diff options
Diffstat (limited to 'vendor/github.com/vmihailenco/bufpool/buffer.go')
| -rw-r--r-- | vendor/github.com/vmihailenco/bufpool/buffer.go | 397 |
1 files changed, 0 insertions, 397 deletions
diff --git a/vendor/github.com/vmihailenco/bufpool/buffer.go b/vendor/github.com/vmihailenco/bufpool/buffer.go deleted file mode 100644 index a061a0b70..000000000 --- a/vendor/github.com/vmihailenco/bufpool/buffer.go +++ /dev/null @@ -1,397 +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 bufpool - -// Simple byte buffer for marshaling data. - -import ( - "bytes" - "errors" - "io" - "unicode/utf8" -) - -// smallBufferSize is an initial allocation minimal capacity. -const smallBufferSize = 64 - -// 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)] - 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. opReadRuneX constants are chosen such that -// converted to int they correspond to the rune size that was read. -type readOp int8 - -// Don't use iota for these, as the values need to correspond with the -// names and comments, which is easier to see when being explicit. -const ( - opRead readOp = -1 // Any other read operation. - opInvalid readOp = 0 // Non-read operation. - opReadRune1 readOp = 1 // Read rune of size 1. -) - -var errNegativeRead = errors.New("bytes.Buffer: reader returned negative count from Read") - -const maxInt = int(^uint(0) >> 1) - -// Bytes returns a slice of length b.Len() holding the unread portion of the buffer. -// The slice is valid for use only until the next buffer modification (that is, -// only until the next call to a method like Read, Write, Reset, or Truncate). -// The slice aliases the buffer content at least until the next buffer modification, -// so immediate changes to the slice will affect the result of future reads. -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>". -// -// To build strings more efficiently, see the strings.Builder type. -func (b *Buffer) String() string { - if b == nil { - // Special case, useful in debugging. - return "<nil>" - } - return string(b.buf[b.off:]) -} - -// empty reports whether the unread portion of the buffer is empty. -func (b *Buffer) empty() bool { return len(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 } - -// Cap returns the capacity of the buffer's underlying byte slice, that is, the -// total space allocated for the buffer's data. -func (b *Buffer) Cap() int { return cap(b.buf) } - -// Truncate discards all but the first n unread bytes from the buffer -// but continues to use the same allocated storage. -// It panics if n is negative or greater than the length of the buffer. -func (b *Buffer) Truncate(n int) { - if n == 0 { - b.Reset() - return - } - b.lastRead = opInvalid - if n < 0 || n > b.Len() { - panic("bytes.Buffer: truncation out of range") - } - b.buf = b.buf[:b.off+n] -} - -// tryGrowByReslice is a inlineable version of grow for the fast-case where the -// internal buffer only needs to be resliced. -// It returns the index where bytes should be written and whether it succeeded. -func (b *Buffer) tryGrowByReslice(n int) (int, bool) { - if l := len(b.buf); n <= cap(b.buf)-l { - b.buf = b.buf[:l+n] - return l, true - } - return 0, false -} - -// 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[: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, ok := b.tryGrowByReslice(len(p)) - if !ok { - 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, ok := b.tryGrowByReslice(len(s)) - if !ok { - 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 - for { - i := b.grow(minRead) - b.buf = b.buf[:i] - m, e := r.Read(b.buf[i:cap(b.buf)]) - if m < 0 { - panic(errNegativeRead) - } - - b.buf = b.buf[:i+m] - n += int64(m) - if e == io.EOF { - return n, nil // e is EOF, so return nil explicitly - } - if e != nil { - return n, e - } - } -} - -// 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 nBytes := b.Len(); nBytes > 0 { - 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.Reset() - return n, nil -} - -// 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, ok := b.tryGrowByReslice(1) - if !ok { - 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 - } - b.lastRead = opInvalid - m, ok := b.tryGrowByReslice(utf8.UTFMax) - if !ok { - m = b.grow(utf8.UTFMax) - } - n = utf8.EncodeRune(b.buf[m:m+utf8.UTFMax], r) - b.buf = b.buf[:m+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.empty() { - // Buffer is empty, reset to recover space. - b.Reset() - if len(p) == 0 { - return 0, nil - } - return 0, io.EOF - } - n = copy(p, b.buf[b.off:]) - b.off += n - if n > 0 { - b.lastRead = opRead - } - return n, nil -} - -// 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() (byte, error) { - if b.empty() { - // Buffer is empty, reset to recover space. - b.Reset() - 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) { - if b.empty() { - // Buffer is empty, reset to recover space. - b.Reset() - return 0, 0, io.EOF - } - c := b.buf[b.off] - if c < utf8.RuneSelf { - b.off++ - b.lastRead = opReadRune1 - return rune(c), 1, nil - } - r, n := utf8.DecodeRune(b.buf[b.off:]) - b.off += n - b.lastRead = readOp(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 successful 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 <= opInvalid { - return errors.New("bytes.Buffer: UnreadRune: previous operation was not a successful ReadRune") - } - if b.off >= int(b.lastRead) { - b.off -= int(b.lastRead) - } - b.lastRead = opInvalid - return nil -} - -var errUnreadByte = errors.New("bytes.Buffer: UnreadByte: previous operation was not a successful read") - -// UnreadByte unreads the last byte returned by the most recent successful -// read operation that read at least one byte. If a write has happened since -// the last read, if the last read returned an error, or if the read read zero -// bytes, UnreadByte returns an error. -func (b *Buffer) UnreadByte() error { - if b.lastRead == opInvalid { - return errUnreadByte - } - 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 line, err -} - -// 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. The new Buffer takes ownership of buf, and the -// caller should not use buf after this call. NewBuffer is intended to -// prepare a Buffer to read existing data. It can also be used to set -// the initial size of 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)} -} |
