Mercurial > hg
view mercurial/store.py @ 26597:d58721d684cb
discovery: reference relevant bug in the faulty code
We extend the comment about this code flaw with more code flaw.
author | Pierre-Yves David <pierre-yves.david@fb.com> |
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date | Fri, 09 Oct 2015 15:44:00 -0700 |
parents | 56b2bcea2529 |
children | a95c975f42e3 |
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# store.py - repository store handling for Mercurial # # Copyright 2008 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from i18n import _ import scmutil, util, parsers, error import os, stat, errno _sha = util.sha1 # This avoids a collision between a file named foo and a dir named # foo.i or foo.d def _encodedir(path): ''' >>> _encodedir('data/foo.i') 'data/foo.i' >>> _encodedir('data/foo.i/bla.i') 'data/foo.i.hg/bla.i' >>> _encodedir('data/foo.i.hg/bla.i') 'data/foo.i.hg.hg/bla.i' >>> _encodedir('data/foo.i\\ndata/foo.i/bla.i\\ndata/foo.i.hg/bla.i\\n') 'data/foo.i\\ndata/foo.i.hg/bla.i\\ndata/foo.i.hg.hg/bla.i\\n' ''' return (path .replace(".hg/", ".hg.hg/") .replace(".i/", ".i.hg/") .replace(".d/", ".d.hg/")) encodedir = getattr(parsers, 'encodedir', _encodedir) def decodedir(path): ''' >>> decodedir('data/foo.i') 'data/foo.i' >>> decodedir('data/foo.i.hg/bla.i') 'data/foo.i/bla.i' >>> decodedir('data/foo.i.hg.hg/bla.i') 'data/foo.i.hg/bla.i' ''' if ".hg/" not in path: return path return (path .replace(".d.hg/", ".d/") .replace(".i.hg/", ".i/") .replace(".hg.hg/", ".hg/")) def _buildencodefun(): ''' >>> enc, dec = _buildencodefun() >>> enc('nothing/special.txt') 'nothing/special.txt' >>> dec('nothing/special.txt') 'nothing/special.txt' >>> enc('HELLO') '_h_e_l_l_o' >>> dec('_h_e_l_l_o') 'HELLO' >>> enc('hello:world?') 'hello~3aworld~3f' >>> dec('hello~3aworld~3f') 'hello:world?' >>> enc('the\x07quick\xADshot') 'the~07quick~adshot' >>> dec('the~07quick~adshot') 'the\\x07quick\\xadshot' ''' e = '_' winreserved = [ord(x) for x in '\\:*?"<>|'] cmap = dict([(chr(x), chr(x)) for x in xrange(127)]) for x in (range(32) + range(126, 256) + winreserved): cmap[chr(x)] = "~%02x" % x for x in range(ord("A"), ord("Z") + 1) + [ord(e)]: cmap[chr(x)] = e + chr(x).lower() dmap = {} for k, v in cmap.iteritems(): dmap[v] = k def decode(s): i = 0 while i < len(s): for l in xrange(1, 4): try: yield dmap[s[i:i + l]] i += l break except KeyError: pass else: raise KeyError return (lambda s: ''.join([cmap[c] for c in s]), lambda s: ''.join(list(decode(s)))) _encodefname, _decodefname = _buildencodefun() def encodefilename(s): ''' >>> encodefilename('foo.i/bar.d/bla.hg/hi:world?/HELLO') 'foo.i.hg/bar.d.hg/bla.hg.hg/hi~3aworld~3f/_h_e_l_l_o' ''' return _encodefname(encodedir(s)) def decodefilename(s): ''' >>> decodefilename('foo.i.hg/bar.d.hg/bla.hg.hg/hi~3aworld~3f/_h_e_l_l_o') 'foo.i/bar.d/bla.hg/hi:world?/HELLO' ''' return decodedir(_decodefname(s)) def _buildlowerencodefun(): ''' >>> f = _buildlowerencodefun() >>> f('nothing/special.txt') 'nothing/special.txt' >>> f('HELLO') 'hello' >>> f('hello:world?') 'hello~3aworld~3f' >>> f('the\x07quick\xADshot') 'the~07quick~adshot' ''' winreserved = [ord(x) for x in '\\:*?"<>|'] cmap = dict([(chr(x), chr(x)) for x in xrange(127)]) for x in (range(32) + range(126, 256) + winreserved): cmap[chr(x)] = "~%02x" % x for x in range(ord("A"), ord("Z") + 1): cmap[chr(x)] = chr(x).lower() return lambda s: "".join([cmap[c] for c in s]) lowerencode = getattr(parsers, 'lowerencode', None) or _buildlowerencodefun() # Windows reserved names: con, prn, aux, nul, com1..com9, lpt1..lpt9 _winres3 = ('aux', 'con', 'prn', 'nul') # length 3 _winres4 = ('com', 'lpt') # length 4 (with trailing 1..9) def _auxencode(path, dotencode): ''' Encodes filenames containing names reserved by Windows or which end in period or space. Does not touch other single reserved characters c. Specifically, c in '\\:*?"<>|' or ord(c) <= 31 are *not* encoded here. Additionally encodes space or period at the beginning, if dotencode is True. Parameter path is assumed to be all lowercase. A segment only needs encoding if a reserved name appears as a basename (e.g. "aux", "aux.foo"). A directory or file named "foo.aux" doesn't need encoding. >>> s = '.foo/aux.txt/txt.aux/con/prn/nul/foo.' >>> _auxencode(s.split('/'), True) ['~2efoo', 'au~78.txt', 'txt.aux', 'co~6e', 'pr~6e', 'nu~6c', 'foo~2e'] >>> s = '.com1com2/lpt9.lpt4.lpt1/conprn/com0/lpt0/foo.' >>> _auxencode(s.split('/'), False) ['.com1com2', 'lp~749.lpt4.lpt1', 'conprn', 'com0', 'lpt0', 'foo~2e'] >>> _auxencode(['foo. '], True) ['foo.~20'] >>> _auxencode([' .foo'], True) ['~20.foo'] ''' for i, n in enumerate(path): if not n: continue if dotencode and n[0] in '. ': n = "~%02x" % ord(n[0]) + n[1:] path[i] = n else: l = n.find('.') if l == -1: l = len(n) if ((l == 3 and n[:3] in _winres3) or (l == 4 and n[3] <= '9' and n[3] >= '1' and n[:3] in _winres4)): # encode third letter ('aux' -> 'au~78') ec = "~%02x" % ord(n[2]) n = n[0:2] + ec + n[3:] path[i] = n if n[-1] in '. ': # encode last period or space ('foo...' -> 'foo..~2e') path[i] = n[:-1] + "~%02x" % ord(n[-1]) return path _maxstorepathlen = 120 _dirprefixlen = 8 _maxshortdirslen = 8 * (_dirprefixlen + 1) - 4 def _hashencode(path, dotencode): digest = _sha(path).hexdigest() le = lowerencode(path[5:]).split('/') # skips prefix 'data/' or 'meta/' parts = _auxencode(le, dotencode) basename = parts[-1] _root, ext = os.path.splitext(basename) sdirs = [] sdirslen = 0 for p in parts[:-1]: d = p[:_dirprefixlen] if d[-1] in '. ': # Windows can't access dirs ending in period or space d = d[:-1] + '_' if sdirslen == 0: t = len(d) else: t = sdirslen + 1 + len(d) if t > _maxshortdirslen: break sdirs.append(d) sdirslen = t dirs = '/'.join(sdirs) if len(dirs) > 0: dirs += '/' res = 'dh/' + dirs + digest + ext spaceleft = _maxstorepathlen - len(res) if spaceleft > 0: filler = basename[:spaceleft] res = 'dh/' + dirs + filler + digest + ext return res def _hybridencode(path, dotencode): '''encodes path with a length limit Encodes all paths that begin with 'data/', according to the following. Default encoding (reversible): Encodes all uppercase letters 'X' as '_x'. All reserved or illegal characters are encoded as '~xx', where xx is the two digit hex code of the character (see encodefilename). Relevant path components consisting of Windows reserved filenames are masked by encoding the third character ('aux' -> 'au~78', see _auxencode). Hashed encoding (not reversible): If the default-encoded path is longer than _maxstorepathlen, a non-reversible hybrid hashing of the path is done instead. This encoding uses up to _dirprefixlen characters of all directory levels of the lowerencoded path, but not more levels than can fit into _maxshortdirslen. Then follows the filler followed by the sha digest of the full path. The filler is the beginning of the basename of the lowerencoded path (the basename is everything after the last path separator). The filler is as long as possible, filling in characters from the basename until the encoded path has _maxstorepathlen characters (or all chars of the basename have been taken). The extension (e.g. '.i' or '.d') is preserved. The string 'data/' at the beginning is replaced with 'dh/', if the hashed encoding was used. ''' path = encodedir(path) ef = _encodefname(path).split('/') res = '/'.join(_auxencode(ef, dotencode)) if len(res) > _maxstorepathlen: res = _hashencode(path, dotencode) return res def _pathencode(path): de = encodedir(path) if len(path) > _maxstorepathlen: return _hashencode(de, True) ef = _encodefname(de).split('/') res = '/'.join(_auxencode(ef, True)) if len(res) > _maxstorepathlen: return _hashencode(de, True) return res _pathencode = getattr(parsers, 'pathencode', _pathencode) def _plainhybridencode(f): return _hybridencode(f, False) def _calcmode(vfs): try: # files in .hg/ will be created using this mode mode = vfs.stat().st_mode # avoid some useless chmods if (0o777 & ~util.umask) == (0o777 & mode): mode = None except OSError: mode = None return mode _data = ('data 00manifest.d 00manifest.i 00changelog.d 00changelog.i' ' phaseroots obsstore') class basicstore(object): '''base class for local repository stores''' def __init__(self, path, vfstype): vfs = vfstype(path) self.path = vfs.base self.createmode = _calcmode(vfs) vfs.createmode = self.createmode self.rawvfs = vfs self.vfs = scmutil.filtervfs(vfs, encodedir) self.opener = self.vfs def join(self, f): return self.path + '/' + encodedir(f) def _walk(self, relpath, recurse): '''yields (unencoded, encoded, size)''' path = self.path if relpath: path += '/' + relpath striplen = len(self.path) + 1 l = [] if self.rawvfs.isdir(path): visit = [path] readdir = self.rawvfs.readdir while visit: p = visit.pop() for f, kind, st in readdir(p, stat=True): fp = p + '/' + f if kind == stat.S_IFREG and f[-2:] in ('.d', '.i'): n = util.pconvert(fp[striplen:]) l.append((decodedir(n), n, st.st_size)) elif kind == stat.S_IFDIR and recurse: visit.append(fp) l.sort() return l def datafiles(self): return self._walk('data', True) def topfiles(self): # yield manifest before changelog return reversed(self._walk('', False)) def walk(self): '''yields (unencoded, encoded, size)''' # yield data files first for x in self.datafiles(): yield x for x in self.topfiles(): yield x def copylist(self): return ['requires'] + _data.split() def write(self, tr): pass def invalidatecaches(self): pass def markremoved(self, fn): pass def __contains__(self, path): '''Checks if the store contains path''' path = "/".join(("data", path)) # file? if self.vfs.exists(path + ".i"): return True # dir? if not path.endswith("/"): path = path + "/" return self.vfs.exists(path) class encodedstore(basicstore): def __init__(self, path, vfstype): vfs = vfstype(path + '/store') self.path = vfs.base self.createmode = _calcmode(vfs) vfs.createmode = self.createmode self.rawvfs = vfs self.vfs = scmutil.filtervfs(vfs, encodefilename) self.opener = self.vfs def datafiles(self): for a, b, size in self._walk('data', True): try: a = decodefilename(a) except KeyError: a = None yield a, b, size def join(self, f): return self.path + '/' + encodefilename(f) def copylist(self): return (['requires', '00changelog.i'] + ['store/' + f for f in _data.split()]) class fncache(object): # the filename used to be partially encoded # hence the encodedir/decodedir dance def __init__(self, vfs): self.vfs = vfs self.entries = None self._dirty = False def _load(self): '''fill the entries from the fncache file''' self._dirty = False try: fp = self.vfs('fncache', mode='rb') except IOError: # skip nonexistent file self.entries = set() return self.entries = set(decodedir(fp.read()).splitlines()) if '' in self.entries: fp.seek(0) for n, line in enumerate(fp): if not line.rstrip('\n'): t = _('invalid entry in fncache, line %s') % (n + 1) raise error.Abort(t) fp.close() def write(self, tr): if self._dirty: tr.addbackup('fncache') fp = self.vfs('fncache', mode='wb', atomictemp=True) if self.entries: fp.write(encodedir('\n'.join(self.entries) + '\n')) fp.close() self._dirty = False def add(self, fn): if self.entries is None: self._load() if fn not in self.entries: self._dirty = True self.entries.add(fn) def remove(self, fn): if self.entries is None: self._load() try: self.entries.remove(fn) self._dirty = True except KeyError: pass def __contains__(self, fn): if self.entries is None: self._load() return fn in self.entries def __iter__(self): if self.entries is None: self._load() return iter(self.entries) class _fncachevfs(scmutil.abstractvfs, scmutil.auditvfs): def __init__(self, vfs, fnc, encode): scmutil.auditvfs.__init__(self, vfs) self.fncache = fnc self.encode = encode def __call__(self, path, mode='r', *args, **kw): if mode not in ('r', 'rb') and path.startswith('data/'): self.fncache.add(path) return self.vfs(self.encode(path), mode, *args, **kw) def join(self, path): if path: return self.vfs.join(self.encode(path)) else: return self.vfs.join(path) class fncachestore(basicstore): def __init__(self, path, vfstype, dotencode): if dotencode: encode = _pathencode else: encode = _plainhybridencode self.encode = encode vfs = vfstype(path + '/store') self.path = vfs.base self.pathsep = self.path + '/' self.createmode = _calcmode(vfs) vfs.createmode = self.createmode self.rawvfs = vfs fnc = fncache(vfs) self.fncache = fnc self.vfs = _fncachevfs(vfs, fnc, encode) self.opener = self.vfs def join(self, f): return self.pathsep + self.encode(f) def getsize(self, path): return self.rawvfs.stat(path).st_size def datafiles(self): for f in sorted(self.fncache): ef = self.encode(f) try: yield f, ef, self.getsize(ef) except OSError as err: if err.errno != errno.ENOENT: raise def copylist(self): d = ('data dh fncache phaseroots obsstore' ' 00manifest.d 00manifest.i 00changelog.d 00changelog.i') return (['requires', '00changelog.i'] + ['store/' + f for f in d.split()]) def write(self, tr): self.fncache.write(tr) def invalidatecaches(self): self.fncache.entries = None def markremoved(self, fn): self.fncache.remove(fn) def _exists(self, f): ef = self.encode(f) try: self.getsize(ef) return True except OSError as err: if err.errno != errno.ENOENT: raise # nonexistent entry return False def __contains__(self, path): '''Checks if the store contains path''' path = "/".join(("data", path)) # check for files (exact match) e = path + '.i' if e in self.fncache and self._exists(e): return True # now check for directories (prefix match) if not path.endswith('/'): path += '/' for e in self.fncache: if e.startswith(path) and self._exists(e): return True return False def store(requirements, path, vfstype): if 'store' in requirements: if 'fncache' in requirements: return fncachestore(path, vfstype, 'dotencode' in requirements) return encodedstore(path, vfstype) return basicstore(path, vfstype)