cvs2svn_lib/fill_source.py

   1 # (Be in -*- python -*- mode.)
   2 #
   3 # ====================================================================
   4 # Copyright (c) 2000-2008 CollabNet.  All rights reserved.
   5 #
   6 # This software is licensed as described in the file COPYING, which
   7 # you should have received as part of this distribution.  The terms
   8 # are also available at http://subversion.tigris.org/license-1.html.
   9 # If newer versions of this license are posted there, you may use a
  10 # newer version instead, at your option.
  11 #
  12 # This software consists of voluntary contributions made by many
  13 # individuals.  For exact contribution history, see the revision
  14 # history and logs, available at http://cvs2svn.tigris.org/.
  15 # ====================================================================
  16
  17 """This module contains classes describing the sources of symbol fills."""
  18
  19
  20 from cvs2svn_lib.common import InternalError
  21 from cvs2svn_lib.common import FatalError
  22 from cvs2svn_lib.common import SVN_INVALID_REVNUM
  23 from cvs2svn_lib.svn_revision_range import SVNRevisionRange
  24 from cvs2svn_lib.svn_revision_range import RevisionScores
  25
  26
  27 class FillSource:
  28   """Representation of a fill source.
  29
  30   A FillSource keeps track of the paths that have to be filled in a
  31   particular symbol fill.
  32
  33   This class holds a SVNRevisionRange instance for each CVSFile that
  34   has to be filled within the subtree of the repository rooted at
  35   self.cvs_path.  The SVNRevisionRange objects are stored in a tree
  36   in which the directory nodes are dictionaries mapping CVSPaths to
  37   subnodes and the leaf nodes are the SVNRevisionRange objects telling
  38   for what source_lod and what range of revisions the leaf could serve
  39   as a source.
  40
  41   FillSource objects are able to compute the score for arbitrary
  42   source LODs and source revision numbers.
  43
  44   These objects are used by the symbol filler in SVNOutputOption."""
  45
  46   def __init__(self, cvs_path, symbol, node_tree):
  47     """Create a fill source.
  48
  49     The best LOD and SVN REVNUM to use as the copy source can be
  50     determined by calling compute_best_source().
  51
  52     Members:
  53
  54       cvs_path -- (CVSPath): the CVSPath described by this FillSource.
  55
  56       _symbol -- (Symbol) the symbol to be filled.
  57
  58       _node_tree -- (dict) a tree stored as a map { CVSPath : node },
  59           where subnodes have the same form.  Leaves are
  60           SVNRevisionRange instances telling the source_lod and range
  61           of SVN revision numbers from which the CVSPath can be
  62           copied.
  63
  64     """
  65
  66     self.cvs_path = cvs_path
  67     self._symbol = symbol
  68     self._node_tree = node_tree
  69
  70   def _set_node(self, cvs_file, svn_revision_range):
  71     parent_node = self._get_node(cvs_file.parent_directory, create=True)
  72     if cvs_file in parent_node:
  73       raise InternalError(
  74           '%s appeared twice in sources for %s' % (cvs_file, self._symbol)
  75           )
  76     parent_node[cvs_file] = svn_revision_range
  77
  78   def _get_node(self, cvs_path, create=False):
  79     if cvs_path == self.cvs_path:
  80       return self._node_tree
  81     else:
  82       parent_node = self._get_node(cvs_path.parent_directory, create=create)
  83       try:
  84         return parent_node[cvs_path]
  85       except KeyError:
  86         if create:
  87           node = {}
  88           parent_node[cvs_path] = node
  89           return node
  90         else:
  91           raise
  92
  93   def compute_best_source(self, preferred_source):
  94     """Determine the best source_lod and subversion revision number to copy.
  95
  96     Return the best source found, as an SVNRevisionRange instance.  If
  97     PREFERRED_SOURCE is not None and its opening is among the sources
  98     with the best scores, return it; otherwise, return the oldest such
  99     revision on the first such source_lod (ordered by the natural LOD
 100     sort order).  The return value's source_lod is the best LOD to
 101     copy from, and its opening_revnum is the best SVN revision."""
 102
 103     # Aggregate openings and closings from our rev tree
 104     svn_revision_ranges = self._get_revision_ranges(self._node_tree)
 105
 106     # Score the lists
 107     revision_scores = RevisionScores(svn_revision_ranges)
 108
 109     best_source_lod, best_revnum, best_score = \
 110         revision_scores.get_best_revnum()
 111
 112     if (
 113         preferred_source is not None
 114         and revision_scores.get_score(preferred_source) == best_score
 115         ):
 116       best_source_lod = preferred_source.source_lod
 117       best_revnum = preferred_source.opening_revnum
 118
 119     if best_revnum == SVN_INVALID_REVNUM:
 120       raise FatalError(
 121           "failed to find a revision to copy from when copying %s"
 122           % self._symbol.name
 123           )
 124
 125     return SVNRevisionRange(best_source_lod, best_revnum)
 126
 127   def _get_revision_ranges(self, node):
 128     """Return a list of all the SVNRevisionRanges at and under NODE.
 129
 130     Include duplicates.  This is a helper method used by
 131     compute_best_source()."""
 132
 133     if isinstance(node, SVNRevisionRange):
 134       # It is a leaf node.
 135       return [ node ]
 136     else:
 137       # It is an intermediate node.
 138       revision_ranges = []
 139       for key, subnode in node.items():
 140         revision_ranges.extend(self._get_revision_ranges(subnode))
 141       return revision_ranges
 142
 143   def get_subsources(self):
 144     """Generate (CVSPath, FillSource) for all direct subsources."""
 145
 146     if not isinstance(self._node_tree, SVNRevisionRange):
 147       for cvs_path, node in self._node_tree.items():
 148         fill_source = FillSource(cvs_path, self._symbol, node)
 149         yield (cvs_path, fill_source)
 150
 151   def get_subsource_map(self):
 152     """Return the map {CVSPath : FillSource} of direct subsources."""
 153
 154     src_entries = {}
 155
 156     for (cvs_path, fill_subsource) in self.get_subsources():
 157       src_entries[cvs_path] = fill_subsource
 158
 159     return src_entries
 160
 161   def __str__(self):
 162     """For convenience only.  The format is subject to change at any time."""
 163
 164     return '%s(%s:%s)' % (
 165         self.__class__.__name__, self._symbol, self.cvs_path,
 166         )
 167
 168   def __repr__(self):
 169     """For convenience only.  The format is subject to change at any time."""
 170
 171     return '%s%r' % (self, self._node_tree,)
 172
 173
 174 def get_source_set(symbol, range_map):
 175   """Return a FillSource describing the fill sources for RANGE_MAP.
 176
 177   SYMBOL is either a Branch or a Tag.  RANGE_MAP is a map { CVSSymbol
 178   : SVNRevisionRange } as returned by
 179   SymbolingsReader.get_range_map().
 180
 181   Use the SVNRevisionRanges from RANGE_MAP to create a FillSource
 182   instance describing the sources for filling SYMBOL."""
 183
 184   root_cvs_directory = symbol.project.get_root_cvs_directory()
 185   fill_source = FillSource(root_cvs_directory, symbol, {})
 186
 187   for cvs_symbol, svn_revision_range in range_map.items():
 188     fill_source._set_node(cvs_symbol.cvs_file, svn_revision_range)
 189
 190   return fill_source
 191
 192