# 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
import util
def _filename(repo):
"""name of a branchcache file for a given repo or repoview"""
filename = "cache/branchheads"
if repo.filtername:
filename = '%s-%s' % (filename, repo.filtername)
return filename
def read(repo):
try:
f = repo.opener(_filename(repo))
lines = f.read().split('\n')
f.close()
except (IOError, OSError):
return None
try:
cachekey = lines.pop(0).split(" ", 2)
last, lrev = cachekey[:2]
last, lrev = bin(last), int(lrev)
filteredhash = None
if len(cachekey) > 2:
filteredhash = bin(cachekey[2])
partial = branchcache(tipnode=last, tiprev=lrev,
filteredhash=filteredhash)
if not partial.validfor(repo):
# invalidate the cache
raise ValueError('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('node %s does not exist' % node)
partial.setdefault(label, []).append(bin(node))
except KeyboardInterrupt:
raise
except Exception, inst:
if repo.ui.debugflag:
msg = 'invalid branchheads cache'
if repo.filtername is not None:
msg += ' (%s)' % repo.filtername
msg += ': %s\n'
repo.ui.warn(msg % inst)
partial = None
return partial
### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.
# This create and ordering used for branchmap purpose.
# the ordering may be partial
subsettable = {None: 'visible',
'visible': 'served',
'served': 'immutable',
'immutable': 'base'}
def updatecache(repo):
cl = repo.changelog
filtername = repo.filtername
partial = repo._branchcaches.get(filtername)
revs = []
if partial is None or not partial.validfor(repo):
partial = read(repo)
if partial is None:
subsetname = subsettable.get(filtername)
if subsetname is None:
partial = branchcache()
else:
subset = repo.filtered(subsetname)
partial = subset.branchmap().copy()
extrarevs = subset.changelog.filteredrevs - cl.filteredrevs
revs.extend(r for r in extrarevs if r <= partial.tiprev)
revs.extend(cl.revs(start=partial.tiprev + 1))
if revs:
partial.update(repo, revs)
partial.write(repo)
assert partial.validfor(repo), filtername
repo._branchcaches[repo.filtername] = partial
class branchcache(dict):
"""A dict like object that hold branches heads cache"""
def __init__(self, entries=(), tipnode=nullid, tiprev=nullrev,
filteredhash=None):
super(branchcache, self).__init__(entries)
self.tipnode = tipnode
self.tiprev = tiprev
self.filteredhash = filteredhash
def _hashfiltered(self, repo):
"""build hash of revision filtered in the current cache
Tracking tipnode and tiprev is not enough to ensure validity of the
cache as they do not help to distinct cache that ignored various
revision bellow tiprev.
To detect such difference, we build a cache of all ignored revisions.
"""
cl = repo.changelog
if not cl.filteredrevs:
return None
key = None
revs = sorted(r for r in cl.filteredrevs if r <= self.tiprev)
if revs:
s = util.sha1()
for rev in revs:
s.update('%s;' % rev)
key = s.digest()
return key
def validfor(self, repo):
"""Is the cache content valid regarding a repo
- False when cached tipnode is unknown or if we detect a strip.
- True when cache is up to date or a subset of current repo."""
try:
return ((self.tipnode == repo.changelog.node(self.tiprev))
and (self.filteredhash == self._hashfiltered(repo)))
except IndexError:
return False
def copy(self):
"""return an deep copy of the branchcache object"""
return branchcache(self, self.tipnode, self.tiprev, self.filteredhash)
def write(self, repo):
try:
f = repo.opener(_filename(repo), "w", atomictemp=True)
cachekey = [hex(self.tipnode), str(self.tiprev)]
if self.filteredhash is not None:
cachekey.append(hex(self.filteredhash))
f.write(" ".join(cachekey) + '\n')
for label, nodes in sorted(self.iteritems()):
for node in nodes:
f.write("%s %s\n" % (hex(node), encoding.fromlocal(label)))
f.close()
except (IOError, OSError, util.Abort):
# Abort may be raise by read only opener
pass
def update(self, repo, revgen):
"""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 = {}
getbranch = cl.branch
for r in revgen:
newbranches.setdefault(getbranch(r), []).append(cl.node(r))
# 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
if not self.validfor(repo):
# 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
self.filteredhash = self._hashfiltered(repo)