http: revised http Handler interface

R=rsc
CC=golang-dev
https://golang.org/cl/1993043

11 files changed, 343 insertions, 313 deletions

diff --git a/src/cmd/godoc/codewalk.go b/src/cmd/godoc/codewalk.go
index 02417bfefb..442ba7b1dd 100644
--- a/src/cmd/godoc/codewalk.go
+++ b/src/cmd/godoc/codewalk.go
@@ -31,26 +31,26 @@ import (
 
 
 // Handler for /doc/codewalk/ and below.
-func codewalk(c *http.Conn, r *http.Request) {
+func codewalk(w http.ResponseWriter, r *http.Request) {
 	relpath := r.URL.Path[len("/doc/codewalk/"):]
 	abspath := absolutePath(r.URL.Path[1:], *goroot)
 
 	r.ParseForm()
 	if f := r.FormValue("fileprint"); f != "" {
-		codewalkFileprint(c, r, f)
+		codewalkFileprint(w, r, f)
 		return
 	}
 
 	// If directory exists, serve list of code walks.
 	dir, err := os.Lstat(abspath)
 	if err == nil && dir.IsDirectory() {
-		codewalkDir(c, r, relpath, abspath)
+		codewalkDir(w, r, relpath, abspath)
 		return
 	}
 
 	// If file exists, serve using standard file server.
 	if err == nil {
-		serveFile(c, r)
+		serveFile(w, r)
 		return
 	}
 
@@ -59,17 +59,17 @@ func codewalk(c *http.Conn, r *http.Request) {
 	cw, err := loadCodewalk(abspath + ".xml")
 	if err != nil {
 		log.Stderr(err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
 	// Canonicalize the path and redirect if changed
-	if redirect(c, r) {
+	if redirect(w, r) {
 		return
 	}
 
 	b := applyTemplate(codewalkHTML, "codewalk", cw)
-	servePage(c, "Codewalk: "+cw.Title, "", "", b)
+	servePage(w, "Codewalk: "+cw.Title, "", "", b)
 }
 
 
@@ -178,7 +178,7 @@ func loadCodewalk(file string) (*Codewalk, os.Error) {
 // codewalkDir serves the codewalk directory listing.
 // It scans the directory for subdirectories or files named *.xml
 // and prepares a table.
-func codewalkDir(c *http.Conn, r *http.Request, relpath, abspath string) {
+func codewalkDir(w http.ResponseWriter, r *http.Request, relpath, abspath string) {
 	type elem struct {
 		Name  string
 		Title string
@@ -187,7 +187,7 @@ func codewalkDir(c *http.Conn, r *http.Request, relpath, abspath string) {
 	dir, err := ioutil.ReadDir(abspath)
 	if err != nil {
 		log.Stderr(err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 	var v vector.Vector
@@ -204,7 +204,7 @@ func codewalkDir(c *http.Conn, r *http.Request, relpath, abspath string) {
 	}
 
 	b := applyTemplate(codewalkdirHTML, "codewalkdir", v)
-	servePage(c, "Codewalks", "", "", b)
+	servePage(w, "Codewalks", "", "", b)
 }
 
 
@@ -214,12 +214,12 @@ func codewalkDir(c *http.Conn, r *http.Request, relpath, abspath string) {
 // in the response.  This format is used for the middle window pane
 // of the codewalk pages.  It is a separate iframe and does not get
 // the usual godoc HTML wrapper.
-func codewalkFileprint(c *http.Conn, r *http.Request, f string) {
+func codewalkFileprint(w http.ResponseWriter, r *http.Request, f string) {
 	abspath := absolutePath(f, *goroot)
 	data, err := ioutil.ReadFile(abspath)
 	if err != nil {
 		log.Stderr(err)
-		serveError(c, r, f, err)
+		serveError(w, r, f, err)
 		return
 	}
 	lo, _ := strconv.Atoi(r.FormValue("lo"))
@@ -243,17 +243,17 @@ func codewalkFileprint(c *http.Conn, r *http.Request, f string) {
 		}
 	}
 
-	io.WriteString(c, `<style type="text/css">@import "/doc/codewalk/codewalk.css";</style><pre>`)
-	template.HTMLEscape(c, data[0:mark])
-	io.WriteString(c, "<a name='mark'></a>")
-	template.HTMLEscape(c, data[mark:lo])
+	io.WriteString(w, `<style type="text/css">@import "/doc/codewalk/codewalk.css";</style><pre>`)
+	template.HTMLEscape(w, data[0:mark])
+	io.WriteString(w, "<a name='mark'></a>")
+	template.HTMLEscape(w, data[mark:lo])
 	if lo < hi {
-		io.WriteString(c, "<div class='codewalkhighlight'>")
-		template.HTMLEscape(c, data[lo:hi])
-		io.WriteString(c, "</div>")
+		io.WriteString(w, "<div class='codewalkhighlight'>")
+		template.HTMLEscape(w, data[lo:hi])
+		io.WriteString(w, "</div>")
 	}
-	template.HTMLEscape(c, data[hi:])
-	io.WriteString(c, "</pre>")
+	template.HTMLEscape(w, data[hi:])
+	io.WriteString(w, "</pre>")
 }
 
 
diff --git a/src/cmd/godoc/godoc.go b/src/cmd/godoc/godoc.go
index d85cb024e0..a101eb24c5 100644
--- a/src/cmd/godoc/godoc.go
+++ b/src/cmd/godoc/godoc.go
@@ -792,7 +792,7 @@ func readTemplates() {
 // ----------------------------------------------------------------------------
 // Generic HTML wrapper
 
-func servePage(c *http.Conn, title, subtitle, query string, content []byte) {
+func servePage(w http.ResponseWriter, title, subtitle, query string, content []byte) {
 	type Data struct {
 		Title    string
 		Subtitle string
@@ -813,15 +813,15 @@ func servePage(c *http.Conn, title, subtitle, query string, content []byte) {
 		Content:  content,
 	}
 
-	if err := godocHTML.Execute(&d, c); err != nil {
+	if err := godocHTML.Execute(&d, w); err != nil {
 		log.Stderrf("godocHTML.Execute: %s", err)
 	}
 }
 
 
-func serveText(c *http.Conn, text []byte) {
-	c.SetHeader("Content-Type", "text/plain; charset=utf-8")
-	c.Write(text)
+func serveText(w http.ResponseWriter, text []byte) {
+	w.SetHeader("Content-Type", "text/plain; charset=utf-8")
+	w.Write(text)
 }
 
 
@@ -844,19 +844,19 @@ func extractString(src []byte, rx *regexp.Regexp) (s string) {
 }
 
 
-func serveHTMLDoc(c *http.Conn, r *http.Request, abspath, relpath string) {
+func serveHTMLDoc(w http.ResponseWriter, r *http.Request, abspath, relpath string) {
 	// get HTML body contents
 	src, err := ioutil.ReadFile(abspath)
 	if err != nil {
 		log.Stderrf("ioutil.ReadFile: %s", err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
 	// if it begins with "<!DOCTYPE " assume it is standalone
 	// html that doesn't need the template wrapping.
 	if bytes.HasPrefix(src, []byte("<!DOCTYPE ")) {
-		c.Write(src)
+		w.Write(src)
 		return
 	}
 
@@ -875,7 +875,7 @@ func serveHTMLDoc(c *http.Conn, r *http.Request, abspath, relpath string) {
 	}
 	subtitle := extractString(src, subtitleRx)
 
-	servePage(c, title, subtitle, "", src)
+	servePage(w, title, subtitle, "", src)
 }
 
 
@@ -888,11 +888,11 @@ func applyTemplate(t *template.Template, name string, data interface{}) []byte {
 }
 
 
-func serveGoSource(c *http.Conn, r *http.Request, abspath, relpath string) {
+func serveGoSource(w http.ResponseWriter, r *http.Request, abspath, relpath string) {
 	file, err := parser.ParseFile(abspath, nil, parser.ParseComments)
 	if err != nil {
 		log.Stderrf("parser.ParseFile: %s", err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
@@ -911,13 +911,13 @@ func serveGoSource(c *http.Conn, r *http.Request, abspath, relpath string) {
 	info := &SourceInfo{styler.idList(), buf.Bytes()}
 
 	contents := applyTemplate(sourceHTML, "sourceHTML", info)
-	servePage(c, "Source file "+relpath, "", "", contents)
+	servePage(w, "Source file "+relpath, "", "", contents)
 }
 
 
-func redirect(c *http.Conn, r *http.Request) (redirected bool) {
+func redirect(w http.ResponseWriter, r *http.Request) (redirected bool) {
 	if canonical := pathutil.Clean(r.URL.Path) + "/"; r.URL.Path != canonical {
-		http.Redirect(c, canonical, http.StatusMovedPermanently)
+		http.Redirect(w, r, canonical, http.StatusMovedPermanently)
 		redirected = true
 	}
 	return
@@ -971,11 +971,11 @@ func isTextFile(path string) bool {
 }
 
 
-func serveTextFile(c *http.Conn, r *http.Request, abspath, relpath string) {
+func serveTextFile(w http.ResponseWriter, r *http.Request, abspath, relpath string) {
 	src, err := ioutil.ReadFile(abspath)
 	if err != nil {
 		log.Stderrf("ioutil.ReadFile: %s", err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
@@ -984,19 +984,19 @@ func serveTextFile(c *http.Conn, r *http.Request, abspath, relpath string) {
 	template.HTMLEscape(&buf, src)
 	fmt.Fprintln(&buf, "</pre>")
 
-	servePage(c, "Text file "+relpath, "", "", buf.Bytes())
+	servePage(w, "Text file "+relpath, "", "", buf.Bytes())
 }
 
 
-func serveDirectory(c *http.Conn, r *http.Request, abspath, relpath string) {
-	if redirect(c, r) {
+func serveDirectory(w http.ResponseWriter, r *http.Request, abspath, relpath string) {
+	if redirect(w, r) {
 		return
 	}
 
 	list, err := ioutil.ReadDir(abspath)
 	if err != nil {
 		log.Stderrf("ioutil.ReadDir: %s", err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
@@ -1007,23 +1007,23 @@ func serveDirectory(c *http.Conn, r *http.Request, abspath, relpath string) {
 	}
 
 	contents := applyTemplate(dirlistHTML, "dirlistHTML", list)
-	servePage(c, "Directory "+relpath, "", "", contents)
+	servePage(w, "Directory "+relpath, "", "", contents)
 }
 
 
-func serveFile(c *http.Conn, r *http.Request) {
+func serveFile(w http.ResponseWriter, r *http.Request) {
 	relpath := r.URL.Path[1:] // serveFile URL paths start with '/'
 	abspath := absolutePath(relpath, *goroot)
 
 	// pick off special cases and hand the rest to the standard file server
 	switch r.URL.Path {
 	case "/":
-		serveHTMLDoc(c, r, pathutil.Join(*goroot, "doc/root.html"), "doc/root.html")
+		serveHTMLDoc(w, r, pathutil.Join(*goroot, "doc/root.html"), "doc/root.html")
 		return
 
 	case "/doc/root.html":
 		// hide landing page from its real name
-		http.Redirect(c, "/", http.StatusMovedPermanently)
+		http.Redirect(w, r, "/", http.StatusMovedPermanently)
 		return
 	}
 
@@ -1032,42 +1032,42 @@ func serveFile(c *http.Conn, r *http.Request) {
 		if strings.HasSuffix(abspath, "/index.html") {
 			// We'll show index.html for the directory.
 			// Use the dir/ version as canonical instead of dir/index.html.
-			http.Redirect(c, r.URL.Path[0:len(r.URL.Path)-len("index.html")], http.StatusMovedPermanently)
+			http.Redirect(w, r, r.URL.Path[0:len(r.URL.Path)-len("index.html")], http.StatusMovedPermanently)
 			return
 		}
-		serveHTMLDoc(c, r, abspath, relpath)
+		serveHTMLDoc(w, r, abspath, relpath)
 		return
 
 	case ".go":
-		serveGoSource(c, r, abspath, relpath)
+		serveGoSource(w, r, abspath, relpath)
 		return
 	}
 
 	dir, err := os.Lstat(abspath)
 	if err != nil {
 		log.Stderr(err)
-		serveError(c, r, relpath, err)
+		serveError(w, r, relpath, err)
 		return
 	}
 
 	if dir != nil && dir.IsDirectory() {
-		if redirect(c, r) {
+		if redirect(w, r) {
 			return
 		}
 		if index := abspath + "/index.html"; isTextFile(index) {
-			serveHTMLDoc(c, r, index, relativePath(index))
+			serveHTMLDoc(w, r, index, relativePath(index))
 			return
 		}
-		serveDirectory(c, r, abspath, relpath)
+		serveDirectory(w, r, abspath, relpath)
 		return
 	}
 
 	if isTextFile(abspath) {
-		serveTextFile(c, r, abspath, relpath)
+		serveTextFile(w, r, abspath, relpath)
 		return
 	}
 
-	fileServer.ServeHTTP(c, r)
+	fileServer.ServeHTTP(w, r)
 }
 
 
@@ -1243,8 +1243,8 @@ func (h *httpHandler) getPageInfo(abspath, relpath, pkgname string, mode PageInf
 }
 
 
-func (h *httpHandler) ServeHTTP(c *http.Conn, r *http.Request) {
-	if redirect(c, r) {
+func (h *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if redirect(w, r) {
 		return
 	}
 
@@ -1257,13 +1257,13 @@ func (h *httpHandler) ServeHTTP(c *http.Conn, r *http.Request) {
 	info := h.getPageInfo(abspath, relpath, r.FormValue("p"), mode)
 	if info.Err != nil {
 		log.Stderr(info.Err)
-		serveError(c, r, relpath, info.Err)
+		serveError(w, r, relpath, info.Err)
 		return
 	}
 
 	if r.FormValue("f") == "text" {
 		contents := applyTemplate(packageText, "packageText", info)
-		serveText(c, contents)
+		serveText(w, contents)
 		return
 	}
 
@@ -1290,7 +1290,7 @@ func (h *httpHandler) ServeHTTP(c *http.Conn, r *http.Request) {
 	}
 
 	contents := applyTemplate(packageHTML, "packageHTML", info)
-	servePage(c, title, subtitle, "", contents)
+	servePage(w, title, subtitle, "", contents)
 }
 
 
@@ -1319,13 +1319,13 @@ func lookup(query string) (result SearchResult) {
 }
 
 
-func search(c *http.Conn, r *http.Request) {
+func search(w http.ResponseWriter, r *http.Request) {
 	query := strings.TrimSpace(r.FormValue("q"))
 	result := lookup(query)
 
 	if r.FormValue("f") == "text" {
 		contents := applyTemplate(searchText, "searchText", result)
-		serveText(c, contents)
+		serveText(w, contents)
 		return
 	}
 
@@ -1337,7 +1337,7 @@ func search(c *http.Conn, r *http.Request) {
 	}
 
 	contents := applyTemplate(searchHTML, "searchHTML", result)
-	servePage(c, title, "", query, contents)
+	servePage(w, title, "", query, contents)
 }
 
 
diff --git a/src/cmd/godoc/main.go b/src/cmd/godoc/main.go
index c13979968a..4a913a0172 100644
--- a/src/cmd/godoc/main.go
+++ b/src/cmd/godoc/main.go
@@ -64,14 +64,14 @@ var (
 )
 
 
-func serveError(c *http.Conn, r *http.Request, relpath string, err os.Error) {
+func serveError(w http.ResponseWriter, r *http.Request, relpath string, err os.Error) {
 	contents := applyTemplate(errorHTML, "errorHTML", err) // err may contain an absolute path!
-	c.WriteHeader(http.StatusNotFound)
-	servePage(c, "File "+relpath, "", "", contents)
+	w.WriteHeader(http.StatusNotFound)
+	servePage(w, "File "+relpath, "", "", contents)
 }
 
 
-func exec(c *http.Conn, args []string) (status int) {
+func exec(rw http.ResponseWriter, args []string) (status int) {
 	r, w, err := os.Pipe()
 	if err != nil {
 		log.Stderrf("os.Pipe(): %v\n", err)
@@ -109,18 +109,18 @@ func exec(c *http.Conn, args []string) (status int) {
 	if *verbose {
 		os.Stderr.Write(buf.Bytes())
 	}
-	if c != nil {
-		c.SetHeader("content-type", "text/plain; charset=utf-8")
-		c.Write(buf.Bytes())
+	if rw != nil {
+		rw.SetHeader("content-type", "text/plain; charset=utf-8")
+		rw.Write(buf.Bytes())
 	}
 
 	return
 }
 
 
-func dosync(c *http.Conn, r *http.Request) {
+func dosync(w http.ResponseWriter, r *http.Request) {
 	args := []string{"/bin/sh", "-c", *syncCmd}
-	switch exec(c, args) {
+	switch exec(w, args) {
 	case 0:
 		// sync succeeded and some files have changed;
 		// update package tree.
@@ -150,9 +150,9 @@ func usage() {
 
 
 func loggingHandler(h http.Handler) http.Handler {
-	return http.HandlerFunc(func(c *http.Conn, req *http.Request) {
-		log.Stderrf("%s\t%s", c.RemoteAddr, req.URL)
-		h.ServeHTTP(c, req)
+	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		log.Stderrf("%s\t%s", w.RemoteAddr(), req.URL)
+		h.ServeHTTP(w, req)
 	})
 }
 
diff --git a/src/pkg/expvar/expvar.go b/src/pkg/expvar/expvar.go
index 4017027b77..9435481dbc 100644
--- a/src/pkg/expvar/expvar.go
+++ b/src/pkg/expvar/expvar.go
@@ -210,18 +210,18 @@ func Iter() <-chan KeyValue {
 	return c
 }
 
-func expvarHandler(c *http.Conn, req *http.Request) {
-	c.SetHeader("content-type", "application/json; charset=utf-8")
-	fmt.Fprintf(c, "{\n")
+func expvarHandler(w http.ResponseWriter, r *http.Request) {
+	w.SetHeader("content-type", "application/json; charset=utf-8")
+	fmt.Fprintf(w, "{\n")
 	first := true
 	for name, value := range vars {
 		if !first {
-			fmt.Fprintf(c, ",\n")
+			fmt.Fprintf(w, ",\n")
 		}
 		first = false
-		fmt.Fprintf(c, "%q: %s", name, value)
+		fmt.Fprintf(w, "%q: %s", name, value)
 	}
-	fmt.Fprintf(c, "\n}\n")
+	fmt.Fprintf(w, "\n}\n")
 }
 
 func memstats() string {
diff --git a/src/pkg/http/fs.go b/src/pkg/http/fs.go
index db80b2f4df..b3047f1827 100644
--- a/src/pkg/http/fs.go
+++ b/src/pkg/http/fs.go
@@ -43,8 +43,8 @@ func isText(b []byte) bool {
 	return true
 }
 
-func dirList(c *Conn, f *os.File) {
-	fmt.Fprintf(c, "<pre>\n")
+func dirList(w ResponseWriter, f *os.File) {
+	fmt.Fprintf(w, "<pre>\n")
 	for {
 		dirs, err := f.Readdir(100)
 		if err != nil || len(dirs) == 0 {
@@ -56,25 +56,25 @@ func dirList(c *Conn, f *os.File) {
 				name += "/"
 			}
 			// TODO htmlescape
-			fmt.Fprintf(c, "<a href=\"%s\">%s</a>\n", name, name)
+			fmt.Fprintf(w, "<a href=\"%s\">%s</a>\n", name, name)
 		}
 	}
-	fmt.Fprintf(c, "</pre>\n")
+	fmt.Fprintf(w, "</pre>\n")
 }
 
-func serveFile(c *Conn, r *Request, name string, redirect bool) {
+func serveFile(w ResponseWriter, r *Request, name string, redirect bool) {
 	const indexPage = "/index.html"
 
 	// redirect .../index.html to .../
 	if strings.HasSuffix(r.URL.Path, indexPage) {
-		Redirect(c, r.URL.Path[0:len(r.URL.Path)-len(indexPage)+1], StatusMovedPermanently)
+		Redirect(w, r, r.URL.Path[0:len(r.URL.Path)-len(indexPage)+1], StatusMovedPermanently)
 		return
 	}
 
 	f, err := os.Open(name, os.O_RDONLY, 0)
 	if err != nil {
 		// TODO expose actual error?
-		NotFound(c, r)
+		NotFound(w, r)
 		return
 	}
 	defer f.Close()
@@ -82,7 +82,7 @@ func serveFile(c *Conn, r *Request, name string, redirect bool) {
 	d, err1 := f.Stat()
 	if err1 != nil {
 		// TODO expose actual error?
-		NotFound(c, r)
+		NotFound(w, r)
 		return
 	}
 
@@ -92,22 +92,22 @@ func serveFile(c *Conn, r *Request, name string, redirect bool) {
 		url := r.URL.Path
 		if d.IsDirectory() {
 			if url[len(url)-1] != '/' {
-				Redirect(c, url+"/", StatusMovedPermanently)
+				Redirect(w, r, url+"/", StatusMovedPermanently)
 				return
 			}
 		} else {
 			if url[len(url)-1] == '/' {
-				Redirect(c, url[0:len(url)-1], StatusMovedPermanently)
+				Redirect(w, r, url[0:len(url)-1], StatusMovedPermanently)
 				return
 			}
 		}
 	}
 
 	if t, _ := time.Parse(TimeFormat, r.Header["If-Modified-Since"]); t != nil && d.Mtime_ns/1e9 <= t.Seconds() {
-		c.WriteHeader(StatusNotModified)
+		w.WriteHeader(StatusNotModified)
 		return
 	}
-	c.SetHeader("Last-Modified", time.SecondsToUTC(d.Mtime_ns/1e9).Format(TimeFormat))
+	w.SetHeader("Last-Modified", time.SecondsToUTC(d.Mtime_ns/1e9).Format(TimeFormat))
 
 	// use contents of index.html for directory, if present
 	if d.IsDirectory() {
@@ -125,7 +125,7 @@ func serveFile(c *Conn, r *Request, name string, redirect bool) {
 	}
 
 	if d.IsDirectory() {
-		dirList(c, f)
+		dirList(w, f)
 		return
 	}
 
@@ -133,25 +133,25 @@ func serveFile(c *Conn, r *Request, name string, redirect bool) {
 	// use extension to find content type.
 	ext := path.Ext(name)
 	if ctype := mime.TypeByExtension(ext); ctype != "" {
-		c.SetHeader("Content-Type", ctype)
+		w.SetHeader("Content-Type", ctype)
 	} else {
 		// read first chunk to decide between utf-8 text and binary
 		var buf [1024]byte
 		n, _ := io.ReadFull(f, buf[0:])
 		b := buf[0:n]
 		if isText(b) {
-			c.SetHeader("Content-Type", "text-plain; charset=utf-8")
+			w.SetHeader("Content-Type", "text-plain; charset=utf-8")
 		} else {
-			c.SetHeader("Content-Type", "application/octet-stream") // generic binary
+			w.SetHeader("Content-Type", "application/octet-stream") // generic binary
 		}
-		c.Write(b)
+		w.Write(b)
 	}
-	io.Copy(c, f)
+	io.Copy(w, f)
 }
 
 // ServeFile replies to the request with the contents of the named file or directory.
-func ServeFile(c *Conn, r *Request, name string) {
-	serveFile(c, r, name, false)
+func ServeFile(w ResponseWriter, r *Request, name string) {
+	serveFile(w, r, name, false)
 }
 
 type fileHandler struct {
@@ -165,12 +165,12 @@ type fileHandler struct {
 // looking up the file name in the file system.
 func FileServer(root, prefix string) Handler { return &fileHandler{root, prefix} }
 
-func (f *fileHandler) ServeHTTP(c *Conn, r *Request) {
+func (f *fileHandler) ServeHTTP(w ResponseWriter, r *Request) {
 	path := r.URL.Path
 	if !strings.HasPrefix(path, f.prefix) {
-		NotFound(c, r)
+		NotFound(w, r)
 		return
 	}
 	path = path[len(f.prefix):]
-	serveFile(c, r, f.root+"/"+path, true)
+	serveFile(w, r, f.root+"/"+path, true)
 }
diff --git a/src/pkg/http/pprof/pprof.go b/src/pkg/http/pprof/pprof.go
index 38d91afbf8..f7db9aab93 100644
--- a/src/pkg/http/pprof/pprof.go
+++ b/src/pkg/http/pprof/pprof.go
@@ -40,28 +40,28 @@ func init() {
 // Cmdline responds with the running program's
 // command line, with arguments separated by NUL bytes.
 // The package initialization registers it as /debug/pprof/cmdline.
-func Cmdline(c *http.Conn, r *http.Request) {
-	c.SetHeader("content-type", "text/plain; charset=utf-8")
-	fmt.Fprintf(c, strings.Join(os.Args, "\x00"))
+func Cmdline(w http.ResponseWriter, r *http.Request) {
+	w.SetHeader("content-type", "text/plain; charset=utf-8")
+	fmt.Fprintf(w, strings.Join(os.Args, "\x00"))
 }
 
 // Heap responds with the pprof-formatted heap profile.
 // The package initialization registers it as /debug/pprof/heap.
-func Heap(c *http.Conn, r *http.Request) {
-	c.SetHeader("content-type", "text/plain; charset=utf-8")
-	pprof.WriteHeapProfile(c)
+func Heap(w http.ResponseWriter, r *http.Request) {
+	w.SetHeader("content-type", "text/plain; charset=utf-8")
+	pprof.WriteHeapProfile(w)
 }
 
 // Symbol looks up the program counters listed in the request,
 // responding with a table mapping program counters to function names.
 // The package initialization registers it as /debug/pprof/symbol.
-func Symbol(c *http.Conn, r *http.Request) {
-	c.SetHeader("content-type", "text/plain; charset=utf-8")
+func Symbol(w http.ResponseWriter, r *http.Request) {
+	w.SetHeader("content-type", "text/plain; charset=utf-8")
 
 	// We don't know how many symbols we have, but we
 	// do have symbol information.  Pprof only cares whether
 	// this number is 0 (no symbols available) or > 0.
-	fmt.Fprintf(c, "num_symbols: 1\n")
+	fmt.Fprintf(w, "num_symbols: 1\n")
 
 	var b *bufio.Reader
 	if r.Method == "POST" {
@@ -71,15 +71,15 @@ func Symbol(c *http.Conn, r *http.Request) {
 	}
 
 	for {
-		w, err := b.ReadSlice('+')
+		word, err := b.ReadSlice('+')
 		if err == nil {
-			w = w[0 : len(w)-1] // trim +
+			word = word[0 : len(word)-1] // trim +
 		}
-		pc, _ := strconv.Btoui64(string(w), 0)
+		pc, _ := strconv.Btoui64(string(word), 0)
 		if pc != 0 {
 			f := runtime.FuncForPC(uintptr(pc))
 			if f != nil {
-				fmt.Fprintf(c, "%#x %s\n", pc, f.Name())
+				fmt.Fprintf(w, "%#x %s\n", pc, f.Name())
 			}
 		}
 
diff --git a/src/pkg/http/server.go b/src/pkg/http/server.go
index 99d5f6b517..4404dda978 100644
--- a/src/pkg/http/server.go
+++ b/src/pkg/http/server.go
@@ -37,32 +37,78 @@ var (
 // registered to serve a particular path or subtree
 // in the HTTP server.
 //
-// ServeHTTP should write reply headers and data to the Conn
+// ServeHTTP should write reply headers and data to the ResponseWriter
 // and then return.  Returning signals that the request is finished
 // and that the HTTP server can move on to the next request on
 // the connection.
 type Handler interface {
-	ServeHTTP(*Conn, *Request)
-}
-
-// A Conn represents the server side of a single active HTTP connection.
-type Conn struct {
-	RemoteAddr string   // network address of remote side
-	Req        *Request // current HTTP request
-
-	rwc      io.ReadWriteCloser // i/o connection
-	buf      *bufio.ReadWriter  // buffered rwc
-	handler  Handler            // request handler
-	hijacked bool               // connection has been hijacked by handler
-
-	// state for the current reply
+	ServeHTTP(ResponseWriter, *Request)
+}
+
+// A ResponseWriter interface is used by an HTTP handler to
+// construct an HTTP response.
+type ResponseWriter interface {
+	// RemoteAddr returns the address of the client that sent the current request
+	RemoteAddr() string
+
+	// UsingTLS returns true if the client is connected using TLS
+	UsingTLS() bool
+
+	// SetHeader sets a header line in the eventual response.
+	// For example, SetHeader("Content-Type", "text/html; charset=utf-8")
+	// will result in the header line
+	//
+	//	Content-Type: text/html; charset=utf-8
+	//
+	// being sent.  UTF-8 encoded HTML is the default setting for
+	// Content-Type in this library, so users need not make that
+	// particular call.  Calls to SetHeader after WriteHeader (or Write)
+	// are ignored.
+	SetHeader(string, string)
+
+	// Write writes the data to the connection as part of an HTTP reply.
+	// If WriteHeader has not yet been called, Write calls WriteHeader(http.StatusOK)
+	// before writing the data.
+	Write([]byte) (int, os.Error)
+
+	// WriteHeader sends an HTTP response header with status code.
+	// If WriteHeader is not called explicitly, the first call to Write
+	// will trigger an implicit WriteHeader(http.StatusOK).
+	// Thus explicit calls to WriteHeader are mainly used to
+	// send error codes.
+	WriteHeader(int)
+
+	// Flush sends any buffered data to the client.
+	Flush()
+
+	// Hijack lets the caller take over the connection.
+	// After a call to Hijack(), the HTTP server library
+	// will not do anything else with the connection.
+	// It becomes the caller's responsibility to manage
+	// and close the connection.
+	Hijack() (io.ReadWriteCloser, *bufio.ReadWriter, os.Error)
+}
+
+// A conn represents the server side of an HTTP connection.
+type conn struct {
+	remoteAddr string             // network address of remote side
+	handler    Handler            // request handler
+	rwc        io.ReadWriteCloser // i/o connection
+	buf        *bufio.ReadWriter  // buffered rwc
+	hijacked   bool               // connection has been hijacked by handler
+	usingTLS   bool               // a flag indicating connection over TLS
+}
+
+// A response represents the server side of an HTTP response.
+type response struct {
+	conn          *conn
+	req           *Request          // request for this response
 	chunking      bool              // using chunked transfer encoding for reply body
 	wroteHeader   bool              // reply header has been written
 	wroteContinue bool              // 100 Continue response was written
 	header        map[string]string // reply header parameters
 	written       int64             // number of bytes written in body
 	status        int               // status code passed to WriteHeader
-	usingTLS      bool              // a flag indicating connection over TLS
 
 	// close connection after this reply.  set on request and
 	// updated after response from handler if there's a
@@ -72,11 +118,9 @@ type Conn struct {
 }
 
 // Create new connection from rwc.
-func newConn(rwc net.Conn, handler Handler) (c *Conn, err os.Error) {
-	c = new(Conn)
-	if a := rwc.RemoteAddr(); a != nil {
-		c.RemoteAddr = a.String()
-	}
+func newConn(rwc net.Conn, handler Handler) (c *conn, err os.Error) {
+	c = new(conn)
+	c.remoteAddr = rwc.RemoteAddr().String()
 	c.handler = handler
 	c.rwc = rwc
 	_, c.usingTLS = rwc.(*tls.Conn)
@@ -89,17 +133,15 @@ func newConn(rwc net.Conn, handler Handler) (c *Conn, err os.Error) {
 // wrapper around io.ReaderCloser which on first read, sends an
 // HTTP/1.1 100 Continue header
 type expectContinueReader struct {
-	conn       *Conn
+	resp       *response
 	readCloser io.ReadCloser
 }
 
 func (ecr *expectContinueReader) Read(p []byte) (n int, err os.Error) {
-	if !ecr.conn.wroteContinue && !ecr.conn.hijacked {
-		ecr.conn.wroteContinue = true
-		if ecr.conn.Req.ProtoAtLeast(1, 1) {
-			io.WriteString(ecr.conn.buf, "HTTP/1.1 100 Continue\r\n\r\n")
-			ecr.conn.buf.Flush()
-		}
+	if !ecr.resp.wroteContinue && !ecr.resp.conn.hijacked {
+		ecr.resp.wroteContinue = true
+		io.WriteString(ecr.resp.conn.buf, "HTTP/1.1 100 Continue\r\n\r\n")
+		ecr.resp.conn.buf.Flush()
 	}
 	return ecr.readCloser.Read(p)
 }
@@ -115,92 +157,80 @@ func (ecr *expectContinueReader) Close() os.Error {
 const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
 
 // Read next request from connection.
-func (c *Conn) readRequest() (req *Request, err os.Error) {
+func (c *conn) readRequest() (w *response, err os.Error) {
 	if c.hijacked {
 		return nil, ErrHijacked
 	}
+	var req *Request
 	if req, err = ReadRequest(c.buf.Reader); err != nil {
 		return nil, err
 	}
 
-	// Reset per-request connection state.
-	c.header = make(map[string]string)
-	c.wroteHeader = false
-	c.wroteContinue = false
-	c.Req = req
+	w = new(response)
+	w.conn = c
+	w.req = req
+	w.header = make(map[string]string)
 
 	// Expect 100 Continue support
-	if req.expectsContinue() {
+	if req.expectsContinue() && req.ProtoAtLeast(1, 1) {
 		// Wrap the Body reader with one that replies on the connection
-		req.Body = &expectContinueReader{readCloser: req.Body, conn: c}
+		req.Body = &expectContinueReader{readCloser: req.Body, resp: w}
 	}
 
 	// Default output is HTML encoded in UTF-8.
-	c.SetHeader("Content-Type", "text/html; charset=utf-8")
-	c.SetHeader("Date", time.UTC().Format(TimeFormat))
+	w.SetHeader("Content-Type", "text/html; charset=utf-8")
+	w.SetHeader("Date", time.UTC().Format(TimeFormat))
 
 	if req.ProtoAtLeast(1, 1) {
 		// HTTP/1.1 or greater: use chunked transfer encoding
 		// to avoid closing the connection at EOF.
-		c.chunking = true
-		c.SetHeader("Transfer-Encoding", "chunked")
+		w.chunking = true
+		w.SetHeader("Transfer-Encoding", "chunked")
 	} else {
 		// HTTP version < 1.1: cannot do chunked transfer
 		// encoding, so signal EOF by closing connection.
 		// Will be overridden if the HTTP handler ends up
 		// writing a Content-Length and the client requested
 		// "Connection: keep-alive"
-		c.closeAfterReply = true
-		c.chunking = false
+		w.closeAfterReply = true
 	}
 
-	return req, nil
+	return w, nil
 }
 
-// UsingTLS returns true if the connection uses transport layer security (TLS).
-func (c *Conn) UsingTLS() bool {
-	return c.usingTLS
+// UsingTLS implements the ResponseWriter.UsingTLS
+func (w *response) UsingTLS() bool {
+	return w.conn.usingTLS
 }
 
-// SetHeader sets a header line in the eventual reply.
-// For example, SetHeader("Content-Type", "text/html; charset=utf-8")
-// will result in the header line
-//
-//	Content-Type: text/html; charset=utf-8
-//
-// being sent.  UTF-8 encoded HTML is the default setting for
-// Content-Type in this library, so users need not make that
-// particular call.  Calls to SetHeader after WriteHeader (or Write)
-// are ignored.
-func (c *Conn) SetHeader(hdr, val string) { c.header[CanonicalHeaderKey(hdr)] = val }
-
-// WriteHeader sends an HTTP response header with status code.
-// If WriteHeader is not called explicitly, the first call to Write
-// will trigger an implicit WriteHeader(http.StatusOK).
-// Thus explicit calls to WriteHeader are mainly used to
-// send error codes.
-func (c *Conn) WriteHeader(code int) {
-	if c.hijacked {
-		log.Stderr("http: Conn.WriteHeader on hijacked connection")
+// RemoteAddr implements the ResponseWriter.RemoteAddr method
+func (w *response) RemoteAddr() string { return w.conn.remoteAddr }
+
+// SetHeader implements the ResponseWriter.SetHeader method
+func (w *response) SetHeader(hdr, val string) { w.header[CanonicalHeaderKey(hdr)] = val }
+
+// WriteHeader implements the ResponseWriter.WriteHeader method
+func (w *response) WriteHeader(code int) {
+	if w.conn.hijacked {
+		log.Stderr("http: response.WriteHeader on hijacked connection")
 		return
 	}
-	if c.wroteHeader {
-		log.Stderr("http: multiple Conn.WriteHeader calls")
+	if w.wroteHeader {
+		log.Stderr("http: multiple response.WriteHeader calls")
 		return
 	}
-	c.wroteHeader = true
-	c.status = code
+	w.wroteHeader = true
+	w.status = code
 	if code == StatusNotModified {
 		// Must not have body.
-		c.header["Content-Type"] = "", false
-		c.header["Transfer-Encoding"] = "", false
+		w.header["Content-Type"] = "", false
+		w.header["Transfer-Encoding"] = "", false
 	}
-	c.written = 0
-	if !c.Req.ProtoAtLeast(1, 0) {
+	if !w.req.ProtoAtLeast(1, 0) {
 		return
 	}
 	proto := "HTTP/1.0"
-	if c.Req.ProtoAtLeast(1, 1) {
+	if w.req.ProtoAtLeast(1, 1) {
 		proto = "HTTP/1.1"
 	}
 	codestring := strconv.Itoa(code)
@@ -208,57 +238,55 @@ func (c *Conn) WriteHeader(code int) {
 	if !ok {
 		text = "status code " + codestring
 	}
-	io.WriteString(c.buf, proto+" "+codestring+" "+text+"\r\n")
-	for k, v := range c.header {
-		io.WriteString(c.buf, k+": "+v+"\r\n")
+	io.WriteString(w.conn.buf, proto+" "+codestring+" "+text+"\r\n")
+	for k, v := range w.header {
+		io.WriteString(w.conn.buf, k+": "+v+"\r\n")
 	}
-	io.WriteString(c.buf, "\r\n")
+	io.WriteString(w.conn.buf, "\r\n")
 }
 
-// Write writes the data to the connection as part of an HTTP reply.
-// If WriteHeader has not yet been called, Write calls WriteHeader(http.StatusOK)
-// before writing the data.
-func (c *Conn) Write(data []byte) (n int, err os.Error) {
-	if c.hijacked {
-		log.Stderr("http: Conn.Write on hijacked connection")
+// Write implements the ResponseWriter.Write method
+func (w *response) Write(data []byte) (n int, err os.Error) {
+	if w.conn.hijacked {
+		log.Stderr("http: response.Write on hijacked connection")
 		return 0, ErrHijacked
 	}
-	if !c.wroteHeader {
-		if c.Req.wantsHttp10KeepAlive() {
-			_, hasLength := c.header["Content-Length"]
+	if !w.wroteHeader {
+		if w.req.wantsHttp10KeepAlive() {
+			_, hasLength := w.header["Content-Length"]
 			if hasLength {
-				_, connectionHeaderSet := c.header["Connection"]
+				_, connectionHeaderSet := w.header["Connection"]
 				if !connectionHeaderSet {
-					c.header["Connection"] = "keep-alive"
+					w.header["Connection"] = "keep-alive"
 				}
 			}
 		}
-		c.WriteHeader(StatusOK)
+		w.WriteHeader(StatusOK)
 	}
 	if len(data) == 0 {
 		return 0, nil
 	}
 
-	if c.status == StatusNotModified {
+	if w.status == StatusNotModified {
 		// Must not have body.
 		return 0, ErrBodyNotAllowed
 	}
 
-	c.written += int64(len(data)) // ignoring errors, for errorKludge
+	w.written += int64(len(data)) // ignoring errors, for errorKludge
 
 	// TODO(rsc): if chunking happened after the buffering,
 	// then there would be fewer chunk headers.
 	// On the other hand, it would make hijacking more difficult.
-	if c.chunking {
-		fmt.Fprintf(c.buf, "%x\r\n", len(data)) // TODO(rsc): use strconv not fmt
+	if w.chunking {
+		fmt.Fprintf(w.conn.buf, "%x\r\n", len(data)) // TODO(rsc): use strconv not fmt
 	}
-	n, err = c.buf.Write(data)
-	if err == nil && c.chunking {
+	n, err = w.conn.buf.Write(data)
+	if err == nil && w.chunking {
 		if n != len(data) {
 			err = io.ErrShortWrite
 		}
 		if err == nil {
-			io.WriteString(c.buf, "\r\n")
+			io.WriteString(w.conn.buf, "\r\n")
 		}
 	}
 
@@ -272,22 +300,22 @@ func (c *Conn) Write(data []byte) (n int, err os.Error) {
 // long enough.  The minimum lengths used in those
 // browsers are in the 256-512 range.
 // Pad to 1024 bytes.
-func errorKludge(c *Conn, req *Request) {
+func errorKludge(w *response) {
 	const min = 1024
 
 	// Is this an error?
-	if kind := c.status / 100; kind != 4 && kind != 5 {
+	if kind := w.status / 100; kind != 4 && kind != 5 {
 		return
 	}
 
 	// Did the handler supply any info?  Enough?
-	if c.written == 0 || c.written >= min {
+	if w.written == 0 || w.written >= min {
 		return
 	}
 
 	// Is it a broken browser?
 	var msg string
-	switch agent := req.UserAgent; {
+	switch agent := w.req.UserAgent; {
 	case strings.Index(agent, "MSIE") >= 0:
 		msg = "Internet Explorer"
 	case strings.Index(agent, "Chrome/") >= 0:
@@ -298,53 +326,53 @@ func errorKludge(c *Conn, req *Request) {
 	msg += " would ignore this error page if this text weren't here.\n"
 
 	// Is it text?  ("Content-Type" is always in the map)
-	baseType := strings.Split(c.header["Content-Type"], ";", 2)[0]
+	baseType := strings.Split(w.header["Content-Type"], ";", 2)[0]
 	switch baseType {
 	case "text/html":
-		io.WriteString(c, "<!-- ")
-		for c.written < min {
-			io.WriteString(c, msg)
+		io.WriteString(w, "<!-- ")
+		for w.written < min {
+			io.WriteString(w, msg)
 		}
-		io.WriteString(c, " -->")
+		io.WriteString(w, " -->")
 	case "text/plain":
-		io.WriteString(c, "\n")
-		for c.written < min {
-			io.WriteString(c, msg)
+		io.WriteString(w, "\n")
+		for w.written < min {
+			io.WriteString(w, msg)
 		}
 	}
 }
 
-func (c *Conn) finishRequest() {
+func (w *response) finishRequest() {
 	// If this was an HTTP/1.0 request with keep-alive and we sent a Content-Length
 	// back, we can make this a keep-alive response ...
-	if c.Req.wantsHttp10KeepAlive() {
-		_, sentLength := c.header["Content-Length"]
-		if sentLength && c.header["Connection"] == "keep-alive" {
-			c.closeAfterReply = false
+	if w.req.wantsHttp10KeepAlive() {
+		_, sentLength := w.header["Content-Length"]
+		if sentLength && w.header["Connection"] == "keep-alive" {
+			w.closeAfterReply = false
 		}
 	}
-	if !c.wroteHeader {
-		c.WriteHeader(StatusOK)
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
 	}
-	errorKludge(c, c.Req)
-	if c.chunking {
-		io.WriteString(c.buf, "0\r\n")
+	errorKludge(w)
+	if w.chunking {
+		io.WriteString(w.conn.buf, "0\r\n")
 		// trailer key/value pairs, followed by blank line
-		io.WriteString(c.buf, "\r\n")
+		io.WriteString(w.conn.buf, "\r\n")
 	}
-	c.buf.Flush()
+	w.conn.buf.Flush()
 }
 
-// Flush sends any buffered data to the client.
-func (c *Conn) Flush() {
-	if !c.wroteHeader {
-		c.WriteHeader(StatusOK)
+// Flush implements the ResponseWriter.Flush method.
+func (w *response) Flush() {
+	if !w.wroteHeader {
+		w.WriteHeader(StatusOK)
 	}
-	c.buf.Flush()
+	w.conn.buf.Flush()
 }
 
 // Close the connection.
-func (c *Conn) close() {
+func (c *conn) close() {
 	if c.buf != nil {
 		c.buf.Flush()
 		c.buf = nil
@@ -356,9 +384,9 @@ func (c *Conn) close() {
 }
 
 // Serve a new connection.
-func (c *Conn) serve() {
+func (c *conn) serve() {
 	for {
-		req, err := c.readRequest()
+		w, err := c.readRequest()
 		if err != nil {
 			break
 		}
@@ -367,32 +395,28 @@ func (c *Conn) serve() {
 		// so we might as well run the handler in this goroutine.
 		// [*] Not strictly true: HTTP pipelining.  We could let them all process
 		// in parallel even if their responses need to be serialized.
-		c.handler.ServeHTTP(c, req)
+		c.handler.ServeHTTP(w, w.req)
 		if c.hijacked {
 			return
 		}
-		c.finishRequest()
-		if c.closeAfterReply {
+		w.finishRequest()
+		if w.closeAfterReply {
 			break
 		}
 	}
 	c.close()
 }
 
-// Hijack lets the caller take over the connection.
-// After a call to c.Hijack(), the HTTP server library
-// will not do anything else with the connection.
-// It becomes the caller's responsibility to manage
-// and close the connection.
-func (c *Conn) Hijack() (rwc io.ReadWriteCloser, buf *bufio.ReadWriter, err os.Error) {
-	if c.hijacked {
+// Hijack impements the ResponseWriter.Hijack method.
+func (w *response) Hijack() (rwc io.ReadWriteCloser, buf *bufio.ReadWriter, err os.Error) {
+	if w.conn.hijacked {
 		return nil, nil, ErrHijacked
 	}
-	c.hijacked = true
-	rwc = c.rwc
-	buf = c.buf
-	c.rwc = nil
-	c.buf = nil
+	w.conn.hijacked = true
+	rwc = w.conn.rwc
+	buf = w.conn.buf
+	w.conn.rwc = nil
+	w.conn.buf = nil
 	return
 }
 
@@ -400,24 +424,24 @@ func (c *Conn) Hijack() (rwc io.ReadWriteCloser, buf *bufio.ReadWriter, err os.E
 // ordinary functions as HTTP handlers.  If f is a function
 // with the appropriate signature, HandlerFunc(f) is a
 // Handler object that calls f.
-type HandlerFunc func(*Conn, *Request)
+type HandlerFunc func(ResponseWriter, *Request)
 
 // ServeHTTP calls f(c, req).
-func (f HandlerFunc) ServeHTTP(c *Conn, req *Request) {
-	f(c, req)
+func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
+	f(w, r)
 }
 
 // Helper handlers
 
 // Error replies to the request with the specified error message and HTTP code.
-func Error(c *Conn, error string, code int) {
-	c.SetHeader("Content-Type", "text/plain; charset=utf-8")
-	c.WriteHeader(code)
-	fmt.Fprintln(c, error)
+func Error(w ResponseWriter, error string, code int) {
+	w.SetHeader("Content-Type", "text/plain; charset=utf-8")
+	w.WriteHeader(code)
+	fmt.Fprintln(w, error)
 }
 
 // NotFound replies to the request with an HTTP 404 not found error.
-func NotFound(c *Conn, req *Request) { Error(c, "404 page not found", StatusNotFound) }
+func NotFound(w ResponseWriter, r *Request) { Error(w, "404 page not found", StatusNotFound) }
 
 // NotFoundHandler returns a simple request handler
 // that replies to each request with a ``404 page not found'' reply.
@@ -425,11 +449,11 @@ func NotFoundHandler() Handler { return HandlerFunc(NotFound) }
 
 // Redirect replies to the request with a redirect to url,
 // which may be a path relative to the request path.
-func Redirect(c *Conn, url string, code int) {
+func Redirect(w ResponseWriter, r *Request, url string, code int) {
 	// RFC2616 recommends that a short note "SHOULD" be included in the
 	// response because older user agents may not understand 301/307.
 	note := "<a href=\"%v\">" + statusText[code] + "</a>.\n"
-	if c.Req.Method == "POST" {
+	if r.Method == "POST" {
 		note = ""
 	}
 
@@ -454,7 +478,7 @@ func Redirect(c *Conn, url string, code int) {
 	// Because of this problem, no one pays attention
 	// to the RFC; they all send back just a new path.
 	// So do we.
-	oldpath := c.Req.URL.Path
+	oldpath := r.URL.Path
 	if oldpath == "" { // should not happen, but avoid a crash if it does
 		oldpath = "/"
 	}
@@ -475,9 +499,9 @@ func Redirect(c *Conn, url string, code int) {
 	}
 
 finish:
-	c.SetHeader("Location", url)
-	c.WriteHeader(code)
-	fmt.Fprintf(c, note, url)
+	w.SetHeader("Location", url)
+	w.WriteHeader(code)
+	fmt.Fprintf(w, note, url)
 }
 
 // Redirect to a fixed URL
@@ -486,8 +510,8 @@ type redirectHandler struct {
 	code int
 }
 
-func (rh *redirectHandler) ServeHTTP(c *Conn, req *Request) {
-	Redirect(c, rh.url, rh.code)
+func (rh *redirectHandler) ServeHTTP(w ResponseWriter, r *Request) {
+	Redirect(w, r, rh.url, rh.code)
 }
 
 // RedirectHandler returns a request handler that redirects
@@ -563,11 +587,11 @@ func cleanPath(p string) string {
 
 // ServeHTTP dispatches the request to the handler whose
 // pattern most closely matches the request URL.
-func (mux *ServeMux) ServeHTTP(c *Conn, req *Request) {
+func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request) {
 	// Clean path to canonical form and redirect.
-	if p := cleanPath(req.URL.Path); p != req.URL.Path {
-		c.SetHeader("Location", p)
-		c.WriteHeader(StatusMovedPermanently)
+	if p := cleanPath(r.URL.Path); p != r.URL.Path {
+		w.SetHeader("Location", p)
+		w.WriteHeader(StatusMovedPermanently)
 		return
 	}
 
@@ -575,7 +599,7 @@ func (mux *ServeMux) ServeHTTP(c *Conn, req *Request) {
 	var h Handler
 	var n = 0
 	for k, v := range mux.m {
-		if !pathMatch(k, req.URL.Path) {
+		if !pathMatch(k, r.URL.Path) {
 			continue
 		}
 		if h == nil || len(k) > n {
@@ -586,7 +610,7 @@ func (mux *ServeMux) ServeHTTP(c *Conn, req *Request) {
 	if h == nil {
 		h = NotFoundHandler()
 	}
-	h.ServeHTTP(c, req)
+	h.ServeHTTP(w, r)
 }
 
 // Handle registers the handler for the given pattern.
@@ -606,7 +630,7 @@ func (mux *ServeMux) Handle(pattern string, handler Handler) {
 }
 
 // HandleFunc registers the handler function for the given pattern.
-func (mux *ServeMux) HandleFunc(pattern string, handler func(*Conn, *Request)) {
+func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
 	mux.Handle(pattern, HandlerFunc(handler))
 }
 
@@ -616,7 +640,7 @@ func Handle(pattern string, handler Handler) { DefaultServeMux.Handle(pattern, h
 
 // HandleFunc registers the handler function for the given pattern
 // in the DefaultServeMux.
-func HandleFunc(pattern string, handler func(*Conn, *Request)) {
+func HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
 	DefaultServeMux.HandleFunc(pattern, handler)
 }
 
@@ -658,8 +682,8 @@ func Serve(l net.Listener, handler Handler) os.Error {
 //	)
 //
 //	// hello world, the web server
-//	func HelloServer(c *http.Conn, req *http.Request) {
-//		io.WriteString(c, "hello, world!\n")
+//	func HelloServer(w http.ResponseWriter, req *http.Request) {
+//		io.WriteString(w, "hello, world!\n")
 //	}
 //
 //	func main() {
@@ -690,9 +714,9 @@ func ListenAndServe(addr string, handler Handler) os.Error {
 //		"log"
 //	)
 //
-//	func handler(conn *http.Conn, req *http.Request) {
-//		conn.SetHeader("Content-Type", "text/plain")
-//		conn.Write([]byte("This is an example server.\n"))
+//	func handler(w http.ResponseWriter, req *http.Request) {
+//		w.SetHeader("Content-Type", "text/plain")
+//		w.Write([]byte("This is an example server.\n"))
 //	}
 //
 //	func main() {
diff --git a/src/pkg/http/status.go b/src/pkg/http/status.go
index 82a66d7ad7..b6e2d65c6a 100644
--- a/src/pkg/http/status.go
+++ b/src/pkg/http/status.go
@@ -98,3 +98,9 @@ var statusText = map[int]string{
 	StatusGatewayTimeout:          "Gateway Timeout",
 	StatusHTTPVersionNotSupported: "HTTP Version Not Supported",
 }
+
+// StatusText returns a text for the HTTP status code. It returns the empty
+// string if the code is unknown.
+func StatusText(code int) string {
+	return statusText[code]
+}
diff --git a/src/pkg/rpc/debug.go b/src/pkg/rpc/debug.go
index 638584f497..e1e53f0905 100644
--- a/src/pkg/rpc/debug.go
+++ b/src/pkg/rpc/debug.go
@@ -62,7 +62,7 @@ func (m methodArray) Less(i, j int) bool { return m[i].name < m[j].name }
 func (m methodArray) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }
 
 // Runs at /debug/rpc
-func debugHTTP(c *http.Conn, req *http.Request) {
+func debugHTTP(w http.ResponseWriter, req *http.Request) {
 	// Build a sorted version of the data.
 	var services = make(serviceArray, len(server.serviceMap))
 	i := 0
@@ -79,8 +79,8 @@ func debugHTTP(c *http.Conn, req *http.Request) {
 	}
 	server.Unlock()
 	sort.Sort(services)
-	err := debug.Execute(services, c)
+	err := debug.Execute(services, w)
 	if err != nil {
-		fmt.Fprintln(c, "rpc: error executing template:", err.String())
+		fmt.Fprintln(w, "rpc: error executing template:", err.String())
 	}
 }
diff --git a/src/pkg/rpc/server.go b/src/pkg/rpc/server.go
index 91b88e23de..db46e35db7 100644
--- a/src/pkg/rpc/server.go
+++ b/src/pkg/rpc/server.go
@@ -445,16 +445,16 @@ var rpcPath string = "/_goRPC_"
 var debugPath string = "/debug/rpc"
 var connected = "200 Connected to Go RPC"
 
-func serveHTTP(c *http.Conn, req *http.Request) {
+func serveHTTP(w http.ResponseWriter, req *http.Request) {
 	if req.Method != "CONNECT" {
-		c.SetHeader("Content-Type", "text/plain; charset=utf-8")
-		c.WriteHeader(http.StatusMethodNotAllowed)
-		io.WriteString(c, "405 must CONNECT to "+rpcPath+"\n")
+		w.SetHeader("Content-Type", "text/plain; charset=utf-8")
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		io.WriteString(w, "405 must CONNECT to "+rpcPath+"\n")
 		return
 	}
-	conn, _, err := c.Hijack()
+	conn, _, err := w.Hijack()
 	if err != nil {
-		log.Stderr("rpc hijacking ", c.RemoteAddr, ": ", err.String())
+		log.Stderr("rpc hijacking ", w.RemoteAddr(), ": ", err.String())
 		return
 	}
 	io.WriteString(conn, "HTTP/1.0 "+connected+"\n\n")
diff --git a/src/pkg/websocket/server.go b/src/pkg/websocket/server.go
index b884884fa5..dd797f24e0 100644
--- a/src/pkg/websocket/server.go
+++ b/src/pkg/websocket/server.go
@@ -57,8 +57,8 @@ func getKeyNumber(s string) (r uint32) {
 }
 
 // ServeHTTP implements the http.Handler interface for a Web Socket
-func (f Handler) ServeHTTP(c *http.Conn, req *http.Request) {
-	rwc, buf, err := c.Hijack()
+func (f Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	rwc, buf, err := w.Hijack()
 	if err != nil {
 		panic("Hijack failed: " + err.String())
 		return
@@ -98,7 +98,7 @@ func (f Handler) ServeHTTP(c *http.Conn, req *http.Request) {
 	}
 
 	var location string
-	if c.UsingTLS() {
+	if w.UsingTLS() {
 		location = "wss://" + req.Host + req.URL.RawPath
 	} else {
 		location = "ws://" + req.Host + req.URL.RawPath
@@ -161,30 +161,30 @@ Draft75Handler is an interface to a WebSocket based on the
 type Draft75Handler func(*Conn)
 
 // ServeHTTP implements the http.Handler interface for a Web Socket.
-func (f Draft75Handler) ServeHTTP(c *http.Conn, req *http.Request) {
+func (f Draft75Handler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	if req.Method != "GET" || req.Proto != "HTTP/1.1" {
-		c.WriteHeader(http.StatusBadRequest)
-		io.WriteString(c, "Unexpected request")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "Unexpected request")
 		return
 	}
 	if req.Header["Upgrade"] != "WebSocket" {
-		c.WriteHeader(http.StatusBadRequest)
-		io.WriteString(c, "missing Upgrade: WebSocket header")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "missing Upgrade: WebSocket header")
 		return
 	}
 	if req.Header["Connection"] != "Upgrade" {
-		c.WriteHeader(http.StatusBadRequest)
-		io.WriteString(c, "missing Connection: Upgrade header")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "missing Connection: Upgrade header")
 		return
 	}
 	origin, found := req.Header["Origin"]
 	if !found {
-		c.WriteHeader(http.StatusBadRequest)
-		io.WriteString(c, "missing Origin header")
+		w.WriteHeader(http.StatusBadRequest)
+		io.WriteString(w, "missing Origin header")
 		return
 	}
 
-	rwc, buf, err := c.Hijack()
+	rwc, buf, err := w.Hijack()
 	if err != nil {
 		panic("Hijack failed: " + err.String())
 		return
@@ -192,7 +192,7 @@ func (f Draft75Handler) ServeHTTP(c *http.Conn, req *http.Request) {
 	defer rwc.Close()
 
 	var location string
-	if c.UsingTLS() {
+	if w.UsingTLS() {
 		location = "wss://" + req.Host + req.URL.RawPath
 	} else {
 		location = "ws://" + req.Host + req.URL.RawPath