Source file src/pkg/http/chunked.go

// 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 http

import (
    "io"
    "os"
    "strconv"
)

// NewChunkedWriter returns a new writer that translates writes into HTTP
// "chunked" format before writing them to w.  Closing the returned writer
// sends the final 0-length chunk that marks the end of the stream.
func NewChunkedWriter(w io.Writer) io.WriteCloser {
    return &chunkedWriter{w}
}

// Writing to ChunkedWriter translates to writing in HTTP chunked Transfer
// Encoding wire format to the undering Wire writer.
type chunkedWriter struct {
    Wire io.Writer
}

// Write the contents of data as one chunk to Wire.
// NOTE: Note that the corresponding chunk-writing procedure in Conn.Write has
// a bug since it does not check for success of io.WriteString
func (cw *chunkedWriter) Write(data []byte) (n int, err os.Error) {

    // Don't send 0-length data. It looks like EOF for chunked encoding.
    if len(data) == 0 {
        return 0, nil
    }

    head := strconv.Itob(len(data), 16) + "\r\n"

    if _, err = io.WriteString(cw.Wire, head); err != nil {
        return 0, err
    }
    if n, err = cw.Wire.Write(data); err != nil {
        return
    }
    if n != len(data) {
        err = io.ErrShortWrite
        return
    }
    _, err = io.WriteString(cw.Wire, "\r\n")

    return
}

func (cw *chunkedWriter) Close() os.Error {
    _, err := io.WriteString(cw.Wire, "0\r\n")
    return err
}