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38 """
39 Provides filesystem-related objects.
40 @sort: FilesystemList, BackupFileList, PurgeItemList
41 @author: Kenneth J. Pronovici <pronovic@ieee.org>
42 """
43
44
45
46
47
48
49
50 import os
51 import re
52 import math
53 import logging
54 import tarfile
55
56
57 from CedarBackup2.knapsack import firstFit, bestFit, worstFit, alternateFit
58 from CedarBackup2.util import AbsolutePathList, UnorderedList, RegexList
59 from CedarBackup2.util import removeKeys, displayBytes, calculateFileAge, encodePath, dereferenceLink
60
61
62
63
64
65
66 logger = logging.getLogger("CedarBackup2.log.filesystem")
74
75
76
77
78
79 """
80 Represents a list of filesystem items.
81
82 This is a generic class that represents a list of filesystem items. Callers
83 can add individual files or directories to the list, or can recursively add
84 the contents of a directory. The class also allows for up-front exclusions
85 in several forms (all files, all directories, all items matching a pattern,
86 all items whose basename matches a pattern, or all directories containing a
87 specific "ignore file"). Symbolic links are typically backed up
88 non-recursively, i.e. the link to a directory is backed up, but not the
89 contents of that link (we don't want to deal with recursive loops, etc.).
90
91 The custom methods such as L{addFile} will only add items if they exist on
92 the filesystem and do not match any exclusions that are already in place.
93 However, since a FilesystemList is a subclass of Python's standard list
94 class, callers can also add items to the list in the usual way, using
95 methods like C{append()} or C{insert()}. No validations apply to items
96 added to the list in this way; however, many list-manipulation methods deal
97 "gracefully" with items that don't exist in the filesystem, often by
98 ignoring them.
99
100 Once a list has been created, callers can remove individual items from the
101 list using standard methods like C{pop()} or C{remove()} or they can use
102 custom methods to remove specific types of entries or entries which match a
103 particular pattern.
104
105 @note: Regular expression patterns that apply to paths are assumed to be
106 bounded at front and back by the beginning and end of the string, i.e. they
107 are treated as if they begin with C{^} and end with C{$}. This is true
108 whether we are matching a complete path or a basename.
109
110 @note: Some platforms, like Windows, do not support soft links. On those
111 platforms, the ignore-soft-links flag can be set, but it won't do any good
112 because the operating system never reports a file as a soft link.
113
114 @sort: __init__, addFile, addDir, addDirContents, removeFiles, removeDirs,
115 removeLinks, removeMatch, removeInvalid, normalize,
116 excludeFiles, excludeDirs, excludeLinks, excludePaths,
117 excludePatterns, excludeBasenamePatterns, ignoreFile
118 """
119
120
121
122
123
124
142
143
144
145
146
147
149 """
150 Property target used to set the exclude files flag.
151 No validations, but we normalize the value to C{True} or C{False}.
152 """
153 if value:
154 self._excludeFiles = True
155 else:
156 self._excludeFiles = False
157
159 """
160 Property target used to get the exclude files flag.
161 """
162 return self._excludeFiles
163
165 """
166 Property target used to set the exclude directories flag.
167 No validations, but we normalize the value to C{True} or C{False}.
168 """
169 if value:
170 self._excludeDirs = True
171 else:
172 self._excludeDirs = False
173
175 """
176 Property target used to get the exclude directories flag.
177 """
178 return self._excludeDirs
179
181 """
182 Property target used to set the exclude soft links flag.
183 No validations, but we normalize the value to C{True} or C{False}.
184 """
185 if value:
186 self._excludeLinks = True
187 else:
188 self._excludeLinks = False
189
191 """
192 Property target used to get the exclude soft links flag.
193 """
194 return self._excludeLinks
195
197 """
198 Property target used to set the exclude paths list.
199 A C{None} value is converted to an empty list.
200 Elements do not have to exist on disk at the time of assignment.
201 @raise ValueError: If any list element is not an absolute path.
202 """
203 self._excludePaths = AbsolutePathList()
204 if value is not None:
205 self._excludePaths.extend(value)
206
208 """
209 Property target used to get the absolute exclude paths list.
210 """
211 return self._excludePaths
212
214 """
215 Property target used to set the exclude patterns list.
216 A C{None} value is converted to an empty list.
217 """
218 self._excludePatterns = RegexList()
219 if value is not None:
220 self._excludePatterns.extend(value)
221
223 """
224 Property target used to get the exclude patterns list.
225 """
226 return self._excludePatterns
227
229 """
230 Property target used to set the exclude basename patterns list.
231 A C{None} value is converted to an empty list.
232 """
233 self._excludeBasenamePatterns = RegexList()
234 if value is not None:
235 self._excludeBasenamePatterns.extend(value)
236
238 """
239 Property target used to get the exclude basename patterns list.
240 """
241 return self._excludeBasenamePatterns
242
244 """
245 Property target used to set the ignore file.
246 The value must be a non-empty string if it is not C{None}.
247 @raise ValueError: If the value is an empty string.
248 """
249 if value is not None:
250 if len(value) < 1:
251 raise ValueError("The ignore file must be a non-empty string.")
252 self._ignoreFile = value
253
255 """
256 Property target used to get the ignore file.
257 """
258 return self._ignoreFile
259
260 excludeFiles = property(_getExcludeFiles, _setExcludeFiles, None, "Boolean indicating whether files should be excluded.")
261 excludeDirs = property(_getExcludeDirs, _setExcludeDirs, None, "Boolean indicating whether directories should be excluded.")
262 excludeLinks = property(_getExcludeLinks, _setExcludeLinks, None, "Boolean indicating whether soft links should be excluded.")
263 excludePaths = property(_getExcludePaths, _setExcludePaths, None, "List of absolute paths to be excluded.")
264 excludePatterns = property(_getExcludePatterns, _setExcludePatterns, None,
265 "List of regular expression patterns (matching complete path) to be excluded.")
266 excludeBasenamePatterns = property(_getExcludeBasenamePatterns, _setExcludeBasenamePatterns,
267 None, "List of regular expression patterns (matching basename) to be excluded.")
268 ignoreFile = property(_getIgnoreFile, _setIgnoreFile, None, "Name of file which will cause directory contents to be ignored.")
269
270
271
272
273
274
276 """
277 Adds a file to the list.
278
279 The path must exist and must be a file or a link to an existing file. It
280 will be added to the list subject to any exclusions that are in place.
281
282 @param path: File path to be added to the list
283 @type path: String representing a path on disk
284
285 @return: Number of items added to the list.
286
287 @raise ValueError: If path is not a file or does not exist.
288 @raise ValueError: If the path could not be encoded properly.
289 """
290 path = encodePath(path)
291 if not os.path.exists(path) or not os.path.isfile(path):
292 logger.debug("Path [%s] is not a file or does not exist on disk.", path)
293 raise ValueError("Path is not a file or does not exist on disk.")
294 if self.excludeLinks and os.path.islink(path):
295 logger.debug("Path [%s] is excluded based on excludeLinks.", path)
296 return 0
297 if self.excludeFiles:
298 logger.debug("Path [%s] is excluded based on excludeFiles.", path)
299 return 0
300 if path in self.excludePaths:
301 logger.debug("Path [%s] is excluded based on excludePaths.", path)
302 return 0
303 for pattern in self.excludePatterns:
304 pattern = encodePath(pattern)
305 if re.compile(r"^%s$" % pattern).match(path):
306 logger.debug("Path [%s] is excluded based on pattern [%s].", path, pattern)
307 return 0
308 for pattern in self.excludeBasenamePatterns:
309 pattern = encodePath(pattern)
310 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
311 logger.debug("Path [%s] is excluded based on basename pattern [%s].", path, pattern)
312 return 0
313 self.append(path)
314 logger.debug("Added file to list: [%s]", path)
315 return 1
316
318 """
319 Adds a directory to the list.
320
321 The path must exist and must be a directory or a link to an existing
322 directory. It will be added to the list subject to any exclusions that
323 are in place. The L{ignoreFile} does not apply to this method, only to
324 L{addDirContents}.
325
326 @param path: Directory path to be added to the list
327 @type path: String representing a path on disk
328
329 @return: Number of items added to the list.
330
331 @raise ValueError: If path is not a directory or does not exist.
332 @raise ValueError: If the path could not be encoded properly.
333 """
334 path = encodePath(path)
335 path = normalizeDir(path)
336 if not os.path.exists(path) or not os.path.isdir(path):
337 logger.debug("Path [%s] is not a directory or does not exist on disk.", path)
338 raise ValueError("Path is not a directory or does not exist on disk.")
339 if self.excludeLinks and os.path.islink(path):
340 logger.debug("Path [%s] is excluded based on excludeLinks.", path)
341 return 0
342 if self.excludeDirs:
343 logger.debug("Path [%s] is excluded based on excludeDirs.", path)
344 return 0
345 if path in self.excludePaths:
346 logger.debug("Path [%s] is excluded based on excludePaths.", path)
347 return 0
348 for pattern in self.excludePatterns:
349 pattern = encodePath(pattern)
350 if re.compile(r"^%s$" % pattern).match(path):
351 logger.debug("Path [%s] is excluded based on pattern [%s].", path, pattern)
352 return 0
353 for pattern in self.excludeBasenamePatterns:
354 pattern = encodePath(pattern)
355 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
356 logger.debug("Path [%s] is excluded based on basename pattern [%s].", path, pattern)
357 return 0
358 self.append(path)
359 logger.debug("Added directory to list: [%s]", path)
360 return 1
361
362 - def addDirContents(self, path, recursive=True, addSelf=True, linkDepth=0, dereference=False):
363 """
364 Adds the contents of a directory to the list.
365
366 The path must exist and must be a directory or a link to a directory.
367 The contents of the directory (as well as the directory path itself) will
368 be recursively added to the list, subject to any exclusions that are in
369 place. If you only want the directory and its immediate contents to be
370 added, then pass in C{recursive=False}.
371
372 @note: If a directory's absolute path matches an exclude pattern or path,
373 or if the directory contains the configured ignore file, then the
374 directory and all of its contents will be recursively excluded from the
375 list.
376
377 @note: If the passed-in directory happens to be a soft link, it will be
378 recursed. However, the linkDepth parameter controls whether any soft
379 links I{within} the directory will be recursed. The link depth is
380 maximum depth of the tree at which soft links should be followed. So, a
381 depth of 0 does not follow any soft links, a depth of 1 follows only
382 links within the passed-in directory, a depth of 2 follows the links at
383 the next level down, etc.
384
385 @note: Any invalid soft links (i.e. soft links that point to
386 non-existent items) will be silently ignored.
387
388 @note: The L{excludeDirs} flag only controls whether any given directory
389 path itself is added to the list once it has been discovered. It does
390 I{not} modify any behavior related to directory recursion.
391
392 @note: If you call this method I{on a link to a directory} that link will
393 never be dereferenced (it may, however, be followed).
394
395 @param path: Directory path whose contents should be added to the list
396 @type path: String representing a path on disk
397
398 @param recursive: Indicates whether directory contents should be added recursively.
399 @type recursive: Boolean value
400
401 @param addSelf: Indicates whether the directory itself should be added to the list.
402 @type addSelf: Boolean value
403
404 @param linkDepth: Maximum depth of the tree at which soft links should be followed
405 @type linkDepth: Integer value, where zero means not to follow any soft links
406
407 @param dereference: Indicates whether soft links, if followed, should be dereferenced
408 @type dereference: Boolean value
409
410 @return: Number of items recursively added to the list
411
412 @raise ValueError: If path is not a directory or does not exist.
413 @raise ValueError: If the path could not be encoded properly.
414 """
415 path = encodePath(path)
416 path = normalizeDir(path)
417 return self._addDirContentsInternal(path, addSelf, recursive, linkDepth, dereference)
418
419 - def _addDirContentsInternal(self, path, includePath=True, recursive=True, linkDepth=0, dereference=False):
420 """
421 Internal implementation of C{addDirContents}.
422
423 This internal implementation exists due to some refactoring. Basically,
424 some subclasses have a need to add the contents of a directory, but not
425 the directory itself. This is different than the standard C{FilesystemList}
426 behavior and actually ends up making a special case out of the first
427 call in the recursive chain. Since I don't want to expose the modified
428 interface, C{addDirContents} ends up being wholly implemented in terms
429 of this method.
430
431 The linkDepth parameter controls whether soft links are followed when we
432 are adding the contents recursively. Any recursive calls reduce the
433 value by one. If the value zero or less, then soft links will just be
434 added as directories, but will not be followed. This means that links
435 are followed to a I{constant depth} starting from the top-most directory.
436
437 There is one difference between soft links and directories: soft links
438 that are added recursively are not placed into the list explicitly. This
439 is because if we do add the links recursively, the resulting tar file
440 gets a little confused (it has a link and a directory with the same
441 name).
442
443 @note: If you call this method I{on a link to a directory} that link will
444 never be dereferenced (it may, however, be followed).
445
446 @param path: Directory path whose contents should be added to the list.
447 @param includePath: Indicates whether to include the path as well as contents.
448 @param recursive: Indicates whether directory contents should be added recursively.
449 @param linkDepth: Depth of soft links that should be followed
450 @param dereference: Indicates whether soft links, if followed, should be dereferenced
451
452 @return: Number of items recursively added to the list
453
454 @raise ValueError: If path is not a directory or does not exist.
455 """
456 added = 0
457 if not os.path.exists(path) or not os.path.isdir(path):
458 logger.debug("Path [%s] is not a directory or does not exist on disk.", path)
459 raise ValueError("Path is not a directory or does not exist on disk.")
460 if path in self.excludePaths:
461 logger.debug("Path [%s] is excluded based on excludePaths.", path)
462 return added
463 for pattern in self.excludePatterns:
464 pattern = encodePath(pattern)
465 if re.compile(r"^%s$" % pattern).match(path):
466 logger.debug("Path [%s] is excluded based on pattern [%s].", path, pattern)
467 return added
468 for pattern in self.excludeBasenamePatterns:
469 pattern = encodePath(pattern)
470 if re.compile(r"^%s$" % pattern).match(os.path.basename(path)):
471 logger.debug("Path [%s] is excluded based on basename pattern [%s].", path, pattern)
472 return added
473 if self.ignoreFile is not None and os.path.exists(os.path.join(path, self.ignoreFile)):
474 logger.debug("Path [%s] is excluded based on ignore file.", path)
475 return added
476 if includePath:
477 added += self.addDir(path)
478 for entry in os.listdir(path):
479 entrypath = os.path.join(path, entry)
480 if os.path.isfile(entrypath):
481 if linkDepth > 0 and dereference:
482 derefpath = dereferenceLink(entrypath)
483 if derefpath != entrypath:
484 added += self.addFile(derefpath)
485 added += self.addFile(entrypath)
486 elif os.path.isdir(entrypath):
487 if os.path.islink(entrypath):
488 if recursive:
489 if linkDepth > 0:
490 newDepth = linkDepth - 1
491 if dereference:
492 derefpath = dereferenceLink(entrypath)
493 if derefpath != entrypath:
494 added += self._addDirContentsInternal(derefpath, True, recursive, newDepth, dereference)
495 added += self.addDir(entrypath)
496 else:
497 added += self._addDirContentsInternal(entrypath, False, recursive, newDepth, dereference)
498 else:
499 added += self.addDir(entrypath)
500 else:
501 added += self.addDir(entrypath)
502 else:
503 if recursive:
504 newDepth = linkDepth - 1
505 added += self._addDirContentsInternal(entrypath, True, recursive, newDepth, dereference)
506 else:
507 added += self.addDir(entrypath)
508 return added
509
510
511
512
513
514
516 """
517 Removes file entries from the list.
518
519 If C{pattern} is not passed in or is C{None}, then all file entries will
520 be removed from the list. Otherwise, only those file entries matching
521 the pattern will be removed. Any entry which does not exist on disk
522 will be ignored (use L{removeInvalid} to purge those entries).
523
524 This method might be fairly slow for large lists, since it must check the
525 type of each item in the list. If you know ahead of time that you want
526 to exclude all files, then you will be better off setting L{excludeFiles}
527 to C{True} before adding items to the list.
528
529 @param pattern: Regular expression pattern representing entries to remove
530
531 @return: Number of entries removed
532 @raise ValueError: If the passed-in pattern is not a valid regular expression.
533 """
534 removed = 0
535 if pattern is None:
536 for entry in self[:]:
537 if os.path.exists(entry) and os.path.isfile(entry):
538 self.remove(entry)
539 logger.debug("Removed path [%s] from list.", entry)
540 removed += 1
541 else:
542 try:
543 pattern = encodePath(pattern)
544 compiled = re.compile(pattern)
545 except re.error:
546 raise ValueError("Pattern is not a valid regular expression.")
547 for entry in self[:]:
548 if os.path.exists(entry) and os.path.isfile(entry):
549 if compiled.match(entry):
550 self.remove(entry)
551 logger.debug("Removed path [%s] from list.", entry)
552 removed += 1
553 logger.debug("Removed a total of %d entries.", removed)
554 return removed
555
557 """
558 Removes directory entries from the list.
559
560 If C{pattern} is not passed in or is C{None}, then all directory entries
561 will be removed from the list. Otherwise, only those directory entries
562 matching the pattern will be removed. Any entry which does not exist on
563 disk will be ignored (use L{removeInvalid} to purge those entries).
564
565 This method might be fairly slow for large lists, since it must check the
566 type of each item in the list. If you know ahead of time that you want
567 to exclude all directories, then you will be better off setting
568 L{excludeDirs} to C{True} before adding items to the list (note that this
569 will not prevent you from recursively adding the I{contents} of
570 directories).
571
572 @param pattern: Regular expression pattern representing entries to remove
573
574 @return: Number of entries removed
575 @raise ValueError: If the passed-in pattern is not a valid regular expression.
576 """
577 removed = 0
578 if pattern is None:
579 for entry in self[:]:
580 if os.path.exists(entry) and os.path.isdir(entry):
581 self.remove(entry)
582 logger.debug("Removed path [%s] from list.", entry)
583 removed += 1
584 else:
585 try:
586 pattern = encodePath(pattern)
587 compiled = re.compile(pattern)
588 except re.error:
589 raise ValueError("Pattern is not a valid regular expression.")
590 for entry in self[:]:
591 if os.path.exists(entry) and os.path.isdir(entry):
592 if compiled.match(entry):
593 self.remove(entry)
594 logger.debug("Removed path [%s] from list based on pattern [%s].", entry, pattern)
595 removed += 1
596 logger.debug("Removed a total of %d entries.", removed)
597 return removed
598
600 """
601 Removes soft link entries from the list.
602
603 If C{pattern} is not passed in or is C{None}, then all soft link entries
604 will be removed from the list. Otherwise, only those soft link entries
605 matching the pattern will be removed. Any entry which does not exist on
606 disk will be ignored (use L{removeInvalid} to purge those entries).
607
608 This method might be fairly slow for large lists, since it must check the
609 type of each item in the list. If you know ahead of time that you want
610 to exclude all soft links, then you will be better off setting
611 L{excludeLinks} to C{True} before adding items to the list.
612
613 @param pattern: Regular expression pattern representing entries to remove
614
615 @return: Number of entries removed
616 @raise ValueError: If the passed-in pattern is not a valid regular expression.
617 """
618 removed = 0
619 if pattern is None:
620 for entry in self[:]:
621 if os.path.exists(entry) and os.path.islink(entry):
622 self.remove(entry)
623 logger.debug("Removed path [%s] from list.", entry)
624 removed += 1
625 else:
626 try:
627 pattern = encodePath(pattern)
628 compiled = re.compile(pattern)
629 except re.error:
630 raise ValueError("Pattern is not a valid regular expression.")
631 for entry in self[:]:
632 if os.path.exists(entry) and os.path.islink(entry):
633 if compiled.match(entry):
634 self.remove(entry)
635 logger.debug("Removed path [%s] from list based on pattern [%s].", entry, pattern)
636 removed += 1
637 logger.debug("Removed a total of %d entries.", removed)
638 return removed
639
641 """
642 Removes from the list all entries matching a pattern.
643
644 This method removes from the list all entries which match the passed in
645 C{pattern}. Since there is no need to check the type of each entry, it
646 is faster to call this method than to call the L{removeFiles},
647 L{removeDirs} or L{removeLinks} methods individually. If you know which
648 patterns you will want to remove ahead of time, you may be better off
649 setting L{excludePatterns} or L{excludeBasenamePatterns} before adding
650 items to the list.
651
652 @note: Unlike when using the exclude lists, the pattern here is I{not}
653 bounded at the front and the back of the string. You can use any pattern
654 you want.
655
656 @param pattern: Regular expression pattern representing entries to remove
657
658 @return: Number of entries removed.
659 @raise ValueError: If the passed-in pattern is not a valid regular expression.
660 """
661 try:
662 pattern = encodePath(pattern)
663 compiled = re.compile(pattern)
664 except re.error:
665 raise ValueError("Pattern is not a valid regular expression.")
666 removed = 0
667 for entry in self[:]:
668 if compiled.match(entry):
669 self.remove(entry)
670 logger.debug("Removed path [%s] from list based on pattern [%s].", entry, pattern)
671 removed += 1
672 logger.debug("Removed a total of %d entries.", removed)
673 return removed
674
676 """
677 Removes from the list all entries that do not exist on disk.
678
679 This method removes from the list all entries which do not currently
680 exist on disk in some form. No attention is paid to whether the entries
681 are files or directories.
682
683 @return: Number of entries removed.
684 """
685 removed = 0
686 for entry in self[:]:
687 if not os.path.exists(entry):
688 self.remove(entry)
689 logger.debug("Removed path [%s] from list.", entry)
690 removed += 1
691 logger.debug("Removed a total of %d entries.", removed)
692 return removed
693
694
695
696
697
698
700 """Normalizes the list, ensuring that each entry is unique."""
701 orig = len(self)
702 self.sort()
703 dups = filter(lambda x, self=self: self[x] == self[x+1], range(0, len(self) - 1))
704 items = map(lambda x, self=self: self[x], dups)
705 map(self.remove, items)
706 new = len(self)
707 logger.debug("Completed normalizing list; removed %d items (%d originally, %d now).", new-orig, orig, new)
708
710 """
711 Verifies that all entries in the list exist on disk.
712 @return: C{True} if all entries exist, C{False} otherwise.
713 """
714 for entry in self:
715 if not os.path.exists(entry):
716 logger.debug("Path [%s] is invalid; list is not valid.", entry)
717 return False
718 logger.debug("All entries in list are valid.")
719 return True
720
721
722
723
724
725
726 -class SpanItem(object):
727 """
728 Item returned by L{BackupFileList.generateSpan}.
729 """
730 - def __init__(self, fileList, size, capacity, utilization):
731 """
732 Create object.
733 @param fileList: List of files
734 @param size: Size (in bytes) of files
735 @param utilization: Utilization, as a percentage (0-100)
736 """
737 self.fileList = fileList
738 self.size = size
739 self.capacity = capacity
740 self.utilization = utilization
741
748
749
750
751
752
753 """
754 List of files to be backed up.
755
756 A BackupFileList is a L{FilesystemList} containing a list of files to be
757 backed up. It only contains files, not directories (soft links are treated
758 like files). On top of the generic functionality provided by
759 L{FilesystemList}, this class adds functionality to keep a hash (checksum)
760 for each file in the list, and it also provides a method to calculate the
761 total size of the files in the list and a way to export the list into tar
762 form.
763
764 @sort: __init__, addDir, totalSize, generateSizeMap, generateDigestMap,
765 generateFitted, generateTarfile, removeUnchanged
766 """
767
768
769
770
771
775
776
777
778
779
780
782 """
783 Adds a directory to the list.
784
785 Note that this class does not allow directories to be added by themselves
786 (a backup list contains only files). However, since links to directories
787 are technically files, we allow them to be added.
788
789 This method is implemented in terms of the superclass method, with one
790 additional validation: the superclass method is only called if the
791 passed-in path is both a directory and a link. All of the superclass's
792 existing validations and restrictions apply.
793
794 @param path: Directory path to be added to the list
795 @type path: String representing a path on disk
796
797 @return: Number of items added to the list.
798
799 @raise ValueError: If path is not a directory or does not exist.
800 @raise ValueError: If the path could not be encoded properly.
801 """
802 path = encodePath(path)
803 path = normalizeDir(path)
804 if os.path.isdir(path) and not os.path.islink(path):
805 return 0
806 else:
807 return FilesystemList.addDir(self, path)
808
809
810
811
812
813
815 """
816 Returns the total size among all files in the list.
817 Only files are counted.
818 Soft links that point at files are ignored.
819 Entries which do not exist on disk are ignored.
820 @return: Total size, in bytes
821 """
822 total = 0.0
823 for entry in self:
824 if os.path.isfile(entry) and not os.path.islink(entry):
825 total += float(os.stat(entry).st_size)
826 return total
827
829 """
830 Generates a mapping from file to file size in bytes.
831 The mapping does include soft links, which are listed with size zero.
832 Entries which do not exist on disk are ignored.
833 @return: Dictionary mapping file to file size
834 """
835 table = { }
836 for entry in self:
837 if os.path.islink(entry):
838 table[entry] = 0.0
839 elif os.path.isfile(entry):
840 table[entry] = float(os.stat(entry).st_size)
841 return table
842
844 """
845 Generates a mapping from file to file digest.
846
847 Currently, the digest is an SHA hash, which should be pretty secure. In
848 the future, this might be a different kind of hash, but we guarantee that
849 the type of the hash will not change unless the library major version
850 number is bumped.
851
852 Entries which do not exist on disk are ignored.
853
854 Soft links are ignored. We would end up generating a digest for the file
855 that the soft link points at, which doesn't make any sense.
856
857 If C{stripPrefix} is passed in, then that prefix will be stripped from
858 each key when the map is generated. This can be useful in generating two
859 "relative" digest maps to be compared to one another.
860
861 @param stripPrefix: Common prefix to be stripped from paths
862 @type stripPrefix: String with any contents
863
864 @return: Dictionary mapping file to digest value
865 @see: L{removeUnchanged}
866 """
867 table = { }
868 if stripPrefix is not None:
869 for entry in self:
870 if os.path.isfile(entry) and not os.path.islink(entry):
871 table[entry.replace(stripPrefix, "", 1)] = BackupFileList._generateDigest(entry)
872 else:
873 for entry in self:
874 if os.path.isfile(entry) and not os.path.islink(entry):
875 table[entry] = BackupFileList._generateDigest(entry)
876 return table
877
878 @staticmethod
880 """
881 Generates an SHA digest for a given file on disk.
882
883 The original code for this function used this simplistic implementation,
884 which requires reading the entire file into memory at once in order to
885 generate a digest value::
886
887 sha.new(open(path).read()).hexdigest()
888
889 Not surprisingly, this isn't an optimal solution. The U{Simple file
890 hashing <http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/259109>}
891 Python Cookbook recipe describes how to incrementally generate a hash
892 value by reading in chunks of data rather than reading the file all at
893 once. The recipe relies on the the C{update()} method of the various
894 Python hashing algorithms.
895
896 In my tests using a 110 MB file on CD, the original implementation
897 requires 111 seconds. This implementation requires only 40-45 seconds,
898 which is a pretty substantial speed-up.
899
900 Experience shows that reading in around 4kB (4096 bytes) at a time yields
901 the best performance. Smaller reads are quite a bit slower, and larger
902 reads don't make much of a difference. The 4kB number makes me a little
903 suspicious, and I think it might be related to the size of a filesystem
904 read at the hardware level. However, I've decided to just hardcode 4096
905 until I have evidence that shows it's worthwhile making the read size
906 configurable.
907
908 @param path: Path to generate digest for.
909
910 @return: ASCII-safe SHA digest for the file.
911 @raise OSError: If the file cannot be opened.
912 """
913
914 try:
915 import hashlib
916 s = hashlib.sha1()
917 except ImportError:
918 import sha
919 s = sha.new()
920 f = open(path, mode="rb")
921 readBytes = 4096
922 while readBytes > 0:
923 readString = f.read(readBytes)
924 s.update(readString)
925 readBytes = len(readString)
926 f.close()
927 digest = s.hexdigest()
928 logger.debug("Generated digest [%s] for file [%s].", digest, path)
929 return digest
930
932 """
933 Generates a list of items that fit in the indicated capacity.
934
935 Sometimes, callers would like to include every item in a list, but are
936 unable to because not all of the items fit in the space available. This
937 method returns a copy of the list, containing only the items that fit in
938 a given capacity. A copy is returned so that we don't lose any
939 information if for some reason the fitted list is unsatisfactory.
940
941 The fitting is done using the functions in the knapsack module. By
942 default, the first fit algorithm is used, but you can also choose
943 from best fit, worst fit and alternate fit.
944
945 @param capacity: Maximum capacity among the files in the new list
946 @type capacity: Integer, in bytes
947
948 @param algorithm: Knapsack (fit) algorithm to use
949 @type algorithm: One of "first_fit", "best_fit", "worst_fit", "alternate_fit"
950
951 @return: Copy of list with total size no larger than indicated capacity
952 @raise ValueError: If the algorithm is invalid.
953 """
954 table = self._getKnapsackTable()
955 function = BackupFileList._getKnapsackFunction(algorithm)
956 return function(table, capacity)[0]
957
959 """
960 Splits the list of items into sub-lists that fit in a given capacity.
961
962 Sometimes, callers need split to a backup file list into a set of smaller
963 lists. For instance, you could use this to "span" the files across a set
964 of discs.
965
966 The fitting is done using the functions in the knapsack module. By
967 default, the first fit algorithm is used, but you can also choose
968 from best fit, worst fit and alternate fit.
969
970 @note: If any of your items are larger than the capacity, then it won't
971 be possible to find a solution. In this case, a value error will be
972 raised.
973
974 @param capacity: Maximum capacity among the files in the new list
975 @type capacity: Integer, in bytes
976
977 @param algorithm: Knapsack (fit) algorithm to use
978 @type algorithm: One of "first_fit", "best_fit", "worst_fit", "alternate_fit"
979
980 @return: List of L{SpanItem} objects.
981
982 @raise ValueError: If the algorithm is invalid.
983 @raise ValueError: If it's not possible to fit some items
984 """
985 spanItems = []
986 function = BackupFileList._getKnapsackFunction(algorithm)
987 table = self._getKnapsackTable(capacity)
988 iteration = 0
989 while len(table) > 0:
990 iteration += 1
991 fit = function(table, capacity)
992 if len(fit[0]) == 0:
993
994 raise ValueError("After iteration %d, unable to add any new items." % iteration)
995 removeKeys(table, fit[0])
996 utilization = (float(fit[1])/float(capacity))*100.0
997 item = SpanItem(fit[0], fit[1], capacity, utilization)
998 spanItems.append(item)
999 return spanItems
1000
1002 """
1003 Converts the list into the form needed by the knapsack algorithms.
1004 @return: Dictionary mapping file name to tuple of (file path, file size).
1005 """
1006 table = { }
1007 for entry in self:
1008 if os.path.islink(entry):
1009 table[entry] = (entry, 0.0)
1010 elif os.path.isfile(entry):
1011 size = float(os.stat(entry).st_size)
1012 if capacity is not None:
1013 if size > capacity:
1014 raise ValueError("File [%s] cannot fit in capacity %s." % (entry, displayBytes(capacity)))
1015 table[entry] = (entry, size)
1016 return table
1017
1018 @staticmethod
1020 """
1021 Returns a reference to the function associated with an algorithm name.
1022 Algorithm name must be one of "first_fit", "best_fit", "worst_fit", "alternate_fit"
1023 @param algorithm: Name of the algorithm
1024 @return: Reference to knapsack function
1025 @raise ValueError: If the algorithm name is unknown.
1026 """
1027 if algorithm == "first_fit":
1028 return firstFit
1029 elif algorithm == "best_fit":
1030 return bestFit
1031 elif algorithm == "worst_fit":
1032 return worstFit
1033 elif algorithm == "alternate_fit":
1034 return alternateFit
1035 else:
1036 raise ValueError("Algorithm [%s] is invalid." % algorithm)
1037
1039 """
1040 Creates a tar file containing the files in the list.
1041
1042 By default, this method will create uncompressed tar files. If you pass
1043 in mode C{'targz'}, then it will create gzipped tar files, and if you
1044 pass in mode C{'tarbz2'}, then it will create bzipped tar files.
1045
1046 The tar file will be created as a GNU tar archive, which enables extended
1047 file name lengths, etc. Since GNU tar is so prevalent, I've decided that
1048 the extra functionality out-weighs the disadvantage of not being
1049 "standard".
1050
1051 If you pass in C{flat=True}, then a "flat" archive will be created, and
1052 all of the files will be added to the root of the archive. So, the file
1053 C{/tmp/something/whatever.txt} would be added as just C{whatever.txt}.
1054
1055 By default, the whole method call fails if there are problems adding any
1056 of the files to the archive, resulting in an exception. Under these
1057 circumstances, callers are advised that they might want to call
1058 L{removeInvalid()} and then attempt to extract the tar file a second
1059 time, since the most common cause of failures is a missing file (a file
1060 that existed when the list was built, but is gone again by the time the
1061 tar file is built).
1062
1063 If you want to, you can pass in C{ignore=True}, and the method will
1064 ignore errors encountered when adding individual files to the archive
1065 (but not errors opening and closing the archive itself).
1066
1067 We'll always attempt to remove the tarfile from disk if an exception will
1068 be thrown.
1069
1070 @note: No validation is done as to whether the entries in the list are
1071 files, since only files or soft links should be in an object like this.
1072 However, to be safe, everything is explicitly added to the tar archive
1073 non-recursively so it's safe to include soft links to directories.
1074
1075 @note: The Python C{tarfile} module, which is used internally here, is
1076 supposed to deal properly with long filenames and links. In my testing,
1077 I have found that it appears to be able to add long really long filenames
1078 to archives, but doesn't do a good job reading them back out, even out of
1079 an archive it created. Fortunately, all Cedar Backup does is add files
1080 to archives.
1081
1082 @param path: Path of tar file to create on disk
1083 @type path: String representing a path on disk
1084
1085 @param mode: Tar creation mode
1086 @type mode: One of either C{'tar'}, C{'targz'} or C{'tarbz2'}
1087
1088 @param ignore: Indicates whether to ignore certain errors.
1089 @type ignore: Boolean
1090
1091 @param flat: Creates "flat" archive by putting all items in root
1092 @type flat: Boolean
1093
1094 @raise ValueError: If mode is not valid
1095 @raise ValueError: If list is empty
1096 @raise ValueError: If the path could not be encoded properly.
1097 @raise TarError: If there is a problem creating the tar file
1098 """
1099
1100 path = encodePath(path)
1101 if len(self) == 0: raise ValueError("Empty list cannot be used to generate tarfile.")
1102 if mode == 'tar': tarmode = "w:"
1103 elif mode == 'targz': tarmode = "w:gz"
1104 elif mode == 'tarbz2': tarmode = "w:bz2"
1105 else: raise ValueError("Mode [%s] is not valid." % mode)
1106 try:
1107 tar = tarfile.open(path, tarmode)
1108 try:
1109 tar.format = tarfile.GNU_FORMAT
1110 except AttributeError:
1111 tar.posix = False
1112 for entry in self:
1113 try:
1114 if flat:
1115 tar.add(entry, arcname=os.path.basename(entry), recursive=False)
1116 else:
1117 tar.add(entry, recursive=False)
1118 except tarfile.TarError, e:
1119 if not ignore:
1120 raise e
1121 logger.info("Unable to add file [%s]; going on anyway.", entry)
1122 except OSError, e:
1123 if not ignore:
1124 raise tarfile.TarError(e)
1125 logger.info("Unable to add file [%s]; going on anyway.", entry)
1126 tar.close()
1127 except tarfile.ReadError, e:
1128 try: tar.close()
1129 except: pass
1130 if os.path.exists(path):
1131 try: os.remove(path)
1132 except: pass
1133 raise tarfile.ReadError("Unable to open [%s]; maybe directory doesn't exist?" % path)
1134 except tarfile.TarError, e:
1135 try: tar.close()
1136 except: pass
1137 if os.path.exists(path):
1138 try: os.remove(path)
1139 except: pass
1140 raise e
1141
1143 """
1144 Removes unchanged entries from the list.
1145
1146 This method relies on a digest map as returned from L{generateDigestMap}.
1147 For each entry in C{digestMap}, if the entry also exists in the current
1148 list I{and} the entry in the current list has the same digest value as in
1149 the map, the entry in the current list will be removed.
1150
1151 This method offers a convenient way for callers to filter unneeded
1152 entries from a list. The idea is that a caller will capture a digest map
1153 from C{generateDigestMap} at some point in time (perhaps the beginning of
1154 the week), and will save off that map using C{pickle} or some other
1155 method. Then, the caller could use this method sometime in the future to
1156 filter out any unchanged files based on the saved-off map.
1157
1158 If C{captureDigest} is passed-in as C{True}, then digest information will
1159 be captured for the entire list before the removal step occurs using the
1160 same rules as in L{generateDigestMap}. The check will involve a lookup
1161 into the complete digest map.
1162
1163 If C{captureDigest} is passed in as C{False}, we will only generate a
1164 digest value for files we actually need to check, and we'll ignore any
1165 entry in the list which isn't a file that currently exists on disk.
1166
1167 The return value varies depending on C{captureDigest}, as well. To
1168 preserve backwards compatibility, if C{captureDigest} is C{False}, then
1169 we'll just return a single value representing the number of entries
1170 removed. Otherwise, we'll return a tuple of C{(entries removed, digest
1171 map)}. The returned digest map will be in exactly the form returned by
1172 L{generateDigestMap}.
1173
1174 @note: For performance reasons, this method actually ends up rebuilding
1175 the list from scratch. First, we build a temporary dictionary containing
1176 all of the items from the original list. Then, we remove items as needed
1177 from the dictionary (which is faster than the equivalent operation on a
1178 list). Finally, we replace the contents of the current list based on the
1179 keys left in the dictionary. This should be transparent to the caller.
1180
1181 @param digestMap: Dictionary mapping file name to digest value.
1182 @type digestMap: Map as returned from L{generateDigestMap}.
1183
1184 @param captureDigest: Indicates that digest information should be captured.
1185 @type captureDigest: Boolean
1186
1187 @return: Results as discussed above (format varies based on arguments)
1188 """
1189 if captureDigest:
1190 removed = 0
1191 table = {}
1192 captured = {}
1193 for entry in self:
1194 if os.path.isfile(entry) and not os.path.islink(entry):
1195 table[entry] = BackupFileList._generateDigest(entry)
1196 captured[entry] = table[entry]
1197 else:
1198 table[entry] = None
1199 for entry in digestMap.keys():
1200 if table.has_key(entry):
1201 if table[entry] is not None:
1202 digest = table[entry]
1203 if digest == digestMap[entry]:
1204 removed += 1
1205 del table[entry]
1206 logger.debug("Discarded unchanged file [%s].", entry)
1207 self[:] = table.keys()
1208 return (removed, captured)
1209 else:
1210 removed = 0
1211 table = {}
1212 for entry in self:
1213 table[entry] = None
1214 for entry in digestMap.keys():
1215 if table.has_key(entry):
1216 if os.path.isfile(entry) and not os.path.islink(entry):
1217 digest = BackupFileList._generateDigest(entry)
1218 if digest == digestMap[entry]:
1219 removed += 1
1220 del table[entry]
1221 logger.debug("Discarded unchanged file [%s].", entry)
1222 self[:] = table.keys()
1223 return removed
1224
1231
1232
1233
1234
1235
1236 """
1237 List of files and directories to be purged.
1238
1239 A PurgeItemList is a L{FilesystemList} containing a list of files and
1240 directories to be purged. On top of the generic functionality provided by
1241 L{FilesystemList}, this class adds functionality to remove items that are
1242 too young to be purged, and to actually remove each item in the list from
1243 the filesystem.
1244
1245 The other main difference is that when you add a directory's contents to a
1246 purge item list, the directory itself is not added to the list. This way,
1247 if someone asks to purge within in C{/opt/backup/collect}, that directory
1248 doesn't get removed once all of the files within it is gone.
1249 """
1250
1251
1252
1253
1254
1258
1259
1260
1261
1262
1263
1264 - def addDirContents(self, path, recursive=True, addSelf=True, linkDepth=0, dereference=False):
1265 """
1266 Adds the contents of a directory to the list.
1267
1268 The path must exist and must be a directory or a link to a directory.
1269 The contents of the directory (but I{not} the directory path itself) will
1270 be recursively added to the list, subject to any exclusions that are in
1271 place. If you only want the directory and its contents to be added, then
1272 pass in C{recursive=False}.
1273
1274 @note: If a directory's absolute path matches an exclude pattern or path,
1275 or if the directory contains the configured ignore file, then the
1276 directory and all of its contents will be recursively excluded from the
1277 list.
1278
1279 @note: If the passed-in directory happens to be a soft link, it will be
1280 recursed. However, the linkDepth parameter controls whether any soft
1281 links I{within} the directory will be recursed. The link depth is
1282 maximum depth of the tree at which soft links should be followed. So, a
1283 depth of 0 does not follow any soft links, a depth of 1 follows only
1284 links within the passed-in directory, a depth of 2 follows the links at
1285 the next level down, etc.
1286
1287 @note: Any invalid soft links (i.e. soft links that point to
1288 non-existent items) will be silently ignored.
1289
1290 @note: The L{excludeDirs} flag only controls whether any given soft link
1291 path itself is added to the list once it has been discovered. It does
1292 I{not} modify any behavior related to directory recursion.
1293
1294 @note: The L{excludeDirs} flag only controls whether any given directory
1295 path itself is added to the list once it has been discovered. It does
1296 I{not} modify any behavior related to directory recursion.
1297
1298 @note: If you call this method I{on a link to a directory} that link will
1299 never be dereferenced (it may, however, be followed).
1300
1301 @param path: Directory path whose contents should be added to the list
1302 @type path: String representing a path on disk
1303
1304 @param recursive: Indicates whether directory contents should be added recursively.
1305 @type recursive: Boolean value
1306
1307 @param addSelf: Ignored in this subclass.
1308
1309 @param linkDepth: Depth of soft links that should be followed
1310 @type linkDepth: Integer value, where zero means not to follow any soft links
1311
1312 @param dereference: Indicates whether soft links, if followed, should be dereferenced
1313 @type dereference: Boolean value
1314
1315 @return: Number of items recursively added to the list
1316
1317 @raise ValueError: If path is not a directory or does not exist.
1318 @raise ValueError: If the path could not be encoded properly.
1319 """
1320 path = encodePath(path)
1321 path = normalizeDir(path)
1322 return super(PurgeItemList, self)._addDirContentsInternal(path, False, recursive, linkDepth, dereference)
1323
1324
1325
1326
1327
1328
1330 """
1331 Removes from the list files younger than a certain age (in days).
1332
1333 Any file whose "age" in days is less than (C{<}) the value of the
1334 C{daysOld} parameter will be removed from the list so that it will not be
1335 purged later when L{purgeItems} is called. Directories and soft links
1336 will be ignored.
1337
1338 The "age" of a file is the amount of time since the file was last used,
1339 per the most recent of the file's C{st_atime} and C{st_mtime} values.
1340
1341 @note: Some people find the "sense" of this method confusing or
1342 "backwards". Keep in mind that this method is used to remove items
1343 I{from the list}, not from the filesystem! It removes from the list
1344 those items that you would I{not} want to purge because they are too
1345 young. As an example, passing in C{daysOld} of zero (0) would remove
1346 from the list no files, which would result in purging all of the files
1347 later. I would be happy to make a synonym of this method with an
1348 easier-to-understand "sense", if someone can suggest one.
1349
1350 @param daysOld: Minimum age of files that are to be kept in the list.
1351 @type daysOld: Integer value >= 0.
1352
1353 @return: Number of entries removed
1354 """
1355 removed = 0
1356 daysOld = int(daysOld)
1357 if daysOld < 0:
1358 raise ValueError("Days old value must be an integer >= 0.")
1359 for entry in self[:]:
1360 if os.path.isfile(entry) and not os.path.islink(entry):
1361 try:
1362 ageInDays = calculateFileAge(entry)
1363 ageInWholeDays = math.floor(ageInDays)
1364 if ageInWholeDays < 0: ageInWholeDays = 0
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