summaryrefslogtreecommitdiffstats
path: root/bitbake/lib/bb/cache.py
blob: 42193dc9d69a2bebb5e3e30db6be35e65131b24d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
#
# BitBake Cache implementation
#
# Caching of bitbake variables before task execution

# Copyright (C) 2006        Richard Purdie
# Copyright (C) 2012        Intel Corporation

# but small sections based on code from bin/bitbake:
# Copyright (C) 2003, 2004  Chris Larson
# Copyright (C) 2003, 2004  Phil Blundell
# Copyright (C) 2003 - 2005 Michael 'Mickey' Lauer
# Copyright (C) 2005        Holger Hans Peter Freyther
# Copyright (C) 2005        ROAD GmbH
#
# SPDX-License-Identifier: GPL-2.0-only
#
# 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 sys
import logging
import pickle
from collections import defaultdict
import bb.utils

logger = logging.getLogger("BitBake.Cache")

__cache_version__ = "152"

def getCacheFile(path, filename, data_hash):
    return os.path.join(path, filename + "." + data_hash)

# RecipeInfoCommon defines common data retrieving methods
# from meta data for caches. CoreRecipeInfo as well as other
# Extra RecipeInfo needs to inherit this class
class RecipeInfoCommon(object):

    @classmethod
    def listvar(cls, var, metadata):
        return cls.getvar(var, metadata).split()

    @classmethod
    def intvar(cls, var, metadata):
        return int(cls.getvar(var, metadata) or 0)

    @classmethod
    def depvar(cls, var, metadata):
        return bb.utils.explode_deps(cls.getvar(var, metadata))

    @classmethod
    def pkgvar(cls, var, packages, metadata):
        return dict((pkg, cls.depvar("%s_%s" % (var, pkg), metadata))
                    for pkg in packages)

    @classmethod
    def taskvar(cls, var, tasks, metadata):
        return dict((task, cls.getvar("%s_task-%s" % (var, task), metadata))
                    for task in tasks)

    @classmethod
    def flaglist(cls, flag, varlist, metadata, squash=False):
        out_dict = dict((var, metadata.getVarFlag(var, flag))
                    for var in varlist)
        if squash:
            return dict((k,v) for (k,v) in out_dict.items() if v)
        else:
            return out_dict

    @classmethod
    def getvar(cls, var, metadata, expand = True):
        return metadata.getVar(var, expand) or ''


class CoreRecipeInfo(RecipeInfoCommon):
    __slots__ = ()

    cachefile = "bb_cache.dat"

    def __init__(self, filename, metadata):
        self.file_depends = metadata.getVar('__depends', False)
        self.timestamp = bb.parse.cached_mtime(filename)
        self.variants = self.listvar('__VARIANTS', metadata) + ['']
        self.appends = self.listvar('__BBAPPEND', metadata)
        self.nocache = self.getvar('BB_DONT_CACHE', metadata)

        self.skipreason = self.getvar('__SKIPPED', metadata)
        if self.skipreason:
            self.pn = self.getvar('PN', metadata) or bb.parse.vars_from_file(filename,metadata)[0]
            self.skipped = True
            self.provides  = self.depvar('PROVIDES', metadata)
            self.rprovides = self.depvar('RPROVIDES', metadata)
            return

        self.tasks = metadata.getVar('__BBTASKS', False)

        self.pn = self.getvar('PN', metadata)
        self.packages = self.listvar('PACKAGES', metadata)
        if not self.packages:
            self.packages.append(self.pn)

        self.basetaskhashes = self.taskvar('BB_BASEHASH', self.tasks, metadata)
        self.hashfilename = self.getvar('BB_HASHFILENAME', metadata)

        self.task_deps = metadata.getVar('_task_deps', False) or {'tasks': [], 'parents': {}}

        self.skipped = False
        self.pe = self.getvar('PE', metadata)
        self.pv = self.getvar('PV', metadata)
        self.pr = self.getvar('PR', metadata)
        self.defaultpref = self.intvar('DEFAULT_PREFERENCE', metadata)
        self.not_world = self.getvar('EXCLUDE_FROM_WORLD', metadata)
        self.stamp = self.getvar('STAMP', metadata)
        self.stampclean = self.getvar('STAMPCLEAN', metadata)
        self.stamp_extrainfo = self.flaglist('stamp-extra-info', self.tasks, metadata)
        self.file_checksums = self.flaglist('file-checksums', self.tasks, metadata, True)
        self.packages_dynamic = self.listvar('PACKAGES_DYNAMIC', metadata)
        self.depends          = self.depvar('DEPENDS', metadata)
        self.provides         = self.depvar('PROVIDES', metadata)
        self.rdepends         = self.depvar('RDEPENDS', metadata)
        self.rprovides        = self.depvar('RPROVIDES', metadata)
        self.rrecommends      = self.depvar('RRECOMMENDS', metadata)
        self.rprovides_pkg    = self.pkgvar('RPROVIDES', self.packages, metadata)
        self.rdepends_pkg     = self.pkgvar('RDEPENDS', self.packages, metadata)
        self.rrecommends_pkg  = self.pkgvar('RRECOMMENDS', self.packages, metadata)
        self.inherits         = self.getvar('__inherit_cache', metadata, expand=False)
        self.fakerootenv      = self.getvar('FAKEROOTENV', metadata)
        self.fakerootdirs     = self.getvar('FAKEROOTDIRS', metadata)
        self.fakerootnoenv    = self.getvar('FAKEROOTNOENV', metadata)
        self.extradepsfunc    = self.getvar('calculate_extra_depends', metadata)

    @classmethod
    def init_cacheData(cls, cachedata):
        # CacheData in Core RecipeInfo Class
        cachedata.task_deps = {}
        cachedata.pkg_fn = {}
        cachedata.pkg_pn = defaultdict(list)
        cachedata.pkg_pepvpr = {}
        cachedata.pkg_dp = {}

        cachedata.stamp = {}
        cachedata.stampclean = {}
        cachedata.stamp_extrainfo = {}
        cachedata.file_checksums = {}
        cachedata.fn_provides = {}
        cachedata.pn_provides = defaultdict(list)
        cachedata.all_depends = []

        cachedata.deps = defaultdict(list)
        cachedata.packages = defaultdict(list)
        cachedata.providers = defaultdict(list)
        cachedata.rproviders = defaultdict(list)
        cachedata.packages_dynamic = defaultdict(list)

        cachedata.rundeps = defaultdict(lambda: defaultdict(list))
        cachedata.runrecs = defaultdict(lambda: defaultdict(list))
        cachedata.possible_world = []
        cachedata.universe_target = []
        cachedata.hashfn = {}

        cachedata.basetaskhash = {}
        cachedata.inherits = {}
        cachedata.fakerootenv = {}
        cachedata.fakerootnoenv = {}
        cachedata.fakerootdirs = {}
        cachedata.extradepsfunc = {}

    def add_cacheData(self, cachedata, fn):
        cachedata.task_deps[fn] = self.task_deps
        cachedata.pkg_fn[fn] = self.pn
        cachedata.pkg_pn[self.pn].append(fn)
        cachedata.pkg_pepvpr[fn] = (self.pe, self.pv, self.pr)
        cachedata.pkg_dp[fn] = self.defaultpref
        cachedata.stamp[fn] = self.stamp
        cachedata.stampclean[fn] = self.stampclean
        cachedata.stamp_extrainfo[fn] = self.stamp_extrainfo
        cachedata.file_checksums[fn] = self.file_checksums

        provides = [self.pn]
        for provide in self.provides:
            if provide not in provides:
                provides.append(provide)
        cachedata.fn_provides[fn] = provides

        for provide in provides:
            cachedata.providers[provide].append(fn)
            if provide not in cachedata.pn_provides[self.pn]:
                cachedata.pn_provides[self.pn].append(provide)

        for dep in self.depends:
            if dep not in cachedata.deps[fn]:
                cachedata.deps[fn].append(dep)
            if dep not in cachedata.all_depends:
                cachedata.all_depends.append(dep)

        rprovides = self.rprovides
        for package in self.packages:
            cachedata.packages[package].append(fn)
            rprovides += self.rprovides_pkg[package]

        for rprovide in rprovides:
            if fn not in cachedata.rproviders[rprovide]:
                cachedata.rproviders[rprovide].append(fn)

        for package in self.packages_dynamic:
            cachedata.packages_dynamic[package].append(fn)

        # Build hash of runtime depends and recommends
        for package in self.packages:
            cachedata.rundeps[fn][package] = list(self.rdepends) + self.rdepends_pkg[package]
            cachedata.runrecs[fn][package] = list(self.rrecommends) + self.rrecommends_pkg[package]

        # Collect files we may need for possible world-dep
        # calculations
        if self.not_world:
            logger.debug(1, "EXCLUDE FROM WORLD: %s", fn)
        else:
            cachedata.possible_world.append(fn)

        # create a collection of all targets for sanity checking
        # tasks, such as upstream versions, license, and tools for
        # task and image creation.
        cachedata.universe_target.append(self.pn)

        cachedata.hashfn[fn] = self.hashfilename
        for task, taskhash in self.basetaskhashes.items():
            identifier = '%s.%s' % (fn, task)
            cachedata.basetaskhash[identifier] = taskhash

        cachedata.inherits[fn] = self.inherits
        cachedata.fakerootenv[fn] = self.fakerootenv
        cachedata.fakerootnoenv[fn] = self.fakerootnoenv
        cachedata.fakerootdirs[fn] = self.fakerootdirs
        cachedata.extradepsfunc[fn] = self.extradepsfunc

def virtualfn2realfn(virtualfn):
    """
    Convert a virtual file name to a real one + the associated subclass keyword
    """
    mc = ""
    if virtualfn.startswith('multiconfig:'):
        elems = virtualfn.split(':')
        mc = elems[1]
        virtualfn = ":".join(elems[2:])

    fn = virtualfn
    cls = ""
    if virtualfn.startswith('virtual:'):
        elems = virtualfn.split(':')
        cls = ":".join(elems[1:-1])
        fn = elems[-1]

    return (fn, cls, mc)

def realfn2virtual(realfn, cls, mc):
    """
    Convert a real filename + the associated subclass keyword to a virtual filename
    """
    if cls:
        realfn = "virtual:" + cls + ":" + realfn
    if mc:
        realfn = "multiconfig:" + mc + ":" + realfn
    return realfn

def variant2virtual(realfn, variant):
    """
    Convert a real filename + the associated subclass keyword to a virtual filename
    """
    if variant == "":
        return realfn
    if variant.startswith("multiconfig:"):
        elems = variant.split(":")
        if elems[2]:
            return "multiconfig:" + elems[1] + ":virtual:" + ":".join(elems[2:]) + ":" + realfn
        return "multiconfig:" + elems[1] + ":" + realfn
    return "virtual:" + variant + ":" + realfn

def parse_recipe(bb_data, bbfile, appends, mc=''):
    """
    Parse a recipe
    """

    chdir_back = False

    bb_data.setVar("__BBMULTICONFIG", mc)

    # expand tmpdir to include this topdir
    bb_data.setVar('TMPDIR', bb_data.getVar('TMPDIR') or "")
    bbfile_loc = os.path.abspath(os.path.dirname(bbfile))
    oldpath = os.path.abspath(os.getcwd())
    bb.parse.cached_mtime_noerror(bbfile_loc)

    # The ConfHandler first looks if there is a TOPDIR and if not
    # then it would call getcwd().
    # Previously, we chdir()ed to bbfile_loc, called the handler
    # and finally chdir()ed back, a couple of thousand times. We now
    # just fill in TOPDIR to point to bbfile_loc if there is no TOPDIR yet.
    if not bb_data.getVar('TOPDIR', False):
        chdir_back = True
        bb_data.setVar('TOPDIR', bbfile_loc)
    try:
        if appends:
            bb_data.setVar('__BBAPPEND', " ".join(appends))
        bb_data = bb.parse.handle(bbfile, bb_data)
        if chdir_back:
            os.chdir(oldpath)
        return bb_data
    except:
        if chdir_back:
            os.chdir(oldpath)
        raise



class NoCache(object):

    def __init__(self, databuilder):
        self.databuilder = databuilder
        self.data = databuilder.data

    def loadDataFull(self, virtualfn, appends):
        """
        Return a complete set of data for fn.
        To do this, we need to parse the file.
        """
        logger.debug(1, "Parsing %s (full)" % virtualfn)
        (fn, virtual, mc) = virtualfn2realfn(virtualfn)
        bb_data = self.load_bbfile(virtualfn, appends, virtonly=True)
        return bb_data[virtual]

    def load_bbfile(self, bbfile, appends, virtonly = False):
        """
        Load and parse one .bb build file
        Return the data and whether parsing resulted in the file being skipped
        """

        if virtonly:
            (bbfile, virtual, mc) = virtualfn2realfn(bbfile)
            bb_data = self.databuilder.mcdata[mc].createCopy()
            bb_data.setVar("__ONLYFINALISE", virtual or "default")
            datastores = parse_recipe(bb_data, bbfile, appends, mc)
            return datastores

        bb_data = self.data.createCopy()
        datastores = parse_recipe(bb_data, bbfile, appends)

        for mc in self.databuilder.mcdata:
            if not mc:
                continue
            bb_data = self.databuilder.mcdata[mc].createCopy()
            newstores = parse_recipe(bb_data, bbfile, appends, mc)
            for ns in newstores:
                datastores["multiconfig:%s:%s" % (mc, ns)] = newstores[ns]

        return datastores

class Cache(NoCache):
    """
    BitBake Cache implementation
    """

    def __init__(self, databuilder, data_hash, caches_array):
        super().__init__(databuilder)
        data = databuilder.data

        # Pass caches_array information into Cache Constructor
        # It will be used later for deciding whether we
        # need extra cache file dump/load support
        self.caches_array = caches_array
        self.cachedir = data.getVar("CACHE")
        self.clean = set()
        self.checked = set()
        self.depends_cache = {}
        self.data_fn = None
        self.cacheclean = True
        self.data_hash = data_hash

        if self.cachedir in [None, '']:
            self.has_cache = False
            logger.info("Not using a cache. "
                        "Set CACHE = <directory> to enable.")
            return

        self.has_cache = True
        self.cachefile = getCacheFile(self.cachedir, "bb_cache.dat", self.data_hash)

        logger.debug(1, "Cache dir: %s", self.cachedir)
        bb.utils.mkdirhier(self.cachedir)

        cache_ok = True
        if self.caches_array:
            for cache_class in self.caches_array:
                cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
                cache_ok = cache_ok and os.path.exists(cachefile)
                cache_class.init_cacheData(self)
        if cache_ok:
            self.load_cachefile()
        elif os.path.isfile(self.cachefile):
            logger.info("Out of date cache found, rebuilding...")
        else:
            logger.debug(1, "Cache file %s not found, building..." % self.cachefile)

    def load_cachefile(self):
        cachesize = 0
        previous_progress = 0
        previous_percent = 0

        # Calculate the correct cachesize of all those cache files
        for cache_class in self.caches_array:
            cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
            with open(cachefile, "rb") as cachefile:
                cachesize += os.fstat(cachefile.fileno()).st_size

        bb.event.fire(bb.event.CacheLoadStarted(cachesize), self.data)

        for cache_class in self.caches_array:
            cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
            logger.debug(1, 'Loading cache file: %s' % cachefile)
            with open(cachefile, "rb") as cachefile:
                pickled = pickle.Unpickler(cachefile)
                # Check cache version information
                try:
                    cache_ver = pickled.load()
                    bitbake_ver = pickled.load()
                except Exception:
                    logger.info('Invalid cache, rebuilding...')
                    return

                if cache_ver != __cache_version__:
                    logger.info('Cache version mismatch, rebuilding...')
                    return
                elif bitbake_ver != bb.__version__:
                    logger.info('Bitbake version mismatch, rebuilding...')
                    return

                # Load the rest of the cache file
                current_progress = 0
                while cachefile:
                    try:
                        key = pickled.load()
                        value = pickled.load()
                    except Exception:
                        break
                    if not isinstance(key, str):
                        bb.warn("%s from extras cache is not a string?" % key)
                        break
                    if not isinstance(value, RecipeInfoCommon):
                        bb.warn("%s from extras cache is not a RecipeInfoCommon class?" % value)
                        break

                    if key in self.depends_cache:
                        self.depends_cache[key].append(value)
                    else:
                        self.depends_cache[key] = [value]
                    # only fire events on even percentage boundaries
                    current_progress = cachefile.tell() + previous_progress
                    if current_progress > cachesize:
                        # we might have calculated incorrect total size because a file
                        # might've been written out just after we checked its size
                        cachesize = current_progress
                    current_percent = 100 * current_progress / cachesize
                    if current_percent > previous_percent:
                        previous_percent = current_percent
                        bb.event.fire(bb.event.CacheLoadProgress(current_progress, cachesize),
                                      self.data)

                previous_progress += current_progress

        # Note: depends cache number is corresponding to the parsing file numbers.
        # The same file has several caches, still regarded as one item in the cache
        bb.event.fire(bb.event.CacheLoadCompleted(cachesize,
                                                  len(self.depends_cache)),
                      self.data)

    def parse(self, filename, appends):
        """Parse the specified filename, returning the recipe information"""
        logger.debug(1, "Parsing %s", filename)
        infos = []
        datastores = self.load_bbfile(filename, appends)
        depends = []
        variants = []
        # Process the "real" fn last so we can store variants list
        for variant, data in sorted(datastores.items(),
                                    key=lambda i: i[0],
                                    reverse=True):
            virtualfn = variant2virtual(filename, variant)
            variants.append(variant)
            depends = depends + (data.getVar("__depends", False) or [])
            if depends and not variant:
                data.setVar("__depends", depends)
            if virtualfn == filename:
                data.setVar("__VARIANTS", " ".join(variants))
            info_array = []
            for cache_class in self.caches_array:
                info = cache_class(filename, data)
                info_array.append(info)
            infos.append((virtualfn, info_array))

        return infos

    def load(self, filename, appends):
        """Obtain the recipe information for the specified filename,
        using cached values if available, otherwise parsing.

        Note that if it does parse to obtain the info, it will not
        automatically add the information to the cache or to your
        CacheData.  Use the add or add_info method to do so after
        running this, or use loadData instead."""
        cached = self.cacheValid(filename, appends)
        if cached:
            infos = []
            # info_array item is a list of [CoreRecipeInfo, XXXRecipeInfo]
            info_array = self.depends_cache[filename]
            for variant in info_array[0].variants:
                virtualfn = variant2virtual(filename, variant)
                infos.append((virtualfn, self.depends_cache[virtualfn]))
        else:
            return self.parse(filename, appends, configdata, self.caches_array)

        return cached, infos

    def loadData(self, fn, appends, cacheData):
        """Load the recipe info for the specified filename,
        parsing and adding to the cache if necessary, and adding
        the recipe information to the supplied CacheData instance."""
        skipped, virtuals = 0, 0

        cached, infos = self.load(fn, appends)
        for virtualfn, info_array in infos:
            if info_array[0].skipped:
                logger.debug(1, "Skipping %s: %s", virtualfn, info_array[0].skipreason)
                skipped += 1
            else:
                self.add_info(virtualfn, info_array, cacheData, not cached)
                virtuals += 1

        return cached, skipped, virtuals

    def cacheValid(self, fn, appends):
        """
        Is the cache valid for fn?
        Fast version, no timestamps checked.
        """
        if fn not in self.checked:
            self.cacheValidUpdate(fn, appends)

        # Is cache enabled?
        if not self.has_cache:
            return False
        if fn in self.clean:
            return True
        return False

    def cacheValidUpdate(self, fn, appends):
        """
        Is the cache valid for fn?
        Make thorough (slower) checks including timestamps.
        """
        # Is cache enabled?
        if not self.has_cache:
            return False

        self.checked.add(fn)

        # File isn't in depends_cache
        if not fn in self.depends_cache:
            logger.debug(2, "Cache: %s is not cached", fn)
            return False

        mtime = bb.parse.cached_mtime_noerror(fn)

        # Check file still exists
        if mtime == 0:
            logger.debug(2, "Cache: %s no longer exists", fn)
            self.remove(fn)
            return False

        info_array = self.depends_cache[fn]
        # Check the file's timestamp
        if mtime != info_array[0].timestamp:
            logger.debug(2, "Cache: %s changed", fn)
            self.remove(fn)
            return False

        # Check dependencies are still valid
        depends = info_array[0].file_depends
        if depends:
            for f, old_mtime in depends:
                fmtime = bb.parse.cached_mtime_noerror(f)
                # Check if file still exists
                if old_mtime != 0 and fmtime == 0:
                    logger.debug(2, "Cache: %s's dependency %s was removed",
                                    fn, f)
                    self.remove(fn)
                    return False

                if (fmtime != old_mtime):
                    logger.debug(2, "Cache: %s's dependency %s changed",
                                    fn, f)
                    self.remove(fn)
                    return False

        if hasattr(info_array[0], 'file_checksums'):
            for _, fl in info_array[0].file_checksums.items():
                fl = fl.strip()
                while fl:
                    # A .split() would be simpler but means spaces or colons in filenames would break
                    a = fl.find(":True")
                    b = fl.find(":False")
                    if ((a < 0) and b) or ((b > 0) and (b < a)):
                        f = fl[:b+6]
                        fl = fl[b+7:]
                    elif ((b < 0) and a) or ((a > 0) and (a < b)):
                        f = fl[:a+5]
                        fl = fl[a+6:]
                    else:
                        break
                    fl = fl.strip()
                    if "*" in f:
                        continue
                    f, exist = f.split(":")
                    if (exist == "True" and not os.path.exists(f)) or (exist == "False" and os.path.exists(f)):
                        logger.debug(2, "Cache: %s's file checksum list file %s changed",
                                        fn, f)
                        self.remove(fn)
                        return False

        if appends != info_array[0].appends:
            logger.debug(2, "Cache: appends for %s changed", fn)
            logger.debug(2, "%s to %s" % (str(appends), str(info_array[0].appends)))
            self.remove(fn)
            return False

        invalid = False
        for cls in info_array[0].variants:
            virtualfn = variant2virtual(fn, cls)
            self.clean.add(virtualfn)
            if virtualfn not in self.depends_cache:
                logger.debug(2, "Cache: %s is not cached", virtualfn)
                invalid = True
            elif len(self.depends_cache[virtualfn]) != len(self.caches_array):
                logger.debug(2, "Cache: Extra caches missing for %s?" % virtualfn)
                invalid = True

        # If any one of the variants is not present, mark as invalid for all
        if invalid:
            for cls in info_array[0].variants:
                virtualfn = variant2virtual(fn, cls)
                if virtualfn in self.clean:
                    logger.debug(2, "Cache: Removing %s from cache", virtualfn)
                    self.clean.remove(virtualfn)
            if fn in self.clean:
                logger.debug(2, "Cache: Marking %s as not clean", fn)
                self.clean.remove(fn)
            return False

        self.clean.add(fn)
        return True

    def remove(self, fn):
        """
        Remove a fn from the cache
        Called from the parser in error cases
        """
        if fn in self.depends_cache:
            logger.debug(1, "Removing %s from cache", fn)
            del self.depends_cache[fn]
        if fn in self.clean:
            logger.debug(1, "Marking %s as unclean", fn)
            self.clean.remove(fn)

    def sync(self):
        """
        Save the cache
        Called from the parser when complete (or exiting)
        """

        if not self.has_cache:
            return

        if self.cacheclean:
            logger.debug(2, "Cache is clean, not saving.")
            return

        for cache_class in self.caches_array:
            cache_class_name = cache_class.__name__
            cachefile = getCacheFile(self.cachedir, cache_class.cachefile, self.data_hash)
            with open(cachefile, "wb") as f:
                p = pickle.Pickler(f, pickle.HIGHEST_PROTOCOL)
                p.dump(__cache_version__)
                p.dump(bb.__version__)

                for key, info_array in self.depends_cache.items():
                    for info in info_array:
                        if isinstance(info, RecipeInfoCommon) and info.__class__.__name__ == cache_class_name:
                            p.dump(key)
                            p.dump(info)

        del self.depends_cache

    @staticmethod
    def mtime(cachefile):
        return bb.parse.cached_mtime_noerror(cachefile)

    def add_info(self, filename, info_array, cacheData, parsed=None, watcher=None):
        if isinstance(info_array[0], CoreRecipeInfo) and (not info_array[0].skipped):
            cacheData.add_from_recipeinfo(filename, info_array)

            if watcher:
                watcher(info_array[0].file_depends)

        if not self.has_cache:
            return

        if (info_array[0].skipped or 'SRCREVINACTION' not in info_array[0].pv) and not info_array[0].nocache:
            if parsed:
                self.cacheclean = False
            self.depends_cache[filename] = info_array

    def add(self, file_name, data, cacheData, parsed=None):
        """
        Save data we need into the cache
        """

        realfn = virtualfn2realfn(file_name)[0]

        info_array = []
        for cache_class in self.caches_array:
            info_array.append(cache_class(realfn, data))
        self.add_info(file_name, info_array, cacheData, parsed)


def init(cooker):
    """
    The Objective: Cache the minimum amount of data possible yet get to the
    stage of building packages (i.e. tryBuild) without reparsing any .bb files.

    To do this, we intercept getVar calls and only cache the variables we see
    being accessed. We rely on the cache getVar calls being made for all
    variables bitbake might need to use to reach this stage. For each cached
    file we need to track:

    * Its mtime
    * The mtimes of all its dependencies
    * Whether it caused a parse.SkipRecipe exception

    Files causing parsing errors are evicted from the cache.

    """
    return Cache(cooker.configuration.data, cooker.configuration.data_hash)


class CacheData(object):
    """
    The data structures we compile from the cached data
    """

    def __init__(self, caches_array):
        self.caches_array = caches_array
        for cache_class in self.caches_array:
            if not issubclass(cache_class, RecipeInfoCommon):
                bb.error("Extra cache data class %s should subclass RecipeInfoCommon class" % cache_class)
            cache_class.init_cacheData(self)

        # Direct cache variables
        self.task_queues = {}
        self.preferred = {}
        self.tasks = {}
        # Indirect Cache variables (set elsewhere)
        self.ignored_dependencies = []
        self.world_target = set()
        self.bbfile_priority = {}

    def add_from_recipeinfo(self, fn, info_array):
        for info in info_array:
            info.add_cacheData(self, fn)

class MultiProcessCache(object):
    """
    BitBake multi-process cache implementation

    Used by the codeparser & file checksum caches
    """

    def __init__(self):
        self.cachefile = None
        self.cachedata = self.create_cachedata()
        self.cachedata_extras = self.create_cachedata()

    def init_cache(self, d, cache_file_name=None):
        cachedir = (d.getVar("PERSISTENT_DIR") or
                    d.getVar("CACHE"))
        if cachedir in [None, '']:
            return
        bb.utils.mkdirhier(cachedir)
        self.cachefile = os.path.join(cachedir,
                                      cache_file_name or self.__class__.cache_file_name)
        logger.debug(1, "Using cache in '%s'", self.cachefile)

        glf = bb.utils.lockfile(self.cachefile + ".lock")

        try:
            with open(self.cachefile, "rb") as f:
                p = pickle.Unpickler(f)
                data, version = p.load()
        except:
            bb.utils.unlockfile(glf)
            return

        bb.utils.unlockfile(glf)

        if version != self.__class__.CACHE_VERSION:
            return

        self.cachedata = data

    def create_cachedata(self):
        data = [{}]
        return data

    def save_extras(self):
        if not self.cachefile:
            return

        glf = bb.utils.lockfile(self.cachefile + ".lock", shared=True)

        i = os.getpid()
        lf = None
        while not lf:
            lf = bb.utils.lockfile(self.cachefile + ".lock." + str(i), retry=False)
            if not lf or os.path.exists(self.cachefile + "-" + str(i)):
                if lf:
                    bb.utils.unlockfile(lf)
                    lf = None
                i = i + 1
                continue

            with open(self.cachefile + "-" + str(i), "wb") as f:
                p = pickle.Pickler(f, -1)
                p.dump([self.cachedata_extras, self.__class__.CACHE_VERSION])

        bb.utils.unlockfile(lf)
        bb.utils.unlockfile(glf)

    def merge_data(self, source, dest):
        for j in range(0,len(dest)):
            for h in source[j]:
                if h not in dest[j]:
                    dest[j][h] = source[j][h]

    def save_merge(self):
        if not self.cachefile:
            return

        glf = bb.utils.lockfile(self.cachefile + ".lock")

        data = self.cachedata

        for f in [y for y in os.listdir(os.path.dirname(self.cachefile)) if y.startswith(os.path.basename(self.cachefile) + '-')]:
            f = os.path.join(os.path.dirname(self.cachefile), f)
            try:
                with open(f, "rb") as fd:
                    p = pickle.Unpickler(fd)
                    extradata, version = p.load()
            except (IOError, EOFError):
                os.unlink(f)
                continue

            if version != self.__class__.CACHE_VERSION:
                os.unlink(f)
                continue

            self.merge_data(extradata, data)
            os.unlink(f)

        with open(self.cachefile, "wb") as f:
            p = pickle.Pickler(f, -1)
            p.dump([data, self.__class__.CACHE_VERSION])

        bb.utils.unlockfile(glf)