largefiles: allow minimum size to be a float

Some old-fashioned people (e.g. me) think that incompressible
binary files >100 kB count as "large".

hgext/largefiles/lfcommands.py

@@ -1,473 +1,473 b''
 # Copyright 2009-2010 Gregory P. Ward
 # Copyright 2009-2010 Intelerad Medical Systems Incorporated
 # Copyright 2010-2011 Fog Creek Software
 # Copyright 2010-2011 Unity Technologies
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''High-level command functions: lfadd() et. al, plus the cmdtable.'''
 
 import os
 import shutil
 
 from mercurial import util, match as match_, hg, node, context, error
 from mercurial.i18n import _
 
 import lfutil
 import basestore
 
 # -- Commands ----------------------------------------------------------
 
 def lfconvert(ui, src, dest, *pats, **opts):
     '''Convert a normal repository to a largefiles repository
 
     Convert source repository creating an identical repository, except that all
     files that match the patterns given, or are over the given size will be
     added as largefiles. The size used to determine whether or not to track a
     file as a largefile is the size of the first version of the file. After
     running this command you will need to make sure that largefiles is enabled
     anywhere you intend to push the new repository.'''
 
     if opts['tonormal']:
         tolfile = False
     else:
         tolfile = True
         size = lfutil.getminsize(ui, True, opts.get('size'), default=None)
     try:
         rsrc = hg.repository(ui, src)
         if not rsrc.local():
             raise util.Abort(_('%s is not a local Mercurial repo') % src)
     except error.RepoError, err:
         ui.traceback()
         raise util.Abort(err.args[0])
     if os.path.exists(dest):
         if not os.path.isdir(dest):
             raise util.Abort(_('destination %s already exists') % dest)
         elif os.listdir(dest):
             raise util.Abort(_('destination %s is not empty') % dest)
     try:
         ui.status(_('initializing destination %s\n') % dest)
         rdst = hg.repository(ui, dest, create=True)
         if not rdst.local():
             raise util.Abort(_('%s is not a local Mercurial repo') % dest)
     except error.RepoError:
         ui.traceback()
         raise util.Abort(_('%s is not a repo') % dest)
 
     success = False
     try:
         # Lock destination to prevent modification while it is converted to.
         # Don't need to lock src because we are just reading from its history
         # which can't change.
         dst_lock = rdst.lock()
 
         # Get a list of all changesets in the source.  The easy way to do this
         # is to simply walk the changelog, using changelog.nodesbewteen().
         # Take a look at mercurial/revlog.py:639 for more details.
         # Use a generator instead of a list to decrease memory usage
         ctxs = (rsrc[ctx] for ctx in rsrc.changelog.nodesbetween(None,
             rsrc.heads())[0])
         revmap = {node.nullid: node.nullid}
         if tolfile:
             lfiles = set()
             normalfiles = set()
             if not pats:
                 pats = ui.config(lfutil.longname, 'patterns', default=())
                 if pats:
                     pats = pats.split(' ')
             if pats:
                 matcher = match_.match(rsrc.root, '', list(pats))
             else:
                 matcher = None
 
             lfiletohash = {}
             for ctx in ctxs:
                 ui.progress(_('converting revisions'), ctx.rev(),
                     unit=_('revision'), total=rsrc['tip'].rev())
                 _lfconvert_addchangeset(rsrc, rdst, ctx, revmap,
                     lfiles, normalfiles, matcher, size, lfiletohash)
             ui.progress(_('converting revisions'), None)
 
             if os.path.exists(rdst.wjoin(lfutil.shortname)):
                 shutil.rmtree(rdst.wjoin(lfutil.shortname))
 
             for f in lfiletohash.keys():
                 if os.path.isfile(rdst.wjoin(f)):
                     os.unlink(rdst.wjoin(f))
                 try:
                     os.removedirs(os.path.dirname(rdst.wjoin(f)))
                 except OSError:
                     pass
 
         else:
             for ctx in ctxs:
                 ui.progress(_('converting revisions'), ctx.rev(),
                     unit=_('revision'), total=rsrc['tip'].rev())
                 _addchangeset(ui, rsrc, rdst, ctx, revmap)
 
             ui.progress(_('converting revisions'), None)
         success = True
     finally:
         if not success:
             # we failed, remove the new directory
             shutil.rmtree(rdst.root)
         dst_lock.release()
 
 def _addchangeset(ui, rsrc, rdst, ctx, revmap):
  # Convert src parents to dst parents
     parents = []
     for p in ctx.parents():
         parents.append(revmap[p.node()])
     while len(parents) < 2:
         parents.append(node.nullid)
 
     # Generate list of changed files
     files = set(ctx.files())
     if node.nullid not in parents:
         mc = ctx.manifest()
         mp1 = ctx.parents()[0].manifest()
         mp2 = ctx.parents()[1].manifest()
         files |= (set(mp1) | set(mp2)) - set(mc)
         for f in mc:
             if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                 files.add(f)
 
     def getfilectx(repo, memctx, f):
         if lfutil.standin(f) in files:
             # if the file isn't in the manifest then it was removed
             # or renamed, raise IOError to indicate this
             try:
                 fctx = ctx.filectx(lfutil.standin(f))
             except error.LookupError:
                 raise IOError()
             renamed = fctx.renamed()
             if renamed:
                 renamed = lfutil.splitstandin(renamed[0])
 
             hash = fctx.data().strip()
             path = lfutil.findfile(rsrc, hash)
             ### TODO: What if the file is not cached?
             data = ''
             fd = None
             try:
                 fd = open(path, 'rb')
                 data = fd.read()
             finally:
                 if fd:
                     fd.close()
             return context.memfilectx(f, data, 'l' in fctx.flags(),
                                       'x' in fctx.flags(), renamed)
         else:
             try:
                 fctx = ctx.filectx(f)
             except error.LookupError:
                 raise IOError()
             renamed = fctx.renamed()
             if renamed:
                 renamed = renamed[0]
             data = fctx.data()
             if f == '.hgtags':
                 newdata = []
                 for line in data.splitlines():
                     id, name = line.split(' ', 1)
                     newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]),
                         name))
                 data = ''.join(newdata)
             return context.memfilectx(f, data, 'l' in fctx.flags(),
                                       'x' in fctx.flags(), renamed)
 
     dstfiles = []
     for file in files:
         if lfutil.isstandin(file):
             dstfiles.append(lfutil.splitstandin(file))
         else:
             dstfiles.append(file)
     # Commit
     mctx = context.memctx(rdst, parents, ctx.description(), dstfiles,
                           getfilectx, ctx.user(), ctx.date(), ctx.extra())
     ret = rdst.commitctx(mctx)
     rdst.dirstate.setparents(ret)
     revmap[ctx.node()] = rdst.changelog.tip()
 
 def _lfconvert_addchangeset(rsrc, rdst, ctx, revmap, lfiles, normalfiles,
         matcher, size, lfiletohash):
     # Convert src parents to dst parents
     parents = []
     for p in ctx.parents():
         parents.append(revmap[p.node()])
     while len(parents) < 2:
         parents.append(node.nullid)
 
     # Generate list of changed files
     files = set(ctx.files())
     if node.nullid not in parents:
         mc = ctx.manifest()
         mp1 = ctx.parents()[0].manifest()
         mp2 = ctx.parents()[1].manifest()
         files |= (set(mp1) | set(mp2)) - set(mc)
         for f in mc:
             if mc[f] != mp1.get(f, None) or mc[f] != mp2.get(f, None):
                 files.add(f)
 
     dstfiles = []
     for f in files:
         if f not in lfiles and f not in normalfiles:
             islfile = _islfile(f, ctx, matcher, size)
             # If this file was renamed or copied then copy
             # the lfileness of its predecessor
             if f in ctx.manifest():
                 fctx = ctx.filectx(f)
                 renamed = fctx.renamed()
                 renamedlfile = renamed and renamed[0] in lfiles
                 islfile |= renamedlfile
                 if 'l' in fctx.flags():
                     if renamedlfile:
                         raise util.Abort(
                             _('Renamed/copied largefile %s becomes symlink')
                             % f)
                     islfile = False
             if islfile:
                 lfiles.add(f)
             else:
                 normalfiles.add(f)
 
         if f in lfiles:
             dstfiles.append(lfutil.standin(f))
             # lfile in manifest if it has not been removed/renamed
             if f in ctx.manifest():
                 if 'l' in ctx.filectx(f).flags():
                     if renamed and renamed[0] in lfiles:
                         raise util.Abort(_('largefile %s becomes symlink') % f)
 
                 # lfile was modified, update standins
                 fullpath = rdst.wjoin(f)
                 lfutil.createdir(os.path.dirname(fullpath))
                 m = util.sha1('')
                 m.update(ctx[f].data())
                 hash = m.hexdigest()
                 if f not in lfiletohash or lfiletohash[f] != hash:
                     try:
                         fd = open(fullpath, 'wb')
                         fd.write(ctx[f].data())
                     finally:
                         if fd:
                             fd.close()
                     executable = 'x' in ctx[f].flags()
                     os.chmod(fullpath, lfutil.getmode(executable))
                     lfutil.writestandin(rdst, lfutil.standin(f), hash,
                         executable)
                     lfiletohash[f] = hash
         else:
             # normal file
             dstfiles.append(f)
 
     def getfilectx(repo, memctx, f):
         if lfutil.isstandin(f):
             # if the file isn't in the manifest then it was removed
             # or renamed, raise IOError to indicate this
             srcfname = lfutil.splitstandin(f)
             try:
                 fctx = ctx.filectx(srcfname)
             except error.LookupError:
                 raise IOError()
             renamed = fctx.renamed()
             if renamed:
                 # standin is always a lfile because lfileness
                 # doesn't change after rename or copy
                 renamed = lfutil.standin(renamed[0])
 
             return context.memfilectx(f, lfiletohash[srcfname], 'l' in
                 fctx.flags(), 'x' in fctx.flags(), renamed)
         else:
             try:
                 fctx = ctx.filectx(f)
             except error.LookupError:
                 raise IOError()
             renamed = fctx.renamed()
             if renamed:
                 renamed = renamed[0]
 
             data = fctx.data()
             if f == '.hgtags':
                 newdata = []
                 for line in data.splitlines():
                     id, name = line.split(' ', 1)
                     newdata.append('%s %s\n' % (node.hex(revmap[node.bin(id)]),
                         name))
                 data = ''.join(newdata)
             return context.memfilectx(f, data, 'l' in fctx.flags(),
                                       'x' in fctx.flags(), renamed)
 
     # Commit
     mctx = context.memctx(rdst, parents, ctx.description(), dstfiles,
                           getfilectx, ctx.user(), ctx.date(), ctx.extra())
     ret = rdst.commitctx(mctx)
     rdst.dirstate.setparents(ret)
     revmap[ctx.node()] = rdst.changelog.tip()
 
 def _islfile(file, ctx, matcher, size):
     '''
     A file is a lfile if it matches a pattern or is over
     the given size.
     '''
     # Never store hgtags or hgignore as lfiles
     if file == '.hgtags' or file == '.hgignore' or file == '.hgsigs':
         return False
     if matcher and matcher(file):
         return True
     try:
         return ctx.filectx(file).size() >= size * 1024 * 1024
     except error.LookupError:
         return False
 
 def uploadlfiles(ui, rsrc, rdst, files):
     '''upload largefiles to the central store'''
 
     # Don't upload locally. All largefiles are in the system wide cache
     # so the other repo can just get them from there.
     if not files or rdst.local():
         return
 
     store = basestore._openstore(rsrc, rdst, put=True)
 
     at = 0
     files = filter(lambda h: not store.exists(h), files)
     for hash in files:
         ui.progress(_('uploading largefiles'), at, unit='largefile',
                     total=len(files))
         source = lfutil.findfile(rsrc, hash)
         if not source:
             raise util.Abort(_('Missing largefile %s needs to be uploaded')
                              % hash)
         # XXX check for errors here
         store.put(source, hash)
         at += 1
     ui.progress(_('uploading largefiles'), None)
 
 def verifylfiles(ui, repo, all=False, contents=False):
     '''Verify that every big file revision in the current changeset
     exists in the central store.  With --contents, also verify that
     the contents of each big file revision are correct (SHA-1 hash
     matches the revision ID).  With --all, check every changeset in
     this repository.'''
     if all:
         # Pass a list to the function rather than an iterator because we know a
         # list will work.
         revs = range(len(repo))
     else:
         revs = ['.']
 
     store = basestore._openstore(repo)
     return store.verify(revs, contents=contents)
 
 def cachelfiles(ui, repo, node):
     '''cachelfiles ensures that all largefiles needed by the specified revision
     are present in the repository's largefile cache.
 
     returns a tuple (cached, missing).  cached is the list of files downloaded
     by this operation; missing is the list of files that were needed but could
     not be found.'''
     lfiles = lfutil.listlfiles(repo, node)
     toget = []
 
     for lfile in lfiles:
         expectedhash = repo[node][lfutil.standin(lfile)].data().strip()
         # if it exists and its hash matches, it might have been locally
         # modified before updating and the user chose 'local'.  in this case,
         # it will not be in any store, so don't look for it.
         if (not os.path.exists(repo.wjoin(lfile)) \
                 or expectedhash != lfutil.hashfile(repo.wjoin(lfile))) and \
                 not lfutil.findfile(repo, expectedhash):
             toget.append((lfile, expectedhash))
 
     if toget:
         store = basestore._openstore(repo)
         ret = store.get(toget)
         return ret
 
     return ([], [])
 
 def updatelfiles(ui, repo, filelist=None, printmessage=True):
     wlock = repo.wlock()
     try:
         lfdirstate = lfutil.openlfdirstate(ui, repo)
         lfiles = set(lfutil.listlfiles(repo)) | set(lfdirstate)
 
         if filelist is not None:
             lfiles = [f for f in lfiles if f in filelist]
 
         printed = False
         if printmessage and lfiles:
             ui.status(_('getting changed largefiles\n'))
             printed = True
             cachelfiles(ui, repo, '.')
 
         updated, removed = 0, 0
         for i in map(lambda f: _updatelfile(repo, lfdirstate, f), lfiles):
             # increment the appropriate counter according to _updatelfile's
             # return value
             updated += i > 0 and i or 0
             removed -= i < 0 and i or 0
             if printmessage and (removed or updated) and not printed:
                 ui.status(_('getting changed largefiles\n'))
                 printed = True
 
         lfdirstate.write()
         if printed and printmessage:
             ui.status(_('%d largefiles updated, %d removed\n') % (updated,
                 removed))
     finally:
         wlock.release()
 
 def _updatelfile(repo, lfdirstate, lfile):
     '''updates a single largefile and copies the state of its standin from
     the repository's dirstate to its state in the lfdirstate.
 
     returns 1 if the file was modified, -1 if the file was removed, 0 if the
     file was unchanged, and None if the needed largefile was missing from the
     cache.'''
     ret = 0
     abslfile = repo.wjoin(lfile)
     absstandin = repo.wjoin(lfutil.standin(lfile))
     if os.path.exists(absstandin):
         if os.path.exists(absstandin+'.orig'):
             shutil.copyfile(abslfile, abslfile+'.orig')
         expecthash = lfutil.readstandin(repo, lfile)
         if expecthash != '' and \
                 (not os.path.exists(abslfile) or \
                 expecthash != lfutil.hashfile(abslfile)):
             if not lfutil.copyfromcache(repo, expecthash, lfile):
                 return None # don't try to set the mode or update the dirstate
             ret = 1
         mode = os.stat(absstandin).st_mode
         if mode != os.stat(abslfile).st_mode:
             os.chmod(abslfile, mode)
             ret = 1
     else:
         if os.path.exists(abslfile):
             os.unlink(abslfile)
             ret = -1
     state = repo.dirstate[lfutil.standin(lfile)]
     if state == 'n':
         lfdirstate.normal(lfile)
     elif state == 'r':
         lfdirstate.remove(lfile)
     elif state == 'a':
         lfdirstate.add(lfile)
     elif state == '?':
         lfdirstate.drop(lfile)
     return ret
 
 # -- hg commands declarations ------------------------------------------------
 
 
 cmdtable = {
     'lfconvert': (lfconvert,
-                  [('s', 'size', 0, 'All files over this size (in megabytes) '
+                  [('s', 'size', '', 'All files over this size (in megabytes) '
                   'will be considered largefiles. This can also be specified '
                   'in your hgrc as [largefiles].size.'),
                   ('','tonormal',False,
                       'Convert from a largefiles repo to a normal repo')],
                   _('hg lfconvert SOURCE DEST [FILE ...]')),
     }

hgext/largefiles/lfutil.py

@@ -1,445 +1,445 b''
 # Copyright 2009-2010 Gregory P. Ward
 # Copyright 2009-2010 Intelerad Medical Systems Incorporated
 # Copyright 2010-2011 Fog Creek Software
 # Copyright 2010-2011 Unity Technologies
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 '''largefiles utility code: must not import other modules in this package.'''
 
 import os
 import errno
 import shutil
 import stat
 import hashlib
 
 from mercurial import dirstate, httpconnection, match as match_, util, scmutil
 from mercurial.i18n import _
 
 shortname = '.hglf'
 longname = 'largefiles'
 
 
 # -- Portability wrappers ----------------------------------------------
 
 def dirstate_walk(dirstate, matcher, unknown=False, ignored=False):
     return dirstate.walk(matcher, [], unknown, ignored)
 
 def repo_add(repo, list):
     add = repo[None].add
     return add(list)
 
 def repo_remove(repo, list, unlink=False):
     def remove(list, unlink):
         wlock = repo.wlock()
         try:
             if unlink:
                 for f in list:
                     try:
                         util.unlinkpath(repo.wjoin(f))
                     except OSError, inst:
                         if inst.errno != errno.ENOENT:
                             raise
             repo[None].forget(list)
         finally:
             wlock.release()
     return remove(list, unlink=unlink)
 
 def repo_forget(repo, list):
     forget = repo[None].forget
     return forget(list)
 
 def findoutgoing(repo, remote, force):
     from mercurial import discovery
     common, _anyinc, _heads = discovery.findcommonincoming(repo,
         remote, force=force)
     return repo.changelog.findmissing(common)
 
 # -- Private worker functions ------------------------------------------
 
 def getminsize(ui, assumelfiles, opt, default=10):
     lfsize = opt
     if not lfsize and assumelfiles:
         lfsize = ui.config(longname, 'size', default=default)
     if lfsize:
         try:
-            lfsize = int(lfsize)
+            lfsize = float(lfsize)
         except ValueError:
-            raise util.Abort(_('largefiles: size must be an integer, was %s\n')
+            raise util.Abort(_('largefiles: size must be number (not %s)\n')
                              % lfsize)
     if lfsize is None:
         raise util.Abort(_('minimum size for largefiles must be specified'))
     return lfsize
 
 def link(src, dest):
     try:
         util.oslink(src, dest)
     except OSError:
         # If hardlinks fail fall back on copy
         shutil.copyfile(src, dest)
         os.chmod(dest, os.stat(src).st_mode)
 
 def systemcachepath(ui, hash):
     path = ui.config(longname, 'systemcache', None)
     if path:
         path = os.path.join(path, hash)
     else:
         if os.name == 'nt':
             path = os.path.join(os.getenv('LOCALAPPDATA') or \
                 os.getenv('APPDATA'), longname, hash)
         elif os.name == 'posix':
             path = os.path.join(os.getenv('HOME'), '.' + longname, hash)
         else:
             raise util.Abort(_('Unknown operating system: %s\n') % os.name)
     return path
 
 def insystemcache(ui, hash):
     return os.path.exists(systemcachepath(ui, hash))
 
 def findfile(repo, hash):
     if incache(repo, hash):
         repo.ui.note(_('Found %s in cache\n') % hash)
         return cachepath(repo, hash)
     if insystemcache(repo.ui, hash):
         repo.ui.note(_('Found %s in system cache\n') % hash)
         return systemcachepath(repo.ui, hash)
     return None
 
 class largefiles_dirstate(dirstate.dirstate):
     def __getitem__(self, key):
         return super(largefiles_dirstate, self).__getitem__(unixpath(key))
     def normal(self, f):
         return super(largefiles_dirstate, self).normal(unixpath(f))
     def remove(self, f):
         return super(largefiles_dirstate, self).remove(unixpath(f))
     def add(self, f):
         return super(largefiles_dirstate, self).add(unixpath(f))
     def drop(self, f):
         return super(largefiles_dirstate, self).drop(unixpath(f))
     def forget(self, f):
         return super(largefiles_dirstate, self).forget(unixpath(f))
 
 def openlfdirstate(ui, repo):
     '''
     Return a dirstate object that tracks big files: i.e. its root is the
     repo root, but it is saved in .hg/largefiles/dirstate.
     '''
     admin = repo.join(longname)
     opener = scmutil.opener(admin)
     if util.safehasattr(repo.dirstate, '_validate'):
         lfdirstate = largefiles_dirstate(opener, ui, repo.root,
             repo.dirstate._validate)
     else:
         lfdirstate = largefiles_dirstate(opener, ui, repo.root)
 
     # If the largefiles dirstate does not exist, populate and create it.  This
     # ensures that we create it on the first meaningful largefiles operation in
     # a new clone.  It also gives us an easy way to forcibly rebuild largefiles
     # state:
     #   rm .hg/largefiles/dirstate && hg status
     # Or even, if things are really messed up:
     #   rm -rf .hg/largefiles && hg status
     if not os.path.exists(os.path.join(admin, 'dirstate')):
         util.makedirs(admin)
         matcher = getstandinmatcher(repo)
         for standin in dirstate_walk(repo.dirstate, matcher):
             lfile = splitstandin(standin)
             hash = readstandin(repo, lfile)
             lfdirstate.normallookup(lfile)
             try:
                 if hash == hashfile(lfile):
                     lfdirstate.normal(lfile)
             except IOError, err:
                 if err.errno != errno.ENOENT:
                     raise
 
         lfdirstate.write()
 
     return lfdirstate
 
 def lfdirstate_status(lfdirstate, repo, rev):
     wlock = repo.wlock()
     try:
         match = match_.always(repo.root, repo.getcwd())
         s = lfdirstate.status(match, [], False, False, False)
         unsure, modified, added, removed, missing, unknown, ignored, clean = s
         for lfile in unsure:
             if repo[rev][standin(lfile)].data().strip() != \
                     hashfile(repo.wjoin(lfile)):
                 modified.append(lfile)
             else:
                 clean.append(lfile)
                 lfdirstate.normal(lfile)
         lfdirstate.write()
     finally:
         wlock.release()
     return (modified, added, removed, missing, unknown, ignored, clean)
 
 def listlfiles(repo, rev=None, matcher=None):
     '''list largefiles in the working copy or specified changeset'''
 
     if matcher is None:
         matcher = getstandinmatcher(repo)
 
     # ignore unknown files in working directory
     return [splitstandin(f) for f in repo[rev].walk(matcher) \
             if rev is not None or repo.dirstate[f] != '?']
 
 def incache(repo, hash):
     return os.path.exists(cachepath(repo, hash))
 
 def createdir(dir):
     if not os.path.exists(dir):
         os.makedirs(dir)
 
 def cachepath(repo, hash):
     return repo.join(os.path.join(longname, hash))
 
 def copyfromcache(repo, hash, filename):
     '''copyfromcache copies the specified largefile from the repo or system
     cache to the specified location in the repository.  It will not throw an
     exception on failure, as it is meant to be called only after ensuring that
     the needed largefile exists in the cache.'''
     path = findfile(repo, hash)
     if path is None:
         return False
     util.makedirs(os.path.dirname(repo.wjoin(filename)))
     shutil.copy(path, repo.wjoin(filename))
     return True
 
 def copytocache(repo, rev, file, uploaded=False):
     hash = readstandin(repo, file)
     if incache(repo, hash):
         return
     copytocacheabsolute(repo, repo.wjoin(file), hash)
 
 def copytocacheabsolute(repo, file, hash):
     createdir(os.path.dirname(cachepath(repo, hash)))
     if insystemcache(repo.ui, hash):
         link(systemcachepath(repo.ui, hash), cachepath(repo, hash))
     else:
         shutil.copyfile(file, cachepath(repo, hash))
         os.chmod(cachepath(repo, hash), os.stat(file).st_mode)
         linktosystemcache(repo, hash)
 
 def linktosystemcache(repo, hash):
     createdir(os.path.dirname(systemcachepath(repo.ui, hash)))
     link(cachepath(repo, hash), systemcachepath(repo.ui, hash))
 
 def getstandinmatcher(repo, pats=[], opts={}):
     '''Return a match object that applies pats to the standin directory'''
     standindir = repo.pathto(shortname)
     if pats:
         # patterns supplied: search standin directory relative to current dir
         cwd = repo.getcwd()
         if os.path.isabs(cwd):
             # cwd is an absolute path for hg -R <reponame>
             # work relative to the repository root in this case
             cwd = ''
         pats = [os.path.join(standindir, cwd, pat) for pat in pats]
     elif os.path.isdir(standindir):
         # no patterns: relative to repo root
         pats = [standindir]
     else:
         # no patterns and no standin dir: return matcher that matches nothing
         match = match_.match(repo.root, None, [], exact=True)
         match.matchfn = lambda f: False
         return match
     return getmatcher(repo, pats, opts, showbad=False)
 
 def getmatcher(repo, pats=[], opts={}, showbad=True):
     '''Wrapper around scmutil.match() that adds showbad: if false, neuter
     the match object\'s bad() method so it does not print any warnings
     about missing files or directories.'''
     match = scmutil.match(repo[None], pats, opts)
 
     if not showbad:
         match.bad = lambda f, msg: None
     return match
 
 def composestandinmatcher(repo, rmatcher):
     '''Return a matcher that accepts standins corresponding to the files
     accepted by rmatcher. Pass the list of files in the matcher as the
     paths specified by the user.'''
     smatcher = getstandinmatcher(repo, rmatcher.files())
     isstandin = smatcher.matchfn
     def composed_matchfn(f):
         return isstandin(f) and rmatcher.matchfn(splitstandin(f))
     smatcher.matchfn = composed_matchfn
 
     return smatcher
 
 def standin(filename):
     '''Return the repo-relative path to the standin for the specified big
     file.'''
     # Notes:
     # 1) Most callers want an absolute path, but _create_standin() needs
     #    it repo-relative so lfadd() can pass it to repo_add().  So leave
     #    it up to the caller to use repo.wjoin() to get an absolute path.
     # 2) Join with '/' because that's what dirstate always uses, even on
     #    Windows. Change existing separator to '/' first in case we are
     #    passed filenames from an external source (like the command line).
     return shortname + '/' + filename.replace(os.sep, '/')
 
 def isstandin(filename):
     '''Return true if filename is a big file standin.  filename must
     be in Mercurial\'s internal form (slash-separated).'''
     return filename.startswith(shortname + '/')
 
 def splitstandin(filename):
     # Split on / because that's what dirstate always uses, even on Windows.
     # Change local separator to / first just in case we are passed filenames
     # from an external source (like the command line).
     bits = filename.replace(os.sep, '/').split('/', 1)
     if len(bits) == 2 and bits[0] == shortname:
         return bits[1]
     else:
         return None
 
 def updatestandin(repo, standin):
     file = repo.wjoin(splitstandin(standin))
     if os.path.exists(file):
         hash = hashfile(file)
         executable = getexecutable(file)
         writestandin(repo, standin, hash, executable)
 
 def readstandin(repo, filename, node=None):
     '''read hex hash from standin for filename at given node, or working
     directory if no node is given'''
     return repo[node][standin(filename)].data().strip()
 
 def writestandin(repo, standin, hash, executable):
     '''write hhash to <repo.root>/<standin>'''
     writehash(hash, repo.wjoin(standin), executable)
 
 def copyandhash(instream, outfile):
     '''Read bytes from instream (iterable) and write them to outfile,
     computing the SHA-1 hash of the data along the way.  Close outfile
     when done and return the binary hash.'''
     hasher = util.sha1('')
     for data in instream:
         hasher.update(data)
         outfile.write(data)
 
     # Blecch: closing a file that somebody else opened is rude and
     # wrong.  But it's so darn convenient and practical!  After all,
     # outfile was opened just to copy and hash.
     outfile.close()
 
     return hasher.digest()
 
 def hashrepofile(repo, file):
     return hashfile(repo.wjoin(file))
 
 def hashfile(file):
     if not os.path.exists(file):
         return ''
     hasher = util.sha1('')
     fd = open(file, 'rb')
     for data in blockstream(fd):
         hasher.update(data)
     fd.close()
     return hasher.hexdigest()
 
 class limitreader(object):
     def __init__(self, f, limit):
         self.f = f
         self.limit = limit
 
     def read(self, length):
         if self.limit == 0:
             return ''
         length = length > self.limit and self.limit or length
         self.limit -= length
         return self.f.read(length)
 
     def close(self):
         pass
 
 def blockstream(infile, blocksize=128 * 1024):
     """Generator that yields blocks of data from infile and closes infile."""
     while True:
         data = infile.read(blocksize)
         if not data:
             break
         yield data
     # Same blecch as above.
     infile.close()
 
 def readhash(filename):
     rfile = open(filename, 'rb')
     hash = rfile.read(40)
     rfile.close()
     if len(hash) < 40:
         raise util.Abort(_('bad hash in \'%s\' (only %d bytes long)')
                          % (filename, len(hash)))
     return hash
 
 def writehash(hash, filename, executable):
     util.makedirs(os.path.dirname(filename))
     if os.path.exists(filename):
         os.unlink(filename)
     wfile = open(filename, 'wb')
 
     try:
         wfile.write(hash)
         wfile.write('\n')
     finally:
         wfile.close()
     if os.path.exists(filename):
         os.chmod(filename, getmode(executable))
 
 def getexecutable(filename):
     mode = os.stat(filename).st_mode
     return (mode & stat.S_IXUSR) and (mode & stat.S_IXGRP) and (mode & \
         stat.S_IXOTH)
 
 def getmode(executable):
     if executable:
         return 0755
     else:
         return 0644
 
 def urljoin(first, second, *arg):
     def join(left, right):
         if not left.endswith('/'):
             left += '/'
         if right.startswith('/'):
             right = right[1:]
         return left + right
 
     url = join(first, second)
     for a in arg:
         url = join(url, a)
     return url
 
 def hexsha1(data):
     """hexsha1 returns the hex-encoded sha1 sum of the data in the file-like
     object data"""
     h = hashlib.sha1()
     for chunk in util.filechunkiter(data):
         h.update(chunk)
     return h.hexdigest()
 
 def httpsendfile(ui, filename):
     return httpconnection.httpsendfile(ui, filename, 'rb')
 
 # Convert a path to a unix style path. This is used to give a
 # canonical path to the lfdirstate.
 def unixpath(path):
     return os.path.normpath(path).replace(os.sep, '/')
 
 def islfilesrepo(repo):
     return ('largefiles' in repo.requirements and
             any_(shortname + '/' in f[0] for f in repo.store.datafiles()))
 
 def any_(gen):
     for x in gen:
         if x:
             return True
     return False
 
 class storeprotonotcapable(BaseException):
     def __init__(self, storetypes):
         self.storetypes = storetypes