Mercurial > hg
view mercurial/copies.py @ 18431:3aa9b2136593
pathencode: add a SHA-1 hash function
This will be used by an upcoming patch.
This calls out to the Python hash implementation.
An earlier version of this function implemented SHA-1 directly, but
the amount of extra code didn't seem like a good tradeoff compared
to the small big-picture increase in performance (long paths are
uncommon).
author | Bryan O'Sullivan <bryano@fb.com> |
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date | Wed, 12 Dec 2012 13:09:34 -0800 |
parents | 5a4f220fbfca |
children | 3cfaace0441e |
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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 _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 _chain(src, dst, a, b): '''chain two sets of copies a->b''' t = a.copy() for k, v in b.iteritems(): if v in t: # found a chain if t[v] != k: # file wasn't renamed back to itself t[k] = t[v] if v not in dst: # chain was a rename, not a copy del t[v] if v in src: # file is a copy of an existing file t[k] = v # remove criss-crossed copies for k, v in t.items(): if k in src and v in dst: del t[k] return t def _tracefile(fctx, actx): '''return file context that is the ancestor of fctx present in actx''' stop = actx.rev() am = actx.manifest() for f in fctx.ancestors(): if am.get(f.path(), None) == f.filenode(): return f if f.rev() < stop: return None def _dirstatecopies(d): ds = d._repo.dirstate c = ds.copies().copy() for k in c.keys(): if ds[k] not in 'anm': del c[k] return c def _forwardcopies(a, b): '''find {dst@b: src@a} copy mapping where a is an ancestor of b''' # check for working copy w = None if b.rev() is None: w = b b = w.p1() if a == b: # short-circuit to avoid issues with merge states return _dirstatecopies(w) # find where new files came from # we currently don't try to find where old files went, too expensive # this means we can miss a case like 'hg rm b; hg cp a b' cm = {} for f in b: if f not in a: ofctx = _tracefile(b[f], a) if ofctx: cm[f] = ofctx.path() # combine copies from dirstate if necessary if w is not None: cm = _chain(a, w, cm, _dirstatecopies(w)) return cm def _backwardrenames(a, b): # Even though we're not taking copies into account, 1:n rename situations # can still exist (e.g. hg cp a b; hg mv a c). In those cases we # arbitrarily pick one of the renames. f = _forwardcopies(b, a) r = {} for k, v in sorted(f.iteritems()): # remove copies if v in a: continue r[v] = k return r def pathcopies(x, y): '''find {dst@y: src@x} copy mapping for directed compare''' if x == y or not x or not y: return {} a = y.ancestor(x) if a == x: return _forwardcopies(x, y) if a == y: return _backwardrenames(x, y) return _chain(x, y, _backwardrenames(x, a), _forwardcopies(a, y)) def mergecopies(repo, c1, c2, ca): """ Find moves and copies between context c1 and c2 that are relevant for merging. Returns four dicts: "copy", "movewithdir", "diverge", and "renamedelete". "copy" is a mapping from destination name -> source name, where source is in c1 and destination is in c2 or vice-versa. "movewithdir" is a mapping from source name -> destination name, where the file at source present in one context but not the other needs to be moved to destination by the merge process, because the other context moved the directory it is in. "diverge" is a mapping of source name -> list of destination names for divergent renames. "renamedelete" is a mapping of source name -> list of destination names for files deleted in c1 that were renamed in c2 or vice-versa. """ # 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.p1(): 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 = {} movewithdir = {} 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 True: 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) renamedelete = {} renamedelete2 = set() diverge2 = set() for of, fl in diverge.items(): if len(fl) == 1 or of in c1 or of in c2: del diverge[of] # not actually divergent, or not a rename if of not in c1 and of not in c2: # renamed on one side, deleted on the other side, but filter # out files that have been renamed and then deleted renamedelete[of] = [f for f in fl if f in c1 or f in c2] renamedelete2.update(fl) # reverse map for below else: diverge2.update(fl) # reverse map for below if fullcopy: repo.ui.debug(" all copies found (* = to merge, ! = divergent, " "% = renamed and deleted):\n") for f in sorted(fullcopy): note = "" if f in copy: note += "*" if f in diverge2: note += "!" if f in renamedelete2: note += "%" repo.ui.debug(" src: '%s' -> dst: '%s' %s\n" % (fullcopy[f], f, note)) del diverge2 if not fullcopy: return copy, movewithdir, diverge, renamedelete repo.ui.debug(" checking for directory renames\n") # generate a directory move map d1, d2 = c1.dirs(), c2.dirs() d1.add('') d2.add('') 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, movewithdir, diverge, renamedelete for d in dirmove: repo.ui.debug(" discovered dir src: '%s' -> dst: '%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: movewithdir[f] = df repo.ui.debug((" pending file src: '%s' -> " "dst: '%s'\n") % (f, df)) break return copy, movewithdir, diverge, renamedelete