1 """Virtual File System interface to bup repository content.
3 This module provides a path-based interface to the content of a bup
6 The VFS is structured like this:
9 /SAVE-NAME/SAVE-DATE/...
12 Each path is represented by an item that has least an item.meta which
13 may be either a Metadata object, or an integer mode. Functions like
14 item_mode() and item_size() will return the mode and size in either
15 case. Any item.meta Metadata instances must not be modified directly.
16 Make a copy to modify via item.meta.copy() if needed, or call
19 The want_meta argument is advisory for calls that accept it, and it
20 may not be honored. Callers must be able to handle an item.meta value
21 that is either an instance of Metadata or an integer mode, perhaps
22 via item_mode() or augment_item_meta().
24 Setting want_meta=False is rarely desirable since it can limit the VFS
25 to only the metadata that git itself can represent, and so for
26 example, fifos and sockets will appear to be regular files
27 (e.g. S_ISREG(item_mode(item)) will be true). But the option is still
28 provided because it may be more efficient when just the path names or
29 the more limited metadata is sufficient.
31 Any given metadata object's size may be None, in which case the size
32 can be computed via item_size() or augment_item_meta(...,
35 When traversing a directory using functions like contents(), the meta
36 value for any directories other than '.' will be a default directory
37 mode, not a Metadata object. This is because the actual metadata for
38 a directory is stored inside the directory (see
39 fill_in_metadata_if_dir() or ensure_item_has_metadata()).
41 Commit items represent commits (e.g. /.tag/some-commit or
42 /foo/latest), and for most purposes, they appear as the underlying
43 tree. S_ISDIR(item_mode(item)) will return true for both tree Items
44 and Commits and the commit's oid is the tree hash; the commit hash is
49 from __future__ import absolute_import, print_function
50 from binascii import hexlify, unhexlify
51 from collections import namedtuple
52 from errno import EINVAL, ELOOP, ENOENT, ENOTDIR
53 from itertools import chain, dropwhile, groupby, tee
54 from random import randrange
55 from stat import S_IFDIR, S_IFLNK, S_IFREG, S_ISDIR, S_ISLNK, S_ISREG
56 from time import localtime, strftime
59 from bup import git, metadata, vint
60 from bup.compat import hexstr, range
61 from bup.git import BUP_CHUNKED, cp, get_commit_items, parse_commit, tree_decode
62 from bup.helpers import debug2, last
63 from bup.io import path_msg
64 from bup.metadata import Metadata
65 from bup.vint import read_bvec, write_bvec
66 from bup.vint import read_vint, write_vint
67 from bup.vint import read_vuint, write_vuint
69 if sys.version_info[0] < 3:
70 from exceptions import IOError as py_IOError
74 # We currently assume that it's always appropriate to just forward IOErrors
77 class IOError(py_IOError):
78 def __init__(self, errno, message, terminus=None):
79 py_IOError.__init__(self, errno, message)
80 self.terminus = terminus
82 def write_ioerror(port, ex):
83 assert isinstance(ex, IOError)
85 (1 if ex.errno is not None else 0)
86 | (2 if ex.strerror is not None else 0)
87 | (4 if ex.terminus is not None else 0))
88 if ex.errno is not None:
89 write_vint(port, ex.errno)
90 if ex.strerror is not None:
91 write_bvec(port, ex.strerror.encode('utf-8'))
92 if ex.terminus is not None:
93 write_resolution(port, ex.terminus)
95 def read_ioerror(port):
96 mask = read_vuint(port)
97 no = read_vint(port) if 1 & mask else None
98 msg = read_bvec(port).decode('utf-8') if 2 & mask else None
99 term = read_resolution(port) if 4 & mask else None
100 return IOError(errno=no, message=msg, terminus=term)
103 default_file_mode = S_IFREG | 0o644
104 default_dir_mode = S_IFDIR | 0o755
105 default_symlink_mode = S_IFLNK | 0o755
107 def _default_mode_for_gitmode(gitmode):
109 return default_file_mode
111 return default_dir_mode
113 return default_symlink_mode
114 raise Exception('unexpected git mode ' + oct(gitmode))
116 def _normal_or_chunked_file_size(repo, oid):
117 """Return the size of the normal or chunked file indicated by oid."""
118 # FIXME: --batch-format CatPipe?
119 it = repo.cat(hexlify(oid))
120 _, obj_t, size = next(it)
122 while obj_t == b'tree':
123 mode, name, last_oid = last(tree_decode(b''.join(it)))
125 it = repo.cat(hexlify(last_oid))
126 _, obj_t, size = next(it)
127 return ofs + sum(len(b) for b in it)
129 def _skip_chunks_before_offset(tree, offset):
130 prev_ent = next(tree, None)
135 ent_ofs = int(ent[1], 16)
137 return chain([prev_ent, ent], tree)
138 if ent_ofs == offset:
139 return chain([ent], tree)
143 def _tree_chunks(repo, tree, startofs):
144 "Tree should be a sequence of (name, mode, hash) as per tree_decode()."
145 assert(startofs >= 0)
146 # name is the chunk's hex offset in the original file
147 for mode, name, oid in _skip_chunks_before_offset(tree, startofs):
149 skipmore = startofs - ofs
152 it = repo.cat(hexlify(oid))
153 _, obj_t, size = next(it)
156 assert obj_t == b'tree'
157 for b in _tree_chunks(repo, tree_decode(data), skipmore):
160 assert obj_t == b'blob'
161 yield data[skipmore:]
164 def __init__(self, repo, oid, startofs):
165 it = repo.cat(hexlify(oid))
166 _, obj_t, size = next(it)
167 isdir = obj_t == b'tree'
170 self.it = _tree_chunks(repo, tree_decode(data), startofs)
174 self.blob = data[startofs:]
177 def next(self, size):
179 while len(out) < size:
180 if self.it and not self.blob:
182 self.blob = next(self.it)
183 except StopIteration:
186 want = size - len(out)
187 out += self.blob[:want]
188 self.blob = self.blob[want:]
191 debug2('next(%d) returned %d\n' % (size, len(out)))
195 class _FileReader(object):
196 def __init__(self, repo, oid, known_size=None):
197 assert len(oid) == 20
202 self._size = known_size
204 def _compute_size(self):
206 self._size = _normal_or_chunked_file_size(self._repo, self.oid)
210 if ofs < 0 or ofs > self._compute_size():
211 raise IOError(EINVAL, 'Invalid seek offset: %d' % ofs)
217 def read(self, count=-1):
218 size = self._compute_size()
222 count = size - self.ofs
223 if not self.reader or self.reader.ofs != self.ofs:
224 self.reader = _ChunkReader(self._repo, self.oid, self.ofs)
226 buf = self.reader.next(count)
229 raise # our offsets will be all screwed up otherwise
238 def __exit__(self, type, value, traceback):
242 _multiple_slashes_rx = re.compile(br'//+')
244 def _decompose_path(path):
245 """Return a boolean indicating whether the path is absolute, and a
246 reversed list of path elements, omitting any occurrences of "."
247 and ignoring any leading or trailing slash. If the path is
248 effectively '/' or '.', return an empty list.
251 path = re.sub(_multiple_slashes_rx, b'/', path)
253 return True, True, []
254 is_absolute = must_be_dir = False
255 if path.startswith(b'/'):
258 for suffix in (b'/', b'/.'):
259 if path.endswith(suffix):
261 path = path[:-len(suffix)]
262 parts = [x for x in path.split(b'/') if x != b'.']
265 must_be_dir = True # e.g. path was effectively '.' or '/', etc.
266 return is_absolute, must_be_dir, parts
269 Item = namedtuple('Item', ('meta', 'oid'))
270 Chunky = namedtuple('Chunky', ('meta', 'oid'))
271 FakeLink = namedtuple('FakeLink', ('meta', 'target'))
272 Root = namedtuple('Root', ('meta'))
273 Tags = namedtuple('Tags', ('meta'))
274 RevList = namedtuple('RevList', ('meta', 'oid'))
275 Commit = namedtuple('Commit', ('meta', 'oid', 'coid'))
277 item_types = frozenset((Item, Chunky, Root, Tags, RevList, Commit))
278 real_tree_types = frozenset((Item, Commit))
280 def write_item(port, item):
282 name = bytes(kind.__name__.encode('ascii'))
284 has_meta = 1 if isinstance(meta, Metadata) else 0
285 if kind in (Item, Chunky, RevList):
286 assert len(item.oid) == 20
288 vint.send(port, 'sVs', name, has_meta, item.oid)
289 Metadata.write(meta, port, include_path=False)
291 vint.send(port, 'sVsV', name, has_meta, item.oid, item.meta)
292 elif kind in (Root, Tags):
294 vint.send(port, 'sV', name, has_meta)
295 Metadata.write(meta, port, include_path=False)
297 vint.send(port, 'sVV', name, has_meta, item.meta)
299 assert len(item.oid) == 20
300 assert len(item.coid) == 20
302 vint.send(port, 'sVss', name, has_meta, item.oid, item.coid)
303 Metadata.write(meta, port, include_path=False)
305 vint.send(port, 'sVssV', name, has_meta, item.oid, item.coid,
307 elif kind == FakeLink:
309 vint.send(port, 'sVs', name, has_meta, item.target)
310 Metadata.write(meta, port, include_path=False)
312 vint.send(port, 'sVsV', name, has_meta, item.target, item.meta)
317 def read_m(port, has_meta):
319 m = Metadata.read(port)
321 return read_vuint(port)
322 kind, has_meta = vint.recv(port, 'sV')
324 oid, meta = read_bvec(port), read_m(port, has_meta)
325 return Item(oid=oid, meta=meta)
326 if kind == b'Chunky':
327 oid, meta = read_bvec(port), read_m(port, has_meta)
328 return Chunky(oid=oid, meta=meta)
329 if kind == b'RevList':
330 oid, meta = read_bvec(port), read_m(port, has_meta)
331 return RevList(oid=oid, meta=meta)
333 return Root(meta=read_m(port, has_meta))
335 return Tags(meta=read_m(port, has_meta))
336 if kind == b'Commit':
337 oid, coid = vint.recv(port, 'ss')
338 meta = read_m(port, has_meta)
339 return Commit(oid=oid, coid=coid, meta=meta)
340 if kind == b'FakeLink':
341 target, meta = read_bvec(port), read_m(port, has_meta)
342 return FakeLink(target=target, meta=meta)
345 def write_resolution(port, resolution):
346 write_vuint(port, len(resolution))
347 for name, item in resolution:
348 write_bvec(port, name)
351 write_item(port, item)
355 def read_resolution(port):
359 name = read_bvec(port)
360 have_item = ord(port.read(1))
361 assert have_item in (0, 1)
362 item = read_item(port) if have_item else None
363 result.append((name, item))
367 _root = Root(meta=default_dir_mode)
368 _tags = Tags(meta=default_dir_mode)
373 ### A general purpose shared cache with (currently) cheap random
374 ### eviction. At the moment there is no weighting so a single commit
375 ### item is just as likely to be evicted as an entire "rev-list". See
376 ### is_valid_cache_key for a description of the expected content.
380 _cache_max_items = 30000
383 global _cache, _cache_keys
387 def is_valid_cache_key(x):
388 """Return logically true if x looks like it could be a valid cache key
389 (with respect to structure). Current valid cache entries:
390 res:... -> resolution
392 rvl:OID -> {'.', commit, '2012...', next_commit, ...}
394 # Suspect we may eventually add "(container_oid, name) -> ...", and others.
398 if tag in (b'itm:', b'rvl:') and len(x) == 24:
405 if not is_valid_cache_key(key):
406 raise Exception('invalid cache key: ' + repr(key))
407 return _cache.get(key)
409 def cache_notice(key, value):
410 global _cache, _cache_keys, _cache_max_items
411 if not is_valid_cache_key(key):
412 raise Exception('invalid cache key: ' + repr(key))
415 if len(_cache) < _cache_max_items:
416 _cache_keys.append(key)
419 victim_i = randrange(0, len(_cache_keys))
420 victim = _cache_keys[victim_i]
422 _cache_keys[victim_i] = key
425 def cache_get_commit_item(oid, need_meta=True):
426 """Return the requested tree item if it can be found in the cache.
427 When need_meta is true don't return a cached item that only has a
429 # tree might be stored independently, or as '.' with its entries.
430 commit_key = b'itm:' + oid
431 item = cache_get(commit_key)
435 if isinstance(item.meta, Metadata):
437 entries = cache_get(b'rvl:' + oid)
442 """Return a completely independent copy of item, such that
443 modifications will not affect the original.
446 meta = getattr(item, 'meta', None)
447 if isinstance(meta, Metadata):
448 return(item._replace(meta=meta.copy()))
452 """Return the integer mode (stat st_mode) for item."""
454 if isinstance(m, Metadata):
458 def _read_dir_meta(bupm):
459 # This is because save writes unmodified Metadata() entries for
460 # fake parents -- test-save-strip-graft.sh demonstrates.
461 m = Metadata.read(bupm)
463 return default_dir_mode
464 assert m.mode is not None
469 def tree_data_and_bupm(repo, oid):
470 """Return (tree_bytes, bupm_oid) where bupm_oid will be None if the
471 tree has no metadata (i.e. older bup save, or non-bup tree).
474 assert len(oid) == 20
475 it = repo.cat(hexlify(oid))
476 _, item_t, size = next(it)
478 if item_t == b'commit':
479 commit = parse_commit(data)
480 it = repo.cat(commit.tree)
481 _, item_t, size = next(it)
483 assert item_t == b'tree'
484 elif item_t != b'tree':
485 raise Exception('%s is not a tree or commit' % hexstr(oid))
486 for _, mangled_name, sub_oid in tree_decode(data):
487 if mangled_name == b'.bupm':
489 if mangled_name > b'.bupm':
493 def _find_treeish_oid_metadata(repo, oid):
494 """Return the metadata for the tree or commit oid, or None if the tree
495 has no metadata (i.e. older bup save, or non-bup tree).
498 tree_data, bupm_oid = tree_data_and_bupm(repo, oid)
500 with _FileReader(repo, bupm_oid) as meta_stream:
501 return _read_dir_meta(meta_stream)
504 def _readlink(repo, oid):
505 return b''.join(repo.join(hexlify(oid)))
507 def readlink(repo, item):
508 """Return the link target of item, which must be a symlink. Reads the
509 target from the repository if necessary."""
511 assert S_ISLNK(item_mode(item))
512 if isinstance(item, FakeLink):
514 if isinstance(item.meta, Metadata):
515 target = item.meta.symlink_target
518 return _readlink(repo, item.oid)
520 def _compute_item_size(repo, item):
521 mode = item_mode(item)
523 size = _normal_or_chunked_file_size(repo, item.oid)
526 if isinstance(item, FakeLink):
527 return len(item.target)
528 return len(_readlink(repo, item.oid))
531 def item_size(repo, item):
532 """Return the size of item, computing it if necessary."""
534 if isinstance(m, Metadata) and m.size is not None:
536 return _compute_item_size(repo, item)
538 def tree_data_reader(repo, oid):
539 """Return an open reader for all of the data contained within oid. If
540 oid refers to a tree, recursively concatenate all of its contents."""
541 return _FileReader(repo, oid)
543 def fopen(repo, item):
544 """Return an open reader for the given file item."""
545 assert S_ISREG(item_mode(item))
546 return tree_data_reader(repo, item.oid)
548 def _commit_item_from_data(oid, data):
549 info = parse_commit(data)
550 return Commit(meta=default_dir_mode,
551 oid=unhexlify(info.tree),
554 def _commit_item_from_oid(repo, oid, require_meta):
555 commit = cache_get_commit_item(oid, need_meta=require_meta)
556 if commit and ((not require_meta) or isinstance(commit.meta, Metadata)):
558 it = repo.cat(hexlify(oid))
559 _, typ, size = next(it)
560 assert typ == b'commit'
561 commit = _commit_item_from_data(oid, b''.join(it))
563 meta = _find_treeish_oid_metadata(repo, commit.oid)
565 commit = commit._replace(meta=meta)
566 commit_key = b'itm:' + oid
567 cache_notice(commit_key, commit)
570 def _revlist_item_from_oid(repo, oid, require_meta):
571 commit = _commit_item_from_oid(repo, oid, require_meta)
572 return RevList(oid=oid, meta=commit.meta)
574 def root_items(repo, names=None, want_meta=True):
575 """Yield (name, item) for the items in '/' in the VFS. Return
576 everything if names is logically false, otherwise return only
577 items with a name in the collection.
580 # FIXME: what about non-leaf refs like 'refs/heads/foo/bar/baz?
586 # FIXME: maybe eventually support repo.clone() or something
587 # and pass in two repos, so we can drop the tuple() and stream
588 # in parallel (i.e. meta vs refs).
589 for name, oid in tuple(repo.refs([], limit_to_heads=True)):
590 assert(name.startswith(b'refs/heads/'))
591 yield name[11:], _revlist_item_from_oid(repo, oid, want_meta)
599 if ref in (b'.', b'.tag'):
601 it = repo.cat(b'refs/heads/' + ref)
602 oidx, typ, size = next(it)
606 assert typ == b'commit'
607 commit = parse_commit(b''.join(it))
608 yield ref, _revlist_item_from_oid(repo, unhexlify(oidx), want_meta)
610 def ordered_tree_entries(tree_data, bupm=None):
611 """Yields (name, mangled_name, kind, gitmode, oid) for each item in
612 tree, sorted by name.
615 # Sadly, the .bupm entries currently aren't in git tree order,
616 # but in unmangled name order. They _do_ account for the fact
617 # that git sorts trees (including chunked trees) as if their
618 # names ended with "/" (so "fo" sorts after "fo." iff fo is a
619 # directory), but we apply this on the unmangled names in save
620 # rather than on the mangled names.
621 # This makes streaming impossible when we need the metadata.
622 def result_from_tree_entry(tree_entry):
623 gitmode, mangled_name, oid = tree_entry
624 name, kind = git.demangle_name(mangled_name, gitmode)
625 return name, mangled_name, kind, gitmode, oid
627 tree_ents = (result_from_tree_entry(x) for x in tree_decode(tree_data))
629 tree_ents = sorted(tree_ents, key=lambda x: x[0])
630 for ent in tree_ents:
633 def tree_items(oid, tree_data, names=frozenset(), bupm=None):
635 def tree_item(ent_oid, kind, gitmode):
636 if kind == BUP_CHUNKED:
637 meta = Metadata.read(bupm) if bupm else default_file_mode
638 return Chunky(oid=ent_oid, meta=meta)
641 # No metadata here (accessable via '.' inside ent_oid).
642 return Item(meta=default_dir_mode, oid=ent_oid)
644 meta = Metadata.read(bupm) if bupm else None
645 # handle the case of metadata being empty/missing in bupm
646 # (or there not being bupm at all)
648 meta = _default_mode_for_gitmode(gitmode)
649 return Item(oid=ent_oid, meta=meta)
651 assert len(oid) == 20
653 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
654 yield b'.', Item(oid=oid, meta=dot_meta)
655 tree_entries = ordered_tree_entries(tree_data, bupm)
656 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
657 if mangled_name == b'.bupm':
660 yield name, tree_item(ent_oid, kind, gitmode)
663 # Assumes the tree is properly formed, i.e. there are no
664 # duplicates, and entries will be in git tree order.
665 if type(names) not in (frozenset, set):
666 names = frozenset(names)
667 remaining = len(names)
669 # Account for the bupm sort order issue (cf. ordered_tree_entries above)
670 last_name = max(names) if bupm else max(names) + b'/'
673 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
674 yield b'.', Item(oid=oid, meta=dot_meta)
679 tree_entries = ordered_tree_entries(tree_data, bupm)
680 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
681 if mangled_name == b'.bupm':
684 if name not in names:
686 break # given bupm sort order, we're finished
687 if (kind == BUP_CHUNKED or not S_ISDIR(gitmode)) and bupm:
690 yield name, tree_item(ent_oid, kind, gitmode)
695 def tree_items_with_meta(repo, oid, tree_data, names):
696 # For now, the .bupm order doesn't quite match git's, and we don't
697 # load the tree data incrementally anyway, so we just work in RAM
699 assert len(oid) == 20
701 for _, mangled_name, sub_oid in tree_decode(tree_data):
702 if mangled_name == b'.bupm':
703 bupm = _FileReader(repo, sub_oid)
705 if mangled_name > b'.bupm':
707 for item in tree_items(oid, tree_data, names, bupm):
710 _save_name_rx = re.compile(br'^\d\d\d\d-\d\d-\d\d-\d{6}(-\d+)?$')
712 def _reverse_suffix_duplicates(strs):
713 """Yields the elements of strs, with any runs of duplicate values
714 suffixed with -N suffixes, where the zero padded integer N
715 decreases to 0 by 1 (e.g. 10, 09, ..., 00).
718 for name, duplicates in groupby(strs):
719 ndup = len(tuple(duplicates))
723 ndig = len(str(ndup - 1))
724 fmt = b'%s-' + b'%0' + (b'%d' % ndig) + b'd'
725 for i in range(ndup - 1, -1, -1):
726 yield fmt % (name, i)
729 items = f.readline().split(None)
730 assert len(items) == 2
731 tree, auth_sec = items
732 return unhexlify(tree), int(auth_sec)
734 def _name_for_rev(rev):
735 commit_oidx, (tree_oid, utc) = rev
736 return strftime('%Y-%m-%d-%H%M%S', localtime(utc)).encode('ascii')
738 def _item_for_rev(rev):
739 commit_oidx, (tree_oid, utc) = rev
740 coid = unhexlify(commit_oidx)
741 item = cache_get_commit_item(coid, need_meta=False)
744 item = Commit(meta=default_dir_mode, oid=tree_oid, coid=coid)
745 commit_key = b'itm:' + coid
746 cache_notice(commit_key, item)
749 def cache_commit(repo, oid):
750 """Build, cache, and return a "name -> commit_item" dict of the entire
754 # For now, always cache with full metadata
756 entries[b'.'] = _revlist_item_from_oid(repo, oid, True)
757 revs = repo.rev_list((hexlify(oid),), format=b'%T %at',
759 rev_items, rev_names = tee(revs)
760 revs = None # Don't disturb the tees
761 rev_names = _reverse_suffix_duplicates(_name_for_rev(x) for x in rev_names)
762 rev_items = (_item_for_rev(x) for x in rev_items)
764 for item in rev_items:
765 name = next(rev_names)
766 tip = tip or (name, item)
768 entries[b'latest'] = FakeLink(meta=default_symlink_mode, target=tip[0])
769 revlist_key = b'rvl:' + tip[1].coid
770 cache_notice(revlist_key, entries)
773 def revlist_items(repo, oid, names):
774 assert len(oid) == 20
776 # Special case '.' instead of caching the whole history since it's
777 # the only way to get the metadata for the commit.
778 if names and all(x == b'.' for x in names):
779 yield b'.', _revlist_item_from_oid(repo, oid, True)
782 # For now, don't worry about the possibility of the contents being
783 # "too big" for the cache.
784 revlist_key = b'rvl:' + oid
785 entries = cache_get(revlist_key)
787 entries = cache_commit(repo, oid)
790 for name in sorted(entries.keys()):
791 yield name, entries[name]
794 names = frozenset(name for name in names
795 if _save_name_rx.match(name) or name in (b'.', b'latest'))
798 yield b'.', entries[b'.']
799 for name in (n for n in names if n != b'.'):
800 commit = entries.get(name)
804 def tags_items(repo, names):
808 assert len(oid) == 20
811 _, typ, size = next(it)
813 return cache_get_commit_item(oid, need_meta=False) \
814 or _commit_item_from_data(oid, b''.join(it))
817 return Item(meta=default_file_mode, oid=oid)
819 return Item(meta=default_dir_mode, oid=oid)
820 raise Exception('unexpected tag type ' + typ.decode('ascii')
821 + ' for tag ' + path_msg(name))
825 # We have to pull these all into ram because tag_item calls cat()
826 for name, oid in tuple(repo.refs(names, limit_to_tags=True)):
827 assert(name.startswith(b'refs/tags/'))
829 yield name, tag_item(oid)
832 # Assumes no duplicate refs
833 if type(names) not in (frozenset, set):
834 names = frozenset(names)
835 remaining = len(names)
836 last_name = max(names)
843 for name, oid in repo.refs(names, limit_to_tags=True):
844 assert(name.startswith(b'refs/tags/'))
848 if name not in names:
850 yield name, tag_item(oid)
855 def contents(repo, item, names=None, want_meta=True):
856 """Yields information about the items contained in item. Yields
857 (name, item) for each name in names, if the name exists, in an
858 unspecified order. If there are no names, then yields (name,
859 item) for all items, including, a first item named '.'
860 representing the container itself.
862 The meta value for any directories other than '.' will be a
863 default directory mode, not a Metadata object. This is because
864 the actual metadata for a directory is stored inside the directory
865 (see fill_in_metadata_if_dir() or ensure_item_has_metadata()).
867 Note that want_meta is advisory. For any given item, item.meta
868 might be a Metadata instance or a mode, and if the former,
869 meta.size might be None. Missing sizes can be computed via via
870 item_size() or augment_item_meta(..., include_size=True).
872 Do not modify any item.meta Metadata instances directly. If
873 needed, make a copy via item.meta.copy() and modify that instead.
876 # Q: are we comfortable promising '.' first when no names?
879 assert S_ISDIR(item_mode(item))
881 if item_t in real_tree_types:
882 it = repo.cat(hexlify(item.oid))
883 _, obj_t, size = next(it)
887 # Note: it shouldn't be possible to see an Item with type
888 # 'commit' since a 'commit' should always produce a Commit.
889 raise Exception('unexpected git ' + obj_t.decode('ascii'))
891 item_gen = tree_items_with_meta(repo, item.oid, data, names)
893 item_gen = tree_items(item.oid, data, names)
894 elif item_t == RevList:
895 item_gen = revlist_items(repo, item.oid, names)
897 item_gen = root_items(repo, names, want_meta)
899 item_gen = tags_items(repo, names)
901 raise Exception('unexpected VFS item ' + str(item))
905 def _resolve_path(repo, path, parent=None, want_meta=True, follow=True):
906 cache_key = b'res:%d%d%d:%s\0%s' \
907 % (bool(want_meta), bool(follow), repo.id(),
908 (b'/'.join(x[0] for x in parent) if parent else b''),
910 resolution = cache_get(cache_key)
914 def notice_resolution(r):
915 cache_notice(cache_key, r)
918 def raise_dir_required_but_not_dir(path, parent, past):
919 raise IOError(ENOTDIR,
920 "path %s%s resolves to non-directory %r"
922 ' (relative to %r)' % parent if parent else '',
931 assert type(x[0]) in (bytes, str)
932 assert type(x[1]) in item_types
933 assert parent[0][1] == _root
934 if not S_ISDIR(item_mode(parent[-1][1])):
935 raise IOError(ENOTDIR,
936 'path resolution parent %r is not a directory'
938 is_absolute, must_be_dir, future = _decompose_path(path)
941 if not future: # path was effectively '.' or '/'
943 return notice_resolution(((b'', _root),))
945 return notice_resolution(tuple(parent))
946 return notice_resolution(((b'', _root),))
948 past = [(b'', _root)]
950 past = list(parent) if parent else [(b'', _root)]
954 if must_be_dir and not S_ISDIR(item_mode(past[-1][1])):
955 raise_dir_required_but_not_dir(path, parent, past)
956 return notice_resolution(tuple(past))
957 segment = future.pop()
960 if len(past) > 1: # .. from / is /
961 assert S_ISDIR(item_mode(past[-1][1]))
964 parent_name, parent_item = past[-1]
965 wanted = (segment,) if not want_meta else (b'.', segment)
966 items = tuple(contents(repo, parent_item, names=wanted,
967 want_meta=want_meta))
969 item = items[0][1] if items else None
970 else: # First item will be '.' and have the metadata
971 item = items[1][1] if len(items) == 2 else None
972 dot, dot_item = items[0]
974 past[-1] = parent_name, parent_item
976 past.append((segment, None),)
977 return notice_resolution(tuple(past))
978 mode = item_mode(item)
979 if not S_ISLNK(mode):
980 if not S_ISDIR(mode):
981 past.append((segment, item),)
983 raise IOError(ENOTDIR,
984 'path %r%s ends internally in non-directory here: %r'
986 ' (relative to %r)' % parent if parent else '',
990 raise_dir_required_but_not_dir(path, parent, past)
991 return notice_resolution(tuple(past))
993 if want_meta and type(item) in real_tree_types:
994 dir_meta = _find_treeish_oid_metadata(repo, item.oid)
996 item = item._replace(meta=dir_meta)
997 past.append((segment, item))
999 if not future and not follow:
1000 past.append((segment, item),)
1003 raise IOError(ELOOP,
1004 'too many symlinks encountered while resolving %r%s'
1005 % (path, ' relative to %r' % parent if parent else ''),
1006 terminus=tuple(past + [(segment, item)]))
1007 target = readlink(repo, item)
1008 is_absolute, _, target_future = _decompose_path(target)
1010 if not target_future: # path was effectively '/'
1011 return notice_resolution(((b'', _root),))
1012 past = [(b'', _root)]
1013 future = target_future
1015 future.extend(target_future)
1018 def resolve(repo, path, parent=None, want_meta=True, follow=True):
1019 """Follow the path in the virtual filesystem and return a tuple
1020 representing the location, if any, denoted by the path. Each
1021 element in the result tuple will be (name, info), where info will
1022 be a VFS item that can be passed to functions like item_mode().
1024 If follow is false, and if the final path element is a symbolic
1025 link, don't follow it, just return it in the result.
1027 If a path segment that does not exist is encountered during
1028 resolution, the result will represent the location of the missing
1029 item, and that item in the result will be None.
1031 Any attempt to traverse a non-directory will raise a VFS ENOTDIR
1034 Any symlinks along the path, including at the end, will be
1035 resolved. A VFS IOError with the errno attribute set to ELOOP
1036 will be raised if too many symlinks are traversed while following
1037 the path. That exception is effectively like a normal
1038 ELOOP IOError exception, but will include a terminus element
1039 describing the location of the failure, which will be a tuple of
1040 (name, info) elements.
1042 The parent, if specified, must be a sequence of (name, item)
1043 tuples, and will provide the starting point for the resolution of
1044 the path. If no parent is specified, resolution will start at
1047 The result may include elements of parent directly, so they must
1048 not be modified later. If this is a concern, pass in "name,
1049 copy_item(item) for name, item in parent" instead.
1051 When want_meta is true, detailed metadata will be included in each
1052 result item if it's avaiable, otherwise item.meta will be an
1053 integer mode. The metadata size may or may not be provided, but
1054 can be computed by item_size() or augment_item_meta(...,
1055 include_size=True). Setting want_meta=False is rarely desirable
1056 since it can limit the VFS to just the metadata git itself can
1057 represent, and so, as an example, fifos and sockets will appear to
1058 be regular files (e.g. S_ISREG(item_mode(item)) will be true) .
1059 But the option is provided because it may be more efficient when
1060 only the path names or the more limited metadata is sufficient.
1062 Do not modify any item.meta Metadata instances directly. If
1063 needed, make a copy via item.meta.copy() and modify that instead.
1066 if repo.is_remote():
1067 # Redirect to the more efficient remote version
1068 return repo.resolve(path, parent=parent, want_meta=want_meta,
1070 result = _resolve_path(repo, path, parent=parent, want_meta=want_meta,
1072 _, leaf_item = result[-1]
1073 if leaf_item and follow:
1074 assert not S_ISLNK(item_mode(leaf_item))
1077 def try_resolve(repo, path, parent=None, want_meta=True):
1078 """If path does not refer to a symlink, does not exist, or refers to a
1079 valid symlink, behave exactly like resolve(..., follow=True). If
1080 path refers to an invalid symlink, behave like resolve(...,
1084 res = resolve(repo, path, parent=parent, want_meta=want_meta, follow=False)
1085 leaf_name, leaf_item = res[-1]
1088 if not S_ISLNK(item_mode(leaf_item)):
1090 follow = resolve(repo, leaf_name, parent=res[:-1], want_meta=want_meta)
1091 follow_name, follow_item = follow[-1]
1096 def augment_item_meta(repo, item, include_size=False):
1097 """Ensure item has a Metadata instance for item.meta. If item.meta is
1098 currently a mode, replace it with a compatible "fake" Metadata
1099 instance. If include_size is true, ensure item.meta.size is
1100 correct, computing it if needed. If item.meta is a Metadata
1101 instance, this call may modify it in place or replace it.
1104 # If we actually had parallelism, we'd need locking...
1107 if isinstance(m, Metadata):
1108 if include_size and m.size is None:
1109 m.size = _compute_item_size(repo, item)
1110 return item._replace(meta=m)
1115 meta.uid = meta.gid = None
1116 meta.atime = meta.mtime = meta.ctime = 0
1118 if isinstance(item, FakeLink):
1119 target = item.target
1121 target = _readlink(repo, item.oid)
1122 meta.symlink_target = target
1123 meta.size = len(target)
1125 meta.size = _compute_item_size(repo, item)
1126 return item._replace(meta=meta)
1128 def fill_in_metadata_if_dir(repo, item):
1129 """If item is a directory and item.meta is not a Metadata instance,
1130 attempt to find the metadata for the directory. If found, return
1131 a new item augmented to include that metadata. Otherwise, return
1132 item. May be useful for the output of contents().
1135 if S_ISDIR(item_mode(item)) and not isinstance(item.meta, Metadata):
1136 items = tuple(contents(repo, item, (b'.',), want_meta=True))
1137 assert len(items) == 1
1138 assert items[0][0] == b'.'
1142 def ensure_item_has_metadata(repo, item, include_size=False):
1143 """If item is a directory, attempt to find and add its metadata. If
1144 the item still doesn't have a Metadata instance for item.meta,
1145 give it one via augment_item_meta(). May be useful for the output
1149 return augment_item_meta(repo,
1150 fill_in_metadata_if_dir(repo, item),
1151 include_size=include_size)