Mercurial > hg
view mercurial/branchmap.py @ 18120:88990d3e3d75
branchmap: extract _updatebranchcache from repo
author | Pierre-Yves David <pierre-yves.david@logilab.fr> |
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date | Wed, 19 Dec 2012 14:49:06 +0100 |
parents | e70ff1e599f4 |
children | f8a13f061a8a |
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# 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 = {} try: f = repo.opener("cache/branchheads") lines = f.read().split('\n') f.close() except (IOError, OSError): return {}, nullid, nullrev 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)) except KeyboardInterrupt: raise except Exception, inst: if repo.ui.debugflag: repo.ui.warn(str(inst), '\n') partial, last, lrev = {}, nullid, nullrev return partial, last, lrev def write(repo, branches, tip, tiprev): try: f = repo.opener("cache/branchheads", "w", atomictemp=True) f.write("%s %s\n" % (hex(tip), tiprev)) for label, nodes in branches.iteritems(): for node in nodes: f.write("%s %s\n" % (hex(node), encoding.fromlocal(label))) f.close() except (IOError, OSError): pass def update(repo, partial, ctxgen): """Given a branchhead cache, partial, 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 partial to be correct. """ # 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 = partial.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 = [repo.changelog.rev(node) for node in bheads if repo.changelog.hasnode(node)] newheadrevs = [repo.changelog.rev(node) for node in newnodes if repo.changelog.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(repo.changelog.ancestors([latest], bheadrevs[0])) if ancestors: bheadrevs = [b for b in bheadrevs if b not in ancestors] partial[branch] = [repo.changelog.node(rev) for rev in bheadrevs] # 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. for branch in partial.keys(): nodes = [head for head in partial[branch] if repo.changelog.hasnode(head)] if not nodes: del partial[branch]