1 # object_store.py -- Object store for git objects
2 # Copyright (C) 2008-2009 Jelmer Vernooij <jelmer@samba.org>
4 # This program is free software; you can redistribute it and/or
5 # modify it under the terms of the GNU General Public License
6 # as published by the Free Software Foundation; either version 2
7 # or (at your option) a later version of the License.
9 # This program is distributed in the hope that it will be useful,
10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 # GNU General Public License for more details.
14 # You should have received a copy of the GNU General Public License
15 # along with this program; if not, write to the Free Software
16 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
20 """Git object store interfaces and implementation."""
30 from dulwich.errors import (
33 from dulwich.file import GitFile
34 from dulwich.objects import (
43 from dulwich.pack import (
56 class BaseObjectStore(object):
57 """Object store interface."""
59 def determine_wants_all(self, refs):
60 return [sha for (ref, sha) in refs.iteritems() if not sha in self and not ref.endswith("^{}")]
62 def iter_shas(self, shas):
63 """Iterate over the objects for the specified shas.
65 :param shas: Iterable object with SHAs
66 :return: Object iterator
68 return ObjectStoreIterator(self, shas)
70 def contains_loose(self, sha):
71 """Check if a particular object is present by SHA1 and is loose."""
72 raise NotImplementedError(self.contains_loose)
74 def contains_packed(self, sha):
75 """Check if a particular object is present by SHA1 and is packed."""
76 raise NotImplementedError(self.contains_packed)
78 def __contains__(self, sha):
79 """Check if a particular object is present by SHA1.
81 This method makes no distinction between loose and packed objects.
83 return self.contains_packed(sha) or self.contains_loose(sha)
87 """Iterable of pack objects."""
88 raise NotImplementedError
90 def get_raw(self, name):
91 """Obtain the raw text for an object.
93 :param name: sha for the object.
94 :return: tuple with object type and object contents.
96 raise NotImplementedError(self.get_raw)
98 def __getitem__(self, sha):
99 """Obtain an object by SHA1."""
100 type, uncomp = self.get_raw(sha)
101 return ShaFile.from_raw_string(type, uncomp)
104 """Iterate over the SHAs that are present in this store."""
105 raise NotImplementedError(self.__iter__)
107 def add_object(self, obj):
108 """Add a single object to this object store.
111 raise NotImplementedError(self.add_object)
113 def add_objects(self, objects):
114 """Add a set of objects to this object store.
116 :param objects: Iterable over a list of objects.
118 raise NotImplementedError(self.add_objects)
120 def tree_changes(self, source, target, want_unchanged=False):
121 """Find the differences between the contents of two trees
123 :param object_store: Object store to use for retrieving tree contents
124 :param tree: SHA1 of the root tree
125 :param want_unchanged: Whether unchanged files should be reported
126 :return: Iterator over tuples with (oldpath, newpath), (oldmode, newmode), (oldsha, newsha)
128 todo = set([(source, target, "")])
130 (sid, tid, path) = todo.pop()
139 for name, oldmode, oldhexsha in stree.iteritems():
143 oldchildpath = "%s/%s" % (path, name)
145 (newmode, newhexsha) = ttree[name]
146 newchildpath = oldchildpath
151 if (want_unchanged or oldmode != newmode or
152 oldhexsha != newhexsha):
153 if stat.S_ISDIR(oldmode):
154 if newmode is None or stat.S_ISDIR(newmode):
155 todo.add((oldhexsha, newhexsha, oldchildpath))
157 # entry became a file
158 todo.add((oldhexsha, None, oldchildpath))
159 yield ((None, newchildpath), (None, newmode), (None, newhexsha))
161 if newmode is not None and stat.S_ISDIR(newmode):
163 yield ((oldchildpath, None), (oldmode, None), (oldhexsha, None))
164 todo.add((None, newhexsha, newchildpath))
166 yield ((oldchildpath, newchildpath), (oldmode, newmode), (oldhexsha, newhexsha))
168 for name, newmode, newhexsha in ttree.iteritems():
172 childpath = "%s/%s" % (path, name)
173 if not name in stree:
174 if not stat.S_ISDIR(newmode):
175 yield ((None, childpath), (None, newmode), (None, newhexsha))
177 todo.add((None, newhexsha, childpath))
179 def iter_tree_contents(self, tree):
180 """Yield (path, mode, hexsha) tuples for all non-Tree objects in a tree.
182 :param tree: SHA1 of the root of the tree
184 todo = set([(tree, "")])
186 (tid, tpath) = todo.pop()
188 for name, mode, hexsha in tree.iteritems():
192 path = "%s/%s" % (tpath, name)
193 if stat.S_ISDIR(mode):
194 todo.add((hexsha, path))
196 yield path, mode, hexsha
198 def find_missing_objects(self, haves, wants, progress=None):
199 """Find the missing objects required for a set of revisions.
201 :param haves: Iterable over SHAs already in common.
202 :param wants: Iterable over SHAs of objects to fetch.
203 :param progress: Simple progress function that will be called with
204 updated progress strings.
205 :return: Iterator over (sha, path) pairs.
207 return iter(MissingObjectFinder(self, haves, wants, progress).next, None)
209 def find_common_revisions(self, graphwalker):
210 """Find which revisions this store has in common using graphwalker.
212 :param graphwalker: A graphwalker object.
213 :return: List of SHAs that are in common
216 sha = graphwalker.next()
221 sha = graphwalker.next()
224 def get_graph_walker(self, heads):
225 """Obtain a graph walker for this object store.
227 :param heads: Local heads to start search with
228 :return: GraphWalker object
230 return ObjectStoreGraphWalker(heads, lambda sha: self[sha].parents)
232 def generate_pack_contents(self, have, want):
233 """Iterate over the contents of a pack file.
235 :param have: List of SHA1s of objects that should not be sent
236 :param want: List of SHA1s of objects that should be sent
238 return self.iter_shas(self.find_missing_objects(have, want))
241 class PackBasedObjectStore(BaseObjectStore):
244 self._pack_cache = None
246 def contains_packed(self, sha):
247 """Check if a particular object is present by SHA1 and is packed."""
248 for pack in self.packs:
253 def _load_packs(self):
254 raise NotImplementedError(self._load_packs)
256 def _add_known_pack(self, pack):
257 """Add a newly appeared pack to the cache by path.
260 if self._pack_cache is not None:
261 self._pack_cache.append(pack)
265 """List with pack objects."""
266 if self._pack_cache is None:
267 self._pack_cache = self._load_packs()
268 return self._pack_cache
270 def _iter_loose_objects(self):
271 raise NotImplementedError(self._iter_loose_objects)
273 def _get_loose_object(self, sha):
274 raise NotImplementedError(self._get_loose_object)
277 """Iterate over the SHAs that are present in this store."""
278 iterables = self.packs + [self._iter_loose_objects()]
279 return itertools.chain(*iterables)
281 def contains_loose(self, sha):
282 """Check if a particular object is present by SHA1 and is loose."""
283 return self._get_loose_object(sha) is not None
285 def get_raw(self, name):
286 """Obtain the raw text for an object.
288 :param name: sha for the object.
289 :return: tuple with object type and object contents.
292 sha = hex_to_sha(name)
294 elif len(name) == 20:
299 for pack in self.packs:
301 return pack.get_raw(sha)
305 hexsha = sha_to_hex(name)
306 ret = self._get_loose_object(hexsha)
308 return ret.type, ret.as_raw_string()
309 raise KeyError(hexsha)
311 def add_objects(self, objects):
312 """Add a set of objects to this object store.
314 :param objects: Iterable over objects, should support __len__.
316 if len(objects) == 0:
317 # Don't bother writing an empty pack file
319 f, commit = self.add_pack()
320 write_pack_data(f, objects, len(objects))
324 class DiskObjectStore(PackBasedObjectStore):
325 """Git-style object store that exists on disk."""
327 def __init__(self, path):
328 """Open an object store.
330 :param path: Path of the object store.
332 super(DiskObjectStore, self).__init__()
334 self.pack_dir = os.path.join(self.path, PACKDIR)
336 def _load_packs(self):
339 for name in os.listdir(self.pack_dir):
340 # TODO: verify that idx exists first
341 if name.startswith("pack-") and name.endswith(".pack"):
342 filename = os.path.join(self.pack_dir, name)
343 pack_files.append((os.stat(filename).st_mtime, filename))
345 if e.errno == errno.ENOENT:
348 pack_files.sort(reverse=True)
349 suffix_len = len(".pack")
350 return [Pack(f[:-suffix_len]) for _, f in pack_files]
352 def _get_shafile_path(self, sha):
355 # Check from object dir
356 return os.path.join(self.path, dir, file)
358 def _iter_loose_objects(self):
359 for base in os.listdir(self.path):
362 for rest in os.listdir(os.path.join(self.path, base)):
365 def _get_loose_object(self, sha):
366 path = self._get_shafile_path(sha)
368 return ShaFile.from_file(path)
370 if e.errno == errno.ENOENT:
374 def move_in_thin_pack(self, path):
375 """Move a specific file containing a pack into the pack directory.
377 :note: The file should be on the same file system as the
380 :param path: Path to the pack file.
382 data = PackData(path)
384 # Write index for the thin pack (do we really need this?)
385 temppath = os.path.join(self.pack_dir,
386 sha_to_hex(urllib2.randombytes(20))+".tempidx")
387 data.create_index_v2(temppath, self.get_raw)
388 p = Pack.from_objects(data, load_pack_index(temppath))
390 # Write a full pack version
391 temppath = os.path.join(self.pack_dir,
392 sha_to_hex(urllib2.randombytes(20))+".temppack")
393 write_pack(temppath, ((o, None) for o in p.iterobjects(self.get_raw)),
395 pack_sha = load_pack_index(temppath+".idx").objects_sha1()
396 newbasename = os.path.join(self.pack_dir, "pack-%s" % pack_sha)
397 os.rename(temppath+".pack", newbasename+".pack")
398 os.rename(temppath+".idx", newbasename+".idx")
399 self._add_known_pack(Pack(newbasename))
401 def move_in_pack(self, path):
402 """Move a specific file containing a pack into the pack directory.
404 :note: The file should be on the same file system as the
407 :param path: Path to the pack file.
410 entries = p.sorted_entries()
411 basename = os.path.join(self.pack_dir,
412 "pack-%s" % iter_sha1(entry[0] for entry in entries))
413 write_pack_index_v2(basename+".idx", entries, p.get_stored_checksum())
415 os.rename(path, basename + ".pack")
416 self._add_known_pack(Pack(basename))
418 def add_thin_pack(self):
419 """Add a new thin pack to this object store.
421 Thin packs are packs that contain deltas with parents that exist
424 fd, path = tempfile.mkstemp(dir=self.pack_dir, suffix=".pack")
425 f = os.fdopen(fd, 'wb')
429 if os.path.getsize(path) > 0:
430 self.move_in_thin_pack(path)
434 """Add a new pack to this object store.
436 :return: Fileobject to write to and a commit function to
437 call when the pack is finished.
439 fd, path = tempfile.mkstemp(dir=self.pack_dir, suffix=".pack")
440 f = os.fdopen(fd, 'wb')
444 if os.path.getsize(path) > 0:
445 self.move_in_pack(path)
448 def add_object(self, obj):
449 """Add a single object to this object store.
451 :param obj: Object to add
453 dir = os.path.join(self.path, obj.id[:2])
454 if not os.path.isdir(dir):
456 path = os.path.join(dir, obj.id[2:])
457 if os.path.exists(path):
458 return # Already there, no need to write again
459 f = GitFile(path, 'wb')
461 f.write(obj.as_legacy_object())
466 class MemoryObjectStore(BaseObjectStore):
467 """Object store that keeps all objects in memory."""
470 super(MemoryObjectStore, self).__init__()
473 def contains_loose(self, sha):
474 """Check if a particular object is present by SHA1 and is loose."""
475 return sha in self._data
477 def contains_packed(self, sha):
478 """Check if a particular object is present by SHA1 and is packed."""
482 """Iterate over the SHAs that are present in this store."""
483 return self._data.iterkeys()
487 """List with pack objects."""
490 def get_raw(self, name):
491 """Obtain the raw text for an object.
493 :param name: sha for the object.
494 :return: tuple with object type and object contents.
496 return self[name].as_raw_string()
498 def __getitem__(self, name):
499 return self._data[name]
501 def add_object(self, obj):
502 """Add a single object to this object store.
505 self._data[obj.id] = obj
507 def add_objects(self, objects):
508 """Add a set of objects to this object store.
510 :param objects: Iterable over a list of objects.
512 for obj, path in objects:
513 self._data[obj.id] = obj
516 class ObjectImporter(object):
517 """Interface for importing objects."""
519 def __init__(self, count):
520 """Create a new ObjectImporter.
522 :param count: Number of objects that's going to be imported.
526 def add_object(self, object):
528 raise NotImplementedError(self.add_object)
530 def finish(self, object):
531 """Finish the imoprt and write objects to disk."""
532 raise NotImplementedError(self.finish)
535 class ObjectIterator(object):
536 """Interface for iterating over objects."""
538 def iterobjects(self):
539 raise NotImplementedError(self.iterobjects)
542 class ObjectStoreIterator(ObjectIterator):
543 """ObjectIterator that works on top of an ObjectStore."""
545 def __init__(self, store, sha_iter):
546 """Create a new ObjectIterator.
548 :param store: Object store to retrieve from
549 :param sha_iter: Iterator over (sha, path) tuples
552 self.sha_iter = sha_iter
556 """Yield tuple with next object and path."""
557 for sha, path in self.itershas():
558 yield self.store[sha], path
560 def iterobjects(self):
561 """Iterate over just the objects."""
566 """Iterate over the SHAs."""
567 for sha in self._shas:
569 for sha in self.sha_iter:
570 self._shas.append(sha)
573 def __contains__(self, needle):
574 """Check if an object is present.
576 :note: This checks if the object is present in
577 the underlying object store, not if it would
578 be yielded by the iterator.
580 :param needle: SHA1 of the object to check for
582 return needle in self.store
584 def __getitem__(self, key):
585 """Find an object by SHA1.
587 :note: This retrieves the object from the underlying
588 object store. It will also succeed if the object would
589 not be returned by the iterator.
591 return self.store[key]
594 """Return the number of objects."""
595 return len(list(self.itershas()))
598 def tree_lookup_path(lookup_obj, root_sha, path):
599 """Lookup an object in a Git tree.
601 :param lookup_obj: Callback for retrieving object by SHA1
602 :param root_sha: SHA1 of the root tree
603 :param path: Path to lookup
605 parts = path.split("/")
608 obj = lookup_obj(sha)
609 if type(obj) is not Tree:
610 raise NotTreeError(sha)
617 class MissingObjectFinder(object):
618 """Find the objects missing from another object store.
620 :param object_store: Object store containing at least all objects to be
622 :param haves: SHA1s of commits not to send (already present in target)
623 :param wants: SHA1s of commits to send
624 :param progress: Optional function to report progress to.
627 def __init__(self, object_store, haves, wants, progress=None):
628 self.sha_done = set(haves)
629 self.objects_to_send = set([(w, None, False) for w in wants if w not in haves])
630 self.object_store = object_store
632 self.progress = lambda x: None
634 self.progress = progress
636 def add_todo(self, entries):
637 self.objects_to_send.update([e for e in entries if not e[0] in self.sha_done])
639 def parse_tree(self, tree):
640 self.add_todo([(sha, name, not stat.S_ISDIR(mode)) for (mode, name, sha) in tree.entries() if not S_ISGITLINK(mode)])
642 def parse_commit(self, commit):
643 self.add_todo([(commit.tree, "", False)])
644 self.add_todo([(p, None, False) for p in commit.parents])
646 def parse_tag(self, tag):
647 self.add_todo([(tag.object[1], None, False)])
650 if not self.objects_to_send:
652 (sha, name, leaf) = self.objects_to_send.pop()
654 o = self.object_store[sha]
655 if isinstance(o, Commit):
657 elif isinstance(o, Tree):
659 elif isinstance(o, Tag):
661 self.sha_done.add(sha)
662 self.progress("counting objects: %d\r" % len(self.sha_done))
666 class ObjectStoreGraphWalker(object):
667 """Graph walker that finds out what commits are missing from an object store."""
669 def __init__(self, local_heads, get_parents):
670 """Create a new instance.
672 :param local_heads: Heads to start search with
673 :param get_parents: Function for finding the parents of a SHA1.
675 self.heads = set(local_heads)
676 self.get_parents = get_parents
680 """Ack that a particular revision and its ancestors are present in the source."""
681 if sha in self.heads:
682 self.heads.remove(sha)
683 if sha in self.parents:
684 for p in self.parents[sha]:
688 """Iterate over ancestors of heads in the target."""
690 ret = self.heads.pop()
691 ps = self.get_parents(ret)
692 self.parents[ret] = ps
693 self.heads.update(ps)