Mercurial > hg
view contrib/shrink-revlog.py @ 10229:9df52218810d stable
shrink-revlog: avoid cryptic error when used as an extension
When shrink-revlog is used as an extension, it would produce an error when
switching back to stable because the script will try to execute itself.
author | Benoit Boissinot <benoit.boissinot@ens-lyon.org> |
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date | Mon, 11 Jan 2010 21:44:04 +0100 |
parents | 18b134ef294c |
children | 9f0c7be7c46c |
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#!/usr/bin/env python """\ Reorder a revlog (by default the the manifest file in the current repository) to save space. Specifically, this topologically sorts the revisions in the revlog so that revisions on the same branch are adjacent as much as possible. This is a workaround for the fact that Mercurial computes deltas relative to the previous revision rather than relative to a parent revision. This is *not* safe to run on a changelog. """ # Originally written by Benoit Boissinot <benoit.boissinot at ens-lyon.org> # as a patch to rewrite-log. Cleaned up, refactored, documented, and # renamed by Greg Ward <greg at gerg.ca>. # XXX would be nice to have a way to verify the repository after shrinking, # e.g. by comparing "before" and "after" states of random changesets # (maybe: export before, shrink, export after, diff). import sys, os, tempfile import optparse from mercurial import ui as ui_, hg, revlog, transaction, node, util def toposort(rl): write = sys.stdout.write children = {} root = [] # build children and roots write('reading %d revs ' % len(rl)) try: for i in rl: children[i] = [] parents = [p for p in rl.parentrevs(i) if p != node.nullrev] # in case of duplicate parents if len(parents) == 2 and parents[0] == parents[1]: del parents[1] for p in parents: assert p in children children[p].append(i) if len(parents) == 0: root.append(i) if i % 1000 == 0: write('.') finally: write('\n') # XXX this is a reimplementation of the 'branchsort' topo sort # algorithm in hgext.convert.convcmd... would be nice not to duplicate # the algorithm write('sorting ...') visit = root ret = [] while visit: i = visit.pop(0) ret.append(i) if i not in children: # This only happens if some node's p1 == p2, which can # happen in the manifest in certain circumstances. continue next = [] for c in children.pop(i): parents_unseen = [p for p in rl.parentrevs(c) if p != node.nullrev and p in children] if len(parents_unseen) == 0: next.append(c) visit = next + visit write('\n') return ret def writerevs(r1, r2, order, tr): write = sys.stdout.write write('writing %d revs ' % len(order)) try: count = 0 for rev in order: n = r1.node(rev) p1, p2 = r1.parents(n) l = r1.linkrev(rev) t = r1.revision(n) n2 = r2.addrevision(t, tr, l, p1, p2) if count % 1000 == 0: write('.') count += 1 finally: write('\n') def report(olddatafn, newdatafn): oldsize = float(os.stat(olddatafn).st_size) newsize = float(os.stat(newdatafn).st_size) # argh: have to pass an int to %d, because a float >= 2^32 # blows up under Python 2.5 or earlier sys.stdout.write('old file size: %12d bytes (%6.1f MiB)\n' % (int(oldsize), oldsize/1024/1024)) sys.stdout.write('new file size: %12d bytes (%6.1f MiB)\n' % (int(newsize), newsize/1024/1024)) shrink_percent = (oldsize - newsize) / oldsize * 100 shrink_factor = oldsize / newsize sys.stdout.write('shrinkage: %.1f%% (%.1fx)\n' % (shrink_percent, shrink_factor)) def main(): # Unbuffer stdout for nice progress output. sys.stdout = os.fdopen(sys.stdout.fileno(), 'w', 0) write = sys.stdout.write parser = optparse.OptionParser(description=__doc__) parser.add_option('-R', '--repository', default=os.path.curdir, metavar='REPO', help='repository root directory [default: current dir]') parser.add_option('--revlog', metavar='FILE', help='shrink FILE [default: REPO/hg/store/00manifest.i]') (options, args) = parser.parse_args() if args: parser.error('too many arguments') # Open the specified repository. ui = ui_.ui() repo = hg.repository(ui, options.repository) if not repo.local(): parser.error('not a local repository: %s' % options.repository) if options.revlog is None: indexfn = repo.sjoin('00manifest.i') else: if not options.revlog.endswith('.i'): parser.error('--revlog option must specify the revlog index file ' '(*.i), not %s' % options.revlog) indexfn = os.path.realpath(options.revlog) store = repo.sjoin('') if not indexfn.startswith(store): parser.error('--revlog option must specify a revlog in %s, not %s' % (store, indexfn)) datafn = indexfn[:-2] + '.d' if not os.path.exists(indexfn): parser.error('no such file: %s' % indexfn) if '00changelog' in indexfn: parser.error('shrinking the changelog will corrupt your repository') if not os.path.exists(datafn): # This is just a lazy shortcut because I can't be bothered to # handle all the special cases that entail from no .d file. parser.error('%s does not exist: revlog not big enough ' 'to be worth shrinking' % datafn) oldindexfn = indexfn + '.old' olddatafn = datafn + '.old' if os.path.exists(oldindexfn) or os.path.exists(olddatafn): parser.error('one or both of\n' ' %s\n' ' %s\n' 'exists from a previous run; please clean up before ' 'running again' % (oldindexfn, olddatafn)) write('shrinking %s\n' % indexfn) prefix = os.path.basename(indexfn)[:-1] (tmpfd, tmpindexfn) = tempfile.mkstemp(dir=os.path.dirname(indexfn), prefix=prefix, suffix='.i') tmpdatafn = tmpindexfn[:-2] + '.d' os.close(tmpfd) r1 = revlog.revlog(util.opener(os.getcwd(), audit=False), indexfn) r2 = revlog.revlog(util.opener(os.getcwd(), audit=False), tmpindexfn) # Don't use repo.transaction(), because then things get hairy with # paths: some need to be relative to .hg, and some need to be # absolute. Doing it this way keeps things simple: everything is an # absolute path. lock = repo.lock(wait=False) tr = transaction.transaction(sys.stderr.write, open, repo.sjoin('journal')) try: try: order = toposort(r1) writerevs(r1, r2, order, tr) report(datafn, tmpdatafn) tr.close() except: # Abort transaction first, so we truncate the files before # deleting them. tr.abort() if os.path.exists(tmpindexfn): os.unlink(tmpindexfn) if os.path.exists(tmpdatafn): os.unlink(tmpdatafn) raise finally: lock.release() os.link(indexfn, oldindexfn) os.link(datafn, olddatafn) os.rename(tmpindexfn, indexfn) os.rename(tmpdatafn, datafn) write('note: old revlog saved in:\n' ' %s\n' ' %s\n' '(You can delete those files when you are satisfied that your\n' 'repository is still sane. ' 'Running \'hg verify\' is strongly recommended.)\n' % (oldindexfn, olddatafn)) if __name__ == "__main__": try: main() except KeyboardInterrupt: sys.exit("interrupted")