# branchmap.py - logic to computes, maintain and stores branchmap for local repo
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from node import bin, hex, nullid, nullrev
import encoding
def read(repo):
partial = branchcache()
try:
f = repo.opener("cache/branchheads")
lines = f.read().split('\n')
f.close()
except (IOError, OSError):
return branchcache()
try:
last, lrev = lines.pop(0).split(" ", 1)
last, lrev = bin(last), int(lrev)
if lrev >= len(repo) or repo[lrev].node() != last:
# invalidate the cache
raise ValueError('invalidating branch cache (tip differs)')
for l in lines:
if not l:
continue
node, label = l.split(" ", 1)
label = encoding.tolocal(label.strip())
if not node in repo:
raise ValueError('invalidating branch cache because node '+
'%s does not exist' % node)
partial.setdefault(label, []).append(bin(node))
partial.tipnode = last
partial.tiprev = lrev
except KeyboardInterrupt:
raise
except Exception, inst:
if repo.ui.debugflag:
repo.ui.warn(str(inst), '\n')
partial = branchcache()
return partial
def updatecache(repo):
repo = repo.unfiltered() # Until we get a smarter cache management
cl = repo.changelog
tip = cl.tip()
partial = repo._branchcache
if partial is not None and partial.tipnode == tip:
return
if partial is None or partial.tipnode not in cl.nodemap:
partial = read(repo)
catip = repo._cacheabletip()
# if partial.tiprev == catip: cache is already up to date
# if partial.tiprev > catip: we have uncachable element in `partial` can't
# write on disk
if partial.tiprev < catip:
ctxgen = (repo[r] for r in cl.revs(partial.tiprev + 1, catip))
partial.update(repo, ctxgen)
partial.write(repo)
# If cacheable tip were lower than actual tip, we need to update the
# cache up to tip. This update (from cacheable to actual tip) is not
# written to disk since it's not cacheable.
tiprev = len(repo) - 1
if partial.tiprev < tiprev:
ctxgen = (repo[r] for r in cl.revs(partial.tiprev + 1, tiprev))
partial.update(repo, ctxgen)
repo._branchcache = partial
class branchcache(dict):
"""A dict like object that hold branches heads cache"""
def __init__(self, entries=(), tipnode=nullid, tiprev=nullrev):
super(branchcache, self).__init__(entries)
self.tipnode = tipnode
self.tiprev = tiprev
def write(self, repo):
try:
f = repo.opener("cache/branchheads", "w", atomictemp=True)
f.write("%s %s\n" % (hex(self.tipnode), self.tiprev))
for label, nodes in self.iteritems():
for node in nodes:
f.write("%s %s\n" % (hex(node), encoding.fromlocal(label)))
f.close()
except (IOError, OSError):
pass
def update(self, repo, ctxgen):
"""Given a branchhead cache, self, that may have extra nodes or be
missing heads, and a generator of nodes that are at least a superset of
heads missing, this function updates self to be correct.
"""
cl = repo.changelog
# collect new branch entries
newbranches = {}
for c in ctxgen:
newbranches.setdefault(c.branch(), []).append(c.node())
# if older branchheads are reachable from new ones, they aren't
# really branchheads. Note checking parents is insufficient:
# 1 (branch a) -> 2 (branch b) -> 3 (branch a)
for branch, newnodes in newbranches.iteritems():
bheads = self.setdefault(branch, [])
# Remove candidate heads that no longer are in the repo (e.g., as
# the result of a strip that just happened). Avoid using 'node in
# self' here because that dives down into branchcache code somewhat
# recursively.
bheadrevs = [cl.rev(node) for node in bheads
if cl.hasnode(node)]
newheadrevs = [cl.rev(node) for node in newnodes
if cl.hasnode(node)]
ctxisnew = bheadrevs and min(newheadrevs) > max(bheadrevs)
# Remove duplicates - nodes that are in newheadrevs and are already
# in bheadrevs. This can happen if you strip a node whose parent
# was already a head (because they're on different branches).
bheadrevs = sorted(set(bheadrevs).union(newheadrevs))
# Starting from tip means fewer passes over reachable. If we know
# the new candidates are not ancestors of existing heads, we don't
# have to examine ancestors of existing heads
if ctxisnew:
iterrevs = sorted(newheadrevs)
else:
iterrevs = list(bheadrevs)
# This loop prunes out two kinds of heads - heads that are
# superseded by a head in newheadrevs, and newheadrevs that are not
# heads because an existing head is their descendant.
while iterrevs:
latest = iterrevs.pop()
if latest not in bheadrevs:
continue
ancestors = set(cl.ancestors([latest],
bheadrevs[0]))
if ancestors:
bheadrevs = [b for b in bheadrevs if b not in ancestors]
self[branch] = [cl.node(rev) for rev in bheadrevs]
tiprev = max(bheadrevs)
if tiprev > self.tiprev:
self.tipnode = cl.node(tiprev)
self.tiprev = tiprev
# There may be branches that cease to exist when the last commit in the
# branch was stripped. This code filters them out. Note that the
# branch that ceased to exist may not be in newbranches because
# newbranches is the set of candidate heads, which when you strip the
# last commit in a branch will be the parent branch.
droppednodes = []
for branch in self.keys():
nodes = [head for head in self[branch]
if cl.hasnode(head)]
if not nodes:
droppednodes.extend(nodes)
del self[branch]
try:
node = cl.node(self.tiprev)
except IndexError:
node = None
if ((self.tipnode != node)
or (self.tipnode in droppednodes)):
# cache key are not valid anymore
self.tipnode = nullid
self.tiprev = nullrev
for heads in self.values():
tiprev = max(cl.rev(node) for node in heads)
if tiprev > self.tiprev:
self.tipnode = cl.node(tiprev)
self.tiprev = tiprev