M7350/oe-core/bitbake/lib/bb/checksum.py
2024-09-09 08:57:42 +00:00

91 lines
2.7 KiB
Python

# Local file checksum cache implementation
#
# Copyright (C) 2012 Intel Corporation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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 stat
import bb.utils
import logging
from bb.cache import MultiProcessCache
logger = logging.getLogger("BitBake.Cache")
try:
import cPickle as pickle
except ImportError:
import pickle
logger.info("Importing cPickle failed. "
"Falling back to a very slow implementation.")
# mtime cache (non-persistent)
# based upon the assumption that files do not change during bitbake run
class FileMtimeCache(object):
cache = {}
def cached_mtime(self, f):
if f not in self.cache:
self.cache[f] = os.stat(f)[stat.ST_MTIME]
return self.cache[f]
def cached_mtime_noerror(self, f):
if f not in self.cache:
try:
self.cache[f] = os.stat(f)[stat.ST_MTIME]
except OSError:
return 0
return self.cache[f]
def update_mtime(self, f):
self.cache[f] = os.stat(f)[stat.ST_MTIME]
return self.cache[f]
def clear(self):
self.cache.clear()
# Checksum + mtime cache (persistent)
class FileChecksumCache(MultiProcessCache):
cache_file_name = "local_file_checksum_cache.dat"
CACHE_VERSION = 1
def __init__(self):
self.mtime_cache = FileMtimeCache()
MultiProcessCache.__init__(self)
def get_checksum(self, f):
entry = self.cachedata[0].get(f)
cmtime = self.mtime_cache.cached_mtime(f)
if entry:
(mtime, hashval) = entry
if cmtime == mtime:
return hashval
else:
bb.debug(2, "file %s changed mtime, recompute checksum" % f)
hashval = bb.utils.md5_file(f)
self.cachedata_extras[0][f] = (cmtime, hashval)
return hashval
def merge_data(self, source, dest):
for h in source[0]:
if h in dest:
(smtime, _) = source[0][h]
(dmtime, _) = dest[0][h]
if smtime > dmtime:
dest[0][h] = source[0][h]
else:
dest[0][h] = source[0][h]