shrink-revlog: preserve mode of the shrunken index and data file.

Otherwise, the shrunken index file always has mode 0600 thanks to
mkstemp(). This is annoying on a server, where multiple users may need
to read/write the manifest. chmod()ing the data file is not strictly
necessary, but it's nice for consistency.

contrib/shrink-revlog.py

@@ -1,237 +1,242 b''
 #!/usr/bin/env python
 
 """\
 reorder a revlog (the manifest by default) 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 os, tempfile, errno
 from mercurial import revlog, transaction, node, util
 from mercurial import changegroup
 from mercurial.i18n import _
 
 def toposort(ui, rl):
 
     children = {}
     root = []
     # build children and roots
     ui.status(_('reading revs\n'))
     try:
         for i in rl:
             ui.progress(_('reading'), i, total=len(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)
     finally:
         ui.progress(_('reading'), None, total=len(rl))
 
     # XXX this is a reimplementation of the 'branchsort' topo sort
     # algorithm in hgext.convert.convcmd... would be nice not to duplicate
     # the algorithm
     ui.status(_('sorting revs\n'))
     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
     return ret
 
 def writerevs(ui, r1, r2, order, tr):
 
     ui.status(_('writing revs\n'))
 
     count = [0]
     def progress(*args):
         ui.progress(_('writing'), count[0], total=len(order))
         count[0] += 1
 
     order = [r1.node(r) for r in order]
 
     # this is a bit ugly, but it works
     lookup = lambda x: "%020d" % r1.linkrev(r1.rev(x))
     unlookup = lambda x: int(x, 10)
 
     try:
         group = util.chunkbuffer(r1.group(order, lookup, progress))
         chunkiter = changegroup.chunkiter(group)
         r2.addgroup(chunkiter, unlookup, tr)
     finally:
         ui.progress(_('writing'), None, len(order))
 
 def report(ui, r1, r2):
     def getsize(r):
         s = 0
         for fn in (r.indexfile, r.datafile):
             try:
                 s += os.stat(fn).st_size
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     raise
         return s
 
     oldsize = float(getsize(r1))
     newsize = float(getsize(r2))
 
     # argh: have to pass an int to %d, because a float >= 2^32
     # blows up under Python 2.5 or earlier
     ui.write(_('old file size: %12d bytes (%6.1f MiB)\n')
              % (int(oldsize), oldsize / 1024 / 1024))
     ui.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
     ui.write(_('shrinkage: %.1f%% (%.1fx)\n')
              % (shrink_percent, shrink_factor))
 
 def shrink(ui, repo, **opts):
     """
     Shrink revlog by re-ordering revisions. Will operate on manifest for
     the given repository if no other revlog is specified."""
 
     if not repo.local():
         raise util.Abort(_('not a local repository: %s') % repo.root)
 
     fn = opts.get('revlog')
     if not fn:
         indexfn = repo.sjoin('00manifest.i')
     else:
         if not fn.endswith('.i'):
             raise util.Abort(_('--revlog option must specify the revlog index '
                                'file (*.i), not %s') % opts.get('revlog'))
 
         indexfn = os.path.realpath(fn)
         store = repo.sjoin('')
         if not indexfn.startswith(store):
             raise util.Abort(_('--revlog option must specify a revlog in %s, '
                                'not %s') % (store, indexfn))
 
     if not os.path.exists(indexfn):
         raise util.Abort(_('no such file: %s') % indexfn)
     if '00changelog' in indexfn:
         raise util.Abort(_('shrinking the changelog '
                            'will corrupt your repository'))
 
     ui.write(_('shrinking %s\n') % indexfn)
     prefix = os.path.basename(indexfn)[:-1]
     (tmpfd, tmpindexfn) = tempfile.mkstemp(dir=os.path.dirname(indexfn),
                                            prefix=prefix,
                                            suffix='.i')
     os.close(tmpfd)
 
     r1 = revlog.revlog(util.opener(os.getcwd(), audit=False), indexfn)
     r2 = revlog.revlog(util.opener(os.getcwd(), audit=False), tmpindexfn)
 
     datafn, tmpdatafn = r1.datafile, r2.datafile
 
     oldindexfn = indexfn + '.old'
     olddatafn = datafn + '.old'
     if os.path.exists(oldindexfn) or os.path.exists(olddatafn):
         raise util.Abort(_('one or both of\n'
                            '  %s\n'
                            '  %s\n'
                            'exists from a previous run; please clean up '
                            'before running again') % (oldindexfn, olddatafn))
 
     # 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(ui.warn,
                                  open,
                                  repo.sjoin('journal'))
 
     def ignoremissing(func):
         def f(*args, **kw):
             try:
                 return func(*args, **kw)
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     raise
         return f
 
     try:
         try:
             order = toposort(ui, r1)
             writerevs(ui, r1, r2, order, tr)
             report(ui, r1, r2)
             tr.close()
         except:
             # Abort transaction first, so we truncate the files before
             # deleting them.
             tr.abort()
             for fn in (tmpindexfn, tmpdatafn):
                 ignoremissing(os.unlink)(fn)
             raise
         if not opts.get('dry_run'):
             # racy, both files cannot be renamed atomically
             # copy files
             util.os_link(indexfn, oldindexfn)
             ignoremissing(util.os_link)(datafn, olddatafn)
+
+            # mkstemp() creates files only readable by the owner
+            os.chmod(tmpindexfn, os.stat(indexfn).st_mode)
+
             # rename
             util.rename(tmpindexfn, indexfn)
             try:
+                os.chmod(tmpdatafn, os.stat(datafn).st_mode)
                 util.rename(tmpdatafn, datafn)
             except OSError, inst:
                 if inst.errno != errno.ENOENT:
                     raise
                 ignoremissing(os.unlink)(datafn)
         else:
             for fn in (tmpindexfn, tmpdatafn):
                 ignoremissing(os.unlink)(fn)
     finally:
         lock.release()
 
     if not opts.get('dry_run'):
         ui.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))
 
 cmdtable = {
     'shrink': (shrink,
                [('', 'revlog', '', _('index (.i) file of the revlog to shrink')),
                 ('n', 'dry-run', None, _('do not shrink, simulate only')),
                 ],
                _('hg shrink [--revlog PATH]'))
 }
 
 if __name__ == "__main__":
     print "shrink-revlog.py is now an extension (see hg help extensions)"