Mercurial > hg
view mercurial/copies.py @ 42257:a4f7dceb07bf
phabricator: fallback to reading metadata from diff for phabread
Differential Revision: https://phab.mercurial-scm.org/D6301
| author | Ian Moody <moz-ian@perix.co.uk> |
|---|---|
| date | Mon, 22 Apr 2019 18:55:26 +0100 |
| parents | 00e065fb1469 |
| children | d1c7446d0c58 |
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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. from __future__ import absolute_import import collections import heapq import os from .i18n import _ from . import ( match as matchmod, node, pathutil, util, ) from .utils import ( stringutil, ) def _findlimit(repo, ctxa, ctxb): """ Find the last revision that needs to be checked to ensure that a full transitive closure for file copies can be properly calculated. Generally, this means finding the earliest revision number that's an ancestor of a or b but not both, except when a or b is a direct descendent of the other, in which case we can return the minimum revnum of a and b. """ # 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 wdirparents = None a = ctxa.rev() b = ctxb.rev() if a is None: wdirparents = (ctxa.p1(), ctxa.p2()) a = node.wdirrev if b is None: assert not wdirparents wdirparents = (ctxb.p1(), ctxb.p2()) b = node.wdirrev side = {a: -1, b: 1} visit = [-a, -b] heapq.heapify(visit) interesting = len(visit) limit = node.wdirrev while interesting: r = -heapq.heappop(visit) if r == node.wdirrev: parents = [pctx.rev() for pctx in wdirparents] else: parents = cl.parentrevs(r) if parents[1] == node.nullrev: parents = parents[:1] for p in parents: 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 if side[r]: limit = r # lowest rev visited interesting -= 1 # Consider the following flow (see test-commit-amend.t under issue4405): # 1/ File 'a0' committed # 2/ File renamed from 'a0' to 'a1' in a new commit (call it 'a1') # 3/ Move back to first commit # 4/ Create a new commit via revert to contents of 'a1' (call it 'a1-amend') # 5/ Rename file from 'a1' to 'a2' and commit --amend 'a1-msg' # # During the amend in step five, we will be in this state: # # @ 3 temporary amend commit for a1-amend # | # o 2 a1-amend # | # | o 1 a1 # |/ # o 0 a0 # # When _findlimit is called, a and b are revs 3 and 0, so limit will be 2, # yet the filelog has the copy information in rev 1 and we will not look # back far enough unless we also look at the a and b as candidates. # This only occurs when a is a descendent of b or visa-versa. return min(limit, a, b) def _chain(src, dst, a, b): """chain two sets of copies 'a' and 'b'""" # When chaining copies in 'a' (from 'src' via some other commit 'mid') with # copies in 'b' (from 'mid' to 'dst'), we can get the different cases in the # following table (not including trivial cases). For example, case 2 is # where a file existed in 'src' and remained under that name in 'mid' and # then was renamed between 'mid' and 'dst'. # # case src mid dst result # 1 x y - - # 2 x y y x->y # 3 x y x - # 4 x y z x->z # 5 - x y - # 6 x x y x->y # Initialize result ('t') from 'a'. This catches cases 1 & 2. We'll remove # case 1 later. We'll also catch cases 3 & 4 here. Case 4 will be # overwritten later, and case 3 will be removed later. t = a.copy() for k, v in b.iteritems(): if v in t: # Found a chain, i.e. cases 3 & 4. We'll remove case 3 later. t[k] = t[v] else: # Renamed only in 'b', i.e. cases 5 & 6. We'll remove case 5 later. t[k] = v for k, v in list(t.items()): # remove copies from files that didn't exist, i.e. case 5 if v not in src: del t[k] # remove criss-crossed copies, i.e. case 3 elif k in src and v in dst: del t[k] # remove copies to files that were then removed, i.e. case 1 # and file 'y' in cases 3 & 4 (in case of rename) elif k not in dst: del t[k] return t def _tracefile(fctx, am, limit): """return file context that is the ancestor of fctx present in ancestor manifest am, stopping after the first ancestor lower than limit""" for f in fctx.ancestors(): if am.get(f.path(), None) == f.filenode(): return f if not f.isintroducedafter(limit): return None def _dirstatecopies(repo, match=None): ds = repo.dirstate c = ds.copies().copy() for k in list(c): if ds[k] not in 'anm' or (match and not match(k)): del c[k] return c def _computeforwardmissing(a, b, match=None): """Computes which files are in b but not a. This is its own function so extensions can easily wrap this call to see what files _forwardcopies is about to process. """ ma = a.manifest() mb = b.manifest() return mb.filesnotin(ma, match=match) def usechangesetcentricalgo(repo): """Checks if we should use changeset-centric copy algorithms""" return (repo.ui.config('experimental', 'copies.read-from') in ('changeset-only', 'compatibility')) def _committedforwardcopies(a, b, match): """Like _forwardcopies(), but b.rev() cannot be None (working copy)""" # files might have to be traced back to the fctx parent of the last # one-side-only changeset, but not further back than that repo = a._repo if usechangesetcentricalgo(repo): return _changesetforwardcopies(a, b, match) debug = repo.ui.debugflag and repo.ui.configbool('devel', 'debug.copies') dbg = repo.ui.debug if debug: dbg('debug.copies: looking into rename from %s to %s\n' % (a, b)) limit = _findlimit(repo, a, b) if debug: dbg('debug.copies: search limit: %d\n' % limit) am = a.manifest() # 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 = {} # Computing the forward missing is quite expensive on large manifests, since # it compares the entire manifests. We can optimize it in the common use # case of computing what copies are in a commit versus its parent (like # during a rebase or histedit). Note, we exclude merge commits from this # optimization, since the ctx.files() for a merge commit is not correct for # this comparison. forwardmissingmatch = match if b.p1() == a and b.p2().node() == node.nullid: filesmatcher = matchmod.exact(b.files()) forwardmissingmatch = matchmod.intersectmatchers(match, filesmatcher) missing = _computeforwardmissing(a, b, match=forwardmissingmatch) ancestrycontext = a._repo.changelog.ancestors([b.rev()], inclusive=True) if debug: dbg('debug.copies: missing files to search: %d\n' % len(missing)) for f in sorted(missing): if debug: dbg('debug.copies: tracing file: %s\n' % f) fctx = b[f] fctx._ancestrycontext = ancestrycontext if debug: start = util.timer() ofctx = _tracefile(fctx, am, limit) if ofctx: if debug: dbg('debug.copies: rename of: %s\n' % ofctx._path) cm[f] = ofctx.path() if debug: dbg('debug.copies: time: %f seconds\n' % (util.timer() - start)) return cm def _changesetforwardcopies(a, b, match): if a.rev() == node.nullrev: return {} repo = a.repo() children = {} cl = repo.changelog missingrevs = cl.findmissingrevs(common=[a.rev()], heads=[b.rev()]) for r in missingrevs: for p in cl.parentrevs(r): if p == node.nullrev: continue if p not in children: children[p] = [r] else: children[p].append(r) roots = set(children) - set(missingrevs) # 'work' contains 3-tuples of a (revision number, parent number, copies). # The parent number is only used for knowing which parent the copies dict # came from. work = [(r, 1, {}) for r in roots] heapq.heapify(work) while work: r, i1, copies1 = heapq.heappop(work) if work and work[0][0] == r: # We are tracing copies from both parents r, i2, copies2 = heapq.heappop(work) copies = {} ctx = repo[r] p1man, p2man = ctx.p1().manifest(), ctx.p2().manifest() allcopies = set(copies1) | set(copies2) # TODO: perhaps this filtering should be done as long as ctx # is merge, whether or not we're tracing from both parent. for dst in allcopies: if not match(dst): continue if dst not in copies2: # Copied on p1 side: mark as copy from p1 side if it didn't # already exist on p2 side if dst not in p2man: copies[dst] = copies1[dst] elif dst not in copies1: # Copied on p2 side: mark as copy from p2 side if it didn't # already exist on p1 side if dst not in p1man: copies[dst] = copies2[dst] else: # Copied on both sides: mark as copy from p1 side copies[dst] = copies1[dst] else: copies = copies1 if r == b.rev(): return copies for c in children[r]: childctx = repo[c] if r == childctx.p1().rev(): parent = 1 childcopies = childctx.p1copies() else: assert r == childctx.p2().rev() parent = 2 childcopies = childctx.p2copies() if not match.always(): childcopies = {dst: src for dst, src in childcopies.items() if match(dst)} childcopies = _chain(a, childctx, copies, childcopies) heapq.heappush(work, (c, parent, childcopies)) assert False def _forwardcopies(a, b, match=None): """find {dst@b: src@a} copy mapping where a is an ancestor of b""" match = a.repo().narrowmatch(match) # check for working copy if b.rev() is None: if a == b.p1(): # short-circuit to avoid issues with merge states return _dirstatecopies(b._repo, match) cm = _committedforwardcopies(a, b.p1(), match) # combine copies from dirstate if necessary return _chain(a, b, cm, _dirstatecopies(b._repo, match)) return _committedforwardcopies(a, b, match) def _backwardrenames(a, b, match): if a._repo.ui.config('experimental', 'copytrace') == 'off': return {} # 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. # We don't want to pass in "match" here, since that would filter # the destination by it. Since we're reversing the copies, we want # to filter the source instead. f = _forwardcopies(b, a) r = {} for k, v in sorted(f.iteritems()): if match and not match(v): continue # remove copies if v in a: continue r[v] = k return r def pathcopies(x, y, match=None): """find {dst@y: src@x} copy mapping for directed compare""" repo = x._repo debug = repo.ui.debugflag and repo.ui.configbool('devel', 'debug.copies') if debug: repo.ui.debug('debug.copies: searching copies from %s to %s\n' % (x, y)) if x == y or not x or not y: return {} a = y.ancestor(x) if a == x: if debug: repo.ui.debug('debug.copies: search mode: forward\n') return _forwardcopies(x, y, match=match) if a == y: if debug: repo.ui.debug('debug.copies: search mode: backward\n') return _backwardrenames(x, y, match=match) if debug: repo.ui.debug('debug.copies: search mode: combined\n') return _chain(x, y, _backwardrenames(x, a, match=match), _forwardcopies(a, y, match=match)) def mergecopies(repo, c1, c2, base): """ Finds moves and copies between context c1 and c2 that are relevant for merging. 'base' will be used as the merge base. Copytracing is used in commands like rebase, merge, unshelve, etc to merge files that were moved/ copied in one merge parent and modified in another. For example: o ---> 4 another commit | | o ---> 3 commit that modifies a.txt | / o / ---> 2 commit that moves a.txt to b.txt |/ o ---> 1 merge base If we try to rebase revision 3 on revision 4, since there is no a.txt in revision 4, and if user have copytrace disabled, we prints the following message: ```other changed <file> which local deleted``` Returns five dicts: "copy", "movewithdir", "diverge", "renamedelete" and "dirmove". "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. "dirmove" is a mapping of detected source dir -> destination dir renames. This is needed for handling changes to new files previously grafted into renamed directories. This function calls different copytracing algorithms based on config. """ # avoid silly behavior for update from empty dir if not c1 or not c2 or c1 == c2: return {}, {}, {}, {}, {} narrowmatch = c1.repo().narrowmatch() # avoid silly behavior for parent -> working dir if c2.node() is None and c1.node() == repo.dirstate.p1(): return _dirstatecopies(repo, narrowmatch), {}, {}, {}, {} copytracing = repo.ui.config('experimental', 'copytrace') if stringutil.parsebool(copytracing) is False: # stringutil.parsebool() returns None when it is unable to parse the # value, so we should rely on making sure copytracing is on such cases return {}, {}, {}, {}, {} if usechangesetcentricalgo(repo): # The heuristics don't make sense when we need changeset-centric algos return _fullcopytracing(repo, c1, c2, base) # Copy trace disabling is explicitly below the node == p1 logic above # because the logic above is required for a simple copy to be kept across a # rebase. if copytracing == 'heuristics': # Do full copytracing if only non-public revisions are involved as # that will be fast enough and will also cover the copies which could # be missed by heuristics if _isfullcopytraceable(repo, c1, base): return _fullcopytracing(repo, c1, c2, base) return _heuristicscopytracing(repo, c1, c2, base) else: return _fullcopytracing(repo, c1, c2, base) def _isfullcopytraceable(repo, c1, base): """ Checks that if base, source and destination are all no-public branches, if yes let's use the full copytrace algorithm for increased capabilities since it will be fast enough. `experimental.copytrace.sourcecommitlimit` can be used to set a limit for number of changesets from c1 to base such that if number of changesets are more than the limit, full copytracing algorithm won't be used. """ if c1.rev() is None: c1 = c1.p1() if c1.mutable() and base.mutable(): sourcecommitlimit = repo.ui.configint('experimental', 'copytrace.sourcecommitlimit') commits = len(repo.revs('%d::%d', base.rev(), c1.rev())) return commits < sourcecommitlimit return False def _checksinglesidecopies(src, dsts1, m1, m2, mb, c2, base, copy, renamedelete): if src not in m2: # deleted on side 2 if src not in m1: # renamed on side 1, deleted on side 2 renamedelete[src] = dsts1 elif m2[src] != mb[src]: if not _related(c2[src], base[src]): return # modified on side 2 for dst in dsts1: if dst not in m2: # dst not added on side 2 (handle as regular # "both created" case in manifestmerge otherwise) copy[dst] = src def _fullcopytracing(repo, c1, c2, base): """ The full copytracing algorithm which finds all the new files that were added from merge base up to the top commit and for each file it checks if this file was copied from another file. This is pretty slow when a lot of changesets are involved but will track all the copies. """ m1 = c1.manifest() m2 = c2.manifest() mb = base.manifest() copies1 = pathcopies(base, c1) copies2 = pathcopies(base, c2) inversecopies1 = {} inversecopies2 = {} for dst, src in copies1.items(): inversecopies1.setdefault(src, []).append(dst) for dst, src in copies2.items(): inversecopies2.setdefault(src, []).append(dst) copy = {} diverge = {} renamedelete = {} allsources = set(inversecopies1) | set(inversecopies2) for src in allsources: dsts1 = inversecopies1.get(src) dsts2 = inversecopies2.get(src) if dsts1 and dsts2: # copied/renamed on both sides if src not in m1 and src not in m2: # renamed on both sides dsts1 = set(dsts1) dsts2 = set(dsts2) # If there's some overlap in the rename destinations, we # consider it not divergent. For example, if side 1 copies 'a' # to 'b' and 'c' and deletes 'a', and side 2 copies 'a' to 'c' # and 'd' and deletes 'a'. if dsts1 & dsts2: for dst in (dsts1 & dsts2): copy[dst] = src else: diverge[src] = sorted(dsts1 | dsts2) elif src in m1 and src in m2: # copied on both sides dsts1 = set(dsts1) dsts2 = set(dsts2) for dst in (dsts1 & dsts2): copy[dst] = src # TODO: Handle cases where it was renamed on one side and copied # on the other side elif dsts1: # copied/renamed only on side 1 _checksinglesidecopies(src, dsts1, m1, m2, mb, c2, base, copy, renamedelete) elif dsts2: # copied/renamed only on side 2 _checksinglesidecopies(src, dsts2, m2, m1, mb, c1, base, copy, renamedelete) renamedeleteset = set() divergeset = set() for dsts in diverge.values(): divergeset.update(dsts) for dsts in renamedelete.values(): renamedeleteset.update(dsts) # find interesting file sets from manifests addedinm1 = m1.filesnotin(mb, repo.narrowmatch()) addedinm2 = m2.filesnotin(mb, repo.narrowmatch()) u1 = sorted(addedinm1 - addedinm2) u2 = sorted(addedinm2 - addedinm1) header = " unmatched files in %s" if u1: repo.ui.debug("%s:\n %s\n" % (header % 'local', "\n ".join(u1))) if u2: repo.ui.debug("%s:\n %s\n" % (header % 'other', "\n ".join(u2))) fullcopy = copies1.copy() fullcopy.update(copies2) if not fullcopy: return copy, {}, diverge, renamedelete, {} if repo.ui.debugflag: 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 divergeset: note += "!" if f in renamedeleteset: note += "%" repo.ui.debug(" src: '%s' -> dst: '%s' %s\n" % (fullcopy[f], f, note)) del divergeset repo.ui.debug(" checking for directory renames\n") # generate a directory move map d1, d2 = c1.dirs(), c2.dirs() # Hack for adding '', which is not otherwise added, to d1 and d2 d1.addpath('/') d2.addpath('/') 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 = pathutil.dirname(src), pathutil.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, renamedelete, {} dirmove = {k + "/": v + "/" for k, v in dirmove.iteritems()} for d in dirmove: repo.ui.debug(" discovered dir src: '%s' -> dst: '%s'\n" % (d, dirmove[d])) movewithdir = {} # 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, dirmove def _heuristicscopytracing(repo, c1, c2, base): """ Fast copytracing using filename heuristics Assumes that moves or renames are of following two types: 1) Inside a directory only (same directory name but different filenames) 2) Move from one directory to another (same filenames but different directory names) Works only when there are no merge commits in the "source branch". Source branch is commits from base up to c2 not including base. If merge is involved it fallbacks to _fullcopytracing(). Can be used by setting the following config: [experimental] copytrace = heuristics In some cases the copy/move candidates found by heuristics can be very large in number and that will make the algorithm slow. The number of possible candidates to check can be limited by using the config `experimental.copytrace.movecandidateslimit` which defaults to 100. """ if c1.rev() is None: c1 = c1.p1() if c2.rev() is None: c2 = c2.p1() copies = {} changedfiles = set() m1 = c1.manifest() if not repo.revs('%d::%d', base.rev(), c2.rev()): # If base is not in c2 branch, we switch to fullcopytracing repo.ui.debug("switching to full copytracing as base is not " "an ancestor of c2\n") return _fullcopytracing(repo, c1, c2, base) ctx = c2 while ctx != base: if len(ctx.parents()) == 2: # To keep things simple let's not handle merges repo.ui.debug("switching to full copytracing because of merges\n") return _fullcopytracing(repo, c1, c2, base) changedfiles.update(ctx.files()) ctx = ctx.p1() cp = _forwardcopies(base, c2) for dst, src in cp.iteritems(): if src in m1: copies[dst] = src # file is missing if it isn't present in the destination, but is present in # the base and present in the source. # Presence in the base is important to exclude added files, presence in the # source is important to exclude removed files. filt = lambda f: f not in m1 and f in base and f in c2 missingfiles = [f for f in changedfiles if filt(f)] if missingfiles: basenametofilename = collections.defaultdict(list) dirnametofilename = collections.defaultdict(list) for f in m1.filesnotin(base.manifest()): basename = os.path.basename(f) dirname = os.path.dirname(f) basenametofilename[basename].append(f) dirnametofilename[dirname].append(f) for f in missingfiles: basename = os.path.basename(f) dirname = os.path.dirname(f) samebasename = basenametofilename[basename] samedirname = dirnametofilename[dirname] movecandidates = samebasename + samedirname # f is guaranteed to be present in c2, that's why # c2.filectx(f) won't fail f2 = c2.filectx(f) # we can have a lot of candidates which can slow down the heuristics # config value to limit the number of candidates moves to check maxcandidates = repo.ui.configint('experimental', 'copytrace.movecandidateslimit') if len(movecandidates) > maxcandidates: repo.ui.status(_("skipping copytracing for '%s', more " "candidates than the limit: %d\n") % (f, len(movecandidates))) continue for candidate in movecandidates: f1 = c1.filectx(candidate) if _related(f1, f2): # if there are a few related copies then we'll merge # changes into all of them. This matches the behaviour # of upstream copytracing copies[candidate] = f return copies, {}, {}, {}, {} def _related(f1, f2): """return True if f1 and f2 filectx have a common ancestor 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 True # a match g1, g2 = f1.ancestors(), f2.ancestors() try: f1r, f2r = f1.linkrev(), f2.linkrev() if f1r is None: f1 = next(g1) if f2r is None: f2 = next(g2) while True: f1r, f2r = f1.linkrev(), f2.linkrev() if f1r > f2r: f1 = next(g1) elif f2r > f1r: f2 = next(g2) else: # f1 and f2 point to files in the same linkrev return f1 == f2 # true if they point to the same file except StopIteration: return False def duplicatecopies(repo, wctx, rev, fromrev, skiprev=None): """reproduce copies from fromrev to rev in the dirstate If skiprev is specified, it's a revision that should be used to filter copy records. Any copies that occur between fromrev and skiprev will not be duplicated, even if they appear in the set of copies between fromrev and rev. """ exclude = {} ctraceconfig = repo.ui.config('experimental', 'copytrace') bctrace = stringutil.parsebool(ctraceconfig) if (skiprev is not None and (ctraceconfig == 'heuristics' or bctrace or bctrace is None)): # copytrace='off' skips this line, but not the entire function because # the line below is O(size of the repo) during a rebase, while the rest # of the function is much faster (and is required for carrying copy # metadata across the rebase anyway). exclude = pathcopies(repo[fromrev], repo[skiprev]) for dst, src in pathcopies(repo[fromrev], repo[rev]).iteritems(): # copies.pathcopies returns backward renames, so dst might not # actually be in the dirstate if dst in exclude: continue wctx[dst].markcopied(src)