| Patrick Williams | c124f4f | 2015-09-15 14:41:29 -0500 | [diff] [blame] | 1 | # Local file checksum cache implementation |
| 2 | # |
| 3 | # Copyright (C) 2012 Intel Corporation |
| 4 | # |
| 5 | # This program is free software; you can redistribute it and/or modify |
| 6 | # it under the terms of the GNU General Public License version 2 as |
| 7 | # published by the Free Software Foundation. |
| 8 | # |
| 9 | # This program is distributed in the hope that it will be useful, |
| 10 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | # GNU General Public License for more details. |
| 13 | # |
| 14 | # You should have received a copy of the GNU General Public License along |
| 15 | # with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | |
| 18 | import os |
| 19 | import stat |
| 20 | import bb.utils |
| 21 | import logging |
| 22 | from bb.cache import MultiProcessCache |
| 23 | |
| 24 | logger = logging.getLogger("BitBake.Cache") |
| 25 | |
| 26 | try: |
| 27 | import cPickle as pickle |
| 28 | except ImportError: |
| 29 | import pickle |
| 30 | logger.info("Importing cPickle failed. " |
| 31 | "Falling back to a very slow implementation.") |
| 32 | |
| 33 | |
| 34 | # mtime cache (non-persistent) |
| 35 | # based upon the assumption that files do not change during bitbake run |
| 36 | class FileMtimeCache(object): |
| 37 | cache = {} |
| 38 | |
| 39 | def cached_mtime(self, f): |
| 40 | if f not in self.cache: |
| 41 | self.cache[f] = os.stat(f)[stat.ST_MTIME] |
| 42 | return self.cache[f] |
| 43 | |
| 44 | def cached_mtime_noerror(self, f): |
| 45 | if f not in self.cache: |
| 46 | try: |
| 47 | self.cache[f] = os.stat(f)[stat.ST_MTIME] |
| 48 | except OSError: |
| 49 | return 0 |
| 50 | return self.cache[f] |
| 51 | |
| 52 | def update_mtime(self, f): |
| 53 | self.cache[f] = os.stat(f)[stat.ST_MTIME] |
| 54 | return self.cache[f] |
| 55 | |
| 56 | def clear(self): |
| 57 | self.cache.clear() |
| 58 | |
| 59 | # Checksum + mtime cache (persistent) |
| 60 | class FileChecksumCache(MultiProcessCache): |
| 61 | cache_file_name = "local_file_checksum_cache.dat" |
| 62 | CACHE_VERSION = 1 |
| 63 | |
| 64 | def __init__(self): |
| 65 | self.mtime_cache = FileMtimeCache() |
| 66 | MultiProcessCache.__init__(self) |
| 67 | |
| 68 | def get_checksum(self, f): |
| 69 | entry = self.cachedata[0].get(f) |
| 70 | cmtime = self.mtime_cache.cached_mtime(f) |
| 71 | if entry: |
| 72 | (mtime, hashval) = entry |
| 73 | if cmtime == mtime: |
| 74 | return hashval |
| 75 | else: |
| 76 | bb.debug(2, "file %s changed mtime, recompute checksum" % f) |
| 77 | |
| 78 | hashval = bb.utils.md5_file(f) |
| 79 | self.cachedata_extras[0][f] = (cmtime, hashval) |
| 80 | return hashval |
| 81 | |
| 82 | def merge_data(self, source, dest): |
| 83 | for h in source[0]: |
| 84 | if h in dest: |
| 85 | (smtime, _) = source[0][h] |
| 86 | (dmtime, _) = dest[0][h] |
| 87 | if smtime > dmtime: |
| 88 | dest[0][h] = source[0][h] |
| 89 | else: |
| 90 | dest[0][h] = source[0][h] |