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 collections import namedtuple
51 from errno import ELOOP, ENOENT, ENOTDIR
52 from itertools import chain, dropwhile, groupby, izip, tee
53 from random import randrange
54 from stat import S_IFDIR, S_IFLNK, S_IFREG, S_ISDIR, S_ISLNK, S_ISREG
55 from time import localtime, strftime
56 import exceptions, re, sys
58 from bup import client, git, metadata
59 from bup.compat import range
60 from bup.git import BUP_CHUNKED, cp, get_commit_items, parse_commit, tree_decode
61 from bup.helpers import debug2, last
62 from bup.metadata import Metadata
63 from bup.repo import LocalRepo, RemoteRepo
66 class IOError(exceptions.IOError):
67 def __init__(self, errno, message, terminus=None):
68 exceptions.IOError.__init__(self, errno, message)
69 self.terminus = terminus
71 default_file_mode = S_IFREG | 0o644
72 default_dir_mode = S_IFDIR | 0o755
73 default_symlink_mode = S_IFLNK | 0o755
75 def _default_mode_for_gitmode(gitmode):
77 return default_file_mode
79 return default_dir_mode
81 return default_symlink_mode
82 raise Exception('unexpected git mode ' + oct(gitmode))
84 def _normal_or_chunked_file_size(repo, oid):
85 """Return the size of the normal or chunked file indicated by oid."""
86 # FIXME: --batch-format CatPipe?
87 it = repo.cat(oid.encode('hex'))
88 _, obj_t, size = next(it)
90 while obj_t == 'tree':
91 mode, name, last_oid = last(tree_decode(''.join(it)))
93 it = repo.cat(last_oid.encode('hex'))
94 _, obj_t, size = next(it)
95 return ofs + sum(len(b) for b in it)
97 def _tree_chunks(repo, tree, startofs):
98 "Tree should be a sequence of (name, mode, hash) as per tree_decode()."
100 # name is the chunk's hex offset in the original file
101 tree = dropwhile(lambda (_1, name, _2): int(name, 16) < startofs, tree)
102 for mode, name, oid in tree:
104 skipmore = startofs - ofs
107 it = repo.cat(oid.encode('hex'))
108 _, obj_t, size = next(it)
111 assert obj_t == 'tree'
112 for b in _tree_chunks(repo, tree_decode(data), skipmore):
115 assert obj_t == 'blob'
116 yield data[skipmore:]
119 def __init__(self, repo, oid, startofs):
120 it = repo.cat(oid.encode('hex'))
121 _, obj_t, size = next(it)
122 isdir = obj_t == 'tree'
125 self.it = _tree_chunks(repo, tree_decode(data), startofs)
129 self.blob = data[startofs:]
132 def next(self, size):
134 while len(out) < size:
135 if self.it and not self.blob:
137 self.blob = self.it.next()
138 except StopIteration:
141 want = size - len(out)
142 out += self.blob[:want]
143 self.blob = self.blob[want:]
146 debug2('next(%d) returned %d\n' % (size, len(out)))
150 class _FileReader(object):
151 def __init__(self, repo, oid, known_size=None):
152 assert len(oid) == 20
157 self._size = known_size
159 def _compute_size(self):
161 self._size = _normal_or_chunked_file_size(self._repo, self.oid)
166 raise IOError(errno.EINVAL, 'Invalid argument')
167 if ofs > self._compute_size():
168 raise IOError(errno.EINVAL, 'Invalid argument')
174 def read(self, count=-1):
176 count = self._compute_size() - self.ofs
177 if not self.reader or self.reader.ofs != self.ofs:
178 self.reader = _ChunkReader(self._repo, self.oid, self.ofs)
180 buf = self.reader.next(count)
183 raise # our offsets will be all screwed up otherwise
192 def __exit__(self, type, value, traceback):
196 _multiple_slashes_rx = re.compile(r'//+')
198 def _decompose_path(path):
199 """Return a boolean indicating whether the path is absolute, and a
200 reversed list of path elements, omitting any occurrences of "."
201 and ignoring any leading or trailing slash. If the path is
202 effectively '/' or '.', return an empty list.
205 path = re.sub(_multiple_slashes_rx, '/', path)
207 return True, True, []
208 is_absolute = must_be_dir = False
209 if path.startswith('/'):
212 for suffix in ('/', '/.'):
213 if path.endswith(suffix):
215 path = path[:-len(suffix)]
216 parts = [x for x in path.split('/') if x != '.']
219 must_be_dir = True # e.g. path was effectively '.' or '/', etc.
220 return is_absolute, must_be_dir, parts
223 Item = namedtuple('Item', ('meta', 'oid'))
224 Chunky = namedtuple('Chunky', ('meta', 'oid'))
225 Root = namedtuple('Root', ('meta'))
226 Tags = namedtuple('Tags', ('meta'))
227 RevList = namedtuple('RevList', ('meta', 'oid'))
228 Commit = namedtuple('Commit', ('meta', 'oid', 'coid'))
230 item_types = frozenset((Item, Chunky, Root, Tags, RevList, Commit))
231 real_tree_types = frozenset((Item, Commit))
233 _root = Root(meta=default_dir_mode)
234 _tags = Tags(meta=default_dir_mode)
239 ### A general purpose shared cache with (currently) cheap random
240 ### eviction. At the moment there is no weighting so a single commit
241 ### item is just as likely to be evicted as an entire "rev-list". See
242 ### is_valid_cache_key for a description of the expected content.
246 _cache_max_items = 30000
249 global _cache, _cache_keys
253 def is_valid_cache_key(x):
254 """Return logically true if x looks like it could be a valid cache key
255 (with respect to structure). Current valid cache entries:
256 (path, parent, want_meta, dref) -> resolution
258 commit_oid + ':r' -> rev-list
259 i.e. rev-list -> {'.', commit, '2012...', next_commit, ...}
261 # Suspect we may eventually add "(container_oid, name) -> ...", and others.
268 if len(x) == 22 and x.endswith(b':r'):
273 assert is_valid_cache_key(key)
274 return _cache.get(key)
276 def cache_notice(key, value):
277 global _cache, _cache_keys, _cache_max_items
278 assert is_valid_cache_key(key)
281 if len(_cache) < _cache_max_items:
282 _cache_keys.append(key)
285 victim_i = randrange(0, len(_cache_keys))
286 victim = _cache_keys[victim_i]
288 _cache_keys[victim_i] = key
291 def cache_get_commit_item(oid, need_meta=True):
292 """Return the requested tree item if it can be found in the cache.
293 When need_meta is true don't return a cached item that only has a
295 # tree might be stored independently, or as '.' with its entries.
296 item = cache_get(oid)
300 if isinstance(item.meta, Metadata):
302 entries = cache_get(oid + b':r')
306 def cache_get_revlist_item(oid, need_meta=True):
307 commit = cache_get_commit_item(oid, need_meta=need_meta)
309 return RevList(oid=oid, meta=commit.meta)
312 """Return a completely independent copy of item, such that
313 modifications will not affect the original.
316 meta = getattr(item, 'meta', None)
317 if isinstance(meta, Metadata):
318 return(item._replace(meta=meta.copy()))
322 """Return the integer mode (stat st_mode) for item."""
324 if isinstance(m, Metadata):
328 def _read_dir_meta(bupm):
329 # This is because save writes unmodified Metadata() entries for
330 # fake parents -- test-save-strip-graft.sh demonstrates.
331 m = Metadata.read(bupm)
333 return default_dir_mode
334 assert m.mode is not None
339 def tree_data_and_bupm(repo, oid):
340 """Return (tree_bytes, bupm_oid) where bupm_oid will be None if the
341 tree has no metadata (i.e. older bup save, or non-bup tree).
344 assert len(oid) == 20
345 it = repo.cat(oid.encode('hex'))
346 _, item_t, size = next(it)
348 if item_t == 'commit':
349 commit = parse_commit(data)
350 it = repo.cat(commit.tree)
351 _, item_t, size = next(it)
353 assert item_t == 'tree'
354 elif item_t != 'tree':
355 raise Exception('%r is not a tree or commit' % oid.encode('hex'))
356 for _, mangled_name, sub_oid in tree_decode(data):
357 if mangled_name == '.bupm':
359 if mangled_name > '.bupm':
363 def _find_treeish_oid_metadata(repo, oid):
364 """Return the metadata for the tree or commit oid, or None if the tree
365 has no metadata (i.e. older bup save, or non-bup tree).
368 tree_data, bupm_oid = tree_data_and_bupm(repo, oid)
370 with _FileReader(repo, bupm_oid) as meta_stream:
371 return _read_dir_meta(meta_stream)
374 def _readlink(repo, oid):
375 return ''.join(repo.join(oid.encode('hex')))
377 def readlink(repo, item):
378 """Return the link target of item, which must be a symlink. Reads the
379 target from the repository if necessary."""
381 assert S_ISLNK(item_mode(item))
382 if isinstance(item.meta, Metadata):
383 target = item.meta.symlink_target
386 return _readlink(repo, item.oid)
388 def _compute_item_size(repo, item):
389 mode = item_mode(item)
391 size = _normal_or_chunked_file_size(repo, item.oid)
394 return len(_readlink(repo, item.oid))
397 def item_size(repo, item):
398 """Return the size of item, computing it if necessary."""
400 if isinstance(m, Metadata) and m.size is not None:
402 return _compute_item_size(repo, item)
404 def tree_data_reader(repo, oid):
405 """Return an open reader for all of the data contained within oid. If
406 oid refers to a tree, recursively concatenate all of its contents."""
407 return _FileReader(repo, oid)
409 def fopen(repo, item):
410 """Return an open reader for the given file item."""
411 assert S_ISREG(item_mode(item))
412 return tree_data_reader(repo, item.oid)
414 def _commit_item_from_data(oid, data):
415 info = parse_commit(data)
416 return Commit(meta=default_dir_mode,
417 oid=info.tree.decode('hex'),
420 def _commit_item_from_oid(repo, oid, require_meta):
421 commit = cache_get_commit_item(oid, need_meta=require_meta)
422 if commit and ((not require_meta) or isinstance(commit.meta, Metadata)):
424 it = repo.cat(oid.encode('hex'))
425 _, typ, size = next(it)
426 assert typ == 'commit'
427 commit = _commit_item_from_data(oid, ''.join(it))
429 meta = _find_treeish_oid_metadata(repo, commit.oid)
431 commit = commit._replace(meta=meta)
432 cache_notice(oid, commit)
435 def _revlist_item_from_oid(repo, oid, require_meta):
436 commit = _commit_item_from_oid(repo, oid, require_meta)
437 return RevList(oid=oid, meta=commit.meta)
439 def root_items(repo, names=None, want_meta=True):
440 """Yield (name, item) for the items in '/' in the VFS. Return
441 everything if names is logically false, otherwise return only
442 items with a name in the collection.
445 # FIXME: what about non-leaf refs like 'refs/heads/foo/bar/baz?
451 # FIXME: maybe eventually support repo.clone() or something
452 # and pass in two repos, so we can drop the tuple() and stream
453 # in parallel (i.e. meta vs refs).
454 for name, oid in tuple(repo.refs([], limit_to_heads=True)):
455 assert(name.startswith('refs/heads/'))
456 yield name[11:], _revlist_item_from_oid(repo, oid, want_meta)
464 if ref in ('.', '.tag'):
466 it = repo.cat('refs/heads/' + ref)
467 oidx, typ, size = next(it)
471 assert typ == 'commit'
472 commit = parse_commit(''.join(it))
473 yield ref, _revlist_item_from_oid(repo, oidx.decode('hex'), want_meta)
475 def ordered_tree_entries(tree_data, bupm=None):
476 """Yields (name, mangled_name, kind, gitmode, oid) for each item in
477 tree, sorted by name.
480 # Sadly, the .bupm entries currently aren't in git tree order,
481 # i.e. they don't account for the fact that git sorts trees
482 # (including our chunked trees) as if their names ended with "/",
483 # so "fo" sorts after "fo." iff fo is a directory. This makes
484 # streaming impossible when we need the metadata.
485 def result_from_tree_entry(tree_entry):
486 gitmode, mangled_name, oid = tree_entry
487 name, kind = git.demangle_name(mangled_name, gitmode)
488 return name, mangled_name, kind, gitmode, oid
490 tree_ents = (result_from_tree_entry(x) for x in tree_decode(tree_data))
492 tree_ents = sorted(tree_ents, key=lambda x: x[0])
493 for ent in tree_ents:
496 def tree_items(oid, tree_data, names=frozenset(), bupm=None):
498 def tree_item(ent_oid, kind, gitmode):
499 if kind == BUP_CHUNKED:
500 meta = Metadata.read(bupm) if bupm else default_file_mode
501 return Chunky(oid=ent_oid, meta=meta)
504 # No metadata here (accessable via '.' inside ent_oid).
505 return Item(meta=default_dir_mode, oid=ent_oid)
507 return Item(oid=ent_oid,
508 meta=(Metadata.read(bupm) if bupm \
509 else _default_mode_for_gitmode(gitmode)))
511 assert len(oid) == 20
513 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
514 yield '.', Item(oid=oid, meta=dot_meta)
515 tree_entries = ordered_tree_entries(tree_data, bupm)
516 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
517 if mangled_name == '.bupm':
520 yield name, tree_item(ent_oid, kind, gitmode)
523 # Assumes the tree is properly formed, i.e. there are no
524 # duplicates, and entries will be in git tree order.
525 if type(names) not in (frozenset, set):
526 names = frozenset(names)
527 remaining = len(names)
529 # Account for the bupm sort order issue (cf. ordered_tree_entries above)
530 last_name = max(names) if bupm else max(names) + '/'
533 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
534 yield '.', Item(oid=oid, meta=dot_meta)
539 tree_entries = ordered_tree_entries(tree_data, bupm)
540 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
541 if mangled_name == '.bupm':
544 if name not in names:
546 break # given bupm sort order, we're finished
547 if (kind == BUP_CHUNKED or not S_ISDIR(gitmode)) and bupm:
550 yield name, tree_item(ent_oid, kind, gitmode)
555 def tree_items_with_meta(repo, oid, tree_data, names):
556 # For now, the .bupm order doesn't quite match git's, and we don't
557 # load the tree data incrementally anyway, so we just work in RAM
559 assert len(oid) == 20
561 for _, mangled_name, sub_oid in tree_decode(tree_data):
562 if mangled_name == '.bupm':
563 bupm = _FileReader(repo, sub_oid)
565 if mangled_name > '.bupm':
567 for item in tree_items(oid, tree_data, names, bupm):
570 _save_name_rx = re.compile(r'^\d\d\d\d-\d\d-\d\d-\d{6}(-\d+)?$')
572 def _reverse_suffix_duplicates(strs):
573 """Yields the elements of strs, with any runs of duplicate values
574 suffixed with -N suffixes, where the zero padded integer N
575 decreases to 0 by 1 (e.g. 10, 09, ..., 00).
578 for name, duplicates in groupby(strs):
579 ndup = len(tuple(duplicates))
583 ndig = len(str(ndup - 1))
584 fmt = '%s-' + '%0' + str(ndig) + 'd'
585 for i in range(ndup - 1, -1, -1):
586 yield fmt % (name, i)
589 items = f.readline().split(None)
590 assert len(items) == 2
591 tree, auth_sec = items
592 return tree.decode('hex'), int(auth_sec)
594 def _name_for_rev(rev):
595 commit_oidx, (tree_oid, utc) = rev
596 return strftime('%Y-%m-%d-%H%M%S', localtime(utc))
598 def _item_for_rev(rev):
599 commit_oidx, (tree_oid, utc) = rev
600 coid = commit_oidx.decode('hex')
601 item = cache_get_commit_item(coid, need_meta=False)
604 item = Commit(meta=default_dir_mode, oid=tree_oid, coid=coid)
605 cache_notice(item.coid, item)
608 def cache_commit(repo, oid):
609 """Build, cache, and return a "name -> commit_item" dict of the entire
613 # For now, always cache with full metadata
615 entries['.'] = _revlist_item_from_oid(repo, oid, True)
616 revs = repo.rev_list((oid.encode('hex'),), format='%T %at',
618 rev_items, rev_names = tee(revs)
619 revs = None # Don't disturb the tees
620 rev_names = _reverse_suffix_duplicates(_name_for_rev(x) for x in rev_names)
621 rev_items = (_item_for_rev(x) for x in rev_items)
623 for item in rev_items:
624 latest = latest or item
625 name = next(rev_names)
627 entries['latest'] = latest
628 cache_notice(latest.coid + b':r', entries)
631 def revlist_items(repo, oid, names):
632 assert len(oid) == 20
634 # Special case '.' instead of caching the whole history since it's
635 # the only way to get the metadata for the commit.
636 if names and all(x == '.' for x in names):
637 yield '.', _revlist_item_from_oid(repo, oid, True)
640 # For now, don't worry about the possibility of the contents being
641 # "too big" for the cache.
642 entries = cache_get(oid + b':r')
644 entries = cache_commit(repo, oid)
647 for name in sorted(entries.keys()):
648 yield name, entries[name]
651 names = frozenset(name for name in names
652 if _save_name_rx.match(name) or name in ('.', 'latest'))
655 yield '.', entries['.']
656 for name in (n for n in names if n != '.'):
657 commit = entries.get(name)
661 def tags_items(repo, names):
665 assert len(oid) == 20
666 oidx = oid.encode('hex')
668 _, typ, size = next(it)
670 return cache_get_commit_item(oid, need_meta=False) \
671 or _commit_item_from_data(oid, ''.join(it))
674 return Item(meta=default_file_mode, oid=oid)
676 return Item(meta=default_dir_mode, oid=oid)
677 raise Exception('unexpected tag type ' + typ + ' for tag ' + name)
681 # We have to pull these all into ram because tag_item calls cat()
682 for name, oid in tuple(repo.refs(names, limit_to_tags=True)):
683 assert(name.startswith('refs/tags/'))
685 yield name, tag_item(oid)
688 # Assumes no duplicate refs
689 if type(names) not in (frozenset, set):
690 names = frozenset(names)
691 remaining = len(names)
692 last_name = max(names)
699 for name, oid in repo.refs(names, limit_to_tags=True):
700 assert(name.startswith('refs/tags/'))
704 if name not in names:
706 yield name, tag_item(oid)
711 def contents(repo, item, names=None, want_meta=True):
712 """Yields information about the items contained in item. Yields
713 (name, item) for each name in names, if the name exists, in an
714 unspecified order. If there are no names, then yields (name,
715 item) for all items, including, a first item named '.'
716 representing the container itself.
718 The meta value for any directories other than '.' will be a
719 default directory mode, not a Metadata object. This is because
720 the actual metadata for a directory is stored inside the directory
721 (see fill_in_metadata_if_dir() or ensure_item_has_metadata()).
723 Note that want_meta is advisory. For any given item, item.meta
724 might be a Metadata instance or a mode, and if the former,
725 meta.size might be None. Missing sizes can be computed via via
726 item_size() or augment_item_meta(..., include_size=True).
728 Do not modify any item.meta Metadata instances directly. If
729 needed, make a copy via item.meta.copy() and modify that instead.
732 # Q: are we comfortable promising '.' first when no names?
735 assert S_ISDIR(item_mode(item))
737 if item_t in real_tree_types:
738 it = repo.cat(item.oid.encode('hex'))
739 _, obj_t, size = next(it)
743 # Note: it shouldn't be possible to see an Item with type
744 # 'commit' since a 'commit' should always produce a Commit.
745 raise Exception('unexpected git ' + obj_t)
747 item_gen = tree_items_with_meta(repo, item.oid, data, names)
749 item_gen = tree_items(item.oid, data, names)
750 elif item_t == RevList:
751 item_gen = revlist_items(repo, item.oid, names)
753 item_gen = root_items(repo, names, want_meta)
755 item_gen = tags_items(repo, names)
757 raise Exception('unexpected VFS item ' + str(item))
761 def _resolve_path(repo, path, parent=None, want_meta=True, deref=False):
762 cache_key = (tuple(path), parent, not not want_meta, not not deref)
763 resolution = cache_get(cache_key)
767 def notice_resolution(r):
768 cache_notice(cache_key, r)
771 def raise_dir_required_but_not_dir(path, parent, past):
772 raise IOError(ENOTDIR,
773 "path %r%s resolves to non-directory %r"
775 ' (relative to %r)' % parent if parent else '',
784 assert type(x[0]) in (bytes, str)
785 assert type(x[1]) in item_types
786 assert parent[0][1] == _root
787 if not S_ISDIR(item_mode(parent[-1][1])):
788 raise IOError(ENOTDIR,
789 'path resolution parent %r is not a directory'
791 is_absolute, must_be_dir, future = _decompose_path(path)
794 if not future: # path was effectively '.' or '/'
796 return notice_resolution((('', _root),))
798 return notice_resolution(tuple(parent))
799 return notice_resolution((('', _root),))
803 past = list(parent) if parent else [('', _root)]
807 if must_be_dir and not S_ISDIR(item_mode(past[-1][1])):
808 raise_dir_required_but_not_dir(path, parent, past)
809 return notice_resolution(tuple(past))
810 segment = future.pop()
813 if len(past) > 1: # .. from / is /
814 assert S_ISDIR(item_mode(past[-1][1]))
817 parent_name, parent_item = past[-1]
818 wanted = (segment,) if not want_meta else ('.', segment)
819 items = tuple(contents(repo, parent_item, names=wanted,
820 want_meta=want_meta))
822 item = items[0][1] if items else None
823 else: # First item will be '.' and have the metadata
824 item = items[1][1] if len(items) == 2 else None
825 dot, dot_item = items[0]
827 past[-1] = parent_name, parent_item
829 past.append((segment, None),)
830 return notice_resolution(tuple(past))
831 mode = item_mode(item)
832 if not S_ISLNK(mode):
833 if not S_ISDIR(mode):
834 past.append((segment, item),)
836 raise IOError(ENOTDIR,
837 'path %r%s ends internally in non-directory here: %r'
839 ' (relative to %r)' % parent if parent else '',
843 raise_dir_required_but_not_dir(path, parent, past)
844 return notice_resolution(tuple(past))
846 if want_meta and type(item) in real_tree_types:
847 dir_meta = _find_treeish_oid_metadata(repo, item.oid)
849 item = item._replace(meta=dir_meta)
850 past.append((segment, item))
852 if not future and not deref:
853 past.append((segment, item),)
857 'too many symlinks encountered while resolving %r%s'
858 % (path, ' relative to %r' % parent if parent else ''),
859 terminus=tuple(past + [(segment, item)]))
860 target = readlink(repo, item)
861 is_absolute, _, target_future = _decompose_path(target)
863 if not target_future: # path was effectively '/'
864 return notice_resolution((('', _root),))
866 future = target_future
868 future.extend(target_future)
871 def lresolve(repo, path, parent=None, want_meta=True):
872 """Perform exactly the same function as resolve(), except if the final
873 path element is a symbolic link, don't follow it, just return it
877 return _resolve_path(repo, path, parent=parent, want_meta=want_meta,
880 def resolve(repo, path, parent=None, want_meta=True):
881 """Follow the path in the virtual filesystem and return a tuple
882 representing the location, if any, denoted by the path. Each
883 element in the result tuple will be (name, info), where info will
884 be a VFS item that can be passed to functions like item_mode().
886 If a path segment that does not exist is encountered during
887 resolution, the result will represent the location of the missing
888 item, and that item in the result will be None.
890 Any attempt to traverse a non-directory will raise a VFS ENOTDIR
893 Any symlinks along the path, including at the end, will be
894 resolved. A VFS IOError with the errno attribute set to ELOOP
895 will be raised if too many symlinks are traversed while following
896 the path. That exception is effectively like a normal
897 ELOOP IOError exception, but will include a terminus element
898 describing the location of the failure, which will be a tuple of
899 (name, info) elements.
901 The parent, if specified, must be a sequence of (name, item)
902 tuples, and will provide the starting point for the resolution of
903 the path. If no parent is specified, resolution will start at
906 The result may include elements of parent directly, so they must
907 not be modified later. If this is a concern, pass in "name,
908 copy_item(item) for name, item in parent" instead.
910 When want_meta is true, detailed metadata will be included in each
911 result item if it's avaiable, otherwise item.meta will be an
912 integer mode. The metadata size may or may not be provided, but
913 can be computed by item_size() or augment_item_meta(...,
914 include_size=True). Setting want_meta=False is rarely desirable
915 since it can limit the VFS to just the metadata git itself can
916 represent, and so, as an example, fifos and sockets will appear to
917 be regular files (e.g. S_ISREG(item_mode(item)) will be true) .
918 But the option is provided because it may be more efficient when
919 only the path names or the more limited metadata is sufficient.
921 Do not modify any item.meta Metadata instances directly. If
922 needed, make a copy via item.meta.copy() and modify that instead.
925 result = _resolve_path(repo, path, parent=parent, want_meta=want_meta,
927 _, leaf_item = result[-1]
929 assert not S_ISLNK(item_mode(leaf_item))
932 def try_resolve(repo, path, parent=None, want_meta=True):
933 """If path does not refer to a symlink, does not exist, or refers to a
934 valid symlink, behave exactly like resolve(). If path refers to
935 an invalid symlink, behave like lresolve.
938 res = lresolve(repo, path, parent=parent, want_meta=want_meta)
939 leaf_name, leaf_item = res[-1]
942 if not S_ISLNK(item_mode(leaf_item)):
944 deref = resolve(repo, leaf_name, parent=res[:-1], want_meta=want_meta)
945 deref_name, deref_item = deref[-1]
950 def augment_item_meta(repo, item, include_size=False):
951 """Ensure item has a Metadata instance for item.meta. If item.meta is
952 currently a mode, replace it with a compatible "fake" Metadata
953 instance. If include_size is true, ensure item.meta.size is
954 correct, computing it if needed. If item.meta is a Metadata
955 instance, this call may modify it in place or replace it.
958 # If we actually had parallelism, we'd need locking...
961 if isinstance(m, Metadata):
962 if include_size and m.size is None:
963 m.size = _compute_item_size(repo, item)
964 return item._replace(meta=m)
969 meta.uid = meta.gid = meta.atime = meta.mtime = meta.ctime = 0
971 target = _readlink(repo, item.oid)
972 meta.symlink_target = target
973 meta.size = len(target)
975 meta.size = _compute_item_size(repo, item)
976 return item._replace(meta=meta)
978 def fill_in_metadata_if_dir(repo, item):
979 """If item is a directory and item.meta is not a Metadata instance,
980 attempt to find the metadata for the directory. If found, return
981 a new item augmented to include that metadata. Otherwise, return
982 item. May be useful for the output of contents().
985 if S_ISDIR(item_mode(item)) and not isinstance(item.meta, Metadata):
986 items = tuple(contents(repo, item, ('.',), want_meta=True))
987 assert len(items) == 1
988 assert items[0][0] == '.'
992 def ensure_item_has_metadata(repo, item, include_size=False):
993 """If item is a directory, attempt to find and add its metadata. If
994 the item still doesn't have a Metadata instance for item.meta,
995 give it one via augment_item_meta(). May be useful for the output
999 return augment_item_meta(repo,
1000 fill_in_metadata_if_dir(repo, item),
1001 include_size=include_size)