1 files changed, 172 insertions, 0 deletions
diff --git a/src/pkg/net/http/httputil/chunked.go b/src/pkg/net/http/httputil/chunked.go
new file mode 100644
index 000000000..29eaf3475
--- /dev/null
+++ b/src/pkg/net/http/httputil/chunked.go
@@ -0,0 +1,172 @@
+// 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.
+
+// The wire protocol for HTTP's "chunked" Transfer-Encoding.
+
+// This code is a duplicate of ../chunked.go with these edits:
+//	s/newChunked/NewChunked/g
+//	s/package http/package httputil/
+// Please make any changes in both files.
+
+package httputil
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"strconv"
+)
+
+const maxLineLength = 4096 // assumed <= bufio.defaultBufSize
+
+var ErrLineTooLong = errors.New("header line too long")
+
+// NewChunkedReader returns a new chunkedReader that translates the data read from r
+// out of HTTP "chunked" format before returning it. 
+// The chunkedReader returns io.EOF when the final 0-length chunk is read.
+//
+// NewChunkedReader is not needed by normal applications. The http package
+// automatically decodes chunking when reading response bodies.
+func NewChunkedReader(r io.Reader) io.Reader {
+	br, ok := r.(*bufio.Reader)
+	if !ok {
+		br = bufio.NewReader(r)
+	}
+	return &chunkedReader{r: br}
+}
+
+type chunkedReader struct {
+	r   *bufio.Reader
+	n   uint64 // unread bytes in chunk
+	err error
+}
+
+func (cr *chunkedReader) beginChunk() {
+	// chunk-size CRLF
+	var line string
+	line, cr.err = readLine(cr.r)
+	if cr.err != nil {
+		return
+	}
+	cr.n, cr.err = strconv.ParseUint(line, 16, 64)
+	if cr.err != nil {
+		return
+	}
+	if cr.n == 0 {
+		cr.err = io.EOF
+	}
+}
+
+func (cr *chunkedReader) Read(b []uint8) (n int, err error) {
+	if cr.err != nil {
+		return 0, cr.err
+	}
+	if cr.n == 0 {
+		cr.beginChunk()
+		if cr.err != nil {
+			return 0, cr.err
+		}
+	}
+	if uint64(len(b)) > cr.n {
+		b = b[0:cr.n]
+	}
+	n, cr.err = cr.r.Read(b)
+	cr.n -= uint64(n)
+	if cr.n == 0 && cr.err == nil {
+		// end of chunk (CRLF)
+		b := make([]byte, 2)
+		if _, cr.err = io.ReadFull(cr.r, b); cr.err == nil {
+			if b[0] != '\r' || b[1] != '\n' {
+				cr.err = errors.New("malformed chunked encoding")
+			}
+		}
+	}
+	return n, cr.err
+}
+
+// Read a line of bytes (up to \n) from b.
+// Give up if the line exceeds maxLineLength.
+// The returned bytes are a pointer into storage in
+// the bufio, so they are only valid until the next bufio read.
+func readLineBytes(b *bufio.Reader) (p []byte, err error) {
+	if p, err = b.ReadSlice('\n'); err != nil {
+		// We always know when EOF is coming.
+		// If the caller asked for a line, there should be a line.
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		} else if err == bufio.ErrBufferFull {
+			err = ErrLineTooLong
+		}
+		return nil, err
+	}
+	if len(p) >= maxLineLength {
+		return nil, ErrLineTooLong
+	}
+
+	// Chop off trailing white space.
+	p = bytes.TrimRight(p, " \r\t\n")
+
+	return p, nil
+}
+
+// readLineBytes, but convert the bytes into a string.
+func readLine(b *bufio.Reader) (s string, err error) {
+	p, e := readLineBytes(b)
+	if e != nil {
+		return "", e
+	}
+	return string(p), nil
+}
+
+// NewChunkedWriter returns a new chunkedWriter that translates writes into HTTP
+// "chunked" format before writing them to w. Closing the returned chunkedWriter
+// sends the final 0-length chunk that marks the end of the stream.
+//
+// NewChunkedWriter is not needed by normal applications. The http
+// package adds chunking automatically if handlers don't set a
+// Content-Length header. Using NewChunkedWriter inside a handler
+// would result in double chunking or chunking with a Content-Length
+// length, both of which are wrong.
+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 underlying Wire chunkedWriter.
+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 error) {
+
+	// Don't send 0-length data. It looks like EOF for chunked encoding.
+	if len(data) == 0 {
+		return 0, nil
+	}
+
+	head := strconv.FormatInt(int64(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() error {
+	_, err := io.WriteString(cw.Wire, "0\r\n")
+	return err
+}