# Copyright 2017-present Facebook. All Rights Reserved. # # faster copytrace implementation # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. '''extension that does copytracing fast :: [copytrace] # whether to enable fast copytracing or not fastcopytrace = False # limits the number of commits in the source "branch" i. e. "branch". # that is rebased or merged. These are the commits from base up to csrc # (see _mergecopies docblock below). # copytracing can be too slow if there are too # many commits in this "branch". sourcecommitlimit = 100 # limits the number of heuristically found move candidates to check maxmovescandidatestocheck = 5 ''' from collections import defaultdict from mercurial import ( commands, copies as copiesmod, dispatch, extensions, filemerge, node, util, ) from mercurial.i18n import _ import os import time _copytracinghint = ("hint: if this message is due to a moved file, you can " + "ask mercurial to attempt to automatically resolve this " + "change by re-running with the --tracecopies flag, but " + "this will significantly slow down the operation, so you " + "will need to be patient.\n" + "Source control team is working on fixing this problem.\n") def uisetup(ui): extensions.wrapfunction(dispatch, "runcommand", _runcommand) def extsetup(ui): commands.globalopts.append( ("", "tracecopies", None, _("enable copytracing. Warning: can be very slow!"))) # With experimental.disablecopytrace=True there can be cryptic merge errors. # Let"s change error message to suggest re-running the command with # enabled copytracing filemerge._localchangedotherdeletedmsg = _( "local%(l)s changed %(fd)s which other%(o)s deleted\n" + _copytracinghint + "use (c)hanged version, (d)elete, or leave (u)nresolved?" "$$ &Changed $$ &Delete $$ &Unresolved") filemerge._otherchangedlocaldeletedmsg = _( "other%(o)s changed %(fd)s which local%(l)s deleted\n" + _copytracinghint + "use (c)hanged version, leave (d)eleted, or leave (u)nresolved?" "$$ &Changed $$ &Deleted $$ &Unresolved") extensions.wrapfunction(filemerge, '_filemerge', _filemerge) extensions.wrapfunction(copiesmod, 'mergecopies', _mergecopies) def _filemerge(origfunc, premerge, repo, mynode, orig, fcd, fco, fca, labels=None, *args, **kwargs): if premerge: # copytracing worked if files to merge have different file names # and filelog contents are different (fco.cmp(fcd) returns True if # they are different). If filelog contents are the same then the file # was moved in the rebase/graft/merge source, but wasn't changed in the # rebase/graft/merge destination. This case mercurial would've handled # even with disabled copytracing, so we don't want to log it. if orig != fco.path() and fco.cmp(fcd): # copytracing was in action, let's record it if not repo.ui.configbool("experimental", "disablecopytrace"): msg = "success" else: msg = "success (fastcopytracing)" try: destctx = _getctxfromfctx(fcd) srcctx = _getctxfromfctx(fco) hexes = '%s, %s' % (_gethex(destctx), _gethex(srcctx)) paths = '%s, %s' % (orig, fco.path()) msg = "%s (%s; %s)" % (msg, hexes, paths) except Exception as e: # we don't expect any exceptions to happen, but to be 100% # sure we don't break hg let's catch everything and log it msg = 'failed to log: %s' % (e,) repo.ui.log("copytrace", msg=msg, reponame=_getreponame(repo, repo.ui)) return origfunc(premerge, repo, mynode, orig, fcd, fco, fca, labels, *args, **kwargs) def _runcommand(orig, lui, repo, cmd, fullargs, ui, *args, **kwargs): if "--tracecopies" in fullargs: ui.setconfig("experimental", "disablecopytrace", False, "--tracecopies") return orig(lui, repo, cmd, fullargs, ui, *args, **kwargs) def _mergecopies(orig, repo, cdst, csrc, base): start = time.time() try: return _domergecopies(orig, repo, cdst, csrc, base) except Exception as e: # make sure we don't break clients repo.ui.log("copytrace", "Copytrace failed: %s" % e, reponame=_getreponame(repo, repo.ui)) return {}, {}, {}, {}, {} finally: repo.ui.log("copytracingduration", "", copytracingduration=time.time() - start, fastcopytraceenabled=_fastcopytraceenabled(repo.ui)) def _domergecopies(orig, repo, cdst, csrc, base): """ Fast copytracing using filename heuristics Handle one case where we assume there are no merge commits in "source branch". Source branch is commits from base up to csrc not including base. If these assumptions don't hold then we fallback to the upstream mergecopies p | p <- cdst - rebase or merge destination, can be draft . . . d <- csrc - commit to be rebased or merged. | | p d <- base | / p <- common ancestor To find copies we are looking for files with similar filenames. See description of the heuristics below. Upstream copytracing function returns five dicts: "copy", "movewithdir", "diverge", "renamedelete" and "dirmove". See below for a more detailed description (mostly copied from upstream). This extension returns "copy" dict only, everything else is empty. "copy" is a mapping from destination name -> source name, where source is in csrc and destination is in cdst 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. On the time of writing this extension it was used only to print warning. "renamedelete" is a mapping of source name -> list of destination names for files deleted in c1 that were renamed in c2 or vice-versa. On the time of writing this extension it was used only to print warning. "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. """ if not repo.ui.configbool("experimental", "disablecopytrace"): # user explicitly enabled copytracing - use it return orig(repo, cdst, csrc, base) if not _fastcopytraceenabled(repo.ui): return orig(repo, cdst, csrc, base) if not cdst or not csrc or cdst == csrc: return {}, {}, {}, {}, {} # avoid silly behavior for parent -> working dir if csrc.node() is None and cdst.node() == repo.dirstate.p1(): return repo.dirstate.copies(), {}, {}, {}, {} if cdst.rev() is None: cdst = cdst.p1() if csrc.rev() is None: csrc = csrc.p1() copies = {} ctx = csrc changedfiles = set() sourcecommitnum = 0 sourcecommitlimit = repo.ui.configint('copytrace', 'sourcecommitlimit', 100) mdst = cdst.manifest() while ctx != base: if len(ctx.parents()) == 2: # To keep things simple let's not handle merges return orig(repo, cdst, csrc, base) changedfiles.update(ctx.files()) ctx = ctx.p1() sourcecommitnum += 1 if sourcecommitnum > sourcecommitlimit: return orig(repo, cdst, csrc, base) cp = copiesmod._forwardcopies(base, csrc) for dst, src in cp.iteritems(): if src in mdst: 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. missingfiles = filter(lambda f: f not in mdst and f in base and f in csrc, changedfiles) if missingfiles: # Use the following file name heuristic to find moves: moves are # usually either directory moves or renames of the files in the # same directory. That means that we can look for the files in dstc # with either the same basename or the same dirname. basenametofilename = defaultdict(list) dirnametofilename = defaultdict(list) for f in mdst.filesnotin(base.manifest()): basename = os.path.basename(f) dirname = os.path.dirname(f) basenametofilename[basename].append(f) dirnametofilename[dirname].append(f) maxmovecandidatestocheck = repo.ui.configint( 'copytrace', 'maxmovescandidatestocheck', 5) # in case of a rebase/graft, base may not be a common ancestor anc = cdst.ancestor(csrc) 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 csrc, that's why # csrc.filectx(f) won't fail f2 = csrc.filectx(f) for candidate in movecandidates[:maxmovecandidatestocheck]: f1 = cdst.filectx(candidate) if copiesmod._related(f1, f2, anc.rev()): # 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 if len(movecandidates) > maxmovecandidatestocheck: msg = "too many moves candidates: %d" % len(movecandidates) repo.ui.log("copytrace", msg=msg, reponame=_getreponame(repo, repo.ui)) return copies, {}, {}, {}, {} def _fastcopytraceenabled(ui): return ui.configbool("copytrace", "fastcopytrace", False) def _getreponame(repo, ui): reporoot = repo.origroot if util.safehasattr(repo, 'origroot') else '' reponame = ui.config('paths', 'default', reporoot) if reponame: reponame = os.path.basename(reponame) return reponame def _getctxfromfctx(fctx): if fctx.isabsent(): return fctx._ctx else: return fctx._changectx def _gethex(ctx): # for workingctx return p1 hex return ctx.hex() if ctx.node() != node.wdirid else ctx.p1().hex()