libbe/diff.py

   1 # Copyright (C) 2005-2010 Aaron Bentley and Panometrics, Inc.
   2 #                         Gianluca Montecchi <gian@grys.it>
   3 #                         W. Trevor King <wking@drexel.edu>
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License along
  16 # with this program; if not, write to the Free Software Foundation, Inc.,
  17 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18
  19 """Tools for comparing two :class:`libbe.bug.BugDir`\s.
  20 """
  21
  22 import difflib
  23 import types
  24
  25 import libbe
  26 import libbe.bugdir
  27 import libbe.bug
  28 import libbe.util.tree
  29 from libbe.storage.util.settings_object import setting_name_to_attr_name
  30 from libbe.util.utility import time_to_str
  31
  32
  33 class SubscriptionType (libbe.util.tree.Tree):
  34     """Trees of subscription types to allow users to select exactly what
  35     notifications they want to subscribe to.
  36     """
  37     def __init__(self, type_name, *args, **kwargs):
  38         libbe.util.tree.Tree.__init__(self, *args, **kwargs)
  39         self.type = type_name
  40     def __str__(self):
  41         return self.type
  42     def __cmp__(self, other):
  43         return cmp(self.type, other.type)
  44     def __repr__(self):
  45         return '<SubscriptionType: %s>' % str(self)
  46     def string_tree(self, indent=0):
  47         lines = []
  48         for depth,node in self.thread():
  49             lines.append('%s%s' % (' '*(indent+2*depth), node))
  50         return '\n'.join(lines)
  51
  52 BUGDIR_ID = 'DIR'
  53 BUGDIR_TYPE_NEW = SubscriptionType('new')
  54 BUGDIR_TYPE_MOD = SubscriptionType('mod')
  55 BUGDIR_TYPE_REM = SubscriptionType('rem')
  56 BUGDIR_TYPE_ALL = SubscriptionType('all',
  57                       [BUGDIR_TYPE_NEW, BUGDIR_TYPE_MOD, BUGDIR_TYPE_REM])
  58
  59 # same name as BUGDIR_TYPE_ALL for consistency
  60 BUG_TYPE_ALL = SubscriptionType(str(BUGDIR_TYPE_ALL))
  61
  62 INVALID_TYPE = SubscriptionType('INVALID')
  63
  64 class InvalidType (ValueError):
  65     def __init__(self, type_name, type_root):
  66         msg = 'Invalid type %s for tree:\n%s' \
  67             % (type_name, type_root.string_tree(4))
  68         ValueError.__init__(self, msg)
  69         self.type_name = type_name
  70         self.type_root = type_root
  71
  72 def type_from_name(name, type_root, default=None, default_ok=False):
  73     if name == str(type_root):
  74         return type_root
  75     for t in type_root.traverse():
  76         if name == str(t):
  77             return t
  78     if default_ok:
  79         return default
  80     raise InvalidType(name, type_root)
  81
  82 class Subscription (object):
  83     """A user subscription.
  84
  85     Examples
  86     --------
  87
  88     >>> subscriptions = [Subscription('XYZ', 'all'),
  89     ...                  Subscription('DIR', 'new'),
  90     ...                  Subscription('ABC', BUG_TYPE_ALL),]
  91     >>> print sorted(subscriptions)
  92     [<Subscription: DIR (new)>, <Subscription: ABC (all)>, <Subscription: XYZ (all)>]
  93     """
  94     def __init__(self, id, subscription_type, **kwargs):
  95         if 'type_root' not in kwargs:
  96             if id == BUGDIR_ID:
  97                 kwargs['type_root'] = BUGDIR_TYPE_ALL
  98             else:
  99                 kwargs['type_root'] = BUG_TYPE_ALL
 100         if type(subscription_type) in types.StringTypes:
 101             subscription_type = type_from_name(subscription_type, **kwargs)
 102         self.id = id
 103         self.type = subscription_type
 104     def __cmp__(self, other):
 105         for attr in 'id', 'type':
 106             value = cmp(getattr(self, attr), getattr(other, attr))
 107             if value != 0:
 108                 if self.id == BUGDIR_ID:
 109                     return -1
 110                 elif other.id == BUGDIR_ID:
 111                     return 1
 112                 return value
 113     def __str__(self):
 114         return str(self.type)
 115     def __repr__(self):
 116         return '<Subscription: %s (%s)>' % (self.id, self.type)
 117
 118 def subscriptions_from_string(string=None, subscription_sep=',', id_sep=':'):
 119     """Provide a simple way for non-Python interfaces to read in subscriptions.
 120
 121     Examples
 122     --------
 123
 124     >>> subscriptions_from_string(None)
 125     [<Subscription: DIR (all)>]
 126     >>> subscriptions_from_string('DIR:new,DIR:rem,ABC:all,XYZ:all')
 127     [<Subscription: DIR (new)>, <Subscription: DIR (rem)>, <Subscription: ABC (all)>, <Subscription: XYZ (all)>]
 128     >>> subscriptions_from_string('DIR::new')
 129     Traceback (most recent call last):
 130       ...
 131     ValueError: Invalid subscription "DIR::new", should be ID:TYPE
 132     """
 133     if string == None:
 134         return [Subscription(BUGDIR_ID, BUGDIR_TYPE_ALL)]
 135     subscriptions = []
 136     for subscription in string.split(','):
 137         fields = subscription.split(':')
 138         if len(fields) != 2:
 139             raise ValueError('Invalid subscription "%s", should be ID:TYPE'
 140                              % subscription)
 141         id,type = fields
 142         subscriptions.append(Subscription(id, type))
 143     return subscriptions
 144
 145 class DiffTree (libbe.util.tree.Tree):
 146     """A tree holding difference data for easy report generation.
 147
 148     Examples
 149     --------
 150
 151     >>> bugdir = DiffTree('bugdir')
 152     >>> bdsettings = DiffTree('settings', data='target: None -> 1.0')
 153     >>> bugdir.append(bdsettings)
 154     >>> bugs = DiffTree('bugs', 'bug-count: 5 -> 6')
 155     >>> bugdir.append(bugs)
 156     >>> new = DiffTree('new', 'new bugs: ABC, DEF')
 157     >>> bugs.append(new)
 158     >>> rem = DiffTree('rem', 'removed bugs: RST, UVW')
 159     >>> bugs.append(rem)
 160     >>> print bugdir.report_string()
 161     target: None -> 1.0
 162     bug-count: 5 -> 6
 163       new bugs: ABC, DEF
 164       removed bugs: RST, UVW
 165     >>> print '\\n'.join(bugdir.paths())
 166     bugdir
 167     bugdir/settings
 168     bugdir/bugs
 169     bugdir/bugs/new
 170     bugdir/bugs/rem
 171     >>> bugdir.child_by_path('/') == bugdir
 172     True
 173     >>> bugdir.child_by_path('/bugs') == bugs
 174     True
 175     >>> bugdir.child_by_path('/bugs/rem') == rem
 176     True
 177     >>> bugdir.child_by_path('bugdir') == bugdir
 178     True
 179     >>> bugdir.child_by_path('bugdir/') == bugdir
 180     True
 181     >>> bugdir.child_by_path('bugdir/bugs') == bugs
 182     True
 183     >>> bugdir.child_by_path('/bugs').masked = True
 184     >>> print bugdir.report_string()
 185     target: None -> 1.0
 186     """
 187     def __init__(self, name, data=None, data_part_fn=str,
 188                  requires_children=False, masked=False):
 189         libbe.util.tree.Tree.__init__(self)
 190         self.name = name
 191         self.data = data
 192         self.data_part_fn = data_part_fn
 193         self.requires_children = requires_children
 194         self.masked = masked
 195     def paths(self, parent_path=None):
 196         paths = []
 197         if parent_path == None:
 198             path = self.name
 199         else:
 200             path = '%s/%s' % (parent_path, self.name)
 201         paths.append(path)
 202         for child in self:
 203             paths.extend(child.paths(path))
 204         return paths
 205     def child_by_path(self, path):
 206         if hasattr(path, 'split'): # convert string path to a list of names
 207             names = path.split('/')
 208             if names[0] == '':
 209                 names[0] = self.name # replace root with self
 210             if len(names) > 1 and names[-1] == '':
 211                 names = names[:-1] # strip empty tail
 212         else: # it was already an array
 213             names = path
 214         assert len(names) > 0, path
 215         if names[0] == self.name:
 216             if len(names) == 1:
 217                 return self
 218             for child in self:
 219                 if names[1] == child.name:
 220                     return child.child_by_path(names[1:])
 221         if len(names) == 1:
 222             raise KeyError, "%s doesn't match '%s'" % (names, self.name)
 223         raise KeyError, '%s points to child not in %s' % (names, [c.name for c in self])
 224     def report_string(self):
 225         report = self.report()
 226         if report == None:
 227             return ''
 228         return '\n'.join(report)
 229     def report(self, root=None, parent=None, depth=0):
 230         if root == None:
 231             root = self.make_root()
 232         if self.masked == True:
 233             return root
 234         data_part = self.data_part(depth)
 235         if self.requires_children == True \
 236                 and len([c for c in self if c.masked == False]) == 0:
 237             pass
 238         else:
 239             self.join(root, parent, data_part)
 240             if data_part != None:
 241                 depth += 1
 242             for child in self:
 243                 root = child.report(root, self, depth)
 244         return root
 245     def make_root(self):
 246         return []
 247     def join(self, root, parent, data_part):
 248         if data_part != None:
 249             root.append(data_part)
 250     def data_part(self, depth, indent=True):
 251         if self.data == None:
 252             return None
 253         if hasattr(self, '_cached_data_part'):
 254             return self._cached_data_part
 255         data_part = self.data_part_fn(self.data)
 256         if indent == True:
 257             data_part_lines = data_part.splitlines()
 258             indent = '  '*(depth)
 259             line_sep = '\n'+indent
 260             data_part = indent+line_sep.join(data_part_lines)
 261         self._cached_data_part = data_part
 262         return data_part
 263
 264 class Diff (object):
 265     """Difference tree generator for BugDirs.
 266
 267     Examples
 268     --------
 269
 270     >>> import copy
 271     >>> bd = libbe.bugdir.SimpleBugDir(memory=True)
 272     >>> bd_new = copy.deepcopy(bd)
 273     >>> bd_new.target = '1.0'
 274     >>> a = bd_new.bug_from_uuid('a')
 275     >>> rep = a.comment_root.new_reply("I'm closing this bug")
 276     >>> rep.uuid = 'acom'
 277     >>> rep.author = 'John Doe <j@doe.com>'
 278     >>> rep.date = 'Thu, 01 Jan 1970 00:00:00 +0000'
 279     >>> a.status = 'closed'
 280     >>> b = bd_new.bug_from_uuid('b')
 281     >>> bd_new.remove_bug(b)
 282     >>> c = bd_new.new_bug('Bug C', _uuid='c')
 283     >>> d = Diff(bd, bd_new)
 284     >>> r = d.report_tree()
 285     >>> print '\\n'.join(r.paths())
 286     bugdir
 287     bugdir/settings
 288     bugdir/bugs
 289     bugdir/bugs/new
 290     bugdir/bugs/new/c
 291     bugdir/bugs/rem
 292     bugdir/bugs/rem/b
 293     bugdir/bugs/mod
 294     bugdir/bugs/mod/a
 295     bugdir/bugs/mod/a/settings
 296     bugdir/bugs/mod/a/comments
 297     bugdir/bugs/mod/a/comments/new
 298     bugdir/bugs/mod/a/comments/new/acom
 299     bugdir/bugs/mod/a/comments/rem
 300     bugdir/bugs/mod/a/comments/mod
 301     >>> print r.report_string()
 302     Changed bug directory settings:
 303       target: None -> 1.0
 304     New bugs:
 305       abc/c:om: Bug C
 306     Removed bugs:
 307       abc/b:cm: Bug B
 308     Modified bugs:
 309       abc/a:cm: Bug A
 310         Changed bug settings:
 311           status: open -> closed
 312         New comments:
 313           from John Doe <j@doe.com> on Thu, 01 Jan 1970 00:00:00 +0000
 314             I'm closing this bug...
 315
 316     You can also limit the report generation by providing a list of
 317     subscriptions.
 318
 319     >>> subscriptions = [Subscription('DIR', BUGDIR_TYPE_NEW),
 320     ...                  Subscription('b', BUG_TYPE_ALL)]
 321     >>> r = d.report_tree(subscriptions)
 322     >>> print r.report_string()
 323     New bugs:
 324       abc/c:om: Bug C
 325     Removed bugs:
 326       abc/b:cm: Bug B
 327
 328     While sending subscriptions to report_tree() makes the report
 329     generation more efficient (because you may not need to compare
 330     _all_ the bugs, etc.), sometimes you will have several sets of
 331     subscriptions.  In that case, it's better to run full_report()
 332     first, and then use report_tree() to avoid redundant comparisons.
 333
 334     >>> d.full_report()
 335     >>> print d.report_tree([subscriptions[0]]).report_string()
 336     New bugs:
 337       abc/c:om: Bug C
 338     >>> print d.report_tree([subscriptions[1]]).report_string()
 339     Removed bugs:
 340       abc/b:cm: Bug B
 341
 342     >>> bd.cleanup()
 343     """
 344     def __init__(self, old_bugdir, new_bugdir):
 345         self.old_bugdir = old_bugdir
 346         self.new_bugdir = new_bugdir
 347
 348     # data assembly methods
 349
 350     def _changed_bugs(self, subscriptions):
 351         """
 352         Search for differences in all bugs between .old_bugdir and
 353         .new_bugdir.  Returns
 354           (added_bugs, modified_bugs, removed_bugs)
 355         where added_bugs and removed_bugs are lists of added and
 356         removed bugs respectively.  modified_bugs is a list of
 357         (old_bug,new_bug) pairs.
 358         """
 359         bugdir_types = [s.type for s in subscriptions if s.id == BUGDIR_ID]
 360         new_uuids = []
 361         old_uuids = []
 362         for bd_type in [BUGDIR_TYPE_ALL, BUGDIR_TYPE_NEW, BUGDIR_TYPE_MOD]:
 363             if bd_type in bugdir_types:
 364                 new_uuids = list(self.new_bugdir.uuids())
 365                 break
 366         for bd_type in [BUGDIR_TYPE_ALL, BUGDIR_TYPE_REM]:
 367             if bd_type in bugdir_types:
 368                 old_uuids = list(self.old_bugdir.uuids())
 369                 break
 370         subscribed_bugs = []
 371         for s in subscriptions:
 372             if s.id != BUGDIR_ID:
 373                 try:
 374                     bug = self.new_bugdir.bug_from_uuid(s.id)
 375                 except libbe.bugdir.NoBugMatches:
 376                     bug = self.old_bugdir.bug_from_uuid(s.id)
 377                 subscribed_bugs.append(bug.uuid)
 378         new_uuids.extend([s for s in subscribed_bugs
 379                           if self.new_bugdir.has_bug(s)])
 380         new_uuids = sorted(set(new_uuids))
 381         old_uuids.extend([s for s in subscribed_bugs
 382                           if self.old_bugdir.has_bug(s)])
 383         old_uuids = sorted(set(old_uuids))
 384
 385         added = []
 386         removed = []
 387         modified = []
 388         if hasattr(self.old_bugdir, 'changed'):
 389             # take advantage of a RevisionedBugDir-style changed() method
 390             new_ids,mod_ids,rem_ids = self.old_bugdir.changed()
 391             for id in new_ids:
 392                 for a_id in self.new_bugdir.storage.ancestors(id):
 393                     if a_id.count('/') == 0:
 394                         if a_id in [b.id.storage() for b in added]:
 395                             break
 396                         try:
 397                             bug = self.new_bugdir.bug_from_uuid(a_id)
 398                             added.append(bug)
 399                         except libbe.bugdir.NoBugMatches:
 400                             pass
 401             for id in rem_ids:
 402                 for a_id in self.old_bugdir.storage.ancestors(id):
 403                     if a_id.count('/') == 0:
 404                         if a_id in [b.id.storage() for b in removed]:
 405                             break
 406                         try:
 407                             bug = self.old_bugdir.bug_from_uuid(a_id)
 408                             removed.append(bug)
 409                         except libbe.bugdir.NoBugMatches:
 410                             pass
 411             for id in mod_ids:
 412                 for a_id in self.new_bugdir.storage.ancestors(id):
 413                     if a_id.count('/') == 0:
 414                         if a_id in [b[0].id.storage() for b in modified]:
 415                             break
 416                         try:
 417                             new_bug = self.new_bugdir.bug_from_uuid(a_id)
 418                             old_bug = self.old_bugdir.bug_from_uuid(a_id)
 419                             modified.append((old_bug, new_bug))
 420                         except libbe.bugdir.NoBugMatches:
 421                             pass
 422         else:
 423             for uuid in new_uuids:
 424                 new_bug = self.new_bugdir.bug_from_uuid(uuid)
 425                 try:
 426                     old_bug = self.old_bugdir.bug_from_uuid(uuid)
 427                 except KeyError:
 428                     if BUGDIR_TYPE_ALL in bugdir_types \
 429                             or BUGDIR_TYPE_NEW in bugdir_types \
 430                             or uuid in subscribed_bugs:
 431                         added.append(new_bug)
 432                     continue
 433                 if BUGDIR_TYPE_ALL in bugdir_types \
 434                         or BUGDIR_TYPE_MOD in bugdir_types \
 435                         or uuid in subscribed_bugs:
 436                     if old_bug.storage != None and old_bug.storage.is_readable():
 437                         old_bug.load_comments()
 438                     if new_bug.storage != None and new_bug.storage.is_readable():
 439                         new_bug.load_comments()
 440                     if old_bug != new_bug:
 441                         modified.append((old_bug, new_bug))
 442             for uuid in old_uuids:
 443                 if not self.new_bugdir.has_bug(uuid):
 444                     old_bug = self.old_bugdir.bug_from_uuid(uuid)
 445                     removed.append(old_bug)
 446         added.sort()
 447         removed.sort()
 448         modified.sort(self._bug_modified_cmp)
 449         return (added, modified, removed)
 450     def _bug_modified_cmp(self, left, right):
 451         return cmp(left[1], right[1])
 452     def _changed_comments(self, old, new):
 453         """
 454         Search for differences in all loaded comments between the bugs
 455         old and new.  Returns
 456           (added_comments, modified_comments, removed_comments)
 457         analogous to ._changed_bugs.
 458         """
 459         if hasattr(self, '__changed_comments'):
 460             if new.uuid in self.__changed_comments:
 461                 return self.__changed_comments[new.uuid]
 462         else:
 463             self.__changed_comments = {}
 464         added = []
 465         removed = []
 466         modified = []
 467         old.comment_root.sort(key=lambda comm : comm.time)
 468         new.comment_root.sort(key=lambda comm : comm.time)
 469         old_comment_ids = [c.uuid for c in old.comments()]
 470         new_comment_ids = [c.uuid for c in new.comments()]
 471         for uuid in new_comment_ids:
 472             new_comment = new.comment_from_uuid(uuid)
 473             try:
 474                 old_comment = old.comment_from_uuid(uuid)
 475             except KeyError:
 476                 added.append(new_comment)
 477             else:
 478                 if old_comment != new_comment:
 479                     modified.append((old_comment, new_comment))
 480         for uuid in old_comment_ids:
 481             if uuid not in new_comment_ids:
 482                 old_comment = old.comment_from_uuid(uuid)
 483                 removed.append(old_comment)
 484         self.__changed_comments[new.uuid] = (added, modified, removed)
 485         return self.__changed_comments[new.uuid]
 486     def _attribute_changes(self, old, new, attributes):
 487         """
 488         Take two objects old and new, and compare the value of *.attr
 489         for attr in the list attribute names.  Returns a list of
 490           (attr_name, old_value, new_value)
 491         tuples.
 492         """
 493         change_list = []
 494         for attr in attributes:
 495             old_value = getattr(old, attr)
 496             new_value = getattr(new, attr)
 497             if old_value != new_value:
 498                 change_list.append((attr, old_value, new_value))
 499         if len(change_list) >= 0:
 500             return change_list
 501         return None
 502     def _settings_properties_attribute_changes(self, old, new,
 503                                               hidden_properties=[]):
 504         properties = sorted(new.settings_properties)
 505         for p in hidden_properties:
 506             properties.remove(p)
 507         attributes = [setting_name_to_attr_name(None, p)
 508                       for p in properties]
 509         return self._attribute_changes(old, new, attributes)
 510     def _bugdir_attribute_changes(self):
 511         return self._settings_properties_attribute_changes( \
 512             self.old_bugdir, self.new_bugdir)
 513     def _bug_attribute_changes(self, old, new):
 514         return self._settings_properties_attribute_changes(old, new)
 515     def _comment_attribute_changes(self, old, new):
 516         return self._settings_properties_attribute_changes(old, new)
 517
 518     # report generation methods
 519
 520     def full_report(self, diff_tree=DiffTree):
 521         """
 522         Generate a full report for efficiency if you'll be using
 523         .report_tree() with several sets of subscriptions.
 524         """
 525         self._cached_full_report = self.report_tree(diff_tree=diff_tree,
 526                                                     allow_cached=False)
 527         self._cached_full_report_diff_tree = diff_tree
 528     def _sub_report(self, subscriptions):
 529         """
 530         Return ._cached_full_report masked for subscriptions.
 531         """
 532         root = self._cached_full_report
 533         bugdir_types = [s.type for s in subscriptions if s.id == BUGDIR_ID]
 534         subscribed_bugs = [s.id for s in subscriptions
 535                            if BUG_TYPE_ALL.has_descendant( \
 536                                      s.type, match_self=True)]
 537         selected_by_bug = [node.name
 538                            for node in root.child_by_path('bugdir/bugs')]
 539         if BUGDIR_TYPE_ALL in bugdir_types:
 540             for node in root.traverse():
 541                 node.masked = False
 542             selected_by_bug = []
 543         else:
 544             try:
 545                 node = root.child_by_path('bugdir/settings')
 546                 node.masked = True
 547             except KeyError:
 548                 pass
 549         for name,type in (('new', BUGDIR_TYPE_NEW),
 550                           ('mod', BUGDIR_TYPE_MOD),
 551                           ('rem', BUGDIR_TYPE_REM)):
 552             if type in bugdir_types:
 553                 bugs = root.child_by_path('bugdir/bugs/%s' % name)
 554                 for bug_node in bugs:
 555                     for node in bug_node.traverse():
 556                         node.masked = False
 557                 selected_by_bug.remove(name)
 558         for name in selected_by_bug:
 559             bugs = root.child_by_path('bugdir/bugs/%s' % name)
 560             for bug_node in bugs:
 561                 if bug_node.name in subscribed_bugs:
 562                     for node in bug_node.traverse():
 563                         node.masked = False
 564                 else:
 565                     for node in bug_node.traverse():
 566                         node.masked = True
 567         return root
 568     def report_tree(self, subscriptions=None, diff_tree=DiffTree,
 569                     allow_cached=True):
 570         """
 571         Pretty bare to make it easy to adjust to specific cases.  You
 572         can pass in a DiffTree subclass via diff_tree to override the
 573         default report assembly process.
 574         """
 575         if allow_cached == True \
 576                 and hasattr(self, '_cached_full_report') \
 577                 and diff_tree == self._cached_full_report_diff_tree:
 578             return self._sub_report(subscriptions)
 579         if subscriptions == None:
 580             subscriptions = [Subscription(BUGDIR_ID, BUGDIR_TYPE_ALL)]
 581         bugdir_settings = sorted(self.new_bugdir.settings_properties)
 582         root = diff_tree('bugdir')
 583         bugdir_subscriptions = [s.type for s in subscriptions
 584                                 if s.id == BUGDIR_ID]
 585         if BUGDIR_TYPE_ALL in bugdir_subscriptions:
 586             bugdir_attribute_changes = self._bugdir_attribute_changes()
 587             if len(bugdir_attribute_changes) > 0:
 588                 bugdir = diff_tree('settings', bugdir_attribute_changes,
 589                                    self.bugdir_attribute_change_string)
 590                 root.append(bugdir)
 591         bug_root = diff_tree('bugs')
 592         root.append(bug_root)
 593         add,mod,rem = self._changed_bugs(subscriptions)
 594         bnew = diff_tree('new', 'New bugs:', requires_children=True)
 595         bug_root.append(bnew)
 596         for bug in add:
 597             b = diff_tree(bug.uuid, bug, self.bug_add_string)
 598             bnew.append(b)
 599         brem = diff_tree('rem', 'Removed bugs:', requires_children=True)
 600         bug_root.append(brem)
 601         for bug in rem:
 602             b = diff_tree(bug.uuid, bug, self.bug_rem_string)
 603             brem.append(b)
 604         bmod = diff_tree('mod', 'Modified bugs:', requires_children=True)
 605         bug_root.append(bmod)
 606         for old,new in mod:
 607             b = diff_tree(new.uuid, (old,new), self.bug_mod_string)
 608             bmod.append(b)
 609             bug_attribute_changes = self._bug_attribute_changes(old, new)
 610             if len(bug_attribute_changes) > 0:
 611                 bset = diff_tree('settings', bug_attribute_changes,
 612                                  self.bug_attribute_change_string)
 613                 b.append(bset)
 614             if old.summary != new.summary:
 615                 data = (old.summary, new.summary)
 616                 bsum = diff_tree('summary', data, self.bug_summary_change_string)
 617                 b.append(bsum)
 618             cr = diff_tree('comments')
 619             b.append(cr)
 620             a,m,d = self._changed_comments(old, new)
 621             cnew = diff_tree('new', 'New comments:', requires_children=True)
 622             for comment in a:
 623                 c = diff_tree(comment.uuid, comment, self.comment_add_string)
 624                 cnew.append(c)
 625             crem = diff_tree('rem', 'Removed comments:',requires_children=True)
 626             for comment in d:
 627                 c = diff_tree(comment.uuid, comment, self.comment_rem_string)
 628                 crem.append(c)
 629             cmod = diff_tree('mod','Modified comments:',requires_children=True)
 630             for o,n in m:
 631                 c = diff_tree(n.uuid, (o,n), self.comment_mod_string)
 632                 cmod.append(c)
 633                 comm_attribute_changes = self._comment_attribute_changes(o, n)
 634                 if len(comm_attribute_changes) > 0:
 635                     cset = diff_tree('settings', comm_attribute_changes,
 636                                      self.comment_attribute_change_string)
 637                 if o.body != n.body:
 638                     data = (o.body, n.body)
 639                     cbody = diff_tree('cbody', data,
 640                                       self.comment_body_change_string)
 641                     c.append(cbody)
 642             cr.extend([cnew, crem, cmod])
 643         return root
 644
 645     # change data -> string methods.
 646     # Feel free to play with these in subclasses.
 647
 648     def attribute_change_string(self, attribute_changes, indent=0):
 649         indent_string = '  '*indent
 650         change_strings = [u'%s: %s -> %s' % f for f in attribute_changes]
 651         for i,change_string in enumerate(change_strings):
 652             change_strings[i] = indent_string+change_string
 653         return u'\n'.join(change_strings)
 654     def bugdir_attribute_change_string(self, attribute_changes):
 655         return 'Changed bug directory settings:\n%s' % \
 656             self.attribute_change_string(attribute_changes, indent=1)
 657     def bug_attribute_change_string(self, attribute_changes):
 658         return 'Changed bug settings:\n%s' % \
 659             self.attribute_change_string(attribute_changes, indent=1)
 660     def comment_attribute_change_string(self, attribute_changes):
 661         return 'Changed comment settings:\n%s' % \
 662             self.attribute_change_string(attribute_changes, indent=1)
 663     def bug_add_string(self, bug):
 664         return bug.string(shortlist=True)
 665     def bug_rem_string(self, bug):
 666         return bug.string(shortlist=True)
 667     def bug_mod_string(self, bugs):
 668         old_bug,new_bug = bugs
 669         return new_bug.string(shortlist=True)
 670     def bug_summary_change_string(self, summaries):
 671         old_summary,new_summary = summaries
 672         return 'summary changed:\n  %s\n  %s' % (old_summary, new_summary)
 673     def _comment_summary_string(self, comment):
 674         return 'from %s on %s' % (comment.author, time_to_str(comment.time))
 675     def comment_add_string(self, comment):
 676         summary = self._comment_summary_string(comment)
 677         first_line = comment.body.splitlines()[0]
 678         return '%s\n  %s...' % (summary, first_line)
 679     def comment_rem_string(self, comment):
 680         summary = self._comment_summary_string(comment)
 681         first_line = comment.body.splitlines()[0]
 682         return '%s\n  %s...' % (summary, first_line)
 683     def comment_mod_string(self, comments):
 684         old_comment,new_comment = comments
 685         return self._comment_summary_string(new_comment)
 686     def comment_body_change_string(self, bodies):
 687         old_body,new_body = bodies
 688         return ''.join(difflib.unified_diff(
 689                 old_body.splitlines(True),
 690                 new_body.splitlines(True),
 691                 'before', 'after'))