libgo: Update to weekly.2011-11-18.

From-SVN: r182266

5 files changed, 188 insertions, 16 deletions

diff --git a/libgo/go/encoding/json/bench_test.go b/libgo/go/encoding/json/bench_test.go
new file mode 100644
index 0000000..f0c5201
--- /dev/null
+++ b/libgo/go/encoding/json/bench_test.go
@@ -0,0 +1,157 @@
+// 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.
+
+// Large data benchmark.
+// The JSON data is a summary of agl's changes in the
+// go, webkit, and chromium open source projects.
+// We benchmark converting between the JSON form
+// and in-memory data structures.
+
+package json
+
+import (
+	"bytes"
+	"compress/gzip"
+	"io/ioutil"
+	"os"
+	"testing"
+)
+
+type codeResponse struct {
+	Tree     *codeNode `json:"tree"`
+	Username string    `json:"username"`
+}
+
+type codeNode struct {
+	Name     string      `json:"name"`
+	Kids     []*codeNode `json:"kids"`
+	CLWeight float64     `json:"cl_weight"`
+	Touches  int         `json:"touches"`
+	MinT     int64       `json:"min_t"`
+	MaxT     int64       `json:"max_t"`
+	MeanT    int64       `json:"mean_t"`
+}
+
+var codeJSON []byte
+var codeStruct codeResponse
+
+func codeInit() {
+	f, err := os.Open("testdata/code.json.gz")
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+	gz, err := gzip.NewReader(f)
+	if err != nil {
+		panic(err)
+	}
+	data, err := ioutil.ReadAll(gz)
+	if err != nil {
+		panic(err)
+	}
+
+	codeJSON = data
+
+	if err := Unmarshal(codeJSON, &codeStruct); err != nil {
+		panic("unmarshal code.json: " + err.Error())
+	}
+
+	if data, err = Marshal(&codeStruct); err != nil {
+		panic("marshal code.json: " + err.Error())
+	}
+
+	if !bytes.Equal(data, codeJSON) {
+		println("different lengths", len(data), len(codeJSON))
+		for i := 0; i < len(data) && i < len(codeJSON); i++ {
+			if data[i] != codeJSON[i] {
+				println("re-marshal: changed at byte", i)
+				println("orig: ", string(codeJSON[i-10:i+10]))
+				println("new: ", string(data[i-10:i+10]))
+				break
+			}
+		}
+		panic("re-marshal code.json: different result")
+	}
+}
+
+func BenchmarkCodeEncoder(b *testing.B) {
+	if codeJSON == nil {
+		b.StopTimer()
+		codeInit()
+		b.StartTimer()
+	}
+	enc := NewEncoder(ioutil.Discard)
+	for i := 0; i < b.N; i++ {
+		if err := enc.Encode(&codeStruct); err != nil {
+			panic(err)
+		}
+	}
+	b.SetBytes(int64(len(codeJSON)))
+}
+
+func BenchmarkCodeMarshal(b *testing.B) {
+	if codeJSON == nil {
+		b.StopTimer()
+		codeInit()
+		b.StartTimer()
+	}
+	for i := 0; i < b.N; i++ {
+		if _, err := Marshal(&codeStruct); err != nil {
+			panic(err)
+		}
+	}
+	b.SetBytes(int64(len(codeJSON)))
+}
+
+func BenchmarkCodeDecoder(b *testing.B) {
+	if codeJSON == nil {
+		b.StopTimer()
+		codeInit()
+		b.StartTimer()
+	}
+	var buf bytes.Buffer
+	dec := NewDecoder(&buf)
+	var r codeResponse
+	for i := 0; i < b.N; i++ {
+		buf.Write(codeJSON)
+		// hide EOF
+		buf.WriteByte('\n')
+		buf.WriteByte('\n')
+		buf.WriteByte('\n')
+		if err := dec.Decode(&r); err != nil {
+			panic(err)
+		}
+	}
+	b.SetBytes(int64(len(codeJSON)))
+}
+
+func BenchmarkCodeUnmarshal(b *testing.B) {
+	if codeJSON == nil {
+		b.StopTimer()
+		codeInit()
+		b.StartTimer()
+	}
+	for i := 0; i < b.N; i++ {
+		var r codeResponse
+		if err := Unmarshal(codeJSON, &r); err != nil {
+			panic(err)
+		}
+	}
+	b.SetBytes(int64(len(codeJSON)))
+}
+
+func BenchmarkCodeUnmarshalReuse(b *testing.B) {
+	if codeJSON == nil {
+		b.StopTimer()
+		codeInit()
+		b.StartTimer()
+	}
+	var r codeResponse
+	for i := 0; i < b.N; i++ {
+		if err := Unmarshal(codeJSON, &r); err != nil {
+			panic(err)
+		}
+	}
+	b.SetBytes(int64(len(codeJSON)))
+}
diff --git a/libgo/go/encoding/json/decode.go b/libgo/go/encoding/json/decode.go
index 41295d2..2ea06c5 100644
--- a/libgo/go/encoding/json/decode.go
+++ b/libgo/go/encoding/json/decode.go
@@ -227,7 +227,7 @@ func (d *decodeState) value(v reflect.Value) {
 		// d.scan thinks we're still at the beginning of the item.
 		// Feed in an empty string - the shortest, simplest value -
 		// so that it knows we got to the end of the value.
-		if d.scan.step == stateRedo {
+		if d.scan.redo {
 			panic("redo")
 		}
 		d.scan.step(&d.scan, '"')
@@ -381,6 +381,7 @@ func (d *decodeState) array(v reflect.Value) {
 			d.error(errPhase)
 		}
 	}
+
 	if i < av.Len() {
 		if !sv.IsValid() {
 			// Array.  Zero the rest.
@@ -392,6 +393,9 @@ func (d *decodeState) array(v reflect.Value) {
 			sv.SetLen(i)
 		}
 	}
+	if i == 0 && av.Kind() == reflect.Slice && sv.IsNil() {
+		sv.Set(reflect.MakeSlice(sv.Type(), 0, 0))
+	}
 }
 
 // object consumes an object from d.data[d.off-1:], decoding into the value v.
diff --git a/libgo/go/encoding/json/scanner.go b/libgo/go/encoding/json/scanner.go
index 1796904..2661f41 100644
--- a/libgo/go/encoding/json/scanner.go
+++ b/libgo/go/encoding/json/scanner.go
@@ -80,6 +80,9 @@ type scanner struct {
 	// on a 64-bit Mac Mini, and it's nicer to read.
 	step func(*scanner, int) int
 
+	// Reached end of top-level value.
+	endTop bool
+
 	// Stack of what we're in the middle of - array values, object keys, object values.
 	parseState []int
 
@@ -87,6 +90,7 @@ type scanner struct {
 	err error
 
 	// 1-byte redo (see undo method)
+	redo      bool
 	redoCode  int
 	redoState func(*scanner, int) int
 
@@ -135,6 +139,8 @@ func (s *scanner) reset() {
 	s.step = stateBeginValue
 	s.parseState = s.parseState[0:0]
 	s.err = nil
+	s.redo = false
+	s.endTop = false
 }
 
 // eof tells the scanner that the end of input has been reached.
@@ -143,11 +149,11 @@ func (s *scanner) eof() int {
 	if s.err != nil {
 		return scanError
 	}
-	if s.step == stateEndTop {
+	if s.endTop {
 		return scanEnd
 	}
 	s.step(s, ' ')
-	if s.step == stateEndTop {
+	if s.endTop {
 		return scanEnd
 	}
 	if s.err == nil {
@@ -166,8 +172,10 @@ func (s *scanner) pushParseState(p int) {
 func (s *scanner) popParseState() {
 	n := len(s.parseState) - 1
 	s.parseState = s.parseState[0:n]
+	s.redo = false
 	if n == 0 {
 		s.step = stateEndTop
+		s.endTop = true
 	} else {
 		s.step = stateEndValue
 	}
@@ -269,6 +277,7 @@ func stateEndValue(s *scanner, c int) int {
 	if n == 0 {
 		// Completed top-level before the current byte.
 		s.step = stateEndTop
+		s.endTop = true
 		return stateEndTop(s, c)
 	}
 	if c <= ' ' && (c == ' ' || c == '\t' || c == '\r' || c == '\n') {
@@ -606,16 +615,18 @@ func quoteChar(c int) string {
 // undo causes the scanner to return scanCode from the next state transition.
 // This gives callers a simple 1-byte undo mechanism.
 func (s *scanner) undo(scanCode int) {
-	if s.step == stateRedo {
-		panic("invalid use of scanner")
+	if s.redo {
+		panic("json: invalid use of scanner")
 	}
 	s.redoCode = scanCode
 	s.redoState = s.step
 	s.step = stateRedo
+	s.redo = true
 }
 
 // stateRedo helps implement the scanner's 1-byte undo.
 func stateRedo(s *scanner, c int) int {
+	s.redo = false
 	s.step = s.redoState
 	return s.redoCode
 }
diff --git a/libgo/go/encoding/json/scanner_test.go b/libgo/go/encoding/json/scanner_test.go
index a0a5995..14d8508 100644
--- a/libgo/go/encoding/json/scanner_test.go
+++ b/libgo/go/encoding/json/scanner_test.go
@@ -186,11 +186,12 @@ func TestNextValueBig(t *testing.T) {
 	}
 }
 
+var benchScan scanner
+
 func BenchmarkSkipValue(b *testing.B) {
 	initBig()
-	var scan scanner
 	for i := 0; i < b.N; i++ {
-		nextValue(jsonBig, &scan)
+		nextValue(jsonBig, &benchScan)
 	}
 	b.SetBytes(int64(len(jsonBig)))
 }
diff --git a/libgo/go/encoding/xml/xml_test.go b/libgo/go/encoding/xml/xml_test.go
index 6c874fa..bcb22af 100644
--- a/libgo/go/encoding/xml/xml_test.go
+++ b/libgo/go/encoding/xml/xml_test.go
@@ -7,7 +7,6 @@ package xml
 import (
 	"bytes"
 	"io"
-	"os"
 	"reflect"
 	"strings"
 	"testing"
@@ -43,17 +42,17 @@ var rawTokens = []Token{
 	CharData([]byte("World <>'\" 白鵬翔")),
 	EndElement{Name{"", "hello"}},
 	CharData([]byte("\n  ")),
-	StartElement{Name{"", "goodbye"}, nil},
+	StartElement{Name{"", "goodbye"}, []Attr{}},
 	EndElement{Name{"", "goodbye"}},
 	CharData([]byte("\n  ")),
 	StartElement{Name{"", "outer"}, []Attr{{Name{"foo", "attr"}, "value"}, {Name{"xmlns", "tag"}, "ns4"}}},
 	CharData([]byte("\n    ")),
-	StartElement{Name{"", "inner"}, nil},
+	StartElement{Name{"", "inner"}, []Attr{}},
 	EndElement{Name{"", "inner"}},
 	CharData([]byte("\n  ")),
 	EndElement{Name{"", "outer"}},
 	CharData([]byte("\n  ")),
-	StartElement{Name{"tag", "name"}, nil},
+	StartElement{Name{"tag", "name"}, []Attr{}},
 	CharData([]byte("\n    ")),
 	CharData([]byte("Some text here.")),
 	CharData([]byte("\n  ")),
@@ -77,17 +76,17 @@ var cookedTokens = []Token{
 	CharData([]byte("World <>'\" 白鵬翔")),
 	EndElement{Name{"ns2", "hello"}},
 	CharData([]byte("\n  ")),
-	StartElement{Name{"ns2", "goodbye"}, nil},
+	StartElement{Name{"ns2", "goodbye"}, []Attr{}},
 	EndElement{Name{"ns2", "goodbye"}},
 	CharData([]byte("\n  ")),
 	StartElement{Name{"ns2", "outer"}, []Attr{{Name{"ns1", "attr"}, "value"}, {Name{"xmlns", "tag"}, "ns4"}}},
 	CharData([]byte("\n    ")),
-	StartElement{Name{"ns2", "inner"}, nil},
+	StartElement{Name{"ns2", "inner"}, []Attr{}},
 	EndElement{Name{"ns2", "inner"}},
 	CharData([]byte("\n  ")),
 	EndElement{Name{"ns2", "outer"}},
 	CharData([]byte("\n  ")),
-	StartElement{Name{"ns3", "name"}, nil},
+	StartElement{Name{"ns3", "name"}, []Attr{}},
 	CharData([]byte("\n    ")),
 	CharData([]byte("Some text here.")),
 	CharData([]byte("\n  ")),
@@ -105,7 +104,7 @@ var rawTokensAltEncoding = []Token{
 	CharData([]byte("\n")),
 	ProcInst{"xml", []byte(`version="1.0" encoding="x-testing-uppercase"`)},
 	CharData([]byte("\n")),
-	StartElement{Name{"", "tag"}, nil},
+	StartElement{Name{"", "tag"}, []Attr{}},
 	CharData([]byte("value")),
 	EndElement{Name{"", "tag"}},
 }
@@ -205,7 +204,7 @@ func (d *downCaser) ReadByte() (c byte, err error) {
 
 func (d *downCaser) Read(p []byte) (int, error) {
 	d.t.Fatalf("unexpected Read call on downCaser reader")
-	return 0, os.EINVAL
+	panic("unreachable")
 }
 
 func TestRawTokenAltEncoding(t *testing.T) {