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39 """
40 Provides filesystem-related objects.
41 @sort: FilesystemList, BackupFileList, PurgeItemList
42 @author: Kenneth J. Pronovici <pronovic@ieee.org>
43 """
44
45
46
47
48
49
50
51 import os
52 import re
53 import math
54 import logging
55 import tarfile
56
57
58 from CedarBackup2.knapsack import firstFit, bestFit, worstFit, alternateFit
59 from CedarBackup2.util import AbsolutePathList, UnorderedList, RegexList
60 from CedarBackup2.util import removeKeys, displayBytes, calculateFileAge, encodePath, dereferenceLink
61
62
63
64
65
66
67 logger = logging.getLogger("CedarBackup2.log.filesystem")
75
76
77
78
79
80 """
81 Represents a list of filesystem items.
82
83 This is a generic class that represents a list of filesystem items. Callers
84 can add individual files or directories to the list, or can recursively add
85 the contents of a directory. The class also allows for up-front exclusions
86 in several forms (all files, all directories, all items matching a pattern,
87 all items whose basename matches a pattern, or all directories containing a
88 specific "ignore file"). Symbolic links are typically backed up
89 non-recursively, i.e. the link to a directory is backed up, but not the
90 contents of that link (we don't want to deal with recursive loops, etc.).
91
92 The custom methods such as L{addFile} will only add items if they exist on
93 the filesystem and do not match any exclusions that are already in place.
94 However, since a FilesystemList is a subclass of Python's standard list
95 class, callers can also add items to the list in the usual way, using
96 methods like C{append()} or C{insert()}. No validations apply to items
97 added to the list in this way; however, many list-manipulation methods deal
98 "gracefully" with items that don't exist in the filesystem, often by
99 ignoring them.
100
101 Once a list has been created, callers can remove individual items from the
102 list using standard methods like C{pop()} or C{remove()} or they can use
103 custom methods to remove specific types of entries or entries which match a
104 particular pattern.
105
106 @note: Regular expression patterns that apply to paths are assumed to be
107 bounded at front and back by the beginning and end of the string, i.e. they
108 are treated as if they begin with C{^} and end with C{$}. This is true
109 whether we are matching a complete path or a basename.
110
111 @note: Some platforms, like Windows, do not support soft links. On those
112 platforms, the ignore-soft-links flag can be set, but it won't do any good
113 because the operating system never reports a file as a soft link.
114
115 @sort: __init__, addFile, addDir, addDirContents, removeFiles, removeDirs,
116 removeLinks, removeMatch, removeInvalid, normalize,
117 excludeFiles, excludeDirs, excludeLinks, excludePaths,
118 excludePatterns, excludeBasenamePatterns, ignoreFile
119 """
120
121
122
123
124
125
143
144
145
146
147
148
150 """
151 Property target used to set the exclude files flag.
152 No validations, but we normalize the value to C{True} or C{False}.
153 """
154 if value:
155 self._excludeFiles = True
156 else:
157 self._excludeFiles = False
158
160 """
161 Property target used to get the exclude files flag.
162 """
163 return self._excludeFiles
164
166 """
167 Property target used to set the exclude directories flag.
168 No validations, but we normalize the value to C{True} or C{False}.
169 """
170 if value:
171 self._excludeDirs = True
172 else:
173 self._excludeDirs = False
174
176 """
177 Property target used to get the exclude directories flag.
178 """
179 return self._excludeDirs
180
182 """
183 Property target used to set the exclude soft links flag.
184 No validations, but we normalize the value to C{True} or C{False}.
185 """
186 if value:
187 self._excludeLinks = True
188 else:
189 self._excludeLinks = False
190
192 """
193 Property target used to get the exclude soft links flag.
194 """
195 return self._excludeLinks
196
198 """
199 Property target used to set the exclude paths list.
200 A C{None} value is converted to an empty list.
201 Elements do not have to exist on disk at the time of assignment.
202 @raise ValueError: If any list element is not an absolute path.
203 """
204 self._excludePaths = AbsolutePathList()
205 if value is not None:
206 self._excludePaths.extend(value)
207
209 """
210 Property target used to get the absolute exclude paths list.
211 """
212 return self._excludePaths
213
215 """
216 Property target used to set the exclude patterns list.
217 A C{None} value is converted to an empty list.
218 """
219 self._excludePatterns = RegexList()
220 if value is not None:
221 self._excludePatterns.extend(value)
222
224 """
225 Property target used to get the exclude patterns list.
226 """
227 return self._excludePatterns
228
230 """
231 Property target used to set the exclude basename patterns list.
232 A C{None} value is converted to an empty list.
233 """
234 self._excludeBasenamePatterns = RegexList()
235 if value is not None:
236 self._excludeBasenamePatterns.extend(value)
237
239 """
240 Property target used to get the exclude basename patterns list.
241 """
242 return self._excludeBasenamePatterns
243
245 """
246 Property target used to set the ignore file.
247 The value must be a non-empty string if it is not C{None}.
248 @raise ValueError: If the value is an empty string.
249 """
250 if value is not None:
251 if len(value) < 1:
252 raise ValueError("The ignore file must be a non-empty string.")
253 self._ignoreFile = value
254
256 """
257 Property target used to get the ignore file.
258 """
259 return self._ignoreFile
260
261 excludeFiles = property(_getExcludeFiles, _setExcludeFiles, None, "Boolean indicating whether files should be excluded.")
262 excludeDirs = property(_getExcludeDirs, _setExcludeDirs, None, "Boolean indicating whether directories should be excluded.")
263 excludeLinks = property(_getExcludeLinks, _setExcludeLinks, None, "Boolean indicating whether soft links should be excluded.")
264 excludePaths = property(_getExcludePaths, _setExcludePaths, None, "List of absolute paths to be excluded.")
265 excludePatterns = property(_getExcludePatterns, _setExcludePatterns, None,
266 "List of regular expression patterns (matching complete path) to be excluded.")
267 excludeBasenamePatterns = property(_getExcludeBasenamePatterns, _setExcludeBasenamePatterns,
268 None, "List of regular expression patterns (matching basename) to be excluded.")
269 ignoreFile = property(_getIgnoreFile, _setIgnoreFile, None, "Name of file which will cause directory contents to be ignored.")
270
271
272
273
274
275
277 """
278 Adds a file to the list.
279
280 The path must exist and must be a file or a link to an existing file. It
281 will be added to the list subject to any exclusions that are in place.
282
283 @param path: File path to be added to the list
284 @type path: String representing a path on disk
285
286 @return: Number of items added to the list.
287
288 @raise ValueError: If path is not a file or does not exist.
289 @raise ValueError: If the path could not be encoded properly.
290 """
291 path = encodePath(path)
292 if not os.path.exists(path) or not os.path.isfile(path):
293 logger.debug("Path [%s] is not a file or does not exist on disk." % path)
294 raise ValueError("Path is not a file or does not exist on disk.")
295 if self.excludeLinks and os.path.islink(path):
296 logger.debug("Path [%s] is excluded based on excludeLinks." % path)
297 return 0
298 if self.excludeFiles:
299 logger.debug("Path [%s] is excluded based on excludeFiles." % path)
300 return 0
301 if path in self.excludePaths:
302 logger.debug("Path [%s] is excluded based on excludePaths." % path)
303 return 0
304 for pattern in self.excludePatterns:
305 pattern = encodePath(pattern)
306 if re.compile(r"^%s$" % pattern).match(path):
307 logger.debug("Path [%s] is excluded based on pattern [%s]." % (path, pattern))
308 return 0
309 for pattern in self.excludeBasenamePatterns:
310 pattern = encodePath(pattern)
311 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
312 logger.debug("Path [%s] is excluded based on basename pattern [%s]." % (path, pattern))
313 return 0
314 self.append(path)
315 logger.debug("Added file to list: [%s]" % path)
316 return 1
317
319 """
320 Adds a directory to the list.
321
322 The path must exist and must be a directory or a link to an existing
323 directory. It will be added to the list subject to any exclusions that
324 are in place. The L{ignoreFile} does not apply to this method, only to
325 L{addDirContents}.
326
327 @param path: Directory path to be added to the list
328 @type path: String representing a path on disk
329
330 @return: Number of items added to the list.
331
332 @raise ValueError: If path is not a directory or does not exist.
333 @raise ValueError: If the path could not be encoded properly.
334 """
335 path = encodePath(path)
336 path = normalizeDir(path)
337 if not os.path.exists(path) or not os.path.isdir(path):
338 logger.debug("Path [%s] is not a directory or does not exist on disk." % path)
339 raise ValueError("Path is not a directory or does not exist on disk.")
340 if self.excludeLinks and os.path.islink(path):
341 logger.debug("Path [%s] is excluded based on excludeLinks." % path)
342 return 0
343 if self.excludeDirs:
344 logger.debug("Path [%s] is excluded based on excludeDirs." % path)
345 return 0
346 if path in self.excludePaths:
347 logger.debug("Path [%s] is excluded based on excludePaths." % path)
348 return 0
349 for pattern in self.excludePatterns:
350 pattern = encodePath(pattern)
351 if re.compile(r"^%s$" % pattern).match(path):
352 logger.debug("Path [%s] is excluded based on pattern [%s]." % (path, pattern))
353 return 0
354 for pattern in self.excludeBasenamePatterns:
355 pattern = encodePath(pattern)
356 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
357 logger.debug("Path [%s] is excluded based on basename pattern [%s]." % (path, pattern))
358 return 0
359 self.append(path)
360 logger.debug("Added directory to list: [%s]" % path)
361 return 1
362
363 - def addDirContents(self, path, recursive=True, addSelf=True, linkDepth=0, dereference=False):
364 """
365 Adds the contents of a directory to the list.
366
367 The path must exist and must be a directory or a link to a directory.
368 The contents of the directory (as well as the directory path itself) will
369 be recursively added to the list, subject to any exclusions that are in
370 place. If you only want the directory and its immediate contents to be
371 added, then pass in C{recursive=False}.
372
373 @note: If a directory's absolute path matches an exclude pattern or path,
374 or if the directory contains the configured ignore file, then the
375 directory and all of its contents will be recursively excluded from the
376 list.
377
378 @note: If the passed-in directory happens to be a soft link, it will be
379 recursed. However, the linkDepth parameter controls whether any soft
380 links I{within} the directory will be recursed. The link depth is
381 maximum depth of the tree at which soft links should be followed. So, a
382 depth of 0 does not follow any soft links, a depth of 1 follows only
383 links within the passed-in directory, a depth of 2 follows the links at
384 the next level down, etc.
385
386 @note: Any invalid soft links (i.e. soft links that point to
387 non-existent items) will be silently ignored.
388
389 @note: The L{excludeDirs} flag only controls whether any given directory
390 path itself is added to the list once it has been discovered. It does
391 I{not} modify any behavior related to directory recursion.
392
393 @note: If you call this method I{on a link to a directory} that link will
394 never be dereferenced (it may, however, be followed).
395
396 @param path: Directory path whose contents should be added to the list
397 @type path: String representing a path on disk
398
399 @param recursive: Indicates whether directory contents should be added recursively.
400 @type recursive: Boolean value
401
402 @param addSelf: Indicates whether the directory itself should be added to the list.
403 @type addSelf: Boolean value
404
405 @param linkDepth: Maximum depth of the tree at which soft links should be followed
406 @type linkDepth: Integer value, where zero means not to follow any soft links
407
408 @param dereference: Indicates whether soft links, if followed, should be dereferenced
409 @type dereference: Boolean value
410
411 @return: Number of items recursively added to the list
412
413 @raise ValueError: If path is not a directory or does not exist.
414 @raise ValueError: If the path could not be encoded properly.
415 """
416 path = encodePath(path)
417 path = normalizeDir(path)
418 return self._addDirContentsInternal(path, addSelf, recursive, linkDepth, dereference)
419
420 - def _addDirContentsInternal(self, path, includePath=True, recursive=True, linkDepth=0, dereference=False):
421 """
422 Internal implementation of C{addDirContents}.
423
424 This internal implementation exists due to some refactoring. Basically,
425 some subclasses have a need to add the contents of a directory, but not
426 the directory itself. This is different than the standard C{FilesystemList}
427 behavior and actually ends up making a special case out of the first
428 call in the recursive chain. Since I don't want to expose the modified
429 interface, C{addDirContents} ends up being wholly implemented in terms
430 of this method.
431
432 The linkDepth parameter controls whether soft links are followed when we
433 are adding the contents recursively. Any recursive calls reduce the
434 value by one. If the value zero or less, then soft links will just be
435 added as directories, but will not be followed. This means that links
436 are followed to a I{constant depth} starting from the top-most directory.
437
438 There is one difference between soft links and directories: soft links
439 that are added recursively are not placed into the list explicitly. This
440 is because if we do add the links recursively, the resulting tar file
441 gets a little confused (it has a link and a directory with the same
442 name).
443
444 @note: If you call this method I{on a link to a directory} that link will
445 never be dereferenced (it may, however, be followed).
446
447 @param path: Directory path whose contents should be added to the list.
448 @param includePath: Indicates whether to include the path as well as contents.
449 @param recursive: Indicates whether directory contents should be added recursively.
450 @param linkDepth: Depth of soft links that should be followed
451 @param dereference: Indicates whether soft links, if followed, should be dereferenced
452
453 @return: Number of items recursively added to the list
454
455 @raise ValueError: If path is not a directory or does not exist.
456 """
457 added = 0
458 if not os.path.exists(path) or not os.path.isdir(path):
459 logger.debug("Path [%s] is not a directory or does not exist on disk." % path)
460 raise ValueError("Path is not a directory or does not exist on disk.")
461 if path in self.excludePaths:
462 logger.debug("Path [%s] is excluded based on excludePaths." % path)
463 return added
464 for pattern in self.excludePatterns:
465 pattern = encodePath(pattern)
466 if re.compile(r"^%s$" % pattern).match(path):
467 logger.debug("Path [%s] is excluded based on pattern [%s]." % (path, pattern))
468 return added
469 for pattern in self.excludeBasenamePatterns:
470 pattern = encodePath(pattern)
471 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
472 logger.debug("Path [%s] is excluded based on basename pattern [%s]." % (path, pattern))
473 return added
474 if self.ignoreFile is not None and os.path.exists(os.path.join(path, self.ignoreFile)):
475 logger.debug("Path [%s] is excluded based on ignore file." % path)
476 return added
477 if includePath:
478 added += self.addDir(path)
479 for entry in os.listdir(path):
480 entrypath = os.path.join(path, entry)
481 if os.path.isfile(entrypath):
482 if linkDepth > 0 and dereference:
483 derefpath = dereferenceLink(entrypath)
484 if derefpath != entrypath:
485 added += self.addFile(derefpath)
486 added += self.addFile(entrypath)
487 elif os.path.isdir(entrypath):
488 if os.path.islink(entrypath):
489 if recursive:
490 if linkDepth > 0:
491 newDepth = linkDepth - 1
492 if dereference:
493 derefpath = dereferenceLink(entrypath)
494 if derefpath != entrypath:
495 added += self._addDirContentsInternal(derefpath, True, recursive, newDepth, dereference)
496 added += self.addDir(entrypath)
497 else:
498 added += self._addDirContentsInternal(entrypath, False, recursive, newDepth, dereference)
499 else:
500 added += self.addDir(entrypath)
501 else:
502 added += self.addDir(entrypath)
503 else:
504 if recursive:
505 newDepth = linkDepth - 1
506 added += self._addDirContentsInternal(entrypath, True, recursive, newDepth, dereference)
507 else:
508 added += self.addDir(entrypath)
509 return added
510
511
512
513
514
515
517 """
518 Removes file entries from the list.
519
520 If C{pattern} is not passed in or is C{None}, then all file entries will
521 be removed from the list. Otherwise, only those file entries matching
522 the pattern will be removed. Any entry which does not exist on disk
523 will be ignored (use L{removeInvalid} to purge those entries).
524
525 This method might be fairly slow for large lists, since it must check the
526 type of each item in the list. If you know ahead of time that you want
527 to exclude all files, then you will be better off setting L{excludeFiles}
528 to C{True} before adding items to the list.
529
530 @param pattern: Regular expression pattern representing entries to remove
531
532 @return: Number of entries removed
533 @raise ValueError: If the passed-in pattern is not a valid regular expression.
534 """
535 removed = 0
536 if pattern is None:
537 for entry in self[:]:
538 if os.path.exists(entry) and os.path.isfile(entry):
539 self.remove(entry)
540 logger.debug("Removed path [%s] from list." % entry)
541 removed += 1
542 else:
543 try:
544 pattern = encodePath(pattern)
545 compiled = re.compile(pattern)
546 except re.error:
547 raise ValueError("Pattern is not a valid regular expression.")
548 for entry in self[:]:
549 if os.path.exists(entry) and os.path.isfile(entry):
550 if compiled.match(entry):
551 self.remove(entry)
552 logger.debug("Removed path [%s] from list." % entry)
553 removed += 1
554 logger.debug("Removed a total of %d entries." % removed)
555 return removed
556
558 """
559 Removes directory entries from the list.
560
561 If C{pattern} is not passed in or is C{None}, then all directory entries
562 will be removed from the list. Otherwise, only those directory entries
563 matching the pattern will be removed. Any entry which does not exist on
564 disk will be ignored (use L{removeInvalid} to purge those entries).
565
566 This method might be fairly slow for large lists, since it must check the
567 type of each item in the list. If you know ahead of time that you want
568 to exclude all directories, then you will be better off setting
569 L{excludeDirs} to C{True} before adding items to the list (note that this
570 will not prevent you from recursively adding the I{contents} of
571 directories).
572
573 @param pattern: Regular expression pattern representing entries to remove
574
575 @return: Number of entries removed
576 @raise ValueError: If the passed-in pattern is not a valid regular expression.
577 """
578 removed = 0
579 if pattern is None:
580 for entry in self[:]:
581 if os.path.exists(entry) and os.path.isdir(entry):
582 self.remove(entry)
583 logger.debug("Removed path [%s] from list." % entry)
584 removed += 1
585 else:
586 try:
587 pattern = encodePath(pattern)
588 compiled = re.compile(pattern)
589 except re.error:
590 raise ValueError("Pattern is not a valid regular expression.")
591 for entry in self[:]:
592 if os.path.exists(entry) and os.path.isdir(entry):
593 if compiled.match(entry):
594 self.remove(entry)
595 logger.debug("Removed path [%s] from list based on pattern [%s]." % (entry, pattern))
596 removed += 1
597 logger.debug("Removed a total of %d entries." % removed)
598 return removed
599
601 """
602 Removes soft link entries from the list.
603
604 If C{pattern} is not passed in or is C{None}, then all soft link entries
605 will be removed from the list. Otherwise, only those soft link entries
606 matching the pattern will be removed. Any entry which does not exist on
607 disk will be ignored (use L{removeInvalid} to purge those entries).
608
609 This method might be fairly slow for large lists, since it must check the
610 type of each item in the list. If you know ahead of time that you want
611 to exclude all soft links, then you will be better off setting
612 L{excludeLinks} to C{True} before adding items to the list.
613
614 @param pattern: Regular expression pattern representing entries to remove
615
616 @return: Number of entries removed
617 @raise ValueError: If the passed-in pattern is not a valid regular expression.
618 """
619 removed = 0
620 if pattern is None:
621 for entry in self[:]:
622 if os.path.exists(entry) and os.path.islink(entry):
623 self.remove(entry)
624 logger.debug("Removed path [%s] from list." % entry)
625 removed += 1
626 else:
627 try:
628 pattern = encodePath(pattern)
629 compiled = re.compile(pattern)
630 except re.error:
631 raise ValueError("Pattern is not a valid regular expression.")
632 for entry in self[:]:
633 if os.path.exists(entry) and os.path.islink(entry):
634 if compiled.match(entry):
635 self.remove(entry)
636 logger.debug("Removed path [%s] from list based on pattern [%s]." % (entry, pattern))
637 removed += 1
638 logger.debug("Removed a total of %d entries." % removed)
639 return removed
640
642 """
643 Removes from the list all entries matching a pattern.
644
645 This method removes from the list all entries which match the passed in
646 C{pattern}. Since there is no need to check the type of each entry, it
647 is faster to call this method than to call the L{removeFiles},
648 L{removeDirs} or L{removeLinks} methods individually. If you know which
649 patterns you will want to remove ahead of time, you may be better off
650 setting L{excludePatterns} or L{excludeBasenamePatterns} before adding
651 items to the list.
652
653 @note: Unlike when using the exclude lists, the pattern here is I{not}
654 bounded at the front and the back of the string. You can use any pattern
655 you want.
656
657 @param pattern: Regular expression pattern representing entries to remove
658
659 @return: Number of entries removed.
660 @raise ValueError: If the passed-in pattern is not a valid regular expression.
661 """
662 try:
663 pattern = encodePath(pattern)
664 compiled = re.compile(pattern)
665 except re.error:
666 raise ValueError("Pattern is not a valid regular expression.")
667 removed = 0
668 for entry in self[:]:
669 if compiled.match(entry):
670 self.remove(entry)
671 logger.debug("Removed path [%s] from list based on pattern [%s]." % (entry, pattern))
672 removed += 1
673 logger.debug("Removed a total of %d entries." % removed)
674 return removed
675
677 """
678 Removes from the list all entries that do not exist on disk.
679
680 This method removes from the list all entries which do not currently
681 exist on disk in some form. No attention is paid to whether the entries
682 are files or directories.
683
684 @return: Number of entries removed.
685 """
686 removed = 0
687 for entry in self[:]:
688 if not os.path.exists(entry):
689 self.remove(entry)
690 logger.debug("Removed path [%s] from list." % entry)
691 removed += 1
692 logger.debug("Removed a total of %d entries." % removed)
693 return removed
694
695
696
697
698
699
701 """Normalizes the list, ensuring that each entry is unique."""
702 orig = len(self)
703 self.sort()
704 dups = filter(lambda x, self=self: self[x] == self[x+1], range(0, len(self) - 1))
705 items = map(lambda x, self=self: self[x], dups)
706 map(self.remove, items)
707 new = len(self)
708 logger.debug("Completed normalizing list; removed %d items (%d originally, %d now)." % (new-orig, orig, new))
709
711 """
712 Verifies that all entries in the list exist on disk.
713 @return: C{True} if all entries exist, C{False} otherwise.
714 """
715 for entry in self:
716 if not os.path.exists(entry):
717 logger.debug("Path [%s] is invalid; list is not valid." % entry)
718 return False
719 logger.debug("All entries in list are valid.")
720 return True
721
722
723
724
725
726
727 -class SpanItem(object):
728 """
729 Item returned by L{BackupFileList.generateSpan}.
730 """
731 - def __init__(self, fileList, size, capacity, utilization):
732 """
733 Create object.
734 @param fileList: List of files
735 @param size: Size (in bytes) of files
736 @param utilization: Utilization, as a percentage (0-100)
737 """
738 self.fileList = fileList
739 self.size = size
740 self.capacity = capacity
741 self.utilization = utilization
742
749
750
751
752
753
754 """
755 List of files to be backed up.
756
757 A BackupFileList is a L{FilesystemList} containing a list of files to be
758 backed up. It only contains files, not directories (soft links are treated
759 like files). On top of the generic functionality provided by
760 L{FilesystemList}, this class adds functionality to keep a hash (checksum)
761 for each file in the list, and it also provides a method to calculate the
762 total size of the files in the list and a way to export the list into tar
763 form.
764
765 @sort: __init__, addDir, totalSize, generateSizeMap, generateDigestMap,
766 generateFitted, generateTarfile, removeUnchanged
767 """
768
769
770
771
772
776
777
778
779
780
781
783 """
784 Adds a directory to the list.
785
786 Note that this class does not allow directories to be added by themselves
787 (a backup list contains only files). However, since links to directories
788 are technically files, we allow them to be added.
789
790 This method is implemented in terms of the superclass method, with one
791 additional validation: the superclass method is only called if the
792 passed-in path is both a directory and a link. All of the superclass's
793 existing validations and restrictions apply.
794
795 @param path: Directory path to be added to the list
796 @type path: String representing a path on disk
797
798 @return: Number of items added to the list.
799
800 @raise ValueError: If path is not a directory or does not exist.
801 @raise ValueError: If the path could not be encoded properly.
802 """
803 path = encodePath(path)
804 path = normalizeDir(path)
805 if os.path.isdir(path) and not os.path.islink(path):
806 return 0
807 else:
808 return FilesystemList.addDir(self, path)
809
810
811
812
813
814
816 """
817 Returns the total size among all files in the list.
818 Only files are counted.
819 Soft links that point at files are ignored.
820 Entries which do not exist on disk are ignored.
821 @return: Total size, in bytes
822 """
823 total = 0.0
824 for entry in self:
825 if os.path.isfile(entry) and not os.path.islink(entry):
826 total += float(os.stat(entry).st_size)
827 return total
828
830 """
831 Generates a mapping from file to file size in bytes.
832 The mapping does include soft links, which are listed with size zero.
833 Entries which do not exist on disk are ignored.
834 @return: Dictionary mapping file to file size
835 """
836 table = { }
837 for entry in self:
838 if os.path.islink(entry):
839 table[entry] = 0.0
840 elif os.path.isfile(entry):
841 table[entry] = float(os.stat(entry).st_size)
842 return table
843
845 """
846 Generates a mapping from file to file digest.
847
848 Currently, the digest is an SHA hash, which should be pretty secure. In
849 the future, this might be a different kind of hash, but we guarantee that
850 the type of the hash will not change unless the library major version
851 number is bumped.
852
853 Entries which do not exist on disk are ignored.
854
855 Soft links are ignored. We would end up generating a digest for the file
856 that the soft link points at, which doesn't make any sense.
857
858 If C{stripPrefix} is passed in, then that prefix will be stripped from
859 each key when the map is generated. This can be useful in generating two
860 "relative" digest maps to be compared to one another.
861
862 @param stripPrefix: Common prefix to be stripped from paths
863 @type stripPrefix: String with any contents
864
865 @return: Dictionary mapping file to digest value
866 @see: L{removeUnchanged}
867 """
868 table = { }
869 if stripPrefix is not None:
870 for entry in self:
871 if os.path.isfile(entry) and not os.path.islink(entry):
872 table[entry.replace(stripPrefix, "", 1)] = BackupFileList._generateDigest(entry)
873 else:
874 for entry in self:
875 if os.path.isfile(entry) and not os.path.islink(entry):
876 table[entry] = BackupFileList._generateDigest(entry)
877 return table
878
879 @staticmethod
881 """
882 Generates an SHA digest for a given file on disk.
883
884 The original code for this function used this simplistic implementation,
885 which requires reading the entire file into memory at once in order to
886 generate a digest value::
887
888 sha.new(open(path).read()).hexdigest()
889
890 Not surprisingly, this isn't an optimal solution. The U{Simple file
891 hashing <http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/259109>}
892 Python Cookbook recipe describes how to incrementally generate a hash
893 value by reading in chunks of data rather than reading the file all at
894 once. The recipe relies on the the C{update()} method of the various
895 Python hashing algorithms.
896
897 In my tests using a 110 MB file on CD, the original implementation
898 requires 111 seconds. This implementation requires only 40-45 seconds,
899 which is a pretty substantial speed-up.
900
901 Experience shows that reading in around 4kB (4096 bytes) at a time yields
902 the best performance. Smaller reads are quite a bit slower, and larger
903 reads don't make much of a difference. The 4kB number makes me a little
904 suspicious, and I think it might be related to the size of a filesystem
905 read at the hardware level. However, I've decided to just hardcode 4096
906 until I have evidence that shows it's worthwhile making the read size
907 configurable.
908
909 @param path: Path to generate digest for.
910
911 @return: ASCII-safe SHA digest for the file.
912 @raise OSError: If the file cannot be opened.
913 """
914
915 try:
916 import hashlib
917 s = hashlib.sha1()
918 except ImportError:
919 import sha
920 s = sha.new()
921 f = open(path, mode="rb")
922 readBytes = 4096
923 while(readBytes > 0):
924 readString = f.read(readBytes)
925 s.update(readString)
926 readBytes = len(readString)
927 f.close()
928 digest = s.hexdigest()
929 logger.debug("Generated digest [%s] for file [%s]." % (digest, path))
930 return digest
931
933 """
934 Generates a list of items that fit in the indicated capacity.
935
936 Sometimes, callers would like to include every item in a list, but are
937 unable to because not all of the items fit in the space available. This
938 method returns a copy of the list, containing only the items that fit in
939 a given capacity. A copy is returned so that we don't lose any
940 information if for some reason the fitted list is unsatisfactory.
941
942 The fitting is done using the functions in the knapsack module. By
943 default, the first fit algorithm is used, but you can also choose
944 from best fit, worst fit and alternate fit.
945
946 @param capacity: Maximum capacity among the files in the new list
947 @type capacity: Integer, in bytes
948
949 @param algorithm: Knapsack (fit) algorithm to use
950 @type algorithm: One of "first_fit", "best_fit", "worst_fit", "alternate_fit"
951
952 @return: Copy of list with total size no larger than indicated capacity
953 @raise ValueError: If the algorithm is invalid.
954 """
955 table = self._getKnapsackTable()
956 function = BackupFileList._getKnapsackFunction(algorithm)
957 return function(table, capacity)[0]
958
960 """
961 Splits the list of items into sub-lists that fit in a given capacity.
962
963 Sometimes, callers need split to a backup file list into a set of smaller
964 lists. For instance, you could use this to "span" the files across a set
965 of discs.
966
967 The fitting is done using the functions in the knapsack module. By
968 default, the first fit algorithm is used, but you can also choose
969 from best fit, worst fit and alternate fit.
970
971 @note: If any of your items are larger than the capacity, then it won't
972 be possible to find a solution. In this case, a value error will be
973 raised.
974
975 @param capacity: Maximum capacity among the files in the new list
976 @type capacity: Integer, in bytes
977
978 @param algorithm: Knapsack (fit) algorithm to use
979 @type algorithm: One of "first_fit", "best_fit", "worst_fit", "alternate_fit"
980
981 @return: List of L{SpanItem} objects.
982
983 @raise ValueError: If the algorithm is invalid.
984 @raise ValueError: If it's not possible to fit some items
985 """
986 spanItems = []
987 function = BackupFileList._getKnapsackFunction(algorithm)
988 table = self._getKnapsackTable(capacity)
989 iteration = 0
990 while len(table) > 0:
991 iteration += 1
992 fit = function(table, capacity)
993 if len(fit[0]) == 0:
994
995 raise ValueError("After iteration %d, unable to add any new items." % iteration)
996 removeKeys(table, fit[0])
997 utilization = (float(fit[1])/float(capacity))*100.0
998 item = SpanItem(fit[0], fit[1], capacity, utilization)
999 spanItems.append(item)
1000 return spanItems
1001
1003 """
1004 Converts the list into the form needed by the knapsack algorithms.
1005 @return: Dictionary mapping file name to tuple of (file path, file size).
1006 """
1007 table = { }
1008 for entry in self:
1009 if os.path.islink(entry):
1010 table[entry] = (entry, 0.0)
1011 elif os.path.isfile(entry):
1012 size = float(os.stat(entry).st_size)
1013 if capacity is not None:
1014 if size > capacity:
1015 raise ValueError("File [%s] cannot fit in capacity %s." % (entry, displayBytes(capacity)))
1016 table[entry] = (entry, size)
1017 return table
1018
1019 @staticmethod
1021 """
1022 Returns a reference to the function associated with an algorithm name.
1023 Algorithm name must be one of "first_fit", "best_fit", "worst_fit", "alternate_fit"
1024 @param algorithm: Name of the algorithm
1025 @return: Reference to knapsack function
1026 @raise ValueError: If the algorithm name is unknown.
1027 """
1028 if algorithm == "first_fit":
1029 return firstFit
1030 elif algorithm == "best_fit":
1031 return bestFit
1032 elif algorithm == "worst_fit":
1033 return worstFit
1034 elif algorithm == "alternate_fit":
1035 return alternateFit
1036 else:
1037 raise ValueError("Algorithm [%s] is invalid." % algorithm)
1038
1040 """
1041 Creates a tar file containing the files in the list.
1042
1043 By default, this method will create uncompressed tar files. If you pass
1044 in mode C{'targz'}, then it will create gzipped tar files, and if you
1045 pass in mode C{'tarbz2'}, then it will create bzipped tar files.
1046
1047 The tar file will be created as a GNU tar archive, which enables extended
1048 file name lengths, etc. Since GNU tar is so prevalent, I've decided that
1049 the extra functionality out-weighs the disadvantage of not being
1050 "standard".
1051
1052 If you pass in C{flat=True}, then a "flat" archive will be created, and
1053 all of the files will be added to the root of the archive. So, the file
1054 C{/tmp/something/whatever.txt} would be added as just C{whatever.txt}.
1055
1056 By default, the whole method call fails if there are problems adding any
1057 of the files to the archive, resulting in an exception. Under these
1058 circumstances, callers are advised that they might want to call
1059 L{removeInvalid()} and then attempt to extract the tar file a second
1060 time, since the most common cause of failures is a missing file (a file
1061 that existed when the list was built, but is gone again by the time the
1062 tar file is built).
1063
1064 If you want to, you can pass in C{ignore=True}, and the method will
1065 ignore errors encountered when adding individual files to the archive
1066 (but not errors opening and closing the archive itself).
1067
1068 We'll always attempt to remove the tarfile from disk if an exception will
1069 be thrown.
1070
1071 @note: No validation is done as to whether the entries in the list are
1072 files, since only files or soft links should be in an object like this.
1073 However, to be safe, everything is explicitly added to the tar archive
1074 non-recursively so it's safe to include soft links to directories.
1075
1076 @note: The Python C{tarfile} module, which is used internally here, is
1077 supposed to deal properly with long filenames and links. In my testing,
1078 I have found that it appears to be able to add long really long filenames
1079 to archives, but doesn't do a good job reading them back out, even out of
1080 an archive it created. Fortunately, all Cedar Backup does is add files
1081 to archives.
1082
1083 @param path: Path of tar file to create on disk
1084 @type path: String representing a path on disk
1085
1086 @param mode: Tar creation mode
1087 @type mode: One of either C{'tar'}, C{'targz'} or C{'tarbz2'}
1088
1089 @param ignore: Indicates whether to ignore certain errors.
1090 @type ignore: Boolean
1091
1092 @param flat: Creates "flat" archive by putting all items in root
1093 @type flat: Boolean
1094
1095 @raise ValueError: If mode is not valid
1096 @raise ValueError: If list is empty
1097 @raise ValueError: If the path could not be encoded properly.
1098 @raise TarError: If there is a problem creating the tar file
1099 """
1100
1101 path = encodePath(path)
1102 if len(self) == 0: raise ValueError("Empty list cannot be used to generate tarfile.")
1103 if(mode == 'tar'): tarmode = "w:"
1104 elif(mode == 'targz'): tarmode = "w:gz"
1105 elif(mode == 'tarbz2'): tarmode = "w:bz2"
1106 else: raise ValueError("Mode [%s] is not valid." % mode)
1107 try:
1108 tar = tarfile.open(path, tarmode)
1109 try:
1110 tar.format = tarfile.GNU_FORMAT
1111 except AttributeError:
1112 tar.posix = False
1113 for entry in self:
1114 try:
1115 if flat:
1116 tar.add(entry, arcname=os.path.basename(entry), recursive=False)
1117 else:
1118 tar.add(entry, recursive=False)
1119 except tarfile.TarError, e:
1120 if not ignore:
1121 raise e
1122 logger.info("Unable to add file [%s]; going on anyway." % entry)
1123 except OSError, e:
1124 if not ignore:
1125 raise tarfile.TarError(e)
1126 logger.info("Unable to add file [%s]; going on anyway." % entry)
1127 tar.close()
1128 except tarfile.ReadError, e:
1129 try: tar.close()
1130 except: pass
1131 if os.path.exists(path):
1132 try: os.remove(path)
1133 except: pass
1134 raise tarfile.ReadError("Unable to open [%s]; maybe directory doesn't exist?" % path)
1135 except tarfile.TarError, e:
1136 try: tar.close()
1137 except: pass
1138 if os.path.exists(path):
1139 try: os.remove(path)
1140 except: pass
1141 raise e
1142
1144 """
1145 Removes unchanged entries from the list.
1146
1147 This method relies on a digest map as returned from L{generateDigestMap}.
1148 For each entry in C{digestMap}, if the entry also exists in the current
1149 list I{and} the entry in the current list has the same digest value as in
1150 the map, the entry in the current list will be removed.
1151
1152 This method offers a convenient way for callers to filter unneeded
1153 entries from a list. The idea is that a caller will capture a digest map
1154 from C{generateDigestMap} at some point in time (perhaps the beginning of
1155 the week), and will save off that map using C{pickle} or some other
1156 method. Then, the caller could use this method sometime in the future to
1157 filter out any unchanged files based on the saved-off map.
1158
1159 If C{captureDigest} is passed-in as C{True}, then digest information will
1160 be captured for the entire list before the removal step occurs using the
1161 same rules as in L{generateDigestMap}. The check will involve a lookup
1162 into the complete digest map.
1163
1164 If C{captureDigest} is passed in as C{False}, we will only generate a
1165 digest value for files we actually need to check, and we'll ignore any
1166 entry in the list which isn't a file that currently exists on disk.
1167
1168 The return value varies depending on C{captureDigest}, as well. To
1169 preserve backwards compatibility, if C{captureDigest} is C{False}, then
1170 we'll just return a single value representing the number of entries
1171 removed. Otherwise, we'll return a tuple of C{(entries removed, digest
1172 map)}. The returned digest map will be in exactly the form returned by
1173 L{generateDigestMap}.
1174
1175 @note: For performance reasons, this method actually ends up rebuilding
1176 the list from scratch. First, we build a temporary dictionary containing
1177 all of the items from the original list. Then, we remove items as needed
1178 from the dictionary (which is faster than the equivalent operation on a
1179 list). Finally, we replace the contents of the current list based on the
1180 keys left in the dictionary. This should be transparent to the caller.
1181
1182 @param digestMap: Dictionary mapping file name to digest value.
1183 @type digestMap: Map as returned from L{generateDigestMap}.
1184
1185 @param captureDigest: Indicates that digest information should be captured.
1186 @type captureDigest: Boolean
1187
1188 @return: Number of entries removed
1189 """
1190 if captureDigest:
1191 removed = 0
1192 table = {}
1193 captured = {}
1194 for entry in self:
1195 if os.path.isfile(entry) and not os.path.islink(entry):
1196 table[entry] = BackupFileList._generateDigest(entry)
1197 captured[entry] = table[entry]
1198 else:
1199 table[entry] = None
1200 for entry in digestMap.keys():
1201 if table.has_key(entry):
1202 if table[entry] is not None:
1203 digest = table[entry]
1204 if digest == digestMap[entry]:
1205 removed += 1
1206 del table[entry]
1207 logger.debug("Discarded unchanged file [%s]." % entry)
1208 self[:] = table.keys()
1209 return (removed, captured)
1210 else:
1211 removed = 0
1212 table = {}
1213 for entry in self:
1214 table[entry] = None
1215 for entry in digestMap.keys():
1216 if table.has_key(entry):
1217 if os.path.isfile(entry) and not os.path.islink(entry):
1218 digest = BackupFileList._generateDigest(entry)
1219 if digest == digestMap[entry]:
1220 removed += 1
1221 del table[entry]
1222 logger.debug("Discarded unchanged file [%s]." % entry)
1223 self[:] = table.keys()
1224 return removed
1225
1232
1233
1234
1235
1236
1237 """
1238 List of files and directories to be purged.
1239
1240 A PurgeItemList is a L{FilesystemList} containing a list of files and
1241 directories to be purged. On top of the generic functionality provided by
1242 L{FilesystemList}, this class adds functionality to remove items that are
1243 too young to be purged, and to actually remove each item in the list from
1244 the filesystem.
1245
1246 The other main difference is that when you add a directory's contents to a
1247 purge item list, the directory itself is not added to the list. This way,
1248 if someone asks to purge within in C{/opt/backup/collect}, that directory
1249 doesn't get removed once all of the files within it is gone.
1250 """
1251
1252
1253
1254
1255
1259
1260
1261
1262
1263
1264
1265 - def addDirContents(self, path, recursive=True, addSelf=True, linkDepth=0, dereference=False):
1266 """
1267 Adds the contents of a directory to the list.
1268
1269 The path must exist and must be a directory or a link to a directory.
1270 The contents of the directory (but I{not} the directory path itself) will
1271 be recursively added to the list, subject to any exclusions that are in
1272 place. If you only want the directory and its contents to be added, then
1273 pass in C{recursive=False}.
1274
1275 @note: If a directory's absolute path matches an exclude pattern or path,
1276 or if the directory contains the configured ignore file, then the
1277 directory and all of its contents will be recursively excluded from the
1278 list.
1279
1280 @note: If the passed-in directory happens to be a soft link, it will be
1281 recursed. However, the linkDepth parameter controls whether any soft
1282 links I{within} the directory will be recursed. The link depth is
1283 maximum depth of the tree at which soft links should be followed. So, a
1284 depth of 0 does not follow any soft links, a depth of 1 follows only
1285 links within the passed-in directory, a depth of 2 follows the links at
1286 the next level down, etc.
1287
1288 @note: Any invalid soft links (i.e. soft links that point to
1289 non-existent items) will be silently ignored.
1290
1291 @note: The L{excludeDirs} flag only controls whether any given soft link
1292 path itself is added to the list once it has been discovered. It does
1293 I{not} modify any behavior related to directory recursion.
1294
1295 @note: The L{excludeDirs} flag only controls whether any given directory
1296 path itself is added to the list once it has been discovered. It does
1297 I{not} modify any behavior related to directory recursion.
1298
1299 @note: If you call this method I{on a link to a directory} that link will
1300 never be dereferenced (it may, however, be followed).
1301
1302 @param path: Directory path whose contents should be added to the list
1303 @type path: String representing a path on disk
1304
1305 @param recursive: Indicates whether directory contents should be added recursively.
1306 @type recursive: Boolean value
1307
1308 @param addSelf: Ignored in this subclass.
1309
1310 @param linkDepth: Depth of soft links that should be followed
1311 @type linkDepth: Integer value, where zero means not to follow any soft links
1312
1313 @param dereference: Indicates whether soft links, if followed, should be dereferenced
1314 @type dereference: Boolean value
1315
1316 @return: Number of items recursively added to the list
1317
1318 @raise ValueError: If path is not a directory or does not exist.
1319 @raise ValueError: If the path could not be encoded properly.
1320 """
1321 path = encodePath(path)
1322 path = normalizeDir(path)
1323 return super(PurgeItemList, self)._addDirContentsInternal(path, False, recursive, linkDepth, dereference)
1324
1325
1326
1327
1328
1329
1331 """
1332 Removes from the list files younger than a certain age (in days).
1333
1334 Any file whose "age" in days is less than (C{<}) the value of the
1335 C{daysOld} parameter will be removed from the list so that it will not be
1336 purged later when L{purgeItems} is called. Directories and soft links
1337 will be ignored.
1338
1339 The "age" of a file is the amount of time since the file was last used,
1340 per the most recent of the file's C{st_atime} and C{st_mtime} values.
1341
1342 @note: Some people find the "sense" of this method confusing or
1343 "backwards". Keep in mind that this method is used to remove items
1344 I{from the list}, not from the filesystem! It removes from the list
1345 those items that you would I{not} want to purge because they are too
1346 young. As an example, passing in C{daysOld} of zero (0) would remove
1347 from the list no files, which would result in purging all of the files
1348 later. I would be happy to make a synonym of this method with an
1349 easier-to-understand "sense", if someone can suggest one.
1350
1351 @param daysOld: Minimum age of files that are to be kept in the list.
1352 @type daysOld: Integer value >= 0.
1353
1354 @return: Number of entries removed
1355 """
1356 removed = 0
1357 daysOld = int(daysOld)
1358 if daysOld < 0:
1359 raise ValueError("Days old value must be an integer >= 0.")
1360 for entry in self[:]:
1361 if os.path.isfile(entry) and not os.path.islink(entry):
1362 try:
1363 ageInDays = calculateFileAge(entry)
1364 ageInWholeDays = math.floor(ageInDays)
1365 if ageInWholeDays < daysOld:
1366 removed += 1
1367 self.remove(entry)
1368 except OSError:
1369 pass
1370 return removed
1371
1373 """
1374 Purges all items in the list.
1375
1376 Every item in the list will be purged. Directories in the list will
1377 I{not} be purged recursively, and hence will only be removed if they are
1378 empty. Errors will be ignored.
1379
1380 To faciliate easy removal of directories that will end up being empty,
1381 the delete process happens in two passes: files first (including soft
1382 links), then directories.
1383
1384 @return: Tuple containing count of (files, dirs) removed
1385 """
1386 files = 0
1387 dirs = 0
1388 for entry in self:
1389 if os.path.exists(entry) and (os.path.isfile(entry) or os.path.islink(entry)):
1390 try:
1391 os.remove(entry)
1392 files += 1
1393 logger.debug("Purged file [%s]." % entry)
1394 except OSError:
1395 pass
1396 for entry in self:
1397 if os.path.exists(entry) and os.path.isdir(entry) and not os.path.islink(entry):
1398 try:
1399 os.rmdir(entry)
1400 dirs += 1
1401 logger.debug("Purged empty directory [%s]." % entry)
1402 except OSError:
1403 pass
1404 return (files, dirs)
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415 -def normalizeDir(path):
1416 """
1417 Normalizes a directory name.
1418
1419 For our purposes, a directory name is normalized by removing the trailing
1420 path separator, if any. This is important because we want directories to
1421 appear within lists in a consistent way, although from the user's
1422 perspective passing in C{/path/to/dir/} and C{/path/to/dir} are equivalent.
1423
1424 @param path: Path to be normalized.
1425 @type path: String representing a path on disk
1426
1427 @return: Normalized path, which should be equivalent to the original.
1428 """
1429 if path != os.sep and path[-1:] == os.sep:
1430 return path[:-1]
1431 return path
1432
1433
1434
1435
1436
1437
1438 -def compareContents(path1, path2, verbose=False):
1439 """
1440 Compares the contents of two directories to see if they are equivalent.
1441
1442 The two directories are recursively compared. First, we check whether they
1443 contain exactly the same set of files. Then, we check to see every given
1444 file has exactly the same contents in both directories.
1445
1446 This is all relatively simple to implement through the magic of
1447 L{BackupFileList.generateDigestMap}, which knows how to strip a path prefix
1448 off the front of each entry in the mapping it generates. This makes our
1449 comparison as simple as creating a list for each path, then generating a
1450 digest map for each path and comparing the two.
1451
1452 If no exception is thrown, the two directories are considered identical.
1453
1454 If the C{verbose} flag is C{True}, then an alternate (but slower) method is
1455 used so that any thrown exception can indicate exactly which file caused the
1456 comparison to fail. The thrown C{ValueError} exception distinguishes
1457 between the directories containing different files, and containing the same
1458 files with differing content.
1459
1460 @note: Symlinks are I{not} followed for the purposes of this comparison.
1461
1462 @param path1: First path to compare.
1463 @type path1: String representing a path on disk
1464
1465 @param path2: First path to compare.
1466 @type path2: String representing a path on disk
1467
1468 @param verbose: Indicates whether a verbose response should be given.
1469 @type verbose: Boolean
1470
1471 @raise ValueError: If a directory doesn't exist or can't be read.
1472 @raise ValueError: If the two directories are not equivalent.
1473 @raise IOError: If there is an unusual problem reading the directories.
1474 """
1475 try:
1476 path1List = BackupFileList()
1477 path1List.addDirContents(path1)
1478 path1Digest = path1List.generateDigestMap(stripPrefix=normalizeDir(path1))
1479 path2List = BackupFileList()
1480 path2List.addDirContents(path2)
1481 path2Digest = path2List.generateDigestMap(stripPrefix=normalizeDir(path2))
1482 compareDigestMaps(path1Digest, path2Digest, verbose)
1483 except IOError, e:
1484 logger.error("I/O error encountered during consistency check.")
1485 raise e
1486
1488 """
1489 Compares two digest maps and throws an exception if they differ.
1490
1491 @param digest1: First digest to compare.
1492 @type digest1: Digest as returned from BackupFileList.generateDigestMap()
1493
1494 @param digest2: Second digest to compare.
1495 @type digest2: Digest as returned from BackupFileList.generateDigestMap()
1496
1497 @param verbose: Indicates whether a verbose response should be given.
1498 @type verbose: Boolean
1499
1500 @raise ValueError: If the two directories are not equivalent.
1501 """
1502 if not verbose:
1503 if digest1 != digest2:
1504 raise ValueError("Consistency check failed.")
1505 else:
1506 list1 = UnorderedList(digest1.keys())
1507 list2 = UnorderedList(digest2.keys())
1508 if list1 != list2:
1509 raise ValueError("Directories contain a different set of files.")
1510 for key in list1:
1511 if digest1[key] != digest2[key]:
1512 raise ValueError("File contents for [%s] vary between directories." % key)
1513