msgio

package
Version: v0.4.0-rc3 Latest Latest
Warning

This package is not in the latest version of its module.

Go to latest
Published: Mar 15, 2016 License: MIT Imports: 7 Imported by: 0

README

go-msgio - Message IO

This is a simple package that helps read and write length-delimited slices. It's helpful for building wire protocols.

Usage

Reading
import "github.com/jbenet/msgio"
rdr := ... // some reader from a wire
mrdr := msgio.NewReader(rdr)

for {
  msg, err := mrdr.ReadMsg()
  if err != nil {
    return err
  }

  doSomething(msg)
}
Writing
import "github.com/jbenet/msgio"
wtr := genReader()
mwtr := msgio.NewWriter(wtr)

for {
  msg := genMessage()
  err := mwtr.WriteMsg(msg)
  if err != nil {
    return err
  }
}
Duplex
import "github.com/jbenet/msgio"
rw := genReadWriter()
mrw := msgio.NewReadWriter(rw)

for {
  msg, err := mrdr.ReadMsg()
  if err != nil {
    return err
  }

  // echo it back :)
  err = mwtr.WriteMsg(msg)
  if err != nil {
    return err
  }
}
Channels
import "github.com/jbenet/msgio"
rw := genReadWriter()
rch := msgio.NewReadChannel(rw)
wch := msgio.NewWriteChannel(rw)

for {
  msg, err := <-rch
  if err != nil {
    return err
  }

  // echo it back :)
  wch<- rw
}

Documentation

Index

Constants

This section is empty.

Variables

View Source
var ErrMsgTooLarge = errors.New("message too large")

ErrMsgTooLarge is returned when the message length is exessive

NBO is NetworkByteOrder

Functions

func LimitedReader added in v0.3.8

func LimitedReader(r io.Reader) (io.Reader, error)

LimitedReader wraps an io.Reader with a msgio framed reader. The LimitedReader will return a reader which will io.EOF when the msg length is done.

func ReadLen added in v0.3.8

func ReadLen(r io.Reader, buf []byte) (int, error)

ReadLen reads a length from the given reader. if buf is non-nil, it reuses the buffer. Ex:

l, err := ReadLen(r, nil)
_, err := ReadLen(r, buf)

func WriteLen added in v0.3.8

func WriteLen(w io.Writer, l int) error

WriteLen writes a length to the given writer.

Types

type Chan

type Chan struct {
	MsgChan   chan []byte
	ErrChan   chan error
	CloseChan chan bool
}

Chan is a msgio duplex channel. It is used to have a channel interface around a msgio.Reader or Writer.

func NewChan

func NewChan(chanSize int) *Chan

NewChan constructs a Chan with a given buffer size.

func (*Chan) Close

func (s *Chan) Close()

Close the Chan

func (*Chan) ReadFrom

func (s *Chan) ReadFrom(r io.Reader)

ReadFrom wraps the given io.Reader with a msgio.Reader, reads all messages, ands sends them down the channel.

func (*Chan) ReadFromWithPool

func (s *Chan) ReadFromWithPool(r io.Reader, p *mpool.Pool)

ReadFromWithPool wraps the given io.Reader with a msgio.Reader, reads all messages, ands sends them down the channel. Uses given Pool

func (*Chan) WriteTo

func (s *Chan) WriteTo(w io.Writer)

WriteTo wraps the given io.Writer with a msgio.Writer, listens on the channel and writes all messages to the writer.

type LimitedWriter added in v0.3.8

type LimitedWriter struct {
	W io.Writer
	B bytes.Buffer
	M sync.Mutex
}

func NewLimitedWriter added in v0.3.8

func NewLimitedWriter(w io.Writer) *LimitedWriter

LimitedWriter wraps an io.Writer with a msgio framed writer. It is the inverse of LimitedReader: it will buffer all writes until "Flush" is called. When Flush is called, it will write the size of the buffer first, flush the buffer, reset the buffer, and begin accept more incoming writes.

func (*LimitedWriter) Flush added in v0.3.8

func (w *LimitedWriter) Flush() error

func (*LimitedWriter) Write added in v0.3.8

func (w *LimitedWriter) Write(buf []byte) (n int, err error)

type ReadCloser

type ReadCloser interface {
	Reader
	io.Closer
}

ReadCloser combines a Reader and Closer.

func NewReader

func NewReader(r io.Reader) ReadCloser

NewReader wraps an io.Reader with a msgio framed reader. The msgio.Reader will read whole messages at a time (using the length). Assumes an equivalent writer on the other side.

func NewReaderWithPool

func NewReaderWithPool(r io.Reader, p *mpool.Pool) ReadCloser

NewReaderWithPool wraps an io.Reader with a msgio framed reader. The msgio.Reader will read whole messages at a time (using the length). Assumes an equivalent writer on the other side. It uses a given mpool.Pool

func NewVarintReader

func NewVarintReader(r io.Reader) ReadCloser

NewVarintReader wraps an io.Reader with a varint msgio framed reader. The msgio.Reader will read whole messages at a time (using the length). Varints read according to https://golang.org/pkg/encoding/binary/#ReadUvarint Assumes an equivalent writer on the other side.

func NewVarintReaderWithPool

func NewVarintReaderWithPool(r io.Reader, p *mpool.Pool) ReadCloser

NewVarintReaderWithPool wraps an io.Reader with a varint msgio framed reader. The msgio.Reader will read whole messages at a time (using the length). Varints read according to https://golang.org/pkg/encoding/binary/#ReadUvarint Assumes an equivalent writer on the other side. It uses a given mpool.Pool

type ReadWriteCloser

type ReadWriteCloser interface {
	Reader
	Writer
	io.Closer
}

ReadWriteCloser combines a Reader, a Writer, and Closer.

func Combine

func Combine(w Writer, r Reader) ReadWriteCloser

Combine wraps a pair of msgio.Writer and msgio.Reader with a msgio.ReadWriter.

func NewReadWriter

func NewReadWriter(rw io.ReadWriter) ReadWriteCloser

NewReadWriter wraps an io.ReadWriter with a msgio.ReadWriter. Writing and Reading will be appropriately framed.

type ReadWriter

type ReadWriter interface {
	Reader
	Writer
}

ReadWriter combines a Reader and Writer.

type Reader

type Reader interface {

	// Read reads the next message from the Reader.
	// The client must pass a buffer large enough, or io.ErrShortBuffer will be
	// returned.
	Read([]byte) (int, error)

	// ReadMsg reads the next message from the Reader.
	// Uses a mpool.Pool internally to reuse buffers. io.ErrShortBuffer will
	// be returned if the Pool.Get(...) returns nil.
	// User may call ReleaseMsg(msg) to signal a buffer can be reused.
	ReadMsg() ([]byte, error)

	// ReleaseMsg signals a buffer can be reused.
	ReleaseMsg([]byte)

	// NextMsgLen returns the length of the next (peeked) message. Does
	// not destroy the message or have other adverse effects
	NextMsgLen() (int, error)
}

Reader is the msgio Reader interface. It reads len-framed messages.

type WriteCloser

type WriteCloser interface {
	Writer
	io.Closer
}

WriteCloser is a Writer + Closer interface. Like in `golang/pkg/io`

func NewVarintWriter

func NewVarintWriter(w io.Writer) WriteCloser

NewVarintWriter wraps an io.Writer with a varint msgio framed writer. The msgio.Writer will write the length prefix of every message written as a varint, using https://golang.org/pkg/encoding/binary/#PutUvarint

func NewWriter

func NewWriter(w io.Writer) WriteCloser

NewWriter wraps an io.Writer with a msgio framed writer. The msgio.Writer will write the length prefix of every message written.

type Writer

type Writer interface {

	// Write writes passed in buffer as a single message.
	Write([]byte) (int, error)

	// WriteMsg writes the msg in the passed in buffer.
	WriteMsg([]byte) error
}

Writer is the msgio Writer interface. It writes len-framed messages.

Directories

Path Synopsis
Package mpool provides a sync.Pool equivalent that buckets incoming requests to one of 32 sub-pools, one for each power of 2, 0-32.
Package mpool provides a sync.Pool equivalent that buckets incoming requests to one of 32 sub-pools, one for each power of 2, 0-32.

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL