http: make httputil's chunked reader/writer code a direct copy

Arrange the code so that it's easier to keep edits in sync.

R=golang-dev, mikioh.mikioh, bradfitz, andybalholm, rsc
CC=golang-dev
https://golang.org/cl/5345041

src/pkg/net/http/chunked.go

@@ -2,20 +2,137 @@
 // 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 duplicated in httputil/chunked.go.
+// Please make any changes in both files.
+
 package http
 
 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.Btoui64(line, 16)
+	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 writer.
+// Writing to chunkedWriter translates to writing in HTTP chunked Transfer
+// Encoding wire format to the underlying Wire chunkedWriter.
 type chunkedWriter struct {
 	Wire io.Writer
 }
@@ -51,7 +168,3 @@ func (cw *chunkedWriter) Close() error {
 	_, err := io.WriteString(cw.Wire, "0\r\n")
 	return err
 }
-
-func newChunkedReader(r *bufio.Reader) io.Reader {
-	return &chunkedReader{r: r}
-}

src/pkg/net/http/chunked_test.go

@@ -0,0 +1,39 @@
+// Copyright 2011 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.
+
+// This code is duplicated in httputil/chunked_test.go.
+// Please make any changes in both files.
+
+package http
+
+import (
+	"bytes"
+	"io/ioutil"
+	"testing"
+)
+
+func TestChunk(t *testing.T) {
+	var b bytes.Buffer
+
+	w := newChunkedWriter(&b)
+	const chunk1 = "hello, "
+	const chunk2 = "world! 0123456789abcdef"
+	w.Write([]byte(chunk1))
+	w.Write([]byte(chunk2))
+	w.Close()
+
+	if g, e := b.String(), "7\r\nhello, \r\n17\r\nworld! 0123456789abcdef\r\n0\r\n"; g != e {
+		t.Fatalf("chunk writer wrote %q; want %q", g, e)
+	}
+
+	r := newChunkedReader(&b)
+	data, err := ioutil.ReadAll(r)
+	if err != nil {
+		t.Logf(`data: "%s"`, data)
+		t.Fatalf("ReadAll from reader: %v", err)
+	}
+	if g, e := string(data), chunk1+chunk2; g != e {
+		t.Errorf("chunk reader read %q; want %q", g, e)
+	}
+}

src/pkg/net/http/httputil/chunked.go

@@ -2,18 +2,126 @@
 // 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"
-	"net/http"
 	"strconv"
-	"strings"
 )
 
-// NewChunkedWriter returns a new writer that translates writes into HTTP
-// "chunked" format before writing them to w. Closing the returned writer
+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.Btoui64(line, 16)
+	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
@@ -25,8 +133,8 @@ 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 writer.
+// Writing to chunkedWriter translates to writing in HTTP chunked Transfer
+// Encoding wire format to the underlying Wire chunkedWriter.
 type chunkedWriter struct {
 	Wire io.Writer
 }
@@ -62,23 +170,3 @@ func (cw *chunkedWriter) Close() error {
 	_, err := io.WriteString(cw.Wire, "0\r\n")
 	return err
 }
-
-// NewChunkedReader returns a new reader that translates the data read from r
-// out of HTTP "chunked" format before returning it. 
-// The reader 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 {
-	// This is a bit of a hack so we don't have to copy chunkedReader into
-	// httputil.  It's a bit more complex than chunkedWriter, which is copied
-	// above.
-	req, err := http.ReadRequest(bufio.NewReader(io.MultiReader(
-		strings.NewReader("POST / HTTP/1.1\r\nTransfer-Encoding: chunked\r\n\r\n"),
-		r,
-		strings.NewReader("\r\n"))))
-	if err != nil {
-		panic("bad fake request: " + err.Error())
-	}
-	return req.Body
-}

src/pkg/net/http/httputil/chunked_test.go

@@ -2,6 +2,11 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// This code is a duplicate of ../chunked_test.go with these edits:
+//	s/newChunked/NewChunked/g
+//	s/package http/package httputil/
+// Please make any changes in both files.
+
 package httputil
 
 import (
@@ -27,7 +32,8 @@ func TestChunk(t *testing.T) {
 	r := NewChunkedReader(&b)
 	data, err := ioutil.ReadAll(r)
 	if err != nil {
-		t.Fatalf("ReadAll from NewChunkedReader: %v", err)
+		t.Logf(`data: "%s"`, data)
+		t.Fatalf("ReadAll from reader: %v", err)
 	}
 	if g, e := string(data), chunk1+chunk2; g != e {
 		t.Errorf("chunk reader read %q; want %q", g, e)

src/pkg/net/http/request.go

@@ -19,12 +19,10 @@ import (
 	"mime/multipart"
 	"net/textproto"
 	"net/url"
-	"strconv"
 	"strings"
 )
 
 const (
-	maxLineLength    = 4096 // assumed <= bufio.defaultBufSize
 	maxValueLength   = 4096
 	maxHeaderLines   = 1024
 	chunkSize        = 4 << 10  // 4 KB chunks
@@ -43,7 +41,6 @@ type ProtocolError struct {
 func (err *ProtocolError) Error() string { return err.ErrorString }
 
 var (
-	ErrLineTooLong          = &ProtocolError{"header line too long"}
 	ErrHeaderTooLong        = &ProtocolError{"header too long"}
 	ErrShortBody            = &ProtocolError{"entity body too short"}
 	ErrNotSupported         = &ProtocolError{"feature not supported"}
@@ -375,44 +372,6 @@ func (req *Request) write(w io.Writer, usingProxy bool, extraHeaders Header) err
 	return nil
 }
 
-// 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.
-	var i int
-	for i = len(p); i > 0; i-- {
-		if c := p[i-1]; c != ' ' && c != '\r' && c != '\t' && c != '\n' {
-			break
-		}
-	}
-	return p[0:i], 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
-}
-
 // Convert decimal at s[i:len(s)] to integer,
 // returning value, string position where the digits stopped,
 // and whether there was a valid number (digits, not too big).
@@ -448,55 +407,6 @@ func ParseHTTPVersion(vers string) (major, minor int, ok bool) {
 	return major, minor, true
 }
 
-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.Btoui64(line, 16)
-	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
-}
-
 // NewRequest returns a new Request given a method, URL, and optional body.
 func NewRequest(method, urlStr string, body io.Reader) (*Request, error) {
 	u, err := url.Parse(urlStr)

src/pkg/net/http/response_test.go

@@ -315,7 +315,7 @@ func TestReadResponseCloseInMiddle(t *testing.T) {
 		}
 		var wr io.Writer = &buf
 		if test.chunked {
-			wr = &chunkedWriter{wr}
+			wr = newChunkedWriter(wr)
 		}
 		if test.compressed {
 			buf.WriteString("Content-Encoding: gzip\r\n")