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 EINVAL, ELOOP, ENOENT, ENOTDIR
52 from itertools import chain, dropwhile, groupby, 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 _skip_chunks_before_offset(tree, offset):
98 prev_ent = next(tree, None)
103 ent_ofs = int(ent[1], 16)
105 return chain([prev_ent, ent], tree)
106 if ent_ofs == offset:
107 return chain([ent], tree)
111 def _tree_chunks(repo, tree, startofs):
112 "Tree should be a sequence of (name, mode, hash) as per tree_decode()."
113 assert(startofs >= 0)
114 # name is the chunk's hex offset in the original file
115 for mode, name, oid in _skip_chunks_before_offset(tree, startofs):
117 skipmore = startofs - ofs
120 it = repo.cat(oid.encode('hex'))
121 _, obj_t, size = next(it)
124 assert obj_t == 'tree'
125 for b in _tree_chunks(repo, tree_decode(data), skipmore):
128 assert obj_t == 'blob'
129 yield data[skipmore:]
132 def __init__(self, repo, oid, startofs):
133 it = repo.cat(oid.encode('hex'))
134 _, obj_t, size = next(it)
135 isdir = obj_t == 'tree'
138 self.it = _tree_chunks(repo, tree_decode(data), startofs)
142 self.blob = data[startofs:]
145 def next(self, size):
147 while len(out) < size:
148 if self.it and not self.blob:
150 self.blob = self.it.next()
151 except StopIteration:
154 want = size - len(out)
155 out += self.blob[:want]
156 self.blob = self.blob[want:]
159 debug2('next(%d) returned %d\n' % (size, len(out)))
163 class _FileReader(object):
164 def __init__(self, repo, oid, known_size=None):
165 assert len(oid) == 20
170 self._size = known_size
172 def _compute_size(self):
174 self._size = _normal_or_chunked_file_size(self._repo, self.oid)
178 if ofs < 0 or ofs > self._compute_size():
179 raise IOError(EINVAL, 'Invalid seek offset: %d' % ofs)
185 def read(self, count=-1):
186 size = self._compute_size()
190 count = size - self.ofs
191 if not self.reader or self.reader.ofs != self.ofs:
192 self.reader = _ChunkReader(self._repo, self.oid, self.ofs)
194 buf = self.reader.next(count)
197 raise # our offsets will be all screwed up otherwise
206 def __exit__(self, type, value, traceback):
210 _multiple_slashes_rx = re.compile(r'//+')
212 def _decompose_path(path):
213 """Return a boolean indicating whether the path is absolute, and a
214 reversed list of path elements, omitting any occurrences of "."
215 and ignoring any leading or trailing slash. If the path is
216 effectively '/' or '.', return an empty list.
219 path = re.sub(_multiple_slashes_rx, '/', path)
221 return True, True, []
222 is_absolute = must_be_dir = False
223 if path.startswith('/'):
226 for suffix in ('/', '/.'):
227 if path.endswith(suffix):
229 path = path[:-len(suffix)]
230 parts = [x for x in path.split('/') if x != '.']
233 must_be_dir = True # e.g. path was effectively '.' or '/', etc.
234 return is_absolute, must_be_dir, parts
237 Item = namedtuple('Item', ('meta', 'oid'))
238 Chunky = namedtuple('Chunky', ('meta', 'oid'))
239 Root = namedtuple('Root', ('meta'))
240 Tags = namedtuple('Tags', ('meta'))
241 RevList = namedtuple('RevList', ('meta', 'oid'))
242 Commit = namedtuple('Commit', ('meta', 'oid', 'coid'))
244 item_types = frozenset((Item, Chunky, Root, Tags, RevList, Commit))
245 real_tree_types = frozenset((Item, Commit))
247 _root = Root(meta=default_dir_mode)
248 _tags = Tags(meta=default_dir_mode)
253 ### A general purpose shared cache with (currently) cheap random
254 ### eviction. At the moment there is no weighting so a single commit
255 ### item is just as likely to be evicted as an entire "rev-list". See
256 ### is_valid_cache_key for a description of the expected content.
260 _cache_max_items = 30000
263 global _cache, _cache_keys
267 def is_valid_cache_key(x):
268 """Return logically true if x looks like it could be a valid cache key
269 (with respect to structure). Current valid cache entries:
270 res:... -> resolution
272 rvl:OID -> {'.', commit, '2012...', next_commit, ...}
274 # Suspect we may eventually add "(container_oid, name) -> ...", and others.
278 if tag in ('itm:', 'rvl:') and len(x) == 24:
285 if not is_valid_cache_key(key):
286 raise Exception('invalid cache key: ' + repr(key))
287 return _cache.get(key)
289 def cache_notice(key, value):
290 global _cache, _cache_keys, _cache_max_items
291 if not is_valid_cache_key(key):
292 raise Exception('invalid cache key: ' + repr(key))
295 if len(_cache) < _cache_max_items:
296 _cache_keys.append(key)
299 victim_i = randrange(0, len(_cache_keys))
300 victim = _cache_keys[victim_i]
302 _cache_keys[victim_i] = key
305 def cache_get_commit_item(oid, need_meta=True):
306 """Return the requested tree item if it can be found in the cache.
307 When need_meta is true don't return a cached item that only has a
309 # tree might be stored independently, or as '.' with its entries.
310 commit_key = b'itm:' + oid
311 item = cache_get(commit_key)
315 if isinstance(item.meta, Metadata):
317 entries = cache_get(b'rvl:' + oid)
321 def cache_get_revlist_item(oid, need_meta=True):
322 commit = cache_get_commit_item(oid, need_meta=need_meta)
324 return RevList(oid=oid, meta=commit.meta)
327 """Return a completely independent copy of item, such that
328 modifications will not affect the original.
331 meta = getattr(item, 'meta', None)
332 if isinstance(meta, Metadata):
333 return(item._replace(meta=meta.copy()))
337 """Return the integer mode (stat st_mode) for item."""
339 if isinstance(m, Metadata):
343 def _read_dir_meta(bupm):
344 # This is because save writes unmodified Metadata() entries for
345 # fake parents -- test-save-strip-graft.sh demonstrates.
346 m = Metadata.read(bupm)
348 return default_dir_mode
349 assert m.mode is not None
354 def tree_data_and_bupm(repo, oid):
355 """Return (tree_bytes, bupm_oid) where bupm_oid will be None if the
356 tree has no metadata (i.e. older bup save, or non-bup tree).
359 assert len(oid) == 20
360 it = repo.cat(oid.encode('hex'))
361 _, item_t, size = next(it)
363 if item_t == 'commit':
364 commit = parse_commit(data)
365 it = repo.cat(commit.tree)
366 _, item_t, size = next(it)
368 assert item_t == 'tree'
369 elif item_t != 'tree':
370 raise Exception('%r is not a tree or commit' % oid.encode('hex'))
371 for _, mangled_name, sub_oid in tree_decode(data):
372 if mangled_name == '.bupm':
374 if mangled_name > '.bupm':
378 def _find_treeish_oid_metadata(repo, oid):
379 """Return the metadata for the tree or commit oid, or None if the tree
380 has no metadata (i.e. older bup save, or non-bup tree).
383 tree_data, bupm_oid = tree_data_and_bupm(repo, oid)
385 with _FileReader(repo, bupm_oid) as meta_stream:
386 return _read_dir_meta(meta_stream)
389 def _readlink(repo, oid):
390 return ''.join(repo.join(oid.encode('hex')))
392 def readlink(repo, item):
393 """Return the link target of item, which must be a symlink. Reads the
394 target from the repository if necessary."""
396 assert S_ISLNK(item_mode(item))
397 if isinstance(item.meta, Metadata):
398 target = item.meta.symlink_target
401 return _readlink(repo, item.oid)
403 def _compute_item_size(repo, item):
404 mode = item_mode(item)
406 size = _normal_or_chunked_file_size(repo, item.oid)
409 return len(_readlink(repo, item.oid))
412 def item_size(repo, item):
413 """Return the size of item, computing it if necessary."""
415 if isinstance(m, Metadata) and m.size is not None:
417 return _compute_item_size(repo, item)
419 def tree_data_reader(repo, oid):
420 """Return an open reader for all of the data contained within oid. If
421 oid refers to a tree, recursively concatenate all of its contents."""
422 return _FileReader(repo, oid)
424 def fopen(repo, item):
425 """Return an open reader for the given file item."""
426 assert S_ISREG(item_mode(item))
427 return tree_data_reader(repo, item.oid)
429 def _commit_item_from_data(oid, data):
430 info = parse_commit(data)
431 return Commit(meta=default_dir_mode,
432 oid=info.tree.decode('hex'),
435 def _commit_item_from_oid(repo, oid, require_meta):
436 commit = cache_get_commit_item(oid, need_meta=require_meta)
437 if commit and ((not require_meta) or isinstance(commit.meta, Metadata)):
439 it = repo.cat(oid.encode('hex'))
440 _, typ, size = next(it)
441 assert typ == 'commit'
442 commit = _commit_item_from_data(oid, ''.join(it))
444 meta = _find_treeish_oid_metadata(repo, commit.oid)
446 commit = commit._replace(meta=meta)
447 commit_key = b'itm:' + oid
448 cache_notice(commit_key, commit)
451 def _revlist_item_from_oid(repo, oid, require_meta):
452 commit = _commit_item_from_oid(repo, oid, require_meta)
453 return RevList(oid=oid, meta=commit.meta)
455 def root_items(repo, names=None, want_meta=True):
456 """Yield (name, item) for the items in '/' in the VFS. Return
457 everything if names is logically false, otherwise return only
458 items with a name in the collection.
461 # FIXME: what about non-leaf refs like 'refs/heads/foo/bar/baz?
467 # FIXME: maybe eventually support repo.clone() or something
468 # and pass in two repos, so we can drop the tuple() and stream
469 # in parallel (i.e. meta vs refs).
470 for name, oid in tuple(repo.refs([], limit_to_heads=True)):
471 assert(name.startswith('refs/heads/'))
472 yield name[11:], _revlist_item_from_oid(repo, oid, want_meta)
480 if ref in ('.', '.tag'):
482 it = repo.cat('refs/heads/' + ref)
483 oidx, typ, size = next(it)
487 assert typ == 'commit'
488 commit = parse_commit(''.join(it))
489 yield ref, _revlist_item_from_oid(repo, oidx.decode('hex'), want_meta)
491 def ordered_tree_entries(tree_data, bupm=None):
492 """Yields (name, mangled_name, kind, gitmode, oid) for each item in
493 tree, sorted by name.
496 # Sadly, the .bupm entries currently aren't in git tree order,
497 # i.e. they don't account for the fact that git sorts trees
498 # (including our chunked trees) as if their names ended with "/",
499 # so "fo" sorts after "fo." iff fo is a directory. This makes
500 # streaming impossible when we need the metadata.
501 def result_from_tree_entry(tree_entry):
502 gitmode, mangled_name, oid = tree_entry
503 name, kind = git.demangle_name(mangled_name, gitmode)
504 return name, mangled_name, kind, gitmode, oid
506 tree_ents = (result_from_tree_entry(x) for x in tree_decode(tree_data))
508 tree_ents = sorted(tree_ents, key=lambda x: x[0])
509 for ent in tree_ents:
512 def tree_items(oid, tree_data, names=frozenset(), bupm=None):
514 def tree_item(ent_oid, kind, gitmode):
515 if kind == BUP_CHUNKED:
516 meta = Metadata.read(bupm) if bupm else default_file_mode
517 return Chunky(oid=ent_oid, meta=meta)
520 # No metadata here (accessable via '.' inside ent_oid).
521 return Item(meta=default_dir_mode, oid=ent_oid)
523 return Item(oid=ent_oid,
524 meta=(Metadata.read(bupm) if bupm \
525 else _default_mode_for_gitmode(gitmode)))
527 assert len(oid) == 20
529 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
530 yield '.', Item(oid=oid, meta=dot_meta)
531 tree_entries = ordered_tree_entries(tree_data, bupm)
532 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
533 if mangled_name == '.bupm':
536 yield name, tree_item(ent_oid, kind, gitmode)
539 # Assumes the tree is properly formed, i.e. there are no
540 # duplicates, and entries will be in git tree order.
541 if type(names) not in (frozenset, set):
542 names = frozenset(names)
543 remaining = len(names)
545 # Account for the bupm sort order issue (cf. ordered_tree_entries above)
546 last_name = max(names) if bupm else max(names) + '/'
549 dot_meta = _read_dir_meta(bupm) if bupm else default_dir_mode
550 yield '.', Item(oid=oid, meta=dot_meta)
555 tree_entries = ordered_tree_entries(tree_data, bupm)
556 for name, mangled_name, kind, gitmode, ent_oid in tree_entries:
557 if mangled_name == '.bupm':
560 if name not in names:
562 break # given bupm sort order, we're finished
563 if (kind == BUP_CHUNKED or not S_ISDIR(gitmode)) and bupm:
566 yield name, tree_item(ent_oid, kind, gitmode)
571 def tree_items_with_meta(repo, oid, tree_data, names):
572 # For now, the .bupm order doesn't quite match git's, and we don't
573 # load the tree data incrementally anyway, so we just work in RAM
575 assert len(oid) == 20
577 for _, mangled_name, sub_oid in tree_decode(tree_data):
578 if mangled_name == '.bupm':
579 bupm = _FileReader(repo, sub_oid)
581 if mangled_name > '.bupm':
583 for item in tree_items(oid, tree_data, names, bupm):
586 _save_name_rx = re.compile(r'^\d\d\d\d-\d\d-\d\d-\d{6}(-\d+)?$')
588 def _reverse_suffix_duplicates(strs):
589 """Yields the elements of strs, with any runs of duplicate values
590 suffixed with -N suffixes, where the zero padded integer N
591 decreases to 0 by 1 (e.g. 10, 09, ..., 00).
594 for name, duplicates in groupby(strs):
595 ndup = len(tuple(duplicates))
599 ndig = len(str(ndup - 1))
600 fmt = '%s-' + '%0' + str(ndig) + 'd'
601 for i in range(ndup - 1, -1, -1):
602 yield fmt % (name, i)
605 items = f.readline().split(None)
606 assert len(items) == 2
607 tree, auth_sec = items
608 return tree.decode('hex'), int(auth_sec)
610 def _name_for_rev(rev):
611 commit_oidx, (tree_oid, utc) = rev
612 return strftime('%Y-%m-%d-%H%M%S', localtime(utc))
614 def _item_for_rev(rev):
615 commit_oidx, (tree_oid, utc) = rev
616 coid = commit_oidx.decode('hex')
617 item = cache_get_commit_item(coid, need_meta=False)
620 item = Commit(meta=default_dir_mode, oid=tree_oid, coid=coid)
621 commit_key = b'itm:' + coid
622 cache_notice(commit_key, item)
625 def cache_commit(repo, oid):
626 """Build, cache, and return a "name -> commit_item" dict of the entire
630 # For now, always cache with full metadata
632 entries['.'] = _revlist_item_from_oid(repo, oid, True)
633 revs = repo.rev_list((oid.encode('hex'),), format='%T %at',
635 rev_items, rev_names = tee(revs)
636 revs = None # Don't disturb the tees
637 rev_names = _reverse_suffix_duplicates(_name_for_rev(x) for x in rev_names)
638 rev_items = (_item_for_rev(x) for x in rev_items)
640 for item in rev_items:
641 latest = latest or item
642 name = next(rev_names)
644 entries['latest'] = latest
645 revlist_key = b'rvl:' + latest.coid
646 cache_notice(revlist_key, entries)
649 def revlist_items(repo, oid, names):
650 assert len(oid) == 20
652 # Special case '.' instead of caching the whole history since it's
653 # the only way to get the metadata for the commit.
654 if names and all(x == '.' for x in names):
655 yield '.', _revlist_item_from_oid(repo, oid, True)
658 # For now, don't worry about the possibility of the contents being
659 # "too big" for the cache.
660 revlist_key = b'rvl:' + oid
661 entries = cache_get(revlist_key)
663 entries = cache_commit(repo, oid)
666 for name in sorted(entries.keys()):
667 yield name, entries[name]
670 names = frozenset(name for name in names
671 if _save_name_rx.match(name) or name in ('.', 'latest'))
674 yield '.', entries['.']
675 for name in (n for n in names if n != '.'):
676 commit = entries.get(name)
680 def tags_items(repo, names):
684 assert len(oid) == 20
685 oidx = oid.encode('hex')
687 _, typ, size = next(it)
689 return cache_get_commit_item(oid, need_meta=False) \
690 or _commit_item_from_data(oid, ''.join(it))
693 return Item(meta=default_file_mode, oid=oid)
695 return Item(meta=default_dir_mode, oid=oid)
696 raise Exception('unexpected tag type ' + typ + ' for tag ' + name)
700 # We have to pull these all into ram because tag_item calls cat()
701 for name, oid in tuple(repo.refs(names, limit_to_tags=True)):
702 assert(name.startswith('refs/tags/'))
704 yield name, tag_item(oid)
707 # Assumes no duplicate refs
708 if type(names) not in (frozenset, set):
709 names = frozenset(names)
710 remaining = len(names)
711 last_name = max(names)
718 for name, oid in repo.refs(names, limit_to_tags=True):
719 assert(name.startswith('refs/tags/'))
723 if name not in names:
725 yield name, tag_item(oid)
730 def contents(repo, item, names=None, want_meta=True):
731 """Yields information about the items contained in item. Yields
732 (name, item) for each name in names, if the name exists, in an
733 unspecified order. If there are no names, then yields (name,
734 item) for all items, including, a first item named '.'
735 representing the container itself.
737 The meta value for any directories other than '.' will be a
738 default directory mode, not a Metadata object. This is because
739 the actual metadata for a directory is stored inside the directory
740 (see fill_in_metadata_if_dir() or ensure_item_has_metadata()).
742 Note that want_meta is advisory. For any given item, item.meta
743 might be a Metadata instance or a mode, and if the former,
744 meta.size might be None. Missing sizes can be computed via via
745 item_size() or augment_item_meta(..., include_size=True).
747 Do not modify any item.meta Metadata instances directly. If
748 needed, make a copy via item.meta.copy() and modify that instead.
751 # Q: are we comfortable promising '.' first when no names?
754 assert S_ISDIR(item_mode(item))
756 if item_t in real_tree_types:
757 it = repo.cat(item.oid.encode('hex'))
758 _, obj_t, size = next(it)
762 # Note: it shouldn't be possible to see an Item with type
763 # 'commit' since a 'commit' should always produce a Commit.
764 raise Exception('unexpected git ' + obj_t)
766 item_gen = tree_items_with_meta(repo, item.oid, data, names)
768 item_gen = tree_items(item.oid, data, names)
769 elif item_t == RevList:
770 item_gen = revlist_items(repo, item.oid, names)
772 item_gen = root_items(repo, names, want_meta)
774 item_gen = tags_items(repo, names)
776 raise Exception('unexpected VFS item ' + str(item))
780 def _resolve_path(repo, path, parent=None, want_meta=True, deref=False):
781 cache_key = b'res:%d%d%d:%s\0%s' \
782 % (bool(want_meta), bool(deref), repo.id(),
783 ('/'.join(x[0] for x in parent) if parent else ''),
785 resolution = cache_get(cache_key)
789 def notice_resolution(r):
790 cache_notice(cache_key, r)
793 def raise_dir_required_but_not_dir(path, parent, past):
794 raise IOError(ENOTDIR,
795 "path %r%s resolves to non-directory %r"
797 ' (relative to %r)' % parent if parent else '',
806 assert type(x[0]) in (bytes, str)
807 assert type(x[1]) in item_types
808 assert parent[0][1] == _root
809 if not S_ISDIR(item_mode(parent[-1][1])):
810 raise IOError(ENOTDIR,
811 'path resolution parent %r is not a directory'
813 is_absolute, must_be_dir, future = _decompose_path(path)
816 if not future: # path was effectively '.' or '/'
818 return notice_resolution((('', _root),))
820 return notice_resolution(tuple(parent))
821 return notice_resolution((('', _root),))
825 past = list(parent) if parent else [('', _root)]
829 if must_be_dir and not S_ISDIR(item_mode(past[-1][1])):
830 raise_dir_required_but_not_dir(path, parent, past)
831 return notice_resolution(tuple(past))
832 segment = future.pop()
835 if len(past) > 1: # .. from / is /
836 assert S_ISDIR(item_mode(past[-1][1]))
839 parent_name, parent_item = past[-1]
840 wanted = (segment,) if not want_meta else ('.', segment)
841 items = tuple(contents(repo, parent_item, names=wanted,
842 want_meta=want_meta))
844 item = items[0][1] if items else None
845 else: # First item will be '.' and have the metadata
846 item = items[1][1] if len(items) == 2 else None
847 dot, dot_item = items[0]
849 past[-1] = parent_name, parent_item
851 past.append((segment, None),)
852 return notice_resolution(tuple(past))
853 mode = item_mode(item)
854 if not S_ISLNK(mode):
855 if not S_ISDIR(mode):
856 past.append((segment, item),)
858 raise IOError(ENOTDIR,
859 'path %r%s ends internally in non-directory here: %r'
861 ' (relative to %r)' % parent if parent else '',
865 raise_dir_required_but_not_dir(path, parent, past)
866 return notice_resolution(tuple(past))
868 if want_meta and type(item) in real_tree_types:
869 dir_meta = _find_treeish_oid_metadata(repo, item.oid)
871 item = item._replace(meta=dir_meta)
872 past.append((segment, item))
874 if not future and not deref:
875 past.append((segment, item),)
879 'too many symlinks encountered while resolving %r%s'
880 % (path, ' relative to %r' % parent if parent else ''),
881 terminus=tuple(past + [(segment, item)]))
882 target = readlink(repo, item)
883 is_absolute, _, target_future = _decompose_path(target)
885 if not target_future: # path was effectively '/'
886 return notice_resolution((('', _root),))
888 future = target_future
890 future.extend(target_future)
893 def lresolve(repo, path, parent=None, want_meta=True):
894 """Perform exactly the same function as resolve(), except if the final
895 path element is a symbolic link, don't follow it, just return it
899 return _resolve_path(repo, path, parent=parent, want_meta=want_meta,
902 def resolve(repo, path, parent=None, want_meta=True):
903 """Follow the path in the virtual filesystem and return a tuple
904 representing the location, if any, denoted by the path. Each
905 element in the result tuple will be (name, info), where info will
906 be a VFS item that can be passed to functions like item_mode().
908 If a path segment that does not exist is encountered during
909 resolution, the result will represent the location of the missing
910 item, and that item in the result will be None.
912 Any attempt to traverse a non-directory will raise a VFS ENOTDIR
915 Any symlinks along the path, including at the end, will be
916 resolved. A VFS IOError with the errno attribute set to ELOOP
917 will be raised if too many symlinks are traversed while following
918 the path. That exception is effectively like a normal
919 ELOOP IOError exception, but will include a terminus element
920 describing the location of the failure, which will be a tuple of
921 (name, info) elements.
923 The parent, if specified, must be a sequence of (name, item)
924 tuples, and will provide the starting point for the resolution of
925 the path. If no parent is specified, resolution will start at
928 The result may include elements of parent directly, so they must
929 not be modified later. If this is a concern, pass in "name,
930 copy_item(item) for name, item in parent" instead.
932 When want_meta is true, detailed metadata will be included in each
933 result item if it's avaiable, otherwise item.meta will be an
934 integer mode. The metadata size may or may not be provided, but
935 can be computed by item_size() or augment_item_meta(...,
936 include_size=True). Setting want_meta=False is rarely desirable
937 since it can limit the VFS to just the metadata git itself can
938 represent, and so, as an example, fifos and sockets will appear to
939 be regular files (e.g. S_ISREG(item_mode(item)) will be true) .
940 But the option is provided because it may be more efficient when
941 only the path names or the more limited metadata is sufficient.
943 Do not modify any item.meta Metadata instances directly. If
944 needed, make a copy via item.meta.copy() and modify that instead.
947 result = _resolve_path(repo, path, parent=parent, want_meta=want_meta,
949 _, leaf_item = result[-1]
951 assert not S_ISLNK(item_mode(leaf_item))
954 def try_resolve(repo, path, parent=None, want_meta=True):
955 """If path does not refer to a symlink, does not exist, or refers to a
956 valid symlink, behave exactly like resolve(). If path refers to
957 an invalid symlink, behave like lresolve.
960 res = lresolve(repo, path, parent=parent, want_meta=want_meta)
961 leaf_name, leaf_item = res[-1]
964 if not S_ISLNK(item_mode(leaf_item)):
966 deref = resolve(repo, leaf_name, parent=res[:-1], want_meta=want_meta)
967 deref_name, deref_item = deref[-1]
972 def augment_item_meta(repo, item, include_size=False):
973 """Ensure item has a Metadata instance for item.meta. If item.meta is
974 currently a mode, replace it with a compatible "fake" Metadata
975 instance. If include_size is true, ensure item.meta.size is
976 correct, computing it if needed. If item.meta is a Metadata
977 instance, this call may modify it in place or replace it.
980 # If we actually had parallelism, we'd need locking...
983 if isinstance(m, Metadata):
984 if include_size and m.size is None:
985 m.size = _compute_item_size(repo, item)
986 return item._replace(meta=m)
991 meta.uid = meta.gid = meta.atime = meta.mtime = meta.ctime = 0
993 target = _readlink(repo, item.oid)
994 meta.symlink_target = target
995 meta.size = len(target)
997 meta.size = _compute_item_size(repo, item)
998 return item._replace(meta=meta)
1000 def fill_in_metadata_if_dir(repo, item):
1001 """If item is a directory and item.meta is not a Metadata instance,
1002 attempt to find the metadata for the directory. If found, return
1003 a new item augmented to include that metadata. Otherwise, return
1004 item. May be useful for the output of contents().
1007 if S_ISDIR(item_mode(item)) and not isinstance(item.meta, Metadata):
1008 items = tuple(contents(repo, item, ('.',), want_meta=True))
1009 assert len(items) == 1
1010 assert items[0][0] == '.'
1014 def ensure_item_has_metadata(repo, item, include_size=False):
1015 """If item is a directory, attempt to find and add its metadata. If
1016 the item still doesn't have a Metadata instance for item.meta,
1017 give it one via augment_item_meta(). May be useful for the output
1021 return augment_item_meta(repo,
1022 fill_in_metadata_if_dir(repo, item),
1023 include_size=include_size)