diff options
author | Ian Lance Taylor <iant@google.com> | 2011-01-21 18:19:03 +0000 |
---|---|---|
committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2011-01-21 18:19:03 +0000 |
commit | ff5f50c52c421d75940ef9392211e3ab24d71332 (patch) | |
tree | 27d8768fb1d25696d3c40b42535eb5e073c278da /libgo/go/bytes/buffer.go | |
parent | d6ed1c8903e728f4233122554bab5910853338bd (diff) | |
download | gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.zip gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.tar.gz gcc-ff5f50c52c421d75940ef9392211e3ab24d71332.tar.bz2 |
Remove the types float and complex.
Update to current version of Go library.
Update testsuite for removed types.
* go-lang.c (go_langhook_init): Omit float_type_size when calling
go_create_gogo.
* go-c.h: Update declaration of go_create_gogo.
From-SVN: r169098
Diffstat (limited to 'libgo/go/bytes/buffer.go')
-rw-r--r-- | libgo/go/bytes/buffer.go | 65 |
1 files changed, 63 insertions, 2 deletions
diff --git a/libgo/go/bytes/buffer.go b/libgo/go/bytes/buffer.go index 6f93869..62cf828 100644 --- a/libgo/go/bytes/buffer.go +++ b/libgo/go/bytes/buffer.go @@ -19,8 +19,20 @@ type Buffer struct { off int // read at &buf[off], write at &buf[len(buf)] runeBytes [utf8.UTFMax]byte // avoid allocation of slice on each WriteByte or Rune bootstrap [64]byte // memory to hold first slice; helps small buffers (Printf) avoid allocation. + lastRead readOp // last read operation, so that Unread* can work correctly. } +// The readOp constants describe the last action performed on +// the buffer, so that UnreadRune and UnreadByte can +// check for invalid usage. +type readOp int + +const ( + opInvalid readOp = iota // Non-read operation. + opReadRune // Read rune. + opRead // Any other read operation. +) + // Bytes returns a slice of the contents of the unread portion of the buffer; // len(b.Bytes()) == b.Len(). If the caller changes the contents of the // returned slice, the contents of the buffer will change provided there @@ -44,6 +56,7 @@ func (b *Buffer) Len() int { return len(b.buf) - b.off } // Truncate discards all but the first n unread bytes from the buffer. // It is an error to call b.Truncate(n) with n > b.Len(). func (b *Buffer) Truncate(n int) { + b.lastRead = opInvalid if n == 0 { // Reuse buffer space. b.off = 0 @@ -82,6 +95,7 @@ func (b *Buffer) grow(n int) int { // Write appends the contents of p to the buffer. The return // value n is the length of p; err is always nil. func (b *Buffer) Write(p []byte) (n int, err os.Error) { + b.lastRead = opInvalid m := b.grow(len(p)) copy(b.buf[m:], p) return len(p), nil @@ -90,6 +104,7 @@ func (b *Buffer) Write(p []byte) (n int, err os.Error) { // WriteString appends the contents of s to the buffer. The return // value n is the length of s; err is always nil. func (b *Buffer) WriteString(s string) (n int, err os.Error) { + b.lastRead = opInvalid m := b.grow(len(s)) return copy(b.buf[m:], s), nil } @@ -105,6 +120,7 @@ const MinRead = 512 // Any error except os.EOF encountered during the read // is also returned. func (b *Buffer) ReadFrom(r io.Reader) (n int64, err os.Error) { + b.lastRead = opInvalid // If buffer is empty, reset to recover space. if b.off >= len(b.buf) { b.Truncate(0) @@ -141,6 +157,7 @@ func (b *Buffer) ReadFrom(r io.Reader) (n int64, err os.Error) { // occurs. The return value n is the number of bytes written. // Any error encountered during the write is also returned. func (b *Buffer) WriteTo(w io.Writer) (n int64, err os.Error) { + b.lastRead = opInvalid for b.off < len(b.buf) { m, e := w.Write(b.buf[b.off:]) n += int64(m) @@ -158,6 +175,7 @@ func (b *Buffer) WriteTo(w io.Writer) (n int64, err os.Error) { // The returned error is always nil, but is included // to match bufio.Writer's WriteByte. func (b *Buffer) WriteByte(c byte) os.Error { + b.lastRead = opInvalid m := b.grow(1) b.buf[m] = c return nil @@ -172,7 +190,7 @@ func (b *Buffer) WriteRune(r int) (n int, err os.Error) { b.WriteByte(byte(r)) return 1, nil } - n = utf8.EncodeRune(r, b.runeBytes[0:]) + n = utf8.EncodeRune(b.runeBytes[0:], r) b.Write(b.runeBytes[0:n]) return n, nil } @@ -182,6 +200,7 @@ func (b *Buffer) WriteRune(r int) (n int, err os.Error) { // buffer has no data to return, err is os.EOF even if len(p) is zero; // otherwise it is nil. func (b *Buffer) Read(p []byte) (n int, err os.Error) { + b.lastRead = opInvalid if b.off >= len(b.buf) { // Buffer is empty, reset to recover space. b.Truncate(0) @@ -189,6 +208,9 @@ func (b *Buffer) Read(p []byte) (n int, err os.Error) { } n = copy(p, b.buf[b.off:]) b.off += n + if n > 0 { + b.lastRead = opRead + } return } @@ -197,18 +219,23 @@ func (b *Buffer) Read(p []byte) (n int, err os.Error) { // If there are fewer than n bytes in the buffer, Next returns the entire buffer. // The slice is only valid until the next call to a read or write method. func (b *Buffer) Next(n int) []byte { + b.lastRead = opInvalid m := b.Len() if n > m { n = m } data := b.buf[b.off : b.off+n] b.off += n + if n > 0 { + b.lastRead = opRead + } return data } // ReadByte reads and returns the next byte from the buffer. // If no byte is available, it returns error os.EOF. func (b *Buffer) ReadByte() (c byte, err os.Error) { + b.lastRead = opInvalid if b.off >= len(b.buf) { // Buffer is empty, reset to recover space. b.Truncate(0) @@ -216,6 +243,7 @@ func (b *Buffer) ReadByte() (c byte, err os.Error) { } c = b.buf[b.off] b.off++ + b.lastRead = opRead return c, nil } @@ -225,11 +253,13 @@ func (b *Buffer) ReadByte() (c byte, err os.Error) { // If the bytes are an erroneous UTF-8 encoding, it // consumes one byte and returns U+FFFD, 1. func (b *Buffer) ReadRune() (r int, size int, err os.Error) { + b.lastRead = opInvalid if b.off >= len(b.buf) { // Buffer is empty, reset to recover space. b.Truncate(0) return 0, 0, os.EOF } + b.lastRead = opReadRune c := b.buf[b.off] if c < utf8.RuneSelf { b.off++ @@ -240,9 +270,40 @@ func (b *Buffer) ReadRune() (r int, size int, err os.Error) { return r, n, nil } +// UnreadRune unreads the last rune returned by ReadRune. +// If the most recent read or write operation on the buffer was +// not a ReadRune, UnreadRune returns an error. (In this regard +// it is stricter than UnreadByte, which will unread the last byte +// from any read operation.) +func (b *Buffer) UnreadRune() os.Error { + if b.lastRead != opReadRune { + return os.ErrorString("bytes.Buffer: UnreadRune: previous operation was not ReadRune") + } + b.lastRead = opInvalid + if b.off > 0 { + _, n := utf8.DecodeLastRune(b.buf[0:b.off]) + b.off -= n + } + return nil +} + +// UnreadByte unreads the last byte returned by the most recent +// read operation. If write has happened since the last read, UnreadByte +// returns an error. +func (b *Buffer) UnreadByte() os.Error { + if b.lastRead != opReadRune && b.lastRead != opRead { + return os.ErrorString("bytes.Buffer: UnreadByte: previous operation was not a read") + } + b.lastRead = opInvalid + if b.off > 0 { + b.off-- + } + return nil +} + // NewBuffer creates and initializes a new Buffer using buf as its initial // contents. It is intended to prepare a Buffer to read existing data. It -// can also be used to to size the internal buffer for writing. To do that, +// can also be used to size the internal buffer for writing. To do that, // buf should have the desired capacity but a length of zero. func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} } |