bufio

Documentation

Overview

Package bufio is a simplified Golang bufio. It mainly avoids calling TCPConn.ReadFrom in Writer.ReadFrom because TCPConn.ReadFrom calls sys calls.

Index

• Variables
• type ReadWriter
  • func NewReadWriter(r *Reader, w *Writer) *ReadWriter
• type Reader
  • func NewReader(rd io.Reader) *Reader
  • func NewReaderSize(rd io.Reader, size int) *Reader
  • func (b *Reader) Buffered() int
  • func (b *Reader) Discard(n int) (discarded int, err error)
  • func (b *Reader) Peek(n int) ([]byte, error)
  • func (b *Reader) Read(p []byte) (n int, err error)
  • func (b *Reader) Reset(r io.Reader)
  • func (b *Reader) Size() int
  • func (b *Reader) WriteTo(w io.Writer) (n int64, err error)
• type Writer
  • func NewWriter(w io.Writer) *Writer
  • func NewWriterSize(w io.Writer, size int) *Writer
  • func (b *Writer) Available() int
  • func (b *Writer) AvailableBuffer() []byte
  • func (b *Writer) Buffered() int
  • func (b *Writer) Flush() error
  • func (b *Writer) ReadFrom(r io.Reader) (n int64, err error)
  • func (b *Writer) Reset(w io.Writer)
  • func (b *Writer) Size() int
  • func (b *Writer) Write(p []byte) (nn int, err error)

Variables

var (
	ErrBufferFull    = errors.New("bufio: buffer full")
	ErrNegativeCount = errors.New("bufio: negative count")
)

Types

type ReadWriter

type ReadWriter struct {
	*Reader
	*Writer
}

ReadWriter stores pointers to a Reader and a Writer. It implements io.ReadWriter.

func NewReadWriter

func NewReadWriter(r *Reader, w *Writer) *ReadWriter

NewReadWriter allocates a new ReadWriter that dispatches to r and w.

type Reader

type Reader struct {
	// contains filtered or unexported fields
}

Reader implements buffering for an io.Reader object.

func NewReader

func NewReader(rd io.Reader) *Reader

NewReader returns a new Reader whose buffer has the default size.

func NewReaderSize

func NewReaderSize(rd io.Reader, size int) *Reader

NewReaderSize returns a new Reader whose buffer has at least the specified size. If the argument io.Reader is already a Reader with large enough size, it returns the underlying Reader.

func (*Reader) Buffered

func (b *Reader) Buffered() int

Buffered returns the number of bytes that can be read from the current buffer.

func (*Reader) Discard

func (b *Reader) Discard(n int) (discarded int, err error)

Discard skips the next n bytes, returning the number of bytes discarded.

If Discard skips fewer than n bytes, it also returns an error. If 0 <= n <= b.Buffered(), Discard is guaranteed to succeed without reading from the underlying io.Reader.

func (*Reader) Peek

func (b *Reader) Peek(n int) ([]byte, error)

Peek returns the next n bytes without advancing the reader. The bytes stop being valid at the next read call. If Peek returns fewer than n bytes, it also returns an error explaining why the read is short. The error is ErrBufferFull if n is larger than b's buffer size.

Calling Peek prevents a UnreadByte or UnreadRune call from succeeding until the next read operation.

func (*Reader) Read

func (b *Reader) Read(p []byte) (n int, err error)

Read reads data into p. It returns the number of bytes read into p. The bytes are taken from at most one Read on the underlying Reader, hence n may be less than len(p). To read exactly len(p) bytes, use io.ReadFull(b, p). If the underlying Reader can return a non-zero count with io.EOF, then this Read method can do so as well; see the io.Reader docs.

func (*Reader) Reset

func (b *Reader) Reset(r io.Reader)

Reset discards any buffered data, resets all state, and switches the buffered reader to read from r. Calling Reset on the zero value of Reader initializes the internal buffer to the default size. Calling b.Reset(b) (that is, resetting a Reader to itself) does nothing.

func (*Reader) Size

func (b *Reader) Size() int

Size returns the size of the underlying buffer in bytes.

func (*Reader) WriteTo

func (b *Reader) WriteTo(w io.Writer) (n int64, err error)

WriteTo implements io.WriterTo. This may make multiple calls to the Read method of the underlying Reader. If the underlying reader supports the WriteTo method, this calls the underlying WriteTo without buffering.

type Writer

type Writer struct {
	// contains filtered or unexported fields
}

Writer implements buffering for an io.Writer object. If an error occurs writing to a Writer, no more data will be accepted and all subsequent writes, and Flush, will return the error. After all data has been written, the client should call the Flush method to guarantee all data has been forwarded to the underlying io.Writer.

func NewWriter

func NewWriter(w io.Writer) *Writer

NewWriter returns a new Writer whose buffer has the default size. If the argument io.Writer is already a Writer with large enough buffer size, it returns the underlying Writer.

func NewWriterSize

func NewWriterSize(w io.Writer, size int) *Writer

NewWriterSize returns a new Writer whose buffer has at least the specified size. If the argument io.Writer is already a Writer with large enough size, it returns the underlying Writer.

func (*Writer) Available

func (b *Writer) Available() int

Available returns how many bytes are unused in the buffer.

func (*Writer) AvailableBuffer

func (b *Writer) AvailableBuffer() []byte

AvailableBuffer returns an empty buffer with b.Available() capacity. This buffer is intended to be appended to and passed to an immediately succeeding Write call. The buffer is only valid until the next write operation on b.

func (*Writer) Buffered

func (b *Writer) Buffered() int

Buffered returns the number of bytes that have been written into the current buffer.

func (*Writer) Flush

func (b *Writer) Flush() error

Flush writes any buffered data to the underlying io.Writer.

func (*Writer) ReadFrom

func (b *Writer) ReadFrom(r io.Reader) (n int64, err error)

ReadFrom implements io.ReaderFrom. If the underlying writer supports the ReadFrom method, this calls the underlying ReadFrom. If there is buffered data and an underlying ReadFrom, this fills the buffer and writes it before calling ReadFrom.

func (*Writer) Reset

func (b *Writer) Reset(w io.Writer)

Reset discards any unflushed buffered data, clears any error, and resets b to write its output to w. Calling Reset on the zero value of Writer initializes the internal buffer to the default size. Calling w.Reset(w) (that is, resetting a Writer to itself) does nothing.

func (*Writer) Size

func (b *Writer) Size() int

Size returns the size of the underlying buffer in bytes.

func (*Writer) Write

func (b *Writer) Write(p []byte) (nn int, err error)

Write writes the contents of p into the buffer. It returns the number of bytes written. If nn < len(p), it also returns an error explaining why the write is short.