Significant extension to http.Response, which now adheres to the

usage pattern of http.Request and paves the way to persistent connection
handling.

R=rsc
CC=golang-dev
https://golang.org/cl/185043

src/pkg/http/Makefile

@@ -6,9 +6,11 @@ include ../../Make.$(GOARCH)
 
 TARG=http
 GOFILES=\
+	chunked.go\
 	client.go\
 	fs.go\
 	request.go\
+	response.go\
 	server.go\
 	status.go\
 	url.go\

src/pkg/http/chunked.go

@@ -0,0 +1,56 @@
+// 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
+}

src/pkg/http/client.go

@@ -13,49 +13,9 @@ import (
 	"io"
 	"net"
 	"os"
-	"strconv"
 	"strings"
 )
 
-// Response represents the response from an HTTP request.
-type Response struct {
-	Status     string // e.g. "200 OK"
-	StatusCode int    // e.g. 200
-
-	// Header maps header keys to values.  If the response had multiple
-	// headers with the same key, they will be concatenated, with comma
-	// delimiters.  (Section 4.2 of RFC 2616 requires that multiple headers
-	// be semantically equivalent to a comma-delimited sequence.)
-	//
-	// Keys in the map are canonicalized (see CanonicalHeaderKey).
-	Header map[string]string
-
-	// Stream from which the response body can be read.
-	Body io.ReadCloser
-}
-
-// GetHeader returns the value of the response header with the given
-// key, and true.  If there were multiple headers with this key, their
-// values are concatenated, with a comma delimiter.  If there were no
-// response headers with the given key, it returns the empty string and
-// false.  Keys are not case sensitive.
-func (r *Response) GetHeader(key string) (value string) {
-	value, _ = r.Header[CanonicalHeaderKey(key)]
-	return
-}
-
-// AddHeader adds a value under the given key.  Keys are not case sensitive.
-func (r *Response) AddHeader(key, value string) {
-	key = CanonicalHeaderKey(key)
-
-	oldValues, oldValuesPresent := r.Header[key]
-	if oldValuesPresent {
-		r.Header[key] = oldValues + "," + value
-	} else {
-		r.Header[key] = value
-	}
-}
-
 // Given a string of the form "host", "host:port", or "[ipv6::address]:port",
 // return true if the string includes a port.
 func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }
@@ -68,43 +28,6 @@ type readClose struct {
 	io.Closer
 }
 
-// ReadResponse reads and returns an HTTP response from r.
-func ReadResponse(r *bufio.Reader) (*Response, os.Error) {
-	resp := new(Response)
-
-	// Parse the first line of the response.
-	resp.Header = make(map[string]string)
-
-	line, err := readLine(r)
-	if err != nil {
-		return nil, err
-	}
-	f := strings.Split(line, " ", 3)
-	if len(f) < 3 {
-		return nil, &badStringError{"malformed HTTP response", line}
-	}
-	resp.Status = f[1] + " " + f[2]
-	resp.StatusCode, err = strconv.Atoi(f[1])
-	if err != nil {
-		return nil, &badStringError{"malformed HTTP status code", f[1]}
-	}
-
-	// Parse the response headers.
-	for {
-		key, value, err := readKeyValue(r)
-		if err != nil {
-			return nil, err
-		}
-		if key == "" {
-			break // end of response header
-		}
-		resp.AddHeader(key, value)
-	}
-
-	return resp, nil
-}
-
-
 // Send issues an HTTP request.  Caller should close resp.Body when done reading it.
 //
 // TODO: support persistent connections (multiple requests on a single connection).
@@ -141,23 +64,13 @@ func send(req *Request) (resp *Response, err os.Error) {
 	}
 
 	reader := bufio.NewReader(conn)
-	resp, err = ReadResponse(reader)
+	resp, err = ReadResponse(reader, req.Method)
 	if err != nil {
 		conn.Close()
 		return nil, err
 	}
 
-	r := io.Reader(reader)
-	if v := resp.GetHeader("Transfer-Encoding"); v == "chunked" {
-		r = newChunkedReader(reader)
-	} else if v := resp.GetHeader("Content-Length"); v != "" {
-		n, err := strconv.Atoi64(v)
-		if err != nil {
-			return nil, &badStringError{"invalid Content-Length", v}
-		}
-		r = io.LimitReader(r, n)
-	}
-	resp.Body = readClose{r, conn}
+	resp.Body = readClose{resp.Body, conn}
 
 	return
 }
@@ -180,8 +93,8 @@ func shouldRedirect(statusCode int) bool {
 //    303 (See Other)
 //    307 (Temporary Redirect)
 //
-// finalURL is the URL from which the response was fetched -- identical to the input
-// URL unless redirects were followed.
+// finalURL is the URL from which the response was fetched -- identical to the
+// input URL unless redirects were followed.
 //
 // Caller should close r.Body when done reading it.
 func Get(url string) (r *Response, finalURL string, err os.Error) {

src/pkg/http/request.go

@@ -34,9 +34,12 @@ type ProtocolError struct {
 }
 
 var (
-	ErrLineTooLong   = &ProtocolError{"header line too long"}
-	ErrHeaderTooLong = &ProtocolError{"header too long"}
-	ErrShortBody     = &ProtocolError{"entity body too short"}
+	ErrLineTooLong          = &ProtocolError{"header line too long"}
+	ErrHeaderTooLong        = &ProtocolError{"header too long"}
+	ErrShortBody            = &ProtocolError{"entity body too short"}
+	ErrNotSupported         = &ProtocolError{"feature not supported"}
+	ErrUnexpectedTrailer    = &ProtocolError{"trailer header without chunked transfer encoding"}
+	ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"}
 )
 
 type badStringError struct {