return err +} + +// Structs that include GobEncodable fields. + +type GobTest0 struct { + X int // guarantee we have something in common with GobTest* + G *ByteStruct +} + +type GobTest1 struct { + X int // guarantee we have something in common with GobTest* + G *StringStruct +} + +type GobTest2 struct { + X int // guarantee we have something in common with GobTest* + G string // not a GobEncoder - should give us errors +} + +type GobTest3 struct { + X int // guarantee we have something in common with GobTest* + G *Gobber +} + +type GobTest4 struct { + X int // guarantee we have something in common with GobTest* + V ValueGobber +} + +type GobTest5 struct { + X int // guarantee we have something in common with GobTest* + V *ValueGobber +} + +type GobTestIgnoreEncoder struct { + X int // guarantee we have something in common with GobTest* +} + +type GobTestValueEncDec struct { + X int // guarantee we have something in common with GobTest* + G StringStruct // not a pointer. +} + +type GobTestIndirectEncDec struct { + X int // guarantee we have something in common with GobTest* + G ***StringStruct // indirections to the receiver. +} + +type GobTestArrayEncDec struct { + X int // guarantee we have something in common with GobTest* + A ArrayStruct // not a pointer. +} + +type GobTestIndirectArrayEncDec struct { + X int // guarantee we have something in common with GobTest* + A ***ArrayStruct // indirections to a large receiver. +} + +func TestGobEncoderField(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + err := enc.Encode(GobTest0{17, &ByteStruct{'A'}}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTest0) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.G.a != 'A' { + t.Errorf("expected 'A' got %c", x.G.a) + } + // Now a field that's not a structure. + b.Reset() + gobber := Gobber(23) + err = enc.Encode(GobTest3{17, &gobber}) + if err != nil { + t.Fatal("encode error:", err) + } + y := new(GobTest3) + err = dec.Decode(y) + if err != nil { + t.Fatal("decode error:", err) + } + if *y.G != 23 { + t.Errorf("expected '23 got %d", *y.G) + } +} + +// Even though the field is a value, we can still take its address +// and should be able to call the methods. +func TestGobEncoderValueField(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + err := enc.Encode(GobTestValueEncDec{17, StringStruct{"HIJKL"}}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestValueEncDec) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.G.s != "HIJKL" { + t.Errorf("expected `HIJKL` got %s", x.G.s) + } +} + +// GobEncode/Decode should work even if the value is +// more indirect than the receiver. +func TestGobEncoderIndirectField(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + s := &StringStruct{"HIJKL"} + sp := &s + err := enc.Encode(GobTestIndirectEncDec{17, &sp}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestIndirectEncDec) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if (***x.G).s != "HIJKL" { + t.Errorf("expected `HIJKL` got %s", (***x.G).s) + } +} + +// Test with a large field with methods. +func TestGobEncoderArrayField(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + var a GobTestArrayEncDec + a.X = 17 + for i := range a.A.a { + a.A.a[i] = byte(i) + } + err := enc.Encode(a) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestArrayEncDec) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + for i, v := range x.A.a { + if v != byte(i) { + t.Errorf("expected %x got %x", byte(i), v) + break + } + } +} + +// Test an indirection to a large field with methods. +func TestGobEncoderIndirectArrayField(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + var a GobTestIndirectArrayEncDec + a.X = 17 + var array ArrayStruct + ap := &array + app := &ap + a.A = &app + for i := range array.a { + array.a[i] = byte(i) + } + err := enc.Encode(a) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestIndirectArrayEncDec) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + for i, v := range (***x.A).a { + if v != byte(i) { + t.Errorf("expected %x got %x", byte(i), v) + break + } + } +} + +// As long as the fields have the same name and implement the +// interface, we can cross-connect them. Not sure it's useful +// and may even be bad but it works and it's hard to prevent +// without exposing the contents of the object, which would +// defeat the purpose. +func TestGobEncoderFieldsOfDifferentType(t *testing.T) { + // first, string in field to byte in field + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(GobTest1{17, &StringStruct{"ABC"}}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTest0) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.G.a != 'A' { + t.Errorf("expected 'A' got %c", x.G.a) + } + // now the other direction, byte in field to string in field + b.Reset() + err = enc.Encode(GobTest0{17, &ByteStruct{'X'}}) + if err != nil { + t.Fatal("encode error:", err) + } + y := new(GobTest1) + err = dec.Decode(y) + if err != nil { + t.Fatal("decode error:", err) + } + if y.G.s != "XYZ" { + t.Fatalf("expected `XYZ` got %c", y.G.s) + } +} + +// Test that we can encode a value and decode into a pointer. +func TestGobEncoderValueEncoder(t *testing.T) { + // first, string in field to byte in field + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(GobTest4{17, ValueGobber("hello")}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTest5) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if *x.V != "hello" { + t.Errorf("expected `hello` got %s", x.V) + } +} + +func TestGobEncoderFieldTypeError(t *testing.T) { + // GobEncoder to non-decoder: error + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(GobTest1{17, &StringStruct{"ABC"}}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := &GobTest2{} + err = dec.Decode(x) + if err == nil { + t.Fatal("expected decode error for mismatched fields (encoder to non-decoder)") + } + if strings.Index(err.Error(), "type") < 0 { + t.Fatal("expected type error; got", err) + } + // Non-encoder to GobDecoder: error + b.Reset() + err = enc.Encode(GobTest2{17, "ABC"}) + if err != nil { + t.Fatal("encode error:", err) + } + y := &GobTest1{} + err = dec.Decode(y) + if err == nil { + t.Fatal("expected decode error for mismatched fields (non-encoder to decoder)") + } + if strings.Index(err.Error(), "type") < 0 { + t.Fatal("expected type error; got", err) + } +} + +// Even though ByteStruct is a struct, it's treated as a singleton at the top level. +func TestGobEncoderStructSingleton(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(&ByteStruct{'A'}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(ByteStruct) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.a != 'A' { + t.Errorf("expected 'A' got %c", x.a) + } +} + +func TestGobEncoderNonStructSingleton(t *testing.T) { + b := new(bytes.Buffer) + enc := NewEncoder(b) + err := enc.Encode(Gobber(1234)) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + var x Gobber + err = dec.Decode(&x) + if err != nil { + t.Fatal("decode error:", err) + } + if x != 1234 { + t.Errorf("expected 1234 got %d", x) + } +} + +func TestGobEncoderIgnoreStructField(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + err := enc.Encode(GobTest0{17, &ByteStruct{'A'}}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestIgnoreEncoder) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.X != 17 { + t.Errorf("expected 17 got %c", x.X) + } +} + +func TestGobEncoderIgnoreNonStructField(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + gobber := Gobber(23) + err := enc.Encode(GobTest3{17, &gobber}) + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTestIgnoreEncoder) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.X != 17 { + t.Errorf("expected 17 got %c", x.X) + } +} + +func TestGobEncoderIgnoreNilEncoder(t *testing.T) { + b := new(bytes.Buffer) + // First a field that's a structure. + enc := NewEncoder(b) + err := enc.Encode(GobTest0{X: 18}) // G is nil + if err != nil { + t.Fatal("encode error:", err) + } + dec := NewDecoder(b) + x := new(GobTest0) + err = dec.Decode(x) + if err != nil { + t.Fatal("decode error:", err) + } + if x.X != 18 { + t.Errorf("expected x.X = 18, got %v", x.X) + } + if x.G != nil { + t.Errorf("expected x.G = nil, got %v", x.G) + } +} + +type gobDecoderBug0 struct { + foo, bar string +} + +func (br *gobDecoderBug0) String() string { + return br.foo + "-" + br.bar +} + +func (br *gobDecoderBug0) GobEncode() ([]byte, error) { + return []byte(br.String()), nil +} + +func (br *gobDecoderBug0) GobDecode(b []byte) error { + br.foo = "foo" + br.bar = "bar" + return nil +} + +// This was a bug: the receiver has a different indirection level +// than the variable. +func TestGobEncoderExtraIndirect(t *testing.T) { + gdb := &gobDecoderBug0{"foo", "bar"} + buf := new(bytes.Buffer) + e := NewEncoder(buf) + if err := e.Encode(gdb); err != nil { + t.Fatalf("encode: %v", err) + } + d := NewDecoder(buf) + var got *gobDecoderBug0 + if err := d.Decode(&got); err != nil { + t.Fatalf("decode: %v", err) + } + if got.foo != gdb.foo || got.bar != gdb.bar { + t.Errorf("got = %q, want %q", got, gdb) + } +} diff --git a/libgo/go/encoding/gob/timing_test.go b/libgo/go/encoding/gob/timing_test.go new file mode 100644 index 0000000..47437a6 --- /dev/null +++ b/libgo/go/encoding/gob/timing_test.go @@ -0,0 +1,94 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "bytes" + "fmt" + "io" + "os" + "runtime" + "testing" +) + +type Bench struct { + A int + B float64 + C string + D []byte +} + +func benchmarkEndToEnd(r io.Reader, w io.Writer, b *testing.B) { + b.StopTimer() + enc := NewEncoder(w) + dec := NewDecoder(r) + bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")} + b.StartTimer() + for i := 0; i < b.N; i++ { + if enc.Encode(bench) != nil { + panic("encode error") + } + if dec.Decode(bench) != nil { + panic("decode error") + } + } +} + +func BenchmarkEndToEndPipe(b *testing.B) { + r, w, err := os.Pipe() + if err != nil { + panic("can't get pipe:" + err.Error()) + } + benchmarkEndToEnd(r, w, b) +} + +func BenchmarkEndToEndByteBuffer(b *testing.B) { + var buf bytes.Buffer + benchmarkEndToEnd(&buf, &buf, b) +} + +func TestCountEncodeMallocs(t *testing.T) { + var buf bytes.Buffer + enc := NewEncoder(&buf) + bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")} + runtime.UpdateMemStats() + mallocs := 0 - runtime.MemStats.Mallocs + const count = 1000 + for i := 0; i < count; i++ { + err := enc.Encode(bench) + if err != nil { + t.Fatal("encode:", err) + } + } + runtime.UpdateMemStats() + mallocs += runtime.MemStats.Mallocs + fmt.Printf("mallocs per encode of type Bench: %d\n", mallocs/count) +} + +func TestCountDecodeMallocs(t *testing.T) { + var buf bytes.Buffer + enc := NewEncoder(&buf) + bench := &Bench{7, 3.2, "now is the time", []byte("for all good men")} + const count = 1000 + for i := 0; i < count; i++ { + err := enc.Encode(bench) + if err != nil { + t.Fatal("encode:", err) + } + } + dec := NewDecoder(&buf) + runtime.UpdateMemStats() + mallocs := 0 - runtime.MemStats.Mallocs + for i := 0; i < count; i++ { + *bench = Bench{} + err := dec.Decode(&bench) + if err != nil { + t.Fatal("decode:", err) + } + } + runtime.UpdateMemStats() + mallocs += runtime.MemStats.Mallocs + fmt.Printf("mallocs per decode of type Bench: %d\n", mallocs/count) +} diff --git a/libgo/go/encoding/gob/type.go b/libgo/go/encoding/gob/type.go new file mode 100644 index 0000000..1b20843 --- /dev/null +++ b/libgo/go/encoding/gob/type.go @@ -0,0 +1,788 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "errors" + "fmt" + "os" + "reflect" + "sync" + "unicode" + "unicode/utf8" +) + +// userTypeInfo stores the information associated with a type the user has handed +// to the package. It's computed once and stored in a map keyed by reflection +// type. +type userTypeInfo struct { + user reflect.Type // the type the user handed us + base reflect.Type // the base type after all indirections + indir int // number of indirections to reach the base type + isGobEncoder bool // does the type implement GobEncoder? + isGobDecoder bool // does the type implement GobDecoder? + encIndir int8 // number of indirections to reach the receiver type; may be negative + decIndir int8 // number of indirections to reach the receiver type; may be negative +} + +var ( + // Protected by an RWMutex because we read it a lot and write + // it only when we see a new type, typically when compiling. + userTypeLock sync.RWMutex + userTypeCache = make(map[reflect.Type]*userTypeInfo) +) + +// validType returns, and saves, the information associated with user-provided type rt. +// If the user type is not valid, err will be non-nil. To be used when the error handler +// is not set up. +func validUserType(rt reflect.Type) (ut *userTypeInfo, err error) { + userTypeLock.RLock() + ut = userTypeCache[rt] + userTypeLock.RUnlock() + if ut != nil { + return + } + // Now set the value under the write lock. + userTypeLock.Lock() + defer userTypeLock.Unlock() + if ut = userTypeCache[rt]; ut != nil { + // Lost the race; not a problem. + return + } + ut = new(userTypeInfo) + ut.base = rt + ut.user = rt + // A type that is just a cycle of pointers (such as type T *T) cannot + // be represented in gobs, which need some concrete data. We use a + // cycle detection algorithm from Knuth, Vol 2, Section 3.1, Ex 6, + // pp 539-540. As we step through indirections, run another type at + // half speed. If they meet up, there's a cycle. + slowpoke := ut.base // walks half as fast as ut.base + for { + pt := ut.base + if pt.Kind() != reflect.Ptr { + break + } + ut.base = pt.Elem() + if ut.base == slowpoke { // ut.base lapped slowpoke + // recursive pointer type. + return nil, errors.New("can't represent recursive pointer type " + ut.base.String()) + } + if ut.indir%2 == 0 { + slowpoke = slowpoke.Elem() + } + ut.indir++ + } + ut.isGobEncoder, ut.encIndir = implementsInterface(ut.user, gobEncoderInterfaceType) + ut.isGobDecoder, ut.decIndir = implementsInterface(ut.user, gobDecoderInterfaceType) + userTypeCache[rt] = ut + return +} + +var ( + gobEncoderInterfaceType = reflect.TypeOf((*GobEncoder)(nil)).Elem() + gobDecoderInterfaceType = reflect.TypeOf((*GobDecoder)(nil)).Elem() +) + +// implementsInterface reports whether the type implements the +// gobEncoder/gobDecoder interface. +// It also returns the number of indirections required to get to the +// implementation. +func implementsInterface(typ, gobEncDecType reflect.Type) (success bool, indir int8) { + if typ == nil { + return + } + rt := typ + // The type might be a pointer and we need to keep + // dereferencing to the base type until we find an implementation. + for { + if rt.Implements(gobEncDecType) { + return true, indir + } + if p := rt; p.Kind() == reflect.Ptr { + indir++ + if indir > 100 { // insane number of indirections + return false, 0 + } + rt = p.Elem() + continue + } + break + } + // No luck yet, but if this is a base type (non-pointer), the pointer might satisfy. + if typ.Kind() != reflect.Ptr { + // Not a pointer, but does the pointer work? + if reflect.PtrTo(typ).Implements(gobEncDecType) { + return true, -1 + } + } + return false, 0 +} + +// userType returns, and saves, the information associated with user-provided type rt. +// If the user type is not valid, it calls error. +func userType(rt reflect.Type) *userTypeInfo { + ut, err := validUserType(rt) + if err != nil { + error_(err) + } + return ut +} +// A typeId represents a gob Type as an integer that can be passed on the wire. +// Internally, typeIds are used as keys to a map to recover the underlying type info. +type typeId int32 + +var nextId typeId // incremented for each new type we build +var typeLock sync.Mutex // set while building a type +const firstUserId = 64 // lowest id number granted to user + +type gobType interface { + id() typeId + setId(id typeId) + name() string + string() string // not public; only for debugging + safeString(seen map[typeId]bool) string +} + +var types = make(map[reflect.Type]gobType) +var idToType = make(map[typeId]gobType) +var builtinIdToType map[typeId]gobType // set in init() after builtins are established + +func setTypeId(typ gobType) { + nextId++ + typ.setId(nextId) + idToType[nextId] = typ +} + +func (t typeId) gobType() gobType { + if t == 0 { + return nil + } + return idToType[t] +} + +// string returns the string representation of the type associated with the typeId. +func (t typeId) string() string { + if t.gobType() == nil { + return "<nil>" + } + return t.gobType().string() +} + +// Name returns the name of the type associated with the typeId. +func (t typeId) name() string { + if t.gobType() == nil { + return "<nil>" + } + return t.gobType().name() +} + +// Common elements of all types. +type CommonType struct { + Name string + Id typeId +} + +func (t *CommonType) id() typeId { return t.Id } + +func (t *CommonType) setId(id typeId) { t.Id = id } + +func (t *CommonType) string() string { return t.Name } + +func (t *CommonType) safeString(seen map[typeId]bool) string { + return t.Name +} + +func (t *CommonType) name() string { return t.Name } + +// Create and check predefined types +// The string for tBytes is "bytes" not "[]byte" to signify its specialness. + +var ( + // Primordial types, needed during initialization. + // Always passed as pointers so the interface{} type + // goes through without losing its interfaceness. + tBool = bootstrapType("bool", (*bool)(nil), 1) + tInt = bootstrapType("int", (*int)(nil), 2) + tUint = bootstrapType("uint", (*uint)(nil), 3) + tFloat = bootstrapType("float", (*float64)(nil), 4) + tBytes = bootstrapType("bytes", (*[]byte)(nil), 5) + tString = bootstrapType("string", (*string)(nil), 6) + tComplex = bootstrapType("complex", (*complex128)(nil), 7) + tInterface = bootstrapType("interface", (*interface{})(nil), 8) + // Reserve some Ids for compatible expansion + tReserved7 = bootstrapType("_reserved1", (*struct{ r7 int })(nil), 9) + tReserved6 = bootstrapType("_reserved1", (*struct{ r6 int })(nil), 10) + tReserved5 = bootstrapType("_reserved1", (*struct{ r5 int })(nil), 11) + tReserved4 = bootstrapType("_reserved1", (*struct{ r4 int })(nil), 12) + tReserved3 = bootstrapType("_reserved1", (*struct{ r3 int })(nil), 13) + tReserved2 = bootstrapType("_reserved1", (*struct{ r2 int })(nil), 14) + tReserved1 = bootstrapType("_reserved1", (*struct{ r1 int })(nil), 15) +) + +// Predefined because it's needed by the Decoder +var tWireType = mustGetTypeInfo(reflect.TypeOf(wireType{})).id +var wireTypeUserInfo *userTypeInfo // userTypeInfo of (*wireType) + +func init() { + // Some magic numbers to make sure there are no surprises. + checkId(16, tWireType) + checkId(17, mustGetTypeInfo(reflect.TypeOf(arrayType{})).id) + checkId(18, mustGetTypeInfo(reflect.TypeOf(CommonType{})).id) + checkId(19, mustGetTypeInfo(reflect.TypeOf(sliceType{})).id) + checkId(20, mustGetTypeInfo(reflect.TypeOf(structType{})).id) + checkId(21, mustGetTypeInfo(reflect.TypeOf(fieldType{})).id) + checkId(23, mustGetTypeInfo(reflect.TypeOf(mapType{})).id) + + builtinIdToType = make(map[typeId]gobType) + for k, v := range idToType { + builtinIdToType[k] = v + } + + // Move the id space upwards to allow for growth in the predefined world + // without breaking existing files. + if nextId > firstUserId { + panic(fmt.Sprintln("nextId too large:", nextId)) + } + nextId = firstUserId + registerBasics() + wireTypeUserInfo = userType(reflect.TypeOf((*wireType)(nil))) +} + +// Array type +type arrayType struct { + CommonType + Elem typeId + Len int +} + +func newArrayType(name string) *arrayType { + a := &arrayType{CommonType{Name: name}, 0, 0} + return a +} + +func (a *arrayType) init(elem gobType, len int) { + // Set our type id before evaluating the element's, in case it's our own. + setTypeId(a) + a.Elem = elem.id() + a.Len = len +} + +func (a *arrayType) safeString(seen map[typeId]bool) string { + if seen[a.Id] { + return a.Name + } + seen[a.Id] = true + return fmt.Sprintf("[%d]%s", a.Len, a.Elem.gobType().safeString(seen)) +} + +func (a *arrayType) string() string { return a.safeString(make(map[typeId]bool)) } + +// GobEncoder type (something that implements the GobEncoder interface) +type gobEncoderType struct { + CommonType +} + +func newGobEncoderType(name string) *gobEncoderType { + g := &gobEncoderType{CommonType{Name: name}} + setTypeId(g) + return g +} + +func (g *gobEncoderType) safeString(seen map[typeId]bool) string { + return g.Name +} + +func (g *gobEncoderType) string() string { return g.Name } + +// Map type +type mapType struct { + CommonType + Key typeId + Elem typeId +} + +func newMapType(name string) *mapType { + m := &mapType{CommonType{Name: name}, 0, 0} + return m +} + +func (m *mapType) init(key, elem gobType) { + // Set our type id before evaluating the element's, in case it's our own. + setTypeId(m) + m.Key = key.id() + m.Elem = elem.id() +} + +func (m *mapType) safeString(seen map[typeId]bool) string { + if seen[m.Id] { + return m.Name + } + seen[m.Id] = true + key := m.Key.gobType().safeString(seen) + elem := m.Elem.gobType().safeString(seen) + return fmt.Sprintf("map[%s]%s", key, elem) +} + +func (m *mapType) string() string { return m.safeString(make(map[typeId]bool)) } + +// Slice type +type sliceType struct { + CommonType + Elem typeId +} + +func newSliceType(name string) *sliceType { + s := &sliceType{CommonType{Name: name}, 0} + return s +} + +func (s *sliceType) init(elem gobType) { + // Set our type id before evaluating the element's, in case it's our own. + setTypeId(s) + s.Elem = elem.id() +} + +func (s *sliceType) safeString(seen map[typeId]bool) string { + if seen[s.Id] { + return s.Name + } + seen[s.Id] = true + return fmt.Sprintf("[]%s", s.Elem.gobType().safeString(seen)) +} + +func (s *sliceType) string() string { return s.safeString(make(map[typeId]bool)) } + +// Struct type +type fieldType struct { + Name string + Id typeId +} + +type structType struct { + CommonType + Field []*fieldType +} + +func (s *structType) safeString(seen map[typeId]bool) string { + if s == nil { + return "<nil>" + } + if _, ok := seen[s.Id]; ok { + return s.Name + } + seen[s.Id] = true + str := s.Name + " = struct { " + for _, f := range s.Field { + str += fmt.Sprintf("%s %s; ", f.Name, f.Id.gobType().safeString(seen)) + } + str += "}" + return str +} + +func (s *structType) string() string { return s.safeString(make(map[typeId]bool)) } + +func newStructType(name string) *structType { + s := &structType{CommonType{Name: name}, nil} + // For historical reasons we set the id here rather than init. + // See the comment in newTypeObject for details. + setTypeId(s) + return s +} + +// newTypeObject allocates a gobType for the reflection type rt. +// Unless ut represents a GobEncoder, rt should be the base type +// of ut. +// This is only called from the encoding side. The decoding side +// works through typeIds and userTypeInfos alone. +func newTypeObject(name string, ut *userTypeInfo, rt reflect.Type) (gobType, error) { + // Does this type implement GobEncoder? + if ut.isGobEncoder { + return newGobEncoderType(name), nil + } + var err error + var type0, type1 gobType + defer func() { + if err != nil { + delete(types, rt) + } + }() + // Install the top-level type before the subtypes (e.g. struct before + // fields) so recursive types can be constructed safely. + switch t := rt; t.Kind() { + // All basic types are easy: they are predefined. + case reflect.Bool: + return tBool.gobType(), nil + + case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: + return tInt.gobType(), nil + + case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: + return tUint.gobType(), nil + + case reflect.Float32, reflect.Float64: + return tFloat.gobType(), nil + + case reflect.Complex64, reflect.Complex128: + return tComplex.gobType(), nil + + case reflect.String: + return tString.gobType(), nil + + case reflect.Interface: + return tInterface.gobType(), nil + + case reflect.Array: + at := newArrayType(name) + types[rt] = at + type0, err = getBaseType("", t.Elem()) + if err != nil { + return nil, err + } + // Historical aside: + // For arrays, maps, and slices, we set the type id after the elements + // are constructed. This is to retain the order of type id allocation after + // a fix made to handle recursive types, which changed the order in + // which types are built. Delaying the setting in this way preserves + // type ids while allowing recursive types to be described. Structs, + // done below, were already handling recursion correctly so they + // assign the top-level id before those of the field. + at.init(type0, t.Len()) + return at, nil + + case reflect.Map: + mt := newMapType(name) + types[rt] = mt + type0, err = getBaseType("", t.Key()) + if err != nil { + return nil, err + } + type1, err = getBaseType("", t.Elem()) + if err != nil { + return nil, err + } + mt.init(type0, type1) + return mt, nil + + case reflect.Slice: + // []byte == []uint8 is a special case + if t.Elem().Kind() == reflect.Uint8 { + return tBytes.gobType(), nil + } + st := newSliceType(name) + types[rt] = st + type0, err = getBaseType(t.Elem().Name(), t.Elem()) + if err != nil { + return nil, err + } + st.init(type0) + return st, nil + + case reflect.Struct: + st := newStructType(name) + types[rt] = st + idToType[st.id()] = st + for i := 0; i < t.NumField(); i++ { + f := t.Field(i) + if !isExported(f.Name) { + continue + } + typ := userType(f.Type).base + tname := typ.Name() + if tname == "" { + t := userType(f.Type).base + tname = t.String() + } + gt, err := getBaseType(tname, f.Type) + if err != nil { + return nil, err + } + st.Field = append(st.Field, &fieldType{f.Name, gt.id()}) + } + return st, nil + + default: + return nil, errors.New("gob NewTypeObject can't handle type: " + rt.String()) + } + return nil, nil +} + +// isExported reports whether this is an exported - upper case - name. +func isExported(name string) bool { + rune, _ := utf8.DecodeRuneInString(name) + return unicode.IsUpper(rune) +} + +// getBaseType returns the Gob type describing the given reflect.Type's base type. +// typeLock must be held. +func getBaseType(name string, rt reflect.Type) (gobType, error) { + ut := userType(rt) + return getType(name, ut, ut.base) +} + +// getType returns the Gob type describing the given reflect.Type. +// Should be called only when handling GobEncoders/Decoders, +// which may be pointers. All other types are handled through the +// base type, never a pointer. +// typeLock must be held. +func getType(name string, ut *userTypeInfo, rt reflect.Type) (gobType, error) { + typ, present := types[rt] + if present { + return typ, nil + } + typ, err := newTypeObject(name, ut, rt) + if err == nil { + types[rt] = typ + } + return typ, err +} + +func checkId(want, got typeId) { + if want != got { + fmt.Fprintf(os.Stderr, "checkId: %d should be %d\n", int(got), int(want)) + panic("bootstrap type wrong id: " + got.name() + " " + got.string() + " not " + want.string()) + } +} + +// used for building the basic types; called only from init(). the incoming +// interface always refers to a pointer. +func bootstrapType(name string, e interface{}, expect typeId) typeId { + rt := reflect.TypeOf(e).Elem() + _, present := types[rt] + if present { + panic("bootstrap type already present: " + name + ", " + rt.String()) + } + typ := &CommonType{Name: name} + types[rt] = typ + setTypeId(typ) + checkId(expect, nextId) + userType(rt) // might as well cache it now + return nextId +} + +// Representation of the information we send and receive about this type. +// Each value we send is preceded by its type definition: an encoded int. +// However, the very first time we send the value, we first send the pair +// (-id, wireType). +// For bootstrapping purposes, we assume that the recipient knows how +// to decode a wireType; it is exactly the wireType struct here, interpreted +// using the gob rules for sending a structure, except that we assume the +// ids for wireType and structType etc. are known. The relevant pieces +// are built in encode.go's init() function. +// To maintain binary compatibility, if you extend this type, always put +// the new fields last. +type wireType struct { + ArrayT *arrayType + SliceT *sliceType + StructT *structType + MapT *mapType + GobEncoderT *gobEncoderType +} + +func (w *wireType) string() string { + const unknown = "unknown type" + if w == nil { + return unknown + } + switch { + case w.ArrayT != nil: + return w.ArrayT.Name + case w.SliceT != nil: + return w.SliceT.Name + case w.StructT != nil: + return w.StructT.Name + case w.MapT != nil: + return w.MapT.Name + case w.GobEncoderT != nil: + return w.GobEncoderT.Name + } + return unknown +} + +type typeInfo struct { + id typeId + encoder *encEngine + wire *wireType +} + +var typeInfoMap = make(map[reflect.Type]*typeInfo) // protected by typeLock + +// typeLock must be held. +func getTypeInfo(ut *userTypeInfo) (*typeInfo, error) { + rt := ut.base + if ut.isGobEncoder { + // We want the user type, not the base type. + rt = ut.user + } + info, ok := typeInfoMap[rt] + if ok { + return info, nil + } + info = new(typeInfo) + gt, err := getBaseType(rt.Name(), rt) + if err != nil { + return nil, err + } + info.id = gt.id() + + if ut.isGobEncoder { + userType, err := getType(rt.Name(), ut, rt) + if err != nil { + return nil, err + } + info.wire = &wireType{GobEncoderT: userType.id().gobType().(*gobEncoderType)} + typeInfoMap[ut.user] = info + return info, nil + } + + t := info.id.gobType() + switch typ := rt; typ.Kind() { + case reflect.Array: + info.wire = &wireType{ArrayT: t.(*arrayType)} + case reflect.Map: + info.wire = &wireType{MapT: t.(*mapType)} + case reflect.Slice: + // []byte == []uint8 is a special case handled separately + if typ.Elem().Kind() != reflect.Uint8 { + info.wire = &wireType{SliceT: t.(*sliceType)} + } + case reflect.Struct: + info.wire = &wireType{StructT: t.(*structType)} + } + typeInfoMap[rt] = info + return info, nil +} + +// Called only when a panic is acceptable and unexpected. +func mustGetTypeInfo(rt reflect.Type) *typeInfo { + t, err := getTypeInfo(userType(rt)) + if err != nil { + panic("getTypeInfo: " + err.Error()) + } + return t +} + +// GobEncoder is the interface describing data that provides its own +// representation for encoding values for transmission to a GobDecoder. +// A type that implements GobEncoder and GobDecoder has complete +// control over the representation of its data and may therefore +// contain things such as private fields, channels, and functions, +// which are not usually transmissible in gob streams. +// +// Note: Since gobs can be stored permanently, It is good design +// to guarantee the encoding used by a GobEncoder is stable as the +// software evolves. For instance, it might make sense for GobEncode +// to include a version number in the encoding. +type GobEncoder interface { + // GobEncode returns a byte slice representing the encoding of the + // receiver for transmission to a GobDecoder, usually of the same + // concrete type. + GobEncode() ([]byte, error) +} + +// GobDecoder is the interface describing data that provides its own +// routine for decoding transmitted values sent by a GobEncoder. +type GobDecoder interface { + // GobDecode overwrites the receiver, which must be a pointer, + // with the value represented by the byte slice, which was written + // by GobEncode, usually for the same concrete type. + GobDecode([]byte) error +} + +var ( + nameToConcreteType = make(map[string]reflect.Type) + concreteTypeToName = make(map[reflect.Type]string) +) + +// RegisterName is like Register but uses the provided name rather than the +// type's default. +func RegisterName(name string, value interface{}) { + if name == "" { + // reserved for nil + panic("attempt to register empty name") + } + ut := userType(reflect.TypeOf(value)) + // Check for incompatible duplicates. The name must refer to the + // same user type, and vice versa. + if t, ok := nameToConcreteType[name]; ok && t != ut.user { + panic(fmt.Sprintf("gob: registering duplicate types for %q: %s != %s", name, t, ut.user)) + } + if n, ok := concreteTypeToName[ut.base]; ok && n != name { + panic(fmt.Sprintf("gob: registering duplicate names for %s: %q != %q", ut.user, n, name)) + } + // Store the name and type provided by the user.... + nameToConcreteType[name] = reflect.TypeOf(value) + // but the flattened type in the type table, since that's what decode needs. + concreteTypeToName[ut.base] = name +} + +// Register records a type, identified by a value for that type, under its +// internal type name. That name will identify the concrete type of a value +// sent or received as an interface variable. Only types that will be +// transferred as implementations of interface values need to be registered. +// Expecting to be used only during initialization, it panics if the mapping +// between types and names is not a bijection. +func Register(value interface{}) { + // Default to printed representation for unnamed types + rt := reflect.TypeOf(value) + name := rt.String() + + // But for named types (or pointers to them), qualify with import path. + // Dereference one pointer looking for a named type. + star := "" + if rt.Name() == "" { + if pt := rt; pt.Kind() == reflect.Ptr { + star = "*" + rt = pt + } + } + if rt.Name() != "" { + if rt.PkgPath() == "" { + name = star + rt.Name() + } else { + name = star + rt.PkgPath() + "." + rt.Name() + } + } + + RegisterName(name, value) +} + +func registerBasics() { + Register(int(0)) + Register(int8(0)) + Register(int16(0)) + Register(int32(0)) + Register(int64(0)) + Register(uint(0)) + Register(uint8(0)) + Register(uint16(0)) + Register(uint32(0)) + Register(uint64(0)) + Register(float32(0)) + Register(float64(0)) + Register(complex64(0i)) + Register(complex128(0i)) + Register(uintptr(0)) + Register(false) + Register("") + Register([]byte(nil)) + Register([]int(nil)) + Register([]int8(nil)) + Register([]int16(nil)) + Register([]int32(nil)) + Register([]int64(nil)) + Register([]uint(nil)) + Register([]uint8(nil)) + Register([]uint16(nil)) + Register([]uint32(nil)) + Register([]uint64(nil)) + Register([]float32(nil)) + Register([]float64(nil)) + Register([]complex64(nil)) + Register([]complex128(nil)) + Register([]uintptr(nil)) + Register([]bool(nil)) + Register([]string(nil)) +} diff --git a/libgo/go/encoding/gob/type_test.go b/libgo/go/encoding/gob/type_test.go new file mode 100644 index 0000000..42bdb4c --- /dev/null +++ b/libgo/go/encoding/gob/type_test.go @@ -0,0 +1,161 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package gob + +import ( + "reflect" + "testing" +) + +type typeT struct { + id typeId + str string +} + +var basicTypes = []typeT{ + {tBool, "bool"}, + {tInt, "int"}, + {tUint, "uint"}, + {tFloat, "float"}, + {tBytes, "bytes"}, + {tString, "string"}, +} + +func getTypeUnlocked(name string, rt reflect.Type) gobType { + typeLock.Lock() + defer typeLock.Unlock() + t, err := getBaseType(name, rt) + if err != nil { + panic("getTypeUnlocked: " + err.Error()) + } + return t +} + +// Sanity checks +func TestBasic(t *testing.T) { + for _, tt := range basicTypes { + if tt.id.string() != tt.str { + t.Errorf("checkType: expected %q got %s", tt.str, tt.id.string()) + } + if tt.id == 0 { + t.Errorf("id for %q is zero", tt.str) + } + } +} + +// Reregister some basic types to check registration is idempotent. +func TestReregistration(t *testing.T) { + newtyp := getTypeUnlocked("int", reflect.TypeOf(int(0))) + if newtyp != tInt.gobType() { + t.Errorf("reregistration of %s got new type", newtyp.string()) + } + newtyp = getTypeUnlocked("uint", reflect.TypeOf(uint(0))) + if newtyp != tUint.gobType() { + t.Errorf("reregistration of %s got new type", newtyp.string()) + } + newtyp = getTypeUnlocked("string", reflect.TypeOf("hello")) + if newtyp != tString.gobType() { + t.Errorf("reregistration of %s got new type", newtyp.string()) + } +} + +func TestArrayType(t *testing.T) { + var a3 [3]int + a3int := getTypeUnlocked("foo", reflect.TypeOf(a3)) + newa3int := getTypeUnlocked("bar", reflect.TypeOf(a3)) + if a3int != newa3int { + t.Errorf("second registration of [3]int creates new type") + } + var a4 [4]int + a4int := getTypeUnlocked("goo", reflect.TypeOf(a4)) + if a3int == a4int { + t.Errorf("registration of [3]int creates same type as [4]int") + } + var b3 [3]bool + a3bool := getTypeUnlocked("", reflect.TypeOf(b3)) + if a3int == a3bool { + t.Errorf("registration of [3]bool creates same type as [3]int") + } + str := a3bool.string() + expected := "[3]bool" + if str != expected { + t.Errorf("array printed as %q; expected %q", str, expected) + } +} + +func TestSliceType(t *testing.T) { + var s []int + sint := getTypeUnlocked("slice", reflect.TypeOf(s)) + var news []int + newsint := getTypeUnlocked("slice1", reflect.TypeOf(news)) + if sint != newsint { + t.Errorf("second registration of []int creates new type") + } + var b []bool + sbool := getTypeUnlocked("", reflect.TypeOf(b)) + if sbool == sint { + t.Errorf("registration of []bool creates same type as []int") + } + str := sbool.string() + expected := "[]bool" + if str != expected { + t.Errorf("slice printed as %q; expected %q", str, expected) + } +} + +func TestMapType(t *testing.T) { + var m map[string]int + mapStringInt := getTypeUnlocked("map", reflect.TypeOf(m)) + var newm map[string]int + newMapStringInt := getTypeUnlocked("map1", reflect.TypeOf(newm)) + if mapStringInt != newMapStringInt { + t.Errorf("second registration of map[string]int creates new type") + } + var b map[string]bool + mapStringBool := getTypeUnlocked("", reflect.TypeOf(b)) + if mapStringBool == mapStringInt { + t.Errorf("registration of map[string]bool creates same type as map[string]int") + } + str := mapStringBool.string() + expected := "map[string]bool" + if str != expected { + t.Errorf("map printed as %q; expected %q", str, expected) + } +} + +type Bar struct { + X string +} + +// This structure has pointers and refers to itself, making it a good test case. +type Foo struct { + A int + B int32 // will become int + C string + D []byte + E *float64 // will become float64 + F ****float64 // will become float64 + G *Bar + H *Bar // should not interpolate the definition of Bar again + I *Foo // will not explode +} + +func TestStructType(t *testing.T) { + sstruct := getTypeUnlocked("Foo", reflect.TypeOf(Foo{})) + str := sstruct.string() + // If we can print it correctly, we built it correctly. + expected := "Foo = struct { A int; B int; C string; D bytes; E float; F float; G Bar = struct { X string; }; H Bar; I Foo; }" + if str != expected { + t.Errorf("struct printed as %q; expected %q", str, expected) + } +} + +// Should be OK to register the same type multiple times, as long as they're +// at the same level of indirection. +func TestRegistration(t *testing.T) { + type T struct{ a int } + Register(new(T)) + Register(new(T)) +} |