http server: support persistent connections.

http server: support persistent connections.

only "hg serve" affected yet.  http server running cgi script will not
use persistent connections.  support for fastcgi will help that.

clients that support keepalive can use one tcp connection for all
commands during clone and pull.  this makes latency of binary search
during pull much lower over wan.

if server does not know content-length, it will force connection to
close at end.  right fix is to use chunked transfer-encoding but this is
easier and does not hurt performance. only command that is affected is
"changegroup" which is always last command during a pull.

--- a/mercurial/hgweb/hgweb_mod.py	Wed Jun 14 15:41:37 2006 -0700
+++ b/mercurial/hgweb/hgweb_mod.py	Thu Jun 15 12:55:58 2006 -0700
@@ -10,7 +10,7 @@
 import os.path
 import mimetypes
 from mercurial.demandload import demandload
-demandload(globals(), "re zlib ConfigParser")
+demandload(globals(), "re zlib ConfigParser cStringIO")
 demandload(globals(), "mercurial:mdiff,ui,hg,util,archival,templater")
 demandload(globals(), "mercurial.hgweb.request:hgrequest")
 demandload(globals(), "mercurial.hgweb.common:get_mtime,staticfile")
@@ -761,26 +761,32 @@
                                    req.form['filenode'][0]))
 
         elif cmd == 'heads':
-            req.httphdr("application/mercurial-0.1")
-            h = self.repo.heads()
-            req.write(" ".join(map(hex, h)) + "\n")
+            resp = " ".join(map(hex, self.repo.heads())) + "\n"
+            req.httphdr("application/mercurial-0.1", length=len(resp))
+            req.write(resp)
 
         elif cmd == 'branches':
-            req.httphdr("application/mercurial-0.1")
             nodes = []
             if req.form.has_key('nodes'):
                 nodes = map(bin, req.form['nodes'][0].split(" "))
+            resp = cStringIO.StringIO()
             for b in self.repo.branches(nodes):
-                req.write(" ".join(map(hex, b)) + "\n")
+                resp.write(" ".join(map(hex, b)) + "\n")
+            resp = resp.getvalue()
+            req.httphdr("application/mercurial-0.1", length=len(resp))
+            req.write(resp)
 
         elif cmd == 'between':
-            req.httphdr("application/mercurial-0.1")
             nodes = []
             if req.form.has_key('pairs'):
                 pairs = [map(bin, p.split("-"))
                          for p in req.form['pairs'][0].split(" ")]
+            resp = cStringIO.StringIO()
             for b in self.repo.between(pairs):
-                req.write(" ".join(map(hex, b)) + "\n")
+                resp.write(" ".join(map(hex, b)) + "\n")
+            resp = resp.getvalue()
+            req.httphdr("application/mercurial-0.1", length=len(resp))
+            req.write(resp)
 
         elif cmd == 'changegroup':
             req.httphdr("application/mercurial-0.1")
@@ -819,3 +825,4 @@
 
         else:
             req.write(self.t("error"))
+        req.done()

--- a/mercurial/hgweb/request.py	Wed Jun 14 15:41:37 2006 -0700
+++ b/mercurial/hgweb/request.py	Thu Jun 15 12:55:58 2006 -0700
@@ -16,6 +16,7 @@
         self.out = out or sys.stdout
         self.env = env or os.environ
         self.form = cgi.parse(self.inp, self.env, keep_blank_values=1)
+        self.will_close = True
 
     def write(self, *things):
         for thing in things:
@@ -29,16 +30,30 @@
                     if inst[0] != errno.ECONNRESET:
                         raise
 
+    def done(self):
+        if self.will_close:
+            self.inp.close()
+            self.out.close()
+        else:
+            self.out.flush()
+
     def header(self, headers=[('Content-type','text/html')]):
         for header in headers:
             self.out.write("%s: %s\r\n" % header)
         self.out.write("\r\n")
 
-    def httphdr(self, type, file="", size=0):
+    def httphdr(self, type, filename=None, length=0):
 
         headers = [('Content-type', type)]
-        if file:
-            headers.append(('Content-disposition', 'attachment; filename=%s' % file))
-        if size > 0:
-            headers.append(('Content-length', str(size)))
+        if filename:
+            headers.append(('Content-disposition', 'attachment; filename=%s' %
+                            filename))
+        # we do not yet support http 1.1 chunked transfer, so we have
+        # to force connection to close if content-length not known
+        if length:
+            headers.append(('Content-length', str(length)))
+            self.will_close = False
+        else:
+            headers.append(('Connection', 'close'))
+            self.will_close = True
         self.header(headers)

--- a/mercurial/hgweb/server.py	Wed Jun 14 15:41:37 2006 -0700
+++ b/mercurial/hgweb/server.py	Thu Jun 15 12:55:58 2006 -0700
@@ -27,6 +27,7 @@
 
 class _hgwebhandler(object, BaseHTTPServer.BaseHTTPRequestHandler):
     def __init__(self, *args, **kargs):
+        self.protocol_version = 'HTTP/1.1'
         BaseHTTPServer.BaseHTTPRequestHandler.__init__(self, *args, **kargs)
 
     def log_error(self, format, *args):
@@ -85,7 +86,7 @@
 
         req = hgrequest(self.rfile, self.wfile, env)
         self.send_response(200, "Script output follows")
-        self.server.make_and_run_handler(req)
+        self.close_connection = self.server.make_and_run_handler(req)
 
 def create_server(ui, repo):
     use_threads = True
@@ -135,6 +136,7 @@
             else:
                 raise hg.RepoError(_('no repo found'))
             hgwebobj.run(req)
+            return req.will_close
 
     class IPv6HTTPServer(MercurialHTTPServer):
         address_family = getattr(socket, 'AF_INET6', None)