+"""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 bup import git, metadata
from helpers import *
+from bup.git import BUP_NORMAL, BUP_CHUNKED
+from bup.hashsplit import GIT_MODE_TREE, GIT_MODE_FILE
EMPTY_SHA='\0'*20
_cp = None
def cp():
+ """Create a git.CatPipe object or reuse the already existing one."""
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
it = cp().get(hash.encode('hex'))
type = it.next()
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)
+ tree = [(int(name,16),stat.S_ISDIR(mode),sha)
for (mode,name,sha)
in _treeget(hash)]
assert(tree == list(sorted(tree)))
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:
+class _FileReader(object):
def __init__(self, hash, size, isdir):
self.hash = hash
self.ofs = 0
pass
-class Node:
+class Node(object):
+ """Base class for file representation."""
def __init__(self, parent, name, mode, hash):
self.parent = parent
self.name = name
self.hash = hash
self.ctime = self.mtime = self.atime = 0
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. """
+ """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, or the root
- level if this node isn't inside a backup set. """
+ """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)
- # 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())
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
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)
- # walk into the given sub-path of this node, and dereference it if it
- # was a symlink.
def resolve(self, path = ''):
+ """Like lresolve(), and dereference it if it was a symlink."""
return self.lresolve(path).lresolve('.')
- # like resolve(), but don't worry if the last symlink points at an
- # invalid path.
- # (still returns an error if any intermediate nodes were invalid)
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):
+ """Get the number of hard links to the current node."""
if self._subs == None:
self._mksubs()
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):
+ """A normal file from bup's repository."""
def __init__(self, parent, name, mode, hash, bupmode):
Node.__init__(self, parent, name, mode, hash)
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
self.bupmode == git.BUP_CHUNKED)
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)
else:
self._cached_size = _chunk_len(self.hash)
- log('<<<<File.size() done.\n')
+ debug1('<<<<File.size() done.\n')
return self._cached_size
_symrefs = 0
class Symlink(File):
+ """A symbolic link from bup's repository."""
def __init__(self, parent, name, hash, bupmode):
File.__init__(self, parent, name, 0120000, hash, bupmode)
def size(self):
+ """Get the file size of the file at which this link points."""
return len(self.readlink())
def readlink(self):
+ """Get the path that this link points at."""
return ''.join(cp().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(),
- stay_inside_fs=True)
- except NoSuchFile:
- raise NoSuchFile("%s: broken symlink to %r"
- % (self.fullname(), 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):
+ """A symlink that is not stored in the bup repository."""
def __init__(self, parent, name, toname):
Symlink.__init__(self, parent, name, EMPTY_SHA, git.BUP_NORMAL)
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'))
it = cp().get(self.hash.encode('hex') + ':')
type = it.next()
assert(type == 'tree')
- for (mode,mangled_name,sha) in git._treeparse(''.join(it)):
- mode = int(mode, 8)
+ 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 = mangled_name
(name,bupmode) = git.demangle_name(mangled_name)
if bupmode == git.BUP_CHUNKED:
- mode = 0100644
+ mode = GIT_MODE_FILE
if stat.S_ISDIR(mode):
self._subs[name] = Dir(self, name, mode, sha)
elif stat.S_ISLNK(mode):
self._subs[name] = Symlink(self, name, sha, bupmode)
else:
self._subs[name] = File(self, name, mode, sha, bupmode)
-
+
+ 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):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA)
+
+ def _mksubs(self):
+ self._subs = {}
+ refs = git.list_refs()
+ for ref in refs:
+ #debug2('ref name: %s\n' % ref[0])
+ revs = git.rev_list(ref[1].encode('hex'))
+ 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._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):
+ """A list of commits with hashes that start with the current node's name."""
+ def __init__(self, parent, name):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA)
+ self.commits = {}
+
+ def _mksubs(self):
+ self._subs = {}
+ for (name, (hash, date)) in self.commits.items():
+ n1 = Dir(self, name, GIT_MODE_TREE, hash)
+ 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):
+ Node.__init__(self, parent, name, GIT_MODE_TREE, EMPTY_SHA)
+
+ def _mksubs(self):
+ self._subs = {}
+ for (name, sha) in git.list_refs():
+ if name.startswith('refs/tags/'):
+ name = name[10:]
+ date = git.get_commit_dates([sha.encode('hex')])[0]
+ commithex = sha.encode('hex')
+ target = '../.commit/%s/%s' % (commithex[:2], commithex[2:])
+ tag1 = FakeSymlink(self, name, target)
+ 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):
- Node.__init__(self, parent, name, 040000, hash)
-
+ Node.__init__(self, parent, name, GIT_MODE_TREE, hash)
+
def _mksubs(self):
self._subs = {}
+
+ tags = git.tags()
+
revs = list(git.rev_list(self.hash.encode('hex')))
+ 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)
+ n1.ctime = n1.mtime = date
+ self._subs[ls] = n1
+
+ for tag in tags.get(commit, []):
+ t1 = FakeSymlink(self, tag, target)
+ t1.ctime = t1.mtime = date
+ self._subs[tag] = t1
+
+ (date, commit) = latest
+ commithex = commit.encode('hex')
+ target = '../.commit/%s/%s' % (commithex[:2], commithex[2:])
+ n1 = FakeSymlink(self, 'latest', target)
+ n1.ctime = n1.mtime = date
+ self._subs['latest'] = n1
+
+
class RefList(Node):
+ """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):
- Node.__init__(self, parent, '/', 040000, EMPTY_SHA)
-
+ Node.__init__(self, parent, '/', GIT_MODE_TREE, EMPTY_SHA)
+
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._subs['.commit'] = commit_dir
+
+ tag_dir = TagDir(self, '.tag')
+ self._subs['.tag'] = tag_dir
+
+ refs_info = [(name[11:], sha) for (name,sha) in git.list_refs() \
+ if name.startswith('refs/heads/')]
+
+ dates = git.get_commit_dates([sha.encode('hex')
+ for (name, sha) in refs_info])
+
+ for (name, sha), date in zip(refs_info, dates):
+ n1 = BranchList(self, name, sha)
+ n1.ctime = n1.mtime = date
+ self._subs[name] = n1
projects / bup.git / blobdiff