Mercurial > hg
view mercurial/copies.py @ 11578:bb7af1de5e38
discovery: remove duplication for new remote head discovery
author | Benoit Boissinot <benoit.boissinot@ens-lyon.org> |
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date | Thu, 15 Jul 2010 21:44:51 +0200 |
parents | 4f11978ae45d |
children | ada47c38f4e5 |
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# copies.py - copy detection for Mercurial # # Copyright 2008 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. import util import heapq def _nonoverlap(d1, d2, d3): "Return list of elements in d1 not in d2 or d3" return sorted([d for d in d1 if d not in d3 and d not in d2]) def _dirname(f): s = f.rfind("/") if s == -1: return "" return f[:s] def _dirs(files): d = set() for f in files: f = _dirname(f) while f not in d: d.add(f) f = _dirname(f) return d def _findlimit(repo, a, b): """Find the earliest revision that's an ancestor of a or b but not both, None if no such revision exists. """ # basic idea: # - mark a and b with different sides # - if a parent's children are all on the same side, the parent is # on that side, otherwise it is on no side # - walk the graph in topological order with the help of a heap; # - add unseen parents to side map # - clear side of any parent that has children on different sides # - track number of interesting revs that might still be on a side # - track the lowest interesting rev seen # - quit when interesting revs is zero cl = repo.changelog working = len(cl) # pseudo rev for the working directory if a is None: a = working if b is None: b = working side = {a: -1, b: 1} visit = [-a, -b] heapq.heapify(visit) interesting = len(visit) hascommonancestor = False limit = working while interesting: r = -heapq.heappop(visit) if r == working: parents = [cl.rev(p) for p in repo.dirstate.parents()] else: parents = cl.parentrevs(r) for p in parents: if p < 0: continue if p not in side: # first time we see p; add it to visit side[p] = side[r] if side[p]: interesting += 1 heapq.heappush(visit, -p) elif side[p] and side[p] != side[r]: # p was interesting but now we know better side[p] = 0 interesting -= 1 hascommonancestor = True if side[r]: limit = r # lowest rev visited interesting -= 1 if not hascommonancestor: return None return limit def copies(repo, c1, c2, ca, checkdirs=False): """ Find moves and copies between context c1 and c2 """ # avoid silly behavior for update from empty dir if not c1 or not c2 or c1 == c2: return {}, {} # avoid silly behavior for parent -> working dir if c2.node() is None and c1.node() == repo.dirstate.parents()[0]: return repo.dirstate.copies(), {} limit = _findlimit(repo, c1.rev(), c2.rev()) if limit is None: # no common ancestor, no copies return {}, {} m1 = c1.manifest() m2 = c2.manifest() ma = ca.manifest() def makectx(f, n): if len(n) != 20: # in a working context? if c1.rev() is None: return c1.filectx(f) return c2.filectx(f) return repo.filectx(f, fileid=n) ctx = util.lrucachefunc(makectx) copy = {} fullcopy = {} diverge = {} def related(f1, f2, limit): # Walk back to common ancestor to see if the two files originate # from the same file. Since workingfilectx's rev() is None it messes # up the integer comparison logic, hence the pre-step check for # None (f1 and f2 can only be workingfilectx's initially). if f1 == f2: return f1 # a match g1, g2 = f1.ancestors(), f2.ancestors() try: f1r, f2r = f1.rev(), f2.rev() if f1r is None: f1 = g1.next() if f2r is None: f2 = g2.next() while 1: f1r, f2r = f1.rev(), f2.rev() if f1r > f2r: f1 = g1.next() elif f2r > f1r: f2 = g2.next() elif f1 == f2: return f1 # a match elif f1r == f2r or f1r < limit or f2r < limit: return False # copy no longer relevant except StopIteration: return False def checkcopies(f, m1, m2): '''check possible copies of f from m1 to m2''' of = None seen = set([f]) for oc in ctx(f, m1[f]).ancestors(): ocr = oc.rev() of = oc.path() if of in seen: # check limit late - grab last rename before if ocr < limit: break continue seen.add(of) fullcopy[f] = of # remember for dir rename detection if of not in m2: continue # no match, keep looking if m2[of] == ma.get(of): break # no merge needed, quit early c2 = ctx(of, m2[of]) cr = related(oc, c2, ca.rev()) if cr and (of == f or of == c2.path()): # non-divergent copy[f] = of of = None break if of in ma: diverge.setdefault(of, []).append(f) repo.ui.debug(" searching for copies back to rev %d\n" % limit) u1 = _nonoverlap(m1, m2, ma) u2 = _nonoverlap(m2, m1, ma) if u1: repo.ui.debug(" unmatched files in local:\n %s\n" % "\n ".join(u1)) if u2: repo.ui.debug(" unmatched files in other:\n %s\n" % "\n ".join(u2)) for f in u1: checkcopies(f, m1, m2) for f in u2: checkcopies(f, m2, m1) diverge2 = set() for of, fl in diverge.items(): if len(fl) == 1: del diverge[of] # not actually divergent else: diverge2.update(fl) # reverse map for below if fullcopy: repo.ui.debug(" all copies found (* = to merge, ! = divergent):\n") for f in fullcopy: note = "" if f in copy: note += "*" if f in diverge2: note += "!" repo.ui.debug(" %s -> %s %s\n" % (f, fullcopy[f], note)) del diverge2 if not fullcopy or not checkdirs: return copy, diverge repo.ui.debug(" checking for directory renames\n") # generate a directory move map d1, d2 = _dirs(m1), _dirs(m2) invalid = set() dirmove = {} # examine each file copy for a potential directory move, which is # when all the files in a directory are moved to a new directory for dst, src in fullcopy.iteritems(): dsrc, ddst = _dirname(src), _dirname(dst) if dsrc in invalid: # already seen to be uninteresting continue elif dsrc in d1 and ddst in d1: # directory wasn't entirely moved locally invalid.add(dsrc) elif dsrc in d2 and ddst in d2: # directory wasn't entirely moved remotely invalid.add(dsrc) elif dsrc in dirmove and dirmove[dsrc] != ddst: # files from the same directory moved to two different places invalid.add(dsrc) else: # looks good so far dirmove[dsrc + "/"] = ddst + "/" for i in invalid: if i in dirmove: del dirmove[i] del d1, d2, invalid if not dirmove: return copy, diverge for d in dirmove: repo.ui.debug(" dir %s -> %s\n" % (d, dirmove[d])) # check unaccounted nonoverlapping files against directory moves for f in u1 + u2: if f not in fullcopy: for d in dirmove: if f.startswith(d): # new file added in a directory that was moved, move it df = dirmove[d] + f[len(d):] if df not in copy: copy[f] = df repo.ui.debug(" file %s -> %s\n" % (f, copy[f])) break return copy, diverge