mbthomas created this revision. Herald added a subscriber: mercurial-devel. Herald added a reviewer: hg-reviewers.
REVISION SUMMARY As mentioned in https://phab.mercurial-scm.org/D1222, the recent pathconflicts change regresses update performance in large repositories when many files are being updated. To mitigate this, we introduce two caches of directories that have already found to be either: - unknown directories, but which are not aliased by files and so don't need to be checked if they are files again; and - missing directores, which cannot cause path conflicts, and cannot contain a file that causes a path conflict. When checking the paths of a file, testing against this caches means we can skip tests that involve touching the filesystem. REPOSITORY rHG Mercurial REVISION DETAIL https://phab.mercurial-scm.org/D1224 AFFECTED FILES mercurial/merge.py CHANGE DETAILS diff --git a/mercurial/merge.py b/mercurial/merge.py --- a/mercurial/merge.py +++ b/mercurial/merge.py @@ -653,23 +653,40 @@ and repo.dirstate.normalize(f) not in repo.dirstate and mctx[f2].cmp(wctx[f])) -def _checkunknowndirs(repo, f): +def _checkunknowndirs(repo, f, unknowndircache, missingdircache): """ Look for any unknown files or directories that may have a path conflict with a file. If any path prefix of the file exists as a file or link, then it conflicts. If the file itself is a directory that contains any file that is not tracked, then it conflicts. + `unknowndircache` is a set of paths known to be good. This prevents + repeated checking of dirs. It will be updated with any new dirs that + are checked and found to be safe. + + `missingdircache` is a set of paths that are known to be absent. This + prevents repeated checking of subdirectories that are known not to exist. + It will be updated with any new dirs that are checked and found to be + absent. + Returns the shortest path at which a conflict occurs, or None if there is no conflict. """ # Check for path prefixes that exist as unknown files. for p in reversed(list(util.finddirs(f))): - if (repo.wvfs.audit.check(p) - and repo.wvfs.isfileorlink(p) - and repo.dirstate.normalize(p) not in repo.dirstate): - return p + if p in missingdircache: + return + if p in unknowndircache: + continue + if repo.wvfs.audit.check(p): + if (repo.wvfs.isfileorlink(p) + and repo.dirstate.normalize(p) not in repo.dirstate): + return p + if not repo.wvfs.lexists(p): + missingdircache.add(p) + return + unknowndircache.add(p) # Check if the file conflicts with a directory containing unknown files. if repo.wvfs.audit.check(f) and repo.wvfs.isdir(f): @@ -700,12 +717,15 @@ elif config == 'warn': warnconflicts.update(conflicts) + unknowndircache = set() + missingdircache = set() for f, (m, args, msg) in actions.iteritems(): if m in ('c', 'dc'): if _checkunknownfile(repo, wctx, mctx, f): fileconflicts.add(f) elif f not in wctx: - path = _checkunknowndirs(repo, f) + path = _checkunknowndirs(repo, f, + unknowndircache, missingdircache) if path is not None: pathconflicts.add(path) elif m == 'dg': To: mbthomas, #hg-reviewers Cc: mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
