cvs2svn_lib/revision_manager.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 describes the interface to the CVS repository."""
  18
  19
  20 class RevisionCollector(object):
  21   """Optionally collect revision information for CVS files."""
  22
  23   def __init__(self):
  24     """Initialize the RevisionCollector.
  25
  26     Please note that a RevisionCollector is instantiated in every
  27     program run, even if the data-collection pass will not be
  28     executed.  (This is to allow it to register the artifacts that it
  29     produces.)  Therefore, the __init__() method should not do much,
  30     and more substantial preparation for use (like actually creating
  31     the artifacts) should be done in start()."""
  32
  33     pass
  34
  35   def register_artifacts(self, which_pass):
  36     """Register artifacts that will be needed while collecting data.
  37
  38     WHICH_PASS is the pass that will call our callbacks, so it should
  39     be used to do the registering (e.g., call
  40     WHICH_PASS.register_temp_file() and/or
  41     WHICH_PASS.register_temp_file_needed())."""
  42
  43     pass
  44
  45   def start(self):
  46     """Data will soon start being collected.
  47
  48     Any non-idempotent initialization should be done here."""
  49
  50     pass
  51
  52   def process_file(self, cvs_file_items):
  53     """Collect data for the file described by CVS_FILE_ITEMS.
  54
  55     CVS_FILE_ITEMS has already been transformed into the logical
  56     representation of the file's history as it should be output.
  57     Therefore it is not necessarily identical to the history as
  58     recorded in the RCS file.
  59
  60     This method is allowed to store a pickleable object to the
  61     CVSItem.revision_reader_token member of CVSItems in
  62     CVS_FILE_ITEMS.  These data are stored with the items and
  63     available for the use of the RevisionReader."""
  64
  65     raise NotImplementedError()
  66
  67   def finish(self):
  68     """All recording is done; clean up."""
  69
  70     pass
  71
  72
  73 class NullRevisionCollector(RevisionCollector):
  74   """A do-nothing variety of RevisionCollector."""
  75
  76   def process_file(self, cvs_file_items):
  77     pass
  78
  79
  80 class RevisionReader(object):
  81   """An object that can read the contents of CVSRevisions."""
  82
  83   def register_artifacts(self, which_pass):
  84     """Register artifacts that will be needed during branch exclusion.
  85
  86     WHICH_PASS is the pass that will call our callbacks, so it should
  87     be used to do the registering (e.g., call
  88     WHICH_PASS.register_temp_file() and/or
  89     WHICH_PASS.register_temp_file_needed())."""
  90
  91     pass
  92
  93   def start(self):
  94     """Prepare for calls to get_content_stream."""
  95
  96     pass
  97
  98   def get_content_stream(self, cvs_rev, suppress_keyword_substitution=False):
  99     """Return a file-like object from which the contents of CVS_REV
 100     can be read.
 101
 102     CVS_REV is a CVSRevision.  If SUPPRESS_KEYWORD_SUBSTITUTION is
 103     True, then suppress the substitution of RCS/CVS keywords in the
 104     output."""
 105
 106     raise NotImplementedError
 107
 108   def finish(self):
 109     """Inform the reader that all calls to get_content_stream are done.
 110     Start may be called again at a later point."""
 111
 112     pass
 113
 114