Avoid unnecessary git symbolic-ref calls during repo sync
If the m/BRANCH ref is already pointing at the value set in the
manifest there is no reason to set it again. Leave it alone,
thus saving a full fork+exec call.
Signed-off-by: Shawn O. Pearce <sop@google.com>
diff --git a/git_refs.py b/git_refs.py
index eefa2ab..b91abc2 100644
--- a/git_refs.py
+++ b/git_refs.py
@@ -31,8 +31,7 @@
@property
def all(self):
- if self._phyref is None or self._NeedUpdate():
- self._LoadAll()
+ self._EnsureLoaded()
return self._phyref
def get(self, name):
@@ -52,6 +51,17 @@
if name in self._mtime:
del self._mtime[name]
+ def symref(self, name):
+ try:
+ self._EnsureLoaded()
+ return self._symref[name]
+ except KeyError:
+ return ''
+
+ def _EnsureLoaded(self):
+ if self._phyref is None or self._NeedUpdate():
+ self._LoadAll()
+
def _NeedUpdate(self):
for name, mtime in self._mtime.iteritems():
try:
diff --git a/project.py b/project.py
index 9f9cf7b..09a768f 100644
--- a/project.py
+++ b/project.py
@@ -997,14 +997,17 @@
if self.manifest.branch:
msg = 'manifest set to %s' % self.revision
ref = R_M + self.manifest.branch
+ cur = self.bare_ref.symref(ref)
if IsId(self.revision):
- dst = self.revision + '^0'
- self.bare_git.UpdateRef(ref, dst, message = msg, detach = True)
+ if cur != '' or self.bare_ref.get(ref) != self.revision:
+ dst = self.revision + '^0'
+ self.bare_git.UpdateRef(ref, dst, message = msg, detach = True)
else:
remote = self.GetRemote(self.remote.name)
dst = remote.ToLocal(self.revision)
- self.bare_git.symbolic_ref('-m', msg, ref, dst)
+ if cur != dst:
+ self.bare_git.symbolic_ref('-m', msg, ref, dst)
def _InitMirrorHead(self):
dst = self.GetRemote(self.remote.name).ToLocal(self.revision)