streamclone: add support for bundle2 based stream clone

The feature put to use the various bits introduced previously. If the server
supports it, the client will request its stream clone through bundle2 instead of
the legacy 'stream_out' commands. The bundle2 version use the better 'v2'
version of stream bundles.

The 'v2' format is not finalized yet. Now that there are some code running it,
we can start working on it again.

Performance numbers are available at the end of this series.

mercurial/bundle2.py

@@ -1487,6 +1487,7 b" capabilities = {'HG20': (),"
                 'remote-changegroup': ('http', 'https'),
                 'hgtagsfnodes': (),
                 'phases': ('heads',),
+                'stream': ('v2',),
                }
 
 def getrepocaps(repo, allowpushback=False):
@@ -1507,6 +1508,8 b' def getrepocaps(repo, allowpushback=Fals'
         caps['checkheads'] = ('related',)
     if 'phases' in repo.ui.configlist('devel', 'legacy.exchange'):
         caps.pop('phases')
+    if not repo.ui.configbool('experimental', 'bundle2.stream'):
+        caps.pop('stream')
     return caps
 
 def bundle2caps(remote):

mercurial/configitems.py

@@ -431,6 +431,9 b" coreconfigitem('experimental', 'bundle2-"
 coreconfigitem('experimental', 'bundle2.pushback',
     default=False,
 )
+coreconfigitem('experimental', 'bundle2.stream',
+    default=False,
+)
 coreconfigitem('experimental', 'bundle2lazylocking',
     default=False,
 )

mercurial/exchange.py

@@ -1455,13 +1455,18 b' def _pullbundle2(pullop):'
 
     # At the moment we don't do stream clones over bundle2. If that is
     # implemented then here's where the check for that will go.
-    streaming = False
+    streaming = streamclone.canperformstreamclone(pullop, bundle2=True)[0]
 
     # declare pull perimeters
     kwargs['common'] = pullop.common
     kwargs['heads'] = pullop.heads or pullop.rheads
 
-    if True:
+    if streaming:
+        kwargs['cg'] = False
+        kwargs['stream'] = True
+        pullop.stepsdone.add('changegroup')
+
+    else:
         # pulling changegroup
         pullop.stepsdone.add('changegroup')
 

tests/test-clone-uncompressed.t

@@ -1,5 +1,14 b''
 #require serve
 
+#testcases stream-legacy stream-bundle2
+
+#if stream-bundle2
+  $ cat << EOF >> $HGRCPATH
+  > [experimental]
+  > bundle2.stream = yes
+  > EOF
+#endif
+
 Initialize repository
 the status call is to check for issue5130
 
@@ -18,24 +27,41 b' the status call is to check for issue513'
 
 Basic clone
 
+#if stream-legacy
   $ hg clone --stream -U http://localhost:$HGPORT clone1
   streaming all changes
   1027 files to transfer, 96.3 KB of data
   transferred 96.3 KB in * seconds (*/sec) (glob)
   searching for changes
   no changes found
+#endif
+#if stream-bundle2
+  $ hg clone --stream -U http://localhost:$HGPORT clone1
+  streaming all changes
+  1027 files to transfer, 96.3 KB of data
+  transferred 96.3 KB in * seconds (* */sec) (glob)
+#endif
 
 --uncompressed is an alias to --stream
 
+#if stream-legacy
   $ hg clone --uncompressed -U http://localhost:$HGPORT clone1-uncompressed
   streaming all changes
   1027 files to transfer, 96.3 KB of data
   transferred 96.3 KB in * seconds (*/sec) (glob)
   searching for changes
   no changes found
+#endif
+#if stream-bundle2
+  $ hg clone --uncompressed -U http://localhost:$HGPORT clone1-uncompressed
+  streaming all changes
+  1027 files to transfer, 96.3 KB of data
+  transferred 96.3 KB in * seconds (* */sec) (glob)
+#endif
 
 Clone with background file closing enabled
 
+#if stream-legacy
   $ hg --debug --config worker.backgroundclose=true --config worker.backgroundcloseminfilecount=1 clone --stream -U http://localhost:$HGPORT clone-background | grep -v adding
   using http://localhost:$HGPORT/
   sending capabilities command
@@ -57,6 +83,28 b' Clone with background file closing enabl'
   bundle2-input-part: total payload size 24
   bundle2-input-bundle: 1 parts total
   checking for updated bookmarks
+#endif
+#if stream-bundle2
+  $ hg --debug --config worker.backgroundclose=true --config worker.backgroundcloseminfilecount=1 clone --stream -U http://localhost:$HGPORT clone-background | grep -v adding
+  using http://localhost:$HGPORT/
+  sending capabilities command
+  query 1; heads
+  sending batch command
+  streaming all changes
+  sending getbundle command
+  bundle2-input-bundle: with-transaction
+  bundle2-input-part: "stream" (params: 4 mandatory) supported
+  applying stream bundle
+  1027 files to transfer, 96.3 KB of data
+  starting 4 threads for background file closing
+  transferred 96.3 KB in * seconds (* */sec) (glob)
+  bundle2-input-part: total payload size 110887
+  bundle2-input-part: "listkeys" (params: 1 mandatory) supported
+  bundle2-input-part: "phase-heads" supported
+  bundle2-input-part: total payload size 24
+  bundle2-input-bundle: 2 parts total
+  checking for updated bookmarks
+#endif
 
 Cannot stream clone when there are secret changesets
 
@@ -79,12 +127,20 b' Streaming of secrets can be overridden b'
   $ cat hg.pid > $DAEMON_PIDS
   $ cd ..
 
+#if stream-legacy
   $ hg clone --stream -U http://localhost:$HGPORT secret-allowed
   streaming all changes
   1027 files to transfer, 96.3 KB of data
   transferred 96.3 KB in * seconds (*/sec) (glob)
   searching for changes
   no changes found
+#endif
+#if stream-bundle2
+  $ hg clone --stream -U http://localhost:$HGPORT secret-allowed
+  streaming all changes
+  1027 files to transfer, 96.3 KB of data
+  transferred 96.3 KB in * seconds (* */sec) (glob)
+#endif
 
   $ killdaemons.py
 
@@ -186,6 +242,7 b' add a bookmark'
 
 clone it
 
+#if stream-legacy
   $ hg clone --stream http://localhost:$HGPORT with-bookmarks
   streaming all changes
   1027 files to transfer, 96.3 KB of data
@@ -194,5 +251,14 b' clone it'
   no changes found
   updating to branch default
   1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
+#endif
+#if stream-bundle2
+  $ hg clone --stream http://localhost:$HGPORT with-bookmarks
+  streaming all changes
+  1027 files to transfer, 96.3 KB of data
+  transferred 96.3 KB in * seconds (* */sec) (glob)
+  updating to branch default
+  1025 files updated, 0 files merged, 0 files removed, 0 files unresolved
+#endif
   $ hg -R with-bookmarks bookmarks
      some-bookmark             1:c17445101a72