code review 2051041: http: add Date to server, Last-Modified and If-Modified...

src/pkg/http/server.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.
 
 // HTTP server.  See RFC 2616.
 
 // TODO(rsc):
 //      logging
 //      cgi support
 //      post support
@@ skipping 83 matching lines @@
                         ecr.conn.buf.Flush()
                 }
         }
         return ecr.readCloser.Read(p)
 }
 
 func (ecr *expectContinueReader) Close() os.Error {
         return ecr.readCloser.Close()
 }
 
+// TimeFormat is the time format to use with
+// time.Parse and time.Time.Format when parsing
+// or generating times in HTTP headers.
+// It is like time.RFC1123 but hard codes GMT as the time zone.
+const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
+
 // Read next request from connection.
 func (c *Conn) readRequest() (req *Request, err os.Error) {
         if c.hijacked {
                 return nil, ErrHijacked
         }
         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
 
         // Expect 100 Continue support
         if req.expectsContinue() {
                 // Wrap the Body reader with one that replies on the connection
                 req.Body = &expectContinueReader{readCloser: req.Body, conn: c}
         }
 
         // Default output is HTML encoded in UTF-8.
         c.SetHeader("Content-Type", "text/html; charset=utf-8")
+        c.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")
         } else {
                 // HTTP version < 1.1: cannot do chunked transfer
                 // encoding, so signal EOF by closing connection.
                 // Could avoid closing the connection if there is
@@ skipping 546 matching lines @@
         }
 
         conn, err := net.Listen("tcp", addr)
         if err != nil {
                 return err
         }
 
         tlsListener := tls.NewListener(conn, config)
         return Serve(tlsListener, handler)
 }