clone: disable stream support on server side by default.

enable in hgrc like this:
[server]
stream=True

doc/hgrc.5.txt

@@ -326,6 +326,18 b' paths::'
     Optional.  Directory or URL to use when pushing if no destination
     is specified.
 
+server::
+  Controls generic server settings.
+  stream;;
+    Whether to allow clients to clone a repo using the uncompressed
+    streaming protocol.  This transfers about 40% more data than a
+    regular clone, but uses less memory and CPU on both server and
+    client.  Over a LAN (100Mbps or better) or a very fast WAN, an
+    uncompressed streaming clone is a lot faster (~10x) than a regular
+    clone.  Over most WAN connections (anything slower than about
+    6Mbps), uncompressed streaming is slower, because of the extra
+    data transfer overhead.  Default is False.
+
 ui::
   User interface controls.
   debug;;

mercurial/hg.py

@@ -97,7 +97,8 b' def clone(ui, source, dest=None, pull=Fa'
 
     pull: always pull from source repository, even in local case
 
-    stream: stream from repository (fast over LAN, slow over WAN)
+    stream: stream raw data uncompressed from repository (fast over
+    LAN, slow over WAN)
 
     rev: revision to clone up to (implies pull=True)
 

mercurial/hgweb/hgweb_mod.py

@@ -860,7 +860,10 b' class hgweb(object):'
                   or self.t("error", error="%r not found" % fname))
 
     def do_capabilities(self, req):
-        resp = 'unbundle stream=%d' % (self.repo.revlogversion,)
+        caps = ['unbundle']
+        if self.repo.ui.configbool('server', 'stream'):
+            caps.append('stream=%d' % self.repo.revlogversion)
+        resp = ' '.join(caps)
         req.httphdr("application/mercurial-0.1", length=len(resp))
         req.write(resp)
 

mercurial/localrepo.py

@@ -2204,8 +2204,11 b' class localrepository(repo.repository):'
             return 1
 
     def stream_in(self, remote):
+        fp = remote.stream_out()
+        resp = int(fp.readline())
+        if resp != 0:
+            raise util.Abort(_('operation forbidden by server'))
         self.ui.status(_('streaming all changes\n'))
-        fp = remote.stream_out()
         total_files, total_bytes = map(int, fp.readline().split(' ', 1))
         self.ui.status(_('%d files to transfer, %s of data\n') %
                        (total_files, util.bytecount(total_bytes)))
@@ -2230,14 +2233,15 b' class localrepository(repo.repository):'
 
         keyword arguments:
         heads: list of revs to clone (forces use of pull)
-        pull: force use of pull, even if remote can stream'''
+        stream: use streaming clone if possible'''
 
-        # now, all clients that can stream can read repo formats
-        # supported by all servers that can stream.
+        # now, all clients that can request uncompressed clones can
+        # read repo formats supported by all servers that can serve
+        # them.
 
         # if revlog format changes, client will have to check version
-        # and format flags on "stream" capability, and stream only if
-        # compatible.
+        # and format flags on "stream" capability, and use
+        # uncompressed only if compatible.
 
         if stream and not heads and remote.capable('stream'):
             return self.stream_in(remote)

mercurial/sshserver.py

@@ -60,8 +60,10 b' class sshserver(object):'
         capabilities: space separated list of tokens
         '''
 
-        r = "capabilities: unbundle stream=%d\n" % (self.repo.revlogversion,)
-        self.respond(r)
+        caps = ['unbundle']
+        if self.ui.configbool('server', 'stream'):
+            caps.append('stream=%d' % self.repo.revlogversion)
+        self.respond("capabilities: %s\n" % (' '.join(caps),))
 
     def do_lock(self):
         '''DEPRECATED - allowing remote client to lock repo is not safe'''

mercurial/streamclone.py

@@ -59,6 +59,13 b' def walkrepo(root):'
 def stream_out(repo, fileobj):
     '''stream out all metadata files in repository.
     writes to file-like object, must support write() and optional flush().'''
+
+    if not repo.ui.configbool('server', 'stream'):
+        fileobj.write('1\n')
+        return
+
+    fileobj.write('0\n')
+
     # get consistent snapshot of repo. lock during scan so lock not
     # needed while we stream, and commits can happen.
     lock = repo.lock()

tests/test-http

@@ -1,23 +1,23 b''
 #!/bin/sh
 
-mkdir test
+hg init test
 cd test
 echo foo>foo
-hg init
-hg addremove
-hg commit -m 1
-hg verify
-hg serve -p 20059 -d --pid-file=hg.pid
-cat hg.pid >> $DAEMON_PIDS
+hg commit -A -d '0 0' -m 1
+hg --config server.stream=True serve -p 20059 -d --pid-file=hg1.pid
+cat hg1.pid >> $DAEMON_PIDS
+hg serve -p 20060 -d --pid-file=hg2.pid
+cat hg2.pid >> $DAEMON_PIDS
 cd ..
 
 echo % clone via stream
-http_proxy= hg clone --stream http://localhost:20059/ copy 2>&1 | \
+http_proxy= hg clone --uncompressed http://localhost:20059/ copy 2>&1 | \
   sed -e 's/[0-9][0-9.]*/XXX/g'
 cd copy
 hg verify
 
-cd ..
+echo % try to clone via stream, should use pull instead
+http_proxy= hg clone --uncompressed http://localhost:20060/ copy2
 
 echo % clone via pull
 http_proxy= hg clone http://localhost:20059/ copy-pull

tests/test-http-proxy

@@ -4,7 +4,7 b' hg init a'
 cd a
 echo a > a
 hg ci -Ama -d '1123456789 0'
-hg serve -p 20059 -d --pid-file=hg.pid
+hg --config server.stream=True serve -p 20059 -d --pid-file=hg.pid
 cat hg.pid >> $DAEMON_PIDS
 
 cd ..
@@ -14,7 +14,7 b' cat proxy.pid >> $DAEMON_PIDS'
 sleep 2
 
 echo %% url for proxy, stream
-http_proxy=http://localhost:20060/ hg --config http_proxy.always=True clone --stream http://localhost:20059/ b | \
+http_proxy=http://localhost:20060/ hg --config http_proxy.always=True clone --uncompressed http://localhost:20059/ b | \
   sed -e 's/[0-9][0-9.]*/XXX/g'
 cd b
 hg verify

tests/test-http.out

@@ -1,10 +1,4 b''
-(the addremove command is deprecated; use add and remove --after instead)
 adding foo
-checking changesets
-checking manifests
-crosschecking files in changesets and manifests
-checking files
-1 files, 1 changesets, 1 total revisions
 % clone via stream
 streaming all changes
 XXX files to transfer, XXX bytes of data
@@ -15,6 +9,13 b' checking manifests'
 crosschecking files in changesets and manifests
 checking files
 1 files, 1 changesets, 1 total revisions
+% try to clone via stream, should use pull instead
+requesting all changes
+adding changesets
+adding manifests
+adding file changes
+added 1 changesets with 1 changes to 1 files
+1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 % clone via pull
 requesting all changes
 adding changesets

tests/test-ssh

@@ -27,11 +27,13 b' hg init remote'
 cd remote
 echo this > foo
 hg ci -A -m "init" -d "1000000 0" foo
+echo '[server]' > .hg/hgrc
+echo 'stream = True' >> .hg/hgrc
 
 cd ..
 
 echo "# clone remote via stream"
-hg clone -e ./dummyssh --stream ssh://user@dummy/remote local-stream 2>&1 | \
+hg clone -e ./dummyssh --uncompressed ssh://user@dummy/remote local-stream 2>&1 | \
   sed -e 's/[0-9][0-9.]*/XXX/g'
 cd local-stream
 hg verify