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Diffstat (limited to 'Godeps/_workspace/src/gopkg.in/bufio.v1/buffer.go')
| -rw-r--r-- | Godeps/_workspace/src/gopkg.in/bufio.v1/buffer.go | 413 |
1 files changed, 0 insertions, 413 deletions
diff --git a/Godeps/_workspace/src/gopkg.in/bufio.v1/buffer.go b/Godeps/_workspace/src/gopkg.in/bufio.v1/buffer.go deleted file mode 100644 index 8b915605b..000000000 --- a/Godeps/_workspace/src/gopkg.in/bufio.v1/buffer.go +++ /dev/null @@ -1,413 +0,0 @@ -// 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 bufio - -// Simple byte buffer for marshaling data. - -import ( - "bytes" - "errors" - "io" - "unicode/utf8" -) - -// A Buffer is a variable-sized buffer of bytes with Read and Write methods. -// The zero value for Buffer is an empty buffer ready to use. -type Buffer struct { - buf []byte // contents are the bytes buf[off : len(buf)] - 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. -) - -// ErrTooLarge is passed to panic if memory cannot be allocated to store data in a buffer. -var ErrTooLarge = errors.New("bytes.Buffer: too large") - -// 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 -// are no intervening method calls on the Buffer. -func (b *Buffer) Bytes() []byte { return b.buf[b.off:] } - -// String returns the contents of the unread portion of the buffer -// as a string. If the Buffer is a nil pointer, it returns "<nil>". -func (b *Buffer) String() string { - if b == nil { - // Special case, useful in debugging. - return "<nil>" - } - return string(b.buf[b.off:]) -} - -// Len returns the number of bytes of the unread portion of the buffer; -// b.Len() == len(b.Bytes()). -func (b *Buffer) Len() int { return len(b.buf) - b.off } - -// Truncate discards all but the first n unread bytes from the buffer. -// It panics if n is negative or greater than the length of the buffer. -func (b *Buffer) Truncate(n int) { - b.lastRead = opInvalid - switch { - case n < 0 || n > b.Len(): - panic("bytes.Buffer: truncation out of range") - case n == 0: - // Reuse buffer space. - b.off = 0 - } - b.buf = b.buf[0 : b.off+n] -} - -// Reset resets the buffer so it has no content. -// b.Reset() is the same as b.Truncate(0). -func (b *Buffer) Reset() { b.Truncate(0) } - -// grow grows the buffer to guarantee space for n more bytes. -// It returns the index where bytes should be written. -// If the buffer can't grow it will panic with ErrTooLarge. -func (b *Buffer) grow(n int) int { - m := b.Len() - // If buffer is empty, reset to recover space. - if m == 0 && b.off != 0 { - b.Truncate(0) - } - if len(b.buf)+n > cap(b.buf) { - var buf []byte - if b.buf == nil && n <= len(b.bootstrap) { - buf = b.bootstrap[0:] - } else if m+n <= cap(b.buf)/2 { - // We can slide things down instead of allocating a new - // slice. We only need m+n <= cap(b.buf) to slide, but - // we instead let capacity get twice as large so we - // don't spend all our time copying. - copy(b.buf[:], b.buf[b.off:]) - buf = b.buf[:m] - } else { - // not enough space anywhere - buf = makeSlice(2*cap(b.buf) + n) - copy(buf, b.buf[b.off:]) - } - b.buf = buf - b.off = 0 - } - b.buf = b.buf[0 : b.off+m+n] - return b.off + m -} - -// Grow grows the buffer's capacity, if necessary, to guarantee space for -// another n bytes. After Grow(n), at least n bytes can be written to the -// buffer without another allocation. -// If n is negative, Grow will panic. -// If the buffer can't grow it will panic with ErrTooLarge. -func (b *Buffer) Grow(n int) { - if n < 0 { - panic("bytes.Buffer.Grow: negative count") - } - m := b.grow(n) - b.buf = b.buf[0:m] -} - -// Write appends the contents of p to the buffer, growing the buffer as -// needed. The return value n is the length of p; err is always nil. If the -// buffer becomes too large, Write will panic with ErrTooLarge. -func (b *Buffer) Write(p []byte) (n int, err error) { - b.lastRead = opInvalid - m := b.grow(len(p)) - return copy(b.buf[m:], p), nil -} - -// WriteString appends the contents of s to the buffer, growing the buffer as -// needed. The return value n is the length of s; err is always nil. If the -// buffer becomes too large, WriteString will panic with ErrTooLarge. -func (b *Buffer) WriteString(s string) (n int, err error) { - b.lastRead = opInvalid - m := b.grow(len(s)) - return copy(b.buf[m:], s), nil -} - -// MinRead is the minimum slice size passed to a Read call by -// Buffer.ReadFrom. As long as the Buffer has at least MinRead bytes beyond -// what is required to hold the contents of r, ReadFrom will not grow the -// underlying buffer. -const MinRead = 512 - -// ReadFrom reads data from r until EOF and appends it to the buffer, growing -// the buffer as needed. The return value n is the number of bytes read. Any -// error except io.EOF encountered during the read is also returned. If the -// buffer becomes too large, ReadFrom will panic with ErrTooLarge. -func (b *Buffer) ReadFrom(r io.Reader) (n int64, err error) { - b.lastRead = opInvalid - // If buffer is empty, reset to recover space. - if b.off >= len(b.buf) { - b.Truncate(0) - } - for { - if free := cap(b.buf) - len(b.buf); free < MinRead { - // not enough space at end - newBuf := b.buf - if b.off+free < MinRead { - // not enough space using beginning of buffer; - // double buffer capacity - newBuf = makeSlice(2*cap(b.buf) + MinRead) - } - copy(newBuf, b.buf[b.off:]) - b.buf = newBuf[:len(b.buf)-b.off] - b.off = 0 - } - m, e := r.Read(b.buf[len(b.buf):cap(b.buf)]) - b.buf = b.buf[0 : len(b.buf)+m] - n += int64(m) - if e == io.EOF { - break - } - if e != nil { - return n, e - } - } - return n, nil // err is EOF, so return nil explicitly -} - -// makeSlice allocates a slice of size n. If the allocation fails, it panics -// with ErrTooLarge. -func makeSlice(n int) []byte { - // If the make fails, give a known error. - defer func() { - if recover() != nil { - panic(ErrTooLarge) - } - }() - return make([]byte, n) -} - -// WriteTo writes data to w until the buffer is drained or an error occurs. -// The return value n is the number of bytes written; it always fits into an -// int, but it is int64 to match the io.WriterTo interface. Any error -// encountered during the write is also returned. -func (b *Buffer) WriteTo(w io.Writer) (n int64, err error) { - b.lastRead = opInvalid - if b.off < len(b.buf) { - nBytes := b.Len() - m, e := w.Write(b.buf[b.off:]) - if m > nBytes { - panic("bytes.Buffer.WriteTo: invalid Write count") - } - b.off += m - n = int64(m) - if e != nil { - return n, e - } - // all bytes should have been written, by definition of - // Write method in io.Writer - if m != nBytes { - return n, io.ErrShortWrite - } - } - // Buffer is now empty; reset. - b.Truncate(0) - return -} - -// WriteByte appends the byte c to the buffer, growing the buffer as needed. -// The returned error is always nil, but is included to match bufio.Writer's -// WriteByte. If the buffer becomes too large, WriteByte will panic with -// ErrTooLarge. -func (b *Buffer) WriteByte(c byte) error { - b.lastRead = opInvalid - m := b.grow(1) - b.buf[m] = c - return nil -} - -// WriteRune appends the UTF-8 encoding of Unicode code point r to the -// buffer, returning its length and an error, which is always nil but is -// included to match bufio.Writer's WriteRune. The buffer is grown as needed; -// if it becomes too large, WriteRune will panic with ErrTooLarge. -func (b *Buffer) WriteRune(r rune) (n int, err error) { - if r < utf8.RuneSelf { - b.WriteByte(byte(r)) - return 1, nil - } - n = utf8.EncodeRune(b.runeBytes[0:], r) - b.Write(b.runeBytes[0:n]) - return n, nil -} - -// Read reads the next len(p) bytes from the buffer or until the buffer -// is drained. The return value n is the number of bytes read. If the -// buffer has no data to return, err is io.EOF (unless len(p) is zero); -// otherwise it is nil. -func (b *Buffer) Read(p []byte) (n int, err error) { - b.lastRead = opInvalid - if b.off >= len(b.buf) { - // Buffer is empty, reset to recover space. - b.Truncate(0) - if len(p) == 0 { - return - } - return 0, io.EOF - } - n = copy(p, b.buf[b.off:]) - b.off += n - if n > 0 { - b.lastRead = opRead - } - return -} - -// Next returns a slice containing the next n bytes from the buffer, -// advancing the buffer as if the bytes had been returned by Read. -// 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 io.EOF. -func (b *Buffer) ReadByte() (c byte, err error) { - b.lastRead = opInvalid - if b.off >= len(b.buf) { - // Buffer is empty, reset to recover space. - b.Truncate(0) - return 0, io.EOF - } - c = b.buf[b.off] - b.off++ - b.lastRead = opRead - return c, nil -} - -// ReadRune reads and returns the next UTF-8-encoded -// Unicode code point from the buffer. -// If no bytes are available, the error returned is io.EOF. -// If the bytes are an erroneous UTF-8 encoding, it -// consumes one byte and returns U+FFFD, 1. -func (b *Buffer) ReadRune() (r rune, size int, err error) { - b.lastRead = opInvalid - if b.off >= len(b.buf) { - // Buffer is empty, reset to recover space. - b.Truncate(0) - return 0, 0, io.EOF - } - b.lastRead = opReadRune - c := b.buf[b.off] - if c < utf8.RuneSelf { - b.off++ - return rune(c), 1, nil - } - r, n := utf8.DecodeRune(b.buf[b.off:]) - b.off += n - 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() error { - if b.lastRead != opReadRune { - return errors.New("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() error { - if b.lastRead != opReadRune && b.lastRead != opRead { - return errors.New("bytes.Buffer: UnreadByte: previous operation was not a read") - } - b.lastRead = opInvalid - if b.off > 0 { - b.off-- - } - return nil -} - -// ReadBytes reads until the first occurrence of delim in the input, -// returning a slice containing the data up to and including the delimiter. -// If ReadBytes encounters an error before finding a delimiter, -// it returns the data read before the error and the error itself (often io.EOF). -// ReadBytes returns err != nil if and only if the returned data does not end in -// delim. -func (b *Buffer) ReadBytes(delim byte) (line []byte, err error) { - slice, err := b.readSlice(delim) - // return a copy of slice. The buffer's backing array may - // be overwritten by later calls. - line = append(line, slice...) - return -} - -// readSlice is like ReadBytes but returns a reference to internal buffer data. -func (b *Buffer) readSlice(delim byte) (line []byte, err error) { - i := bytes.IndexByte(b.buf[b.off:], delim) - end := b.off + i + 1 - if i < 0 { - end = len(b.buf) - err = io.EOF - } - line = b.buf[b.off:end] - b.off = end - b.lastRead = opRead - return line, err -} - -// ReadString reads until the first occurrence of delim in the input, -// returning a string containing the data up to and including the delimiter. -// If ReadString encounters an error before finding a delimiter, -// it returns the data read before the error and the error itself (often io.EOF). -// ReadString returns err != nil if and only if the returned data does not end -// in delim. -func (b *Buffer) ReadString(delim byte) (line string, err error) { - slice, err := b.readSlice(delim) - return string(slice), err -} - -// 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 size the internal buffer for writing. To do that, -// buf should have the desired capacity but a length of zero. -// -// In most cases, new(Buffer) (or just declaring a Buffer variable) is -// sufficient to initialize a Buffer. -func NewBuffer(buf []byte) *Buffer { return &Buffer{buf: buf} } - -// NewBufferString creates and initializes a new Buffer using string s as its -// initial contents. It is intended to prepare a buffer to read an existing -// string. -// -// In most cases, new(Buffer) (or just declaring a Buffer variable) is -// sufficient to initialize a Buffer. -func NewBufferString(s string) *Buffer { - return &Buffer{buf: []byte(s)} -} |