+"""Virtual File System representing bup's repository contents.
+
+The vfs.py library makes it possible to expose contents from bup's repository
+and abstracts internal name mangling and storage from the exposition layer.
+"""
+
import os, re, stat, time
-from bup import git
-from helpers import *
+
+from bup import git, metadata
+from helpers import debug1, debug2
+from bup.git import BUP_NORMAL, BUP_CHUNKED, cp
+from bup.hashsplit import GIT_MODE_TREE, GIT_MODE_FILE
EMPTY_SHA='\0'*20
-_cp = None
-def cp():
- global _cp
- if not _cp:
- _cp = git.CatPipe()
- return _cp
class NodeError(Exception):
+ """VFS base exception."""
pass
+
class NoSuchFile(NodeError):
+ """Request of a file that does not exist."""
pass
+
class NotDir(NodeError):
+ """Attempt to do a directory action on a file that is not one."""
pass
+
class NotFile(NodeError):
+ """Access to a node that does not represent a file."""
pass
+
class TooManySymlinks(NodeError):
+ """Symlink dereferencing level is too deep."""
pass
-def _treeget(hash):
- it = cp().get(hash.encode('hex'))
- type = it.next()
+def _treeget(hash, repo_dir=None):
+ it = cp(repo_dir).get(hash.encode('hex'))
+ _, type, _ = next(it)
assert(type == 'tree')
- return git._treeparse(''.join(it))
+ return git.tree_decode(''.join(it))
-def _tree_decode(hash):
- tree = [(int(name,16),stat.S_ISDIR(int(mode,8)),sha)
+def _tree_decode(hash, repo_dir=None):
+ tree = [(int(name,16),stat.S_ISDIR(mode),sha)
for (mode,name,sha)
- in _treeget(hash)]
+ in _treeget(hash, repo_dir)]
assert(tree == list(sorted(tree)))
return tree
-def _chunk_len(hash):
- return sum(len(b) for b in cp().join(hash.encode('hex')))
+def _chunk_len(hash, repo_dir=None):
+ return sum(len(b) for b in cp(repo_dir).join(hash.encode('hex')))
-def _last_chunk_info(hash):
- tree = _tree_decode(hash)
+def _last_chunk_info(hash, repo_dir=None):
+ tree = _tree_decode(hash, repo_dir)
assert(tree)
(ofs,isdir,sha) = tree[-1]
if isdir:
- (subofs, sublen) = _last_chunk_info(sha)
+ (subofs, sublen) = _last_chunk_info(sha, repo_dir)
return (ofs+subofs, sublen)
else:
return (ofs, _chunk_len(sha))
-def _total_size(hash):
- (lastofs, lastsize) = _last_chunk_info(hash)
+def _total_size(hash, repo_dir=None):
+ (lastofs, lastsize) = _last_chunk_info(hash, repo_dir)
return lastofs + lastsize
-def _chunkiter(hash, startofs):
+def _chunkiter(hash, startofs, repo_dir=None):
assert(startofs >= 0)
- tree = _tree_decode(hash)
+ tree = _tree_decode(hash, repo_dir)
# skip elements before startofs
for i in xrange(len(tree)):
if skipmore < 0:
skipmore = 0
if isdir:
- for b in _chunkiter(sha, skipmore):
+ for b in _chunkiter(sha, skipmore, repo_dir):
yield b
else:
- yield ''.join(cp().join(sha.encode('hex')))[skipmore:]
+ yield ''.join(cp(repo_dir).join(sha.encode('hex')))[skipmore:]
class _ChunkReader:
- def __init__(self, hash, isdir, startofs):
+ def __init__(self, hash, isdir, startofs, repo_dir=None):
if isdir:
- self.it = _chunkiter(hash, startofs)
+ self.it = _chunkiter(hash, startofs, repo_dir)
self.blob = None
else:
self.it = None
- self.blob = ''.join(cp().join(hash.encode('hex')))[startofs:]
+ self.blob = ''.join(cp(repo_dir).join(hash.encode('hex')))[startofs:]
self.ofs = startofs
def next(self, size):
while len(out) < size:
if self.it and not self.blob:
try:
- self.blob = self.it.next()
+ self.blob = next(self.it)
except StopIteration:
self.it = None
if self.blob:
self.blob = self.blob[want:]
if not self.it:
break
- log('next(%d) returned %d\n' % (size, len(out)))
+ debug2('next(%d) returned %d\n' % (size, len(out)))
self.ofs += len(out)
return out
-class _FileReader:
- def __init__(self, hash, size, isdir):
+class _FileReader(object):
+ def __init__(self, hash, size, isdir, repo_dir=None):
self.hash = hash
self.ofs = 0
self.size = size
self.isdir = isdir
self.reader = None
+ self._repo_dir = repo_dir
def seek(self, ofs):
if ofs > self.size:
if count < 0:
count = self.size - self.ofs
if not self.reader or self.reader.ofs != self.ofs:
- self.reader = _ChunkReader(self.hash, self.isdir, self.ofs)
+ self.reader = _ChunkReader(self.hash, self.isdir, self.ofs,
+ self._repo_dir)
try:
buf = self.reader.next(count)
except:
self.ofs += len(buf)
return buf
+ def close(self):
+ pass
-class Node:
- def __init__(self, parent, name, mode, hash):
+
+class Node(object):
+ """Base class for file representation."""
+ def __init__(self, parent, name, mode, hash, repo_dir=None):
self.parent = parent
self.name = name
self.mode = mode
self.hash = hash
self.ctime = self.mtime = self.atime = 0
+ self._repo_dir = repo_dir
self._subs = None
-
+ self._metadata = None
+
+ def __repr__(self):
+ return "<%s object at %s - name:%r hash:%s parent:%r>" \
+ % (self.__class__, hex(id(self)),
+ self.name, self.hash.encode('hex'),
+ self.parent.name if self.parent else None)
+
def __cmp__(a, b):
- return cmp(a.name or None, b.name or None)
-
+ if a is b:
+ return 0
+ return (cmp(a and a.parent, b and b.parent) or
+ cmp(a and a.name, b and b.name))
+
def __iter__(self):
return iter(self.subs())
-
- def fullname(self):
- if self.parent:
- return os.path.join(self.parent.fullname(), self.name)
+
+ def fullname(self, stop_at=None):
+ """Get this file's full path."""
+ assert(self != stop_at) # would be the empty string; too weird
+ if self.parent and self.parent != stop_at:
+ return os.path.join(self.parent.fullname(stop_at=stop_at),
+ self.name)
else:
return self.name
-
+
def _mksubs(self):
self._subs = {}
-
+
def subs(self):
+ """Get a list of nodes that are contained in this node."""
if self._subs == None:
self._mksubs()
return sorted(self._subs.values())
-
+
def sub(self, name):
+ """Get node named 'name' that is contained in this node."""
if self._subs == None:
self._mksubs()
ret = self._subs.get(name)
return ret
def top(self):
+ """Return the very top node of the tree."""
if self.parent:
return self.parent.top()
else:
return self
+ def fs_top(self):
+ """Return the top node of the particular backup set.
+
+ If this node isn't inside a backup set, return the root level.
+ """
+ if self.parent and not isinstance(self.parent, CommitList):
+ return self.parent.fs_top()
+ else:
+ return self
+
def _lresolve(self, parts):
- #log('_lresolve %r in %r\n' % (parts, self.name))
+ #debug2('_lresolve %r in %r\n' % (parts, self.name))
if not parts:
return self
(first, rest) = (parts[0], parts[1:])
else:
return self.sub(first)
- def lresolve(self, path):
+ def lresolve(self, path, stay_inside_fs=False):
+ """Walk into a given sub-path of this node.
+
+ If the last element is a symlink, leave it as a symlink, don't resolve
+ it. (like lstat())
+ """
start = self
+ if not path:
+ return start
if path.startswith('/'):
- start = self.top()
+ if stay_inside_fs:
+ start = self.fs_top()
+ else:
+ start = self.top()
path = path[1:]
parts = re.split(r'/+', path or '.')
if not parts[-1]:
parts[-1] = '.'
- #log('parts: %r %r\n' % (path, parts))
+ #debug2('parts: %r %r\n' % (path, parts))
return start._lresolve(parts)
- def resolve(self, path):
- return self.lresolve(path).lresolve('')
-
+ def resolve(self, path = ''):
+ """Like lresolve(), and dereference it if it was a symlink."""
+ return self.lresolve(path).lresolve('.')
+
+ def try_resolve(self, path = ''):
+ """Like resolve(), but don't worry if a symlink uses an invalid path.
+
+ Returns an error if any intermediate nodes were invalid.
+ """
+ n = self.lresolve(path)
+ try:
+ n = n.lresolve('.')
+ except NoSuchFile:
+ pass
+ return n
+
def nlinks(self):
- if self._subs == None:
- self._mksubs()
+ """Get the number of hard links to the current node."""
return 1
def size(self):
+ """Get the size of the current node."""
return 0
def open(self):
+ """Open the current node. It is an error to open a non-file node."""
raise NotFile('%s is not a regular file' % self.name)
+ def _populate_metadata(self, force=False):
+ # Only Dirs contain .bupm files, so by default, do nothing.
+ pass
+
+ def metadata(self):
+ """Return this Node's Metadata() object, if any."""
+ if not self._metadata and self.parent:
+ self.parent._populate_metadata(force=True)
+ return self._metadata
+
+ def release(self):
+ """Release resources that can be automatically restored (at a cost)."""
+ self._metadata = None
+ self._subs = None
+
class File(Node):
- def __init__(self, parent, name, mode, hash, bupmode):
- Node.__init__(self, parent, name, mode, hash)
+ """A normal file from bup's repository."""
+ def __init__(self, parent, name, mode, hash, bupmode, repo_dir=None):
+ Node.__init__(self, parent, name, mode, hash, repo_dir)
self.bupmode = bupmode
self._cached_size = None
self._filereader = None
-
+
def open(self):
+ """Open the file."""
# You'd think FUSE might call this only once each time a file is
# opened, but no; it's really more of a refcount, and it's called
# once per read(). Thus, it's important to cache the filereader
# object here so we're not constantly re-seeking.
if not self._filereader:
self._filereader = _FileReader(self.hash, self.size(),
- self.bupmode == git.BUP_CHUNKED)
+ self.bupmode == git.BUP_CHUNKED,
+ repo_dir = self._repo_dir)
self._filereader.seek(0)
return self._filereader
-
+
def size(self):
+ """Get this file's size."""
if self._cached_size == None:
- log('<<<<File.size() is calculating...\n')
+ debug1('<<<<File.size() is calculating (for %r)...\n' % self.name)
if self.bupmode == git.BUP_CHUNKED:
- self._cached_size = _total_size(self.hash)
+ self._cached_size = _total_size(self.hash,
+ repo_dir = self._repo_dir)
else:
- self._cached_size = _chunk_len(self.hash)
- log('<<<<File.size() done.\n')
+ self._cached_size = _chunk_len(self.hash,
+ repo_dir = self._repo_dir)
+ debug1('<<<<File.size() done.\n')
return self._cached_size
_symrefs = 0
class Symlink(File):
- def __init__(self, parent, name, hash, bupmode):
- File.__init__(self, parent, name, 0120000, hash, bupmode)
+ """A symbolic link from bup's repository."""
+ def __init__(self, parent, name, hash, bupmode, repo_dir=None):
+ File.__init__(self, parent, name, 0o120000, hash, bupmode,
+ repo_dir = repo_dir)
def size(self):
+ """Get the file size of the file at which this link points."""
return len(self.readlink())
def readlink(self):
- return ''.join(cp().join(self.hash.encode('hex')))
+ """Get the path that this link points at."""
+ return ''.join(cp(self._repo_dir).join(self.hash.encode('hex')))
def dereference(self):
+ """Get the node that this link points at.
+
+ If the path is invalid, raise a NoSuchFile exception. If the level of
+ indirection of symlinks is 100 levels deep, raise a TooManySymlinks
+ exception.
+ """
global _symrefs
if _symrefs > 100:
raise TooManySymlinks('too many levels of symlinks: %r'
% self.fullname())
_symrefs += 1
try:
- return self.parent.lresolve(self.readlink())
+ try:
+ return self.parent.lresolve(self.readlink(),
+ stay_inside_fs=True)
+ except NoSuchFile:
+ raise NoSuchFile("%s: broken symlink to %r"
+ % (self.fullname(), self.readlink()))
finally:
_symrefs -= 1
def _lresolve(self, parts):
return self.dereference()._lresolve(parts)
-
+
class FakeSymlink(Symlink):
- def __init__(self, parent, name, toname):
- Symlink.__init__(self, parent, name, EMPTY_SHA, git.BUP_NORMAL)
+ """A symlink that is not stored in the bup repository."""
+ def __init__(self, parent, name, toname, repo_dir=None):
+ Symlink.__init__(self, parent, name, EMPTY_SHA, git.BUP_NORMAL,
+ repo_dir = repo_dir)
self.toname = toname
-
+
def readlink(self):
+ """Get the path that this link points at."""
return self.toname
-
+
class Dir(Node):
+ """A directory stored inside of bup's repository."""
+
+ def __init__(self, *args, **kwargs):
+ Node.__init__(self, *args, **kwargs)
+ self._bupm = None
+
+ def _populate_metadata(self, force=False):
+ if self._metadata and not force:
+ return
+ if not self._subs:
+ self._mksubs()
+ if not self._bupm:
+ return
+ meta_stream = self._bupm.open()
+ dir_meta = metadata.Metadata.read(meta_stream)
+ for sub in self:
+ if not stat.S_ISDIR(sub.mode):
+ sub._metadata = metadata.Metadata.read(meta_stream)
+ self._metadata = dir_meta
+
def _mksubs(self):
self._subs = {}
- it = cp().get(self.hash.encode('hex'))
- type = it.next()
+ it = cp(self._repo_dir).get(self.hash.encode('hex'))
+ _, type, _ = next(it)
if type == 'commit':
del it
- it = cp().get(self.hash.encode('hex') + ':')
- type = it.next()
+ it = cp(self._repo_dir).get(self.hash.encode('hex') + ':')
+ _, type, _ = next(it)
assert(type == 'tree')
- for (mode,mangled_name,sha) in git._treeparse(''.join(it)):
- mode = int(mode, 8)
- name = mangled_name
- (name,bupmode) = git.demangle_name(mangled_name)
+ for (mode,mangled_name,sha) in git.tree_decode(''.join(it)):
+ if mangled_name == '.bupm':
+ bupmode = stat.S_ISDIR(mode) and BUP_CHUNKED or BUP_NORMAL
+ self._bupm = File(self, mangled_name, GIT_MODE_FILE, sha,
+ bupmode)
+ continue
+ name, bupmode = git.demangle_name(mangled_name, mode)
if bupmode == git.BUP_CHUNKED:
- mode = 0100644
+ mode = GIT_MODE_FILE
if stat.S_ISDIR(mode):
- self._subs[name] = Dir(self, name, mode, sha)
+ self._subs[name] = Dir(self, name, mode, sha, self._repo_dir)
elif stat.S_ISLNK(mode):
- self._subs[name] = Symlink(self, name, sha, bupmode)
+ self._subs[name] = Symlink(self, name, sha, bupmode,
+ self._repo_dir)
else:
- self._subs[name] = File(self, name, mode, sha, bupmode)
-
+ self._subs[name] = File(self, name, mode, sha, bupmode,
+ self._repo_dir)
+
+ def metadata(self):
+ """Return this Dir's Metadata() object, if any."""
+ self._populate_metadata()
+ return self._metadata
+
+ def metadata_file(self):
+ """Return this Dir's .bupm File, if any."""
+ if not self._subs:
+ self._mksubs()
+ return self._bupm
+
+ def release(self):
+ """Release restorable resources held by this node."""
+ self._bupm = None
+ super(Dir, self).release()
+
+
+class CommitDir(Node):
+ """A directory that contains all commits that are reachable by a ref.
+
+ Contains a set of subdirectories named after the commits' first byte in
+ hexadecimal. Each of those directories contain all commits with hashes that
+ start the same as the directory name. The name used for those
+ subdirectories is the hash of the commit without the first byte. This
+ separation helps us avoid having too much directories on the same level as
+ the number of commits grows big.
+ """
+ def __init__(self, parent, name, repo_dir=None):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA, repo_dir)
+
+ def _mksubs(self):
+ self._subs = {}
+ refs = git.list_refs(repo_dir = self._repo_dir)
+ for ref in refs:
+ #debug2('ref name: %s\n' % ref[0])
+ revs = git.rev_list(ref[1].encode('hex'), repo_dir = self._repo_dir)
+ for (date, commit) in revs:
+ #debug2('commit: %s date: %s\n' % (commit.encode('hex'), date))
+ commithex = commit.encode('hex')
+ containername = commithex[:2]
+ dirname = commithex[2:]
+ n1 = self._subs.get(containername)
+ if not n1:
+ n1 = CommitList(self, containername, self._repo_dir)
+ self._subs[containername] = n1
+
+ if n1.commits.get(dirname):
+ # Stop work for this ref, the rest should already be present
+ break
+
+ n1.commits[dirname] = (commit, date)
+
class CommitList(Node):
- def __init__(self, parent, name, hash):
- Node.__init__(self, parent, name, 040000, hash)
-
+ """A list of commits with hashes that start with the current node's name."""
+ def __init__(self, parent, name, repo_dir=None):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA, repo_dir)
+ self.commits = {}
+
def _mksubs(self):
self._subs = {}
- revs = list(git.rev_list(self.hash.encode('hex')))
+ for (name, (hash, date)) in self.commits.items():
+ n1 = Dir(self, name, GIT_MODE_TREE, hash, self._repo_dir)
+ n1.ctime = n1.mtime = date
+ self._subs[name] = n1
+
+
+class TagDir(Node):
+ """A directory that contains all tags in the repository."""
+ def __init__(self, parent, name, repo_dir = None):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA, repo_dir)
+
+ def _mksubs(self):
+ self._subs = {}
+ for (name, sha) in git.list_refs(repo_dir = self._repo_dir):
+ if name.startswith('refs/tags/'):
+ name = name[10:]
+ date = git.get_commit_dates([sha.encode('hex')],
+ repo_dir=self._repo_dir)[0]
+ commithex = sha.encode('hex')
+ target = '../.commit/%s/%s' % (commithex[:2], commithex[2:])
+ tag1 = FakeSymlink(self, name, target, self._repo_dir)
+ tag1.ctime = tag1.mtime = date
+ self._subs[name] = tag1
+
+
+class BranchList(Node):
+ """A list of links to commits reachable by a branch in bup's repository.
+
+ Represents each commit as a symlink that points to the commit directory in
+ /.commit/??/ . The symlink is named after the commit date.
+ """
+ def __init__(self, parent, name, hash, repo_dir=None):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, hash, repo_dir)
+
+ def _mksubs(self):
+ self._subs = {}
+
+ revs = list(git.rev_list(self.hash.encode('hex'),
+ repo_dir=self._repo_dir))
+ latest = revs[0]
for (date, commit) in revs:
l = time.localtime(date)
ls = time.strftime('%Y-%m-%d-%H%M%S', l)
- commithex = '.' + commit.encode('hex')
- n1 = Dir(self, commithex, 040000, commit)
- n2 = FakeSymlink(self, ls, commithex)
- n1.ctime = n1.mtime = n2.ctime = n2.mtime = date
- self._subs[commithex] = n1
- self._subs[ls] = n2
- latest = max(revs)
- if latest:
- (date, commit) = latest
- commithex = '.' + commit.encode('hex')
- n2 = FakeSymlink(self, 'latest', commithex)
- n2.ctime = n2.mtime = date
- self._subs['latest'] = n2
-
-
+ commithex = commit.encode('hex')
+ target = '../.commit/%s/%s' % (commithex[:2], commithex[2:])
+ n1 = FakeSymlink(self, ls, target, self._repo_dir)
+ n1.ctime = n1.mtime = date
+ self._subs[ls] = n1
+
+ (date, commit) = latest
+ commithex = commit.encode('hex')
+ target = '../.commit/%s/%s' % (commithex[:2], commithex[2:])
+ n1 = FakeSymlink(self, 'latest', target, self._repo_dir)
+ n1.ctime = n1.mtime = date
+ self._subs['latest'] = n1
+
+
class RefList(Node):
- def __init__(self, parent):
- Node.__init__(self, parent, '/', 040000, EMPTY_SHA)
-
+ """A list of branches in bup's repository.
+
+ The sub-nodes of the ref list are a series of CommitList for each commit
+ hash pointed to by a branch.
+
+ Also, a special sub-node named '.commit' contains all commit directories
+ that are reachable via a ref (e.g. a branch). See CommitDir for details.
+ """
+ def __init__(self, parent, repo_dir=None):
+ Node.__init__(self, parent, '/', GIT_MODE_TREE, EMPTY_SHA, repo_dir)
+
def _mksubs(self):
self._subs = {}
- for (name,sha) in git.list_refs():
- if name.startswith('refs/heads/'):
- name = name[11:]
- date = git.rev_get_date(sha.encode('hex'))
- n1 = CommitList(self, name, sha)
- n1.ctime = n1.mtime = date
- self._subs[name] = n1
-
+ commit_dir = CommitDir(self, '.commit', self._repo_dir)
+ self._subs['.commit'] = commit_dir
+
+ tag_dir = TagDir(self, '.tag', self._repo_dir)
+ self._subs['.tag'] = tag_dir
+
+ refs_info = [(name[11:], sha) for (name,sha)
+ in git.list_refs(repo_dir=self._repo_dir)
+ if name.startswith('refs/heads/')]
+ dates = git.get_commit_dates([sha.encode('hex')
+ for (name, sha) in refs_info],
+ repo_dir=self._repo_dir)
+ for (name, sha), date in zip(refs_info, dates):
+ n1 = BranchList(self, name, sha, self._repo_dir)
+ n1.ctime = n1.mtime = date
+ self._subs[name] = n1
projects / bup.git / blobdiff