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# object_store.py -- Object store for git objects
# Copyright (C) 2008 Jelmer Vernooij <jelmer@samba.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# or (at your option) a later version of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
# MA 02110-1301, USA.
import os
import tempfile
import urllib2
from dulwich.objects import (
hex_to_sha,
sha_to_hex,
ShaFile,
)
from dulwich.pack import (
Pack,
iter_sha1,
load_packs,
write_pack,
write_pack_data,
write_pack_index_v2,
PackData,
)
PACKDIR = 'pack'
class ObjectStore(object):
def __init__(self, path):
self.path = path
self._packs = None
self.pack_dir = os.path.join(self.path, PACKDIR)
def determine_wants_all(self, refs):
return [sha for (ref, sha) in refs.iteritems() if not sha in self and not ref.endswith("^{}")]
def iter_shas(self, shas):
"""Iterate over the objects for the specified shas.
:param shas: Iterable object with SHAs
"""
return ObjectStoreIterator(self, shas)
def __contains__(self, sha):
# TODO: This can be more efficient
try:
self[sha]
return True
except KeyError:
return False
@property
def packs(self):
"""List with pack objects."""
if self._packs is None:
self._packs = list(load_packs(self.pack_dir))
return self._packs
def _add_known_pack(self, path):
if self._packs is not None:
self._packs.append(Pack(path))
def _get_shafile_path(self, sha):
dir = sha[:2]
file = sha[2:]
# Check from object dir
return os.path.join(self.path, dir, file)
def _get_shafile(self, sha):
path = self._get_shafile_path(sha)
if os.path.exists(path):
return ShaFile.from_file(path)
return None
def _add_shafile(self, sha, o):
path = self._get_shafile_path(sha)
f = os.path.open(path, 'w')
try:
f.write(o._header())
f.write(o._text)
finally:
f.close()
def get_raw(self, sha):
"""Obtain the raw text for an object.
:param sha: Sha for the object.
:return: tuple with object type and object contents.
"""
for pack in self.packs:
if sha in pack:
return pack.get_raw(sha, self.get_raw)
# FIXME: Are thin pack deltas ever against on-disk shafiles ?
ret = self._get_shafile(sha)
if ret is not None:
return ret.as_raw_string()
raise KeyError(sha)
def __getitem__(self, sha):
assert len(sha) == 40, "Incorrect length sha: %s" % str(sha)
ret = self._get_shafile(sha)
if ret is not None:
return ret
# Check from packs
type, uncomp = self.get_raw(sha)
return ShaFile.from_raw_string(type, uncomp)
def move_in_thin_pack(self, path):
"""Move a specific file containing a pack into the pack directory.
:note: The file should be on the same file system as the
packs directory.
:param path: Path to the pack file.
"""
p = PackData(path)
temppath = os.path.join(self.pack_dir,
sha_to_hex(urllib2.randombytes(20))+".temppack")
write_pack(temppath, p.iterobjects(self.get_raw), len(p))
pack_sha = PackIndex(temppath+".idx").objects_sha1()
newbasename = os.path.join(self.pack_dir, "pack-%s" % pack_sha)
os.rename(temppath+".pack", newbasename+".pack")
os.rename(temppath+".idx", newbasename+".idx")
self._add_known_pack(newbasename)
def move_in_pack(self, path):
"""Move a specific file containing a pack into the pack directory.
:note: The file should be on the same file system as the
packs directory.
:param path: Path to the pack file.
"""
p = PackData(path)
entries = p.sorted_entries()
basename = os.path.join(self.pack_dir,
"pack-%s" % iter_sha1(entry[0] for entry in entries))
write_pack_index_v2(basename+".idx", entries, p.get_stored_checksum())
os.rename(path, basename + ".pack")
self._add_known_pack(basename)
def add_thin_pack(self):
"""Add a new thin pack to this object store.
Thin packs are packs that contain deltas with parents that exist
in a different pack.
"""
fd, path = tempfile.mkstemp(dir=self.pack_dir, suffix=".pack")
f = os.fdopen(fd, 'w')
def commit():
os.fsync(fd)
f.close()
if os.path.getsize(path) > 0:
self.move_in_thin_pack(path)
return f, commit
def add_pack(self):
"""Add a new pack to this object store.
:return: Fileobject to write to and a commit function to
call when the pack is finished.
"""
fd, path = tempfile.mkstemp(dir=self.pack_dir, suffix=".pack")
f = os.fdopen(fd, 'w')
def commit():
os.fsync(fd)
f.close()
if os.path.getsize(path) > 0:
self.move_in_pack(path)
return f, commit
def add_objects(self, objects):
if len(objects) == 0:
return
f, commit = self.add_pack()
write_pack_data(f, objects, len(objects))
commit()
class ObjectImporter(object):
def __init__(self, count):
self.count = count
def add_object(self, object):
raise NotImplementedError(self.add_object)
def finish(self, object):
raise NotImplementedError(self.finish)
class ObjectIterator(object):
def iterobjects(self):
raise NotImplementedError(self.iterobjects)
class ObjectStoreIterator(ObjectIterator):
def __init__(self, store, sha_iter):
self.store = store
self.shas = list(sha_iter)
def __iter__(self):
return ((self.store[sha], path) for sha, path in self.shas)
def iterobjects(self):
for o, path in self:
yield o
def __contains__(self, needle):
"""Check if an object is present.
:param needle: SHA1 of the object to check for
"""
# FIXME: This could be more efficient
for sha, path in self.shas:
if sha == needle:
return True
return False
def __getitem__(self, key):
"""Find an object by SHA1."""
return self.store[key]
def __len__(self):
"""Return the number of objects."""
return len(self.shas)
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