index.py

   1 import os, stat, time, struct, tempfile
   2 from helpers import *
   3
   4 EMPTY_SHA = '\0'*20
   5 FAKE_SHA = '\x01'*20
   6 INDEX_HDR = 'BUPI\0\0\0\2'
   7 INDEX_SIG = '!IIIIIQII20sHII'
   8 ENTLEN = struct.calcsize(INDEX_SIG)
   9 FOOTER_SIG = '!Q'
  10 FOOTLEN = struct.calcsize(FOOTER_SIG)
  11
  12 IX_EXISTS = 0x8000
  13 IX_HASHVALID = 0x4000
  14
  15 class Error(Exception):
  16     pass
  17
  18
  19 class Level:
  20     def __init__(self, ename, parent):
  21         self.parent = parent
  22         self.ename = ename
  23         self.list = []
  24         self.count = 0
  25
  26     def write(self, f):
  27         (ofs,n) = (f.tell(), len(self.list))
  28         if self.list:
  29             count = len(self.list)
  30             #log('popping %r with %d entries\n'
  31             #    % (''.join(self.ename), count))
  32             for e in self.list:
  33                 e.write(f)
  34             if self.parent:
  35                 self.parent.count += count + self.count
  36         return (ofs,n)
  37
  38
  39 def _golevel(level, f, ename, newentry):
  40     # close nodes back up the tree
  41     assert(level)
  42     while ename[:len(level.ename)] != level.ename:
  43         n = BlankNewEntry(level.ename[-1])
  44         (n.children_ofs,n.children_n) = level.write(f)
  45         level.parent.list.append(n)
  46         level = level.parent
  47
  48     # create nodes down the tree
  49     while len(level.ename) < len(ename):
  50         level = Level(ename[:len(level.ename)+1], level)
  51
  52     # are we in precisely the right place?
  53     assert(ename == level.ename)
  54     n = newentry or BlankNewEntry(ename and level.ename[-1] or None)
  55     (n.children_ofs,n.children_n) = level.write(f)
  56     if level.parent:
  57         level.parent.list.append(n)
  58     level = level.parent
  59
  60     return level
  61
  62
  63 class Entry:
  64     def __init__(self, basename, name):
  65         self.basename = str(basename)
  66         self.name = str(name)
  67         self.children_ofs = 0
  68         self.children_n = 0
  69
  70     def __repr__(self):
  71         return ("(%s,0x%04x,%d,%d,%d,%d,%d,0x%04x,0x%08x/%d)"
  72                 % (self.name, self.dev,
  73                    self.ctime, self.mtime, self.uid, self.gid,
  74                    self.size, self.flags, self.children_ofs, self.children_n))
  75
  76     def packed(self):
  77         return struct.pack(INDEX_SIG,
  78                            self.dev, self.ctime, self.mtime,
  79                            self.uid, self.gid, self.size, self.mode,
  80                            self.gitmode, self.sha, self.flags,
  81                            self.children_ofs, self.children_n)
  82
  83     def from_stat(self, st, tstart):
  84         old = (self.dev, self.ctime, self.mtime,
  85                self.uid, self.gid, self.size, self.flags & IX_EXISTS)
  86         new = (st.st_dev, int(st.st_ctime), int(st.st_mtime),
  87                st.st_uid, st.st_gid, st.st_size, IX_EXISTS)
  88         self.dev = st.st_dev
  89         self.ctime = int(st.st_ctime)
  90         self.mtime = int(st.st_mtime)
  91         self.uid = st.st_uid
  92         self.gid = st.st_gid
  93         self.size = st.st_size
  94         self.mode = st.st_mode
  95         self.flags |= IX_EXISTS
  96         if int(st.st_ctime) >= tstart or old != new:
  97             self.invalidate()
  98
  99     def is_valid(self):
 100         f = IX_HASHVALID|IX_EXISTS
 101         return (self.flags & f) == f
 102
 103     def invalidate(self):
 104         self.flags &= ~IX_HASHVALID
 105         self.set_dirty()
 106
 107     def validate(self, gitmode, sha):
 108         assert(sha)
 109         self.gitmode = gitmode
 110         self.sha = sha
 111         self.flags |= IX_HASHVALID|IX_EXISTS
 112
 113     def is_deleted(self):
 114         return (self.flags & IX_EXISTS) == 0
 115
 116     def set_deleted(self):
 117         if self.flags & IX_EXISTS:
 118             self.flags &= ~(IX_EXISTS | IX_HASHVALID)
 119             self.set_dirty()
 120
 121     def set_dirty(self):
 122         pass # FIXME
 123
 124     def is_real(self):
 125         return not self.is_fake()
 126
 127     def is_fake(self):
 128         return not self.ctime
 129
 130     def __cmp__(a, b):
 131         return (cmp(a.name, b.name)
 132                 or -cmp(a.is_valid(), b.is_valid())
 133                 or -cmp(a.is_fake(), b.is_fake()))
 134
 135     def write(self, f):
 136         f.write(self.basename + '\0' + self.packed())
 137
 138
 139 class NewEntry(Entry):
 140     def __init__(self, basename, name, dev, ctime, mtime, uid, gid,
 141                  size, mode, gitmode, sha, flags, children_ofs, children_n):
 142         Entry.__init__(self, basename, name)
 143         (self.dev, self.ctime, self.mtime, self.uid, self.gid,
 144          self.size, self.mode, self.gitmode, self.sha,
 145          self.flags, self.children_ofs, self.children_n
 146          ) = (dev, int(ctime), int(mtime), uid, gid,
 147               size, mode, gitmode, sha, flags, children_ofs, children_n)
 148
 149
 150 class BlankNewEntry(NewEntry):
 151     def __init__(self, basename):
 152         NewEntry.__init__(self, basename, basename,
 153                           0, 0, 0, 0, 0, 0, 0,
 154                           0, EMPTY_SHA, 0, 0, 0)
 155
 156
 157 class ExistingEntry(Entry):
 158     def __init__(self, parent, basename, name, m, ofs):
 159         Entry.__init__(self, basename, name)
 160         self.parent = parent
 161         self._m = m
 162         self._ofs = ofs
 163         (self.dev, self.ctime, self.mtime, self.uid, self.gid,
 164          self.size, self.mode, self.gitmode, self.sha,
 165          self.flags, self.children_ofs, self.children_n
 166          ) = struct.unpack(INDEX_SIG, str(buffer(m, ofs, ENTLEN)))
 167
 168     def repack(self):
 169         self._m[self._ofs:self._ofs+ENTLEN] = self.packed()
 170         if self.parent and not self.is_valid():
 171             self.parent.invalidate()
 172             self.parent.repack()
 173
 174     def iter(self, name=None, wantrecurse=None):
 175         dname = name
 176         if dname and not dname.endswith('/'):
 177             dname += '/'
 178         ofs = self.children_ofs
 179         assert(ofs <= len(self._m))
 180         assert(self.children_n < 1000000)
 181         for i in xrange(self.children_n):
 182             eon = self._m.find('\0', ofs)
 183             assert(eon >= 0)
 184             assert(eon >= ofs)
 185             assert(eon > ofs)
 186             basename = str(buffer(self._m, ofs, eon-ofs))
 187             child = ExistingEntry(self, basename, self.name + basename,
 188                                   self._m, eon+1)
 189             if (not dname
 190                  or child.name.startswith(dname)
 191                  or child.name.endswith('/') and dname.startswith(child.name)):
 192                 if not wantrecurse or wantrecurse(child):
 193                     for e in child.iter(name=name, wantrecurse=wantrecurse):
 194                         yield e
 195             if not name or child.name == name or child.name.startswith(dname):
 196                 yield child
 197             ofs = eon + 1 + ENTLEN
 198
 199     def __iter__(self):
 200         return self.iter()
 201
 202
 203 class Reader:
 204     def __init__(self, filename):
 205         self.filename = filename
 206         self.m = ''
 207         self.writable = False
 208         self.count = 0
 209         f = None
 210         try:
 211             f = open(filename, 'r+')
 212         except IOError, e:
 213             if e.errno == errno.ENOENT:
 214                 pass
 215             else:
 216                 raise
 217         if f:
 218             b = f.read(len(INDEX_HDR))
 219             if b != INDEX_HDR:
 220                 log('warning: %s: header: expected %r, got %r'
 221                                  % (filename, INDEX_HDR, b))
 222             else:
 223                 st = os.fstat(f.fileno())
 224                 if st.st_size:
 225                     self.m = mmap_readwrite(f)
 226                     self.writable = True
 227                     self.count = struct.unpack(FOOTER_SIG,
 228                           str(buffer(self.m, st.st_size-FOOTLEN, FOOTLEN)))[0]
 229
 230     def __del__(self):
 231         self.close()
 232
 233     def __len__(self):
 234         return int(self.count)
 235
 236     def forward_iter(self):
 237         ofs = len(INDEX_HDR)
 238         while ofs+ENTLEN <= len(self.m)-FOOTLEN:
 239             eon = self.m.find('\0', ofs)
 240             assert(eon >= 0)
 241             assert(eon >= ofs)
 242             assert(eon > ofs)
 243             basename = str(buffer(self.m, ofs, eon-ofs))
 244             yield ExistingEntry(None, basename, basename, self.m, eon+1)
 245             ofs = eon + 1 + ENTLEN
 246
 247     def iter(self, name=None, wantrecurse=None):
 248         if len(self.m) > len(INDEX_HDR)+ENTLEN:
 249             dname = name
 250             if dname and not dname.endswith('/'):
 251                 dname += '/'
 252             root = ExistingEntry(None, '/', '/',
 253                                  self.m, len(self.m)-FOOTLEN-ENTLEN)
 254             for sub in root.iter(name=name, wantrecurse=wantrecurse):
 255                 yield sub
 256             if not dname or dname == root.name:
 257                 yield root
 258
 259     def __iter__(self):
 260         return self.iter()
 261
 262     def exists(self):
 263         return self.m
 264
 265     def save(self):
 266         if self.writable and self.m:
 267             self.m.flush()
 268
 269     def close(self):
 270         self.save()
 271         if self.writable and self.m:
 272             self.m = None
 273             self.writable = False
 274
 275     def filter(self, prefixes, wantrecurse=None):
 276         for (rp, path) in reduce_paths(prefixes):
 277             for e in self.iter(rp, wantrecurse=wantrecurse):
 278                 assert(e.name.startswith(rp))
 279                 name = path + e.name[len(rp):]
 280                 yield (name, e)
 281
 282
 283 class Writer:
 284     def __init__(self, filename):
 285         self.rootlevel = self.level = Level([], None)
 286         self.f = None
 287         self.count = 0
 288         self.lastfile = None
 289         self.filename = None
 290         self.filename = filename = realpath(filename)
 291         (dir,name) = os.path.split(filename)
 292         (ffd,self.tmpname) = tempfile.mkstemp('.tmp', filename, dir)
 293         self.f = os.fdopen(ffd, 'wb', 65536)
 294         self.f.write(INDEX_HDR)
 295
 296     def __del__(self):
 297         self.abort()
 298
 299     def abort(self):
 300         f = self.f
 301         self.f = None
 302         if f:
 303             f.close()
 304             os.unlink(self.tmpname)
 305
 306     def flush(self):
 307         if self.level:
 308             self.level = _golevel(self.level, self.f, [], None)
 309             self.count = self.rootlevel.count
 310             if self.count:
 311                 self.count += 1
 312             self.f.write(struct.pack(FOOTER_SIG, self.count))
 313             self.f.flush()
 314         assert(self.level == None)
 315
 316     def close(self):
 317         self.flush()
 318         f = self.f
 319         self.f = None
 320         if f:
 321             f.close()
 322             os.rename(self.tmpname, self.filename)
 323
 324     def _add(self, ename, entry):
 325         if self.lastfile and self.lastfile <= ename:
 326             raise Error('%r must come before %r'
 327                              % (''.join(e.name), ''.join(self.lastfile)))
 328             self.lastfile = e.name
 329         self.level = _golevel(self.level, self.f, ename, entry)
 330
 331     def add(self, name, st, hashgen = None):
 332         endswith = name.endswith('/')
 333         ename = pathsplit(name)
 334         basename = ename[-1]
 335         #log('add: %r %r\n' % (basename, name))
 336         flags = IX_EXISTS
 337         sha = None
 338         if hashgen:
 339             (gitmode, sha) = hashgen(name)
 340             flags |= IX_HASHVALID
 341         else:
 342             (gitmode, sha) = (0, EMPTY_SHA)
 343         if st:
 344             isdir = stat.S_ISDIR(st.st_mode)
 345             assert(isdir == endswith)
 346             e = NewEntry(basename, name, st.st_dev, int(st.st_ctime),
 347                          int(st.st_mtime), st.st_uid, st.st_gid,
 348                          st.st_size, st.st_mode, gitmode, sha, flags,
 349                          0, 0)
 350         else:
 351             assert(endswith)
 352             e = BlankNewEntry(basename)
 353             e.gitmode = gitmode
 354             e.sha = sha
 355             e.flags = flags
 356         self._add(ename, e)
 357
 358     def add_ixentry(self, e):
 359         e.children_ofs = e.children_n = 0
 360         self._add(pathsplit(e.name), e)
 361
 362     def new_reader(self):
 363         self.flush()
 364         return Reader(self.tmpname)
 365
 366
 367 def reduce_paths(paths):
 368     xpaths = []
 369     for p in paths:
 370         rp = realpath(p)
 371         try:
 372             st = os.lstat(rp)
 373             if stat.S_ISDIR(st.st_mode):
 374                 rp = slashappend(rp)
 375                 p = slashappend(p)
 376         except OSError, e:
 377             if e.errno != errno.ENOENT:
 378                 raise
 379         xpaths.append((rp, p))
 380     xpaths.sort()
 381
 382     paths = []
 383     prev = None
 384     for (rp, p) in xpaths:
 385         if prev and (prev == rp
 386                      or (prev.endswith('/') and rp.startswith(prev))):
 387             continue # already superceded by previous path
 388         paths.append((rp, p))
 389         prev = rp
 390     paths.sort(reverse=True)
 391     return paths
 392
 393
 394 class MergeIter:
 395     def __init__(self, iters):
 396         self.iters = iters
 397
 398     def __len__(self):
 399         # FIXME: doesn't remove duplicated entries between iters.
 400         # That only happens for parent directories, but will mean the
 401         # actual iteration returns fewer entries than this function counts.
 402         return sum(len(it) for it in self.iters)
 403
 404     def __iter__(self):
 405         total = len(self)
 406         l = [iter(it) for it in self.iters]
 407         l = [(next(it),it) for it in l]
 408         l = filter(lambda x: x[0], l)
 409         count = 0
 410         lastname = None
 411         while l:
 412             if not (count % 1024):
 413                 progress('bup: merging indexes (%d/%d)\r' % (count, total))
 414             l.sort()
 415             (e,it) = l.pop()
 416             if not e:
 417                 continue
 418             if e.name != lastname:
 419                 yield e
 420                 lastname = e.name
 421             n = next(it)
 422             if n:
 423                 l.append((n,it))
 424             count += 1
 425         log('bup: merging indexes (%d/%d), done.\n' % (count, total))