I am trying to make branchcache make lazy load and only validate nodes if required. This will speed up operations and loading of branchcache. Right now loading of branchcache validates all the nodes which is not required until the branch which has that node is accessed. I believe doing this will speed up things. However the current dict interface of branchcache object is making this hard, hence I have sent only this patch for now.

if not bcache.validfor(repo):
    # invalidate the cache
    raise ValueError(r'tip differs')

• cl = repo.changelog
• for line in lineiter:
• line = line.rstrip('\n')
• if not line:
• continue
• node, state, label = line.split(" ", 2)
• if state not in 'oc':
• raise ValueError(r'invalid branch state')
• label = encoding.tolocal(label.strip())
• node = bin(node)
• if not cl.hasnode(node):
• raise ValueError(
• r'node %s does not exist' % pycompat.sysstr(hex(node)))
• bcache.setdefault(label, []).append(node)
• if state == 'c':
• bcache._closednodes.add(node) -

+ bcache.load(repo, f)

except (IOError, OSError):
    return None

@@ -214,6 +198,26 @@

return bcache

+ def load(self, repo, f):
+ """ fully loads the branchcache by reading from the file f """
+ cl = repo.changelog
+ lineiter = iter(f)

Breaks test-static-http.t probably because f is read twice through
different iterators.