exchange: perform stream clone with clone bundle with --uncompressed

exchange: perform stream clone with clone bundle with --uncompressed

Previously, `hg clone --uncompressed` would always clone from the
origin server, even if a streaming clone bundle were available.

With this change, we invoke the clone bundle mechanism before the
stream clone mechanism, giving clone bundles the opportunity to
handle --uncompressed (which is mapped to pullop.streamclonepreferred).

The clone bundle filtering code now filters out entries that aren't
stream clones when a stream clone is requested. If a stream clone
clone bundle entry is present, it will be used. Otherwise, the client
will fall back to a server-based streaming clone.

.. feature::

   `hg clone --uncompressed` uses clone bundles when possible

Differential Revision: https://phab.mercurial-scm.org/D833

--- a/mercurial/exchange.py	Thu Sep 28 12:17:30 2017 +0200
+++ b/mercurial/exchange.py	Thu Sep 28 15:24:54 2017 +0100
@@ -1239,10 +1239,10 @@
         wlock = pullop.repo.wlock()
         lock = pullop.repo.lock()
         pullop.trmanager = transactionmanager(repo, 'pull', remote.url())
-        streamclone.maybeperformlegacystreamclone(pullop)
         # This should ideally be in _pullbundle2(). However, it needs to run
         # before discovery to avoid extra work.
         _maybeapplyclonebundle(pullop)
+        streamclone.maybeperformlegacystreamclone(pullop)
         _pulldiscovery(pullop)
         if pullop.canusebundle2:
             _pullbundle2(pullop)
@@ -1864,7 +1864,9 @@
                        'falling back to regular clone\n'))
         return
 
-    entries = filterclonebundleentries(repo, entries)
+    entries = filterclonebundleentries(
+        repo, entries, streamclonerequested=pullop.streamclonerequested)
+
     if not entries:
         # There is a thundering herd concern here. However, if a server
         # operator doesn't advertise bundles appropriate for its clients,
@@ -1933,7 +1935,7 @@
 
     return m
 
-def filterclonebundleentries(repo, entries):
+def filterclonebundleentries(repo, entries, streamclonerequested=False):
     """Remove incompatible clone bundle manifest entries.
 
     Accepts a list of entries parsed with ``parseclonebundlesmanifest``
@@ -1948,7 +1950,15 @@
         spec = entry.get('BUNDLESPEC')
         if spec:
             try:
-                parsebundlespec(repo, spec, strict=True)
+                comp, version, params = parsebundlespec(repo, spec, strict=True)
+
+                # If a stream clone was requested, filter out non-streamclone
+                # entries.
+                if streamclonerequested and (comp != 'UN' or version != 's1'):
+                    repo.ui.debug('filtering %s because not a stream clone\n' %
+                                  entry['URL'])
+                    continue
+
             except error.InvalidBundleSpecification as e:
                 repo.ui.debug(str(e) + '\n')
                 continue
@@ -1956,6 +1966,12 @@
                 repo.ui.debug('filtering %s because unsupported bundle '
                               'spec: %s\n' % (entry['URL'], str(e)))
                 continue
+        # If we don't have a spec and requested a stream clone, we don't know
+        # what the entry is so don't attempt to apply it.
+        elif streamclonerequested:
+            repo.ui.debug('filtering %s because cannot determine if a stream '
+                          'clone bundle\n' % entry['URL'])
+            continue
 
         if 'REQUIRESNI' in entry and not sslutil.hassni:
             repo.ui.debug('filtering %s because SNI not supported\n' %

--- a/tests/test-clonebundles.t	Thu Sep 28 12:17:30 2017 +0200
+++ b/tests/test-clonebundles.t	Thu Sep 28 15:24:54 2017 +0100
@@ -441,6 +441,8 @@
   > EOF
 
   $ hg clone -U --uncompressed http://localhost:$HGPORT uncompressed-gzip
+  no compatible clone bundles available on server; falling back to regular clone
+  (you may want to report this to the server operator)
   streaming all changes
   4 files to transfer, 613 bytes of data
   transferred 613 bytes in * seconds (*) (glob)
@@ -454,6 +456,8 @@
   > EOF
 
   $ hg clone -U --uncompressed http://localhost:$HGPORT uncompressed-no-bundlespec
+  no compatible clone bundles available on server; falling back to regular clone
+  (you may want to report this to the server operator)
   streaming all changes
   4 files to transfer, 613 bytes of data
   transferred 613 bytes in * seconds (*) (glob)
@@ -468,9 +472,10 @@
   > EOF
 
   $ hg clone -U --uncompressed http://localhost:$HGPORT uncompressed-gzip-packed
-  streaming all changes
+  applying clone bundle from http://localhost:$HGPORT1/packed.hg
   4 files to transfer, 613 bytes of data
   transferred 613 bytes in * seconds (*) (glob)
+  finished applying clone bundle
   searching for changes
   no changes found
 
@@ -482,9 +487,10 @@
   > EOF
 
   $ hg clone -U --uncompressed http://localhost:$HGPORT uncompressed-gzip-packed-requirements
-  streaming all changes
+  applying clone bundle from http://localhost:$HGPORT1/packed.hg
   4 files to transfer, 613 bytes of data
   transferred 613 bytes in * seconds (*) (glob)
+  finished applying clone bundle
   searching for changes
   no changes found
 
@@ -496,6 +502,8 @@
   > EOF
 
   $ hg clone -U --uncompressed http://localhost:$HGPORT uncompressed-gzip-packed-unsupported-requirements
+  no compatible clone bundles available on server; falling back to regular clone
+  (you may want to report this to the server operator)
   streaming all changes
   4 files to transfer, 613 bytes of data
   transferred 613 bytes in * seconds (*) (glob)