blob: 112414386f69af18f7245e35203675d8842f4cfb [file] [log] [blame]
#
# Copyright (C) 2009 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
from trace import Trace
HEAD = 'HEAD'
R_HEADS = 'refs/heads/'
R_TAGS = 'refs/tags/'
R_PUB = 'refs/published/'
R_M = 'refs/remotes/m/'
class GitRefs(object):
def __init__(self, gitdir):
self._gitdir = gitdir
self._phyref = None
self._symref = None
self._mtime = {}
@property
def all(self):
self._EnsureLoaded()
return self._phyref
def get(self, name):
try:
return self.all[name]
except KeyError:
return ''
def deleted(self, name):
if self._phyref is not None:
if name in self._phyref:
del self._phyref[name]
if name in self._symref:
del self._symref[name]
if name in self._mtime:
del self._mtime[name]
def symref(self, name):
try:
self._EnsureLoaded()
return self._symref[name]
except KeyError:
return ''
def _EnsureLoaded(self):
if self._phyref is None or self._NeedUpdate():
self._LoadAll()
def _NeedUpdate(self):
Trace(': scan refs %s', self._gitdir)
for name, mtime in self._mtime.iteritems():
try:
if mtime != os.path.getmtime(os.path.join(self._gitdir, name)):
return True
except OSError:
return True
return False
def _LoadAll(self):
Trace(': load refs %s', self._gitdir)
self._phyref = {}
self._symref = {}
self._mtime = {}
self._ReadPackedRefs()
self._ReadLoose('refs/')
self._ReadLoose1(os.path.join(self._gitdir, HEAD), HEAD)
scan = self._symref
attempts = 0
while scan and attempts < 5:
scan_next = {}
for name, dest in scan.iteritems():
if dest in self._phyref:
self._phyref[name] = self._phyref[dest]
else:
scan_next[name] = dest
scan = scan_next
attempts += 1
def _ReadPackedRefs(self):
path = os.path.join(self._gitdir, 'packed-refs')
try:
fd = open(path, 'rb')
mtime = os.path.getmtime(path)
except IOError:
return
except OSError:
return
try:
for line in fd:
if line[0] == '#':
continue
if line[0] == '^':
continue
line = line[:-1]
p = line.split(' ')
id = p[0]
name = p[1]
self._phyref[name] = id
finally:
fd.close()
self._mtime['packed-refs'] = mtime
def _ReadLoose(self, prefix):
base = os.path.join(self._gitdir, prefix)
for name in os.listdir(base):
p = os.path.join(base, name)
if os.path.isdir(p):
self._mtime[prefix] = os.path.getmtime(base)
self._ReadLoose(prefix + name + '/')
elif name.endswith('.lock'):
pass
else:
self._ReadLoose1(p, prefix + name)
def _ReadLoose1(self, path, name):
try:
fd = open(path, 'rb')
except:
return
try:
try:
mtime = os.path.getmtime(path)
id = fd.readline()
except:
return
finally:
fd.close()
if not id:
return
id = id[:-1]
if id.startswith('ref: '):
self._symref[name] = id[5:]
else:
self._phyref[name] = id
self._mtime[name] = mtime