cvs2svn_lib/persistence_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 contains class PersistenceManager."""
  18
  19
  20 from cvs2svn_lib import config
  21 from cvs2svn_lib.common import DB_OPEN_NEW
  22 from cvs2svn_lib.common import DB_OPEN_READ
  23 from cvs2svn_lib.common import SVN_INVALID_REVNUM
  24 from cvs2svn_lib.artifact_manager import artifact_manager
  25 from cvs2svn_lib.record_table import SignedIntegerPacker
  26 from cvs2svn_lib.record_table import RecordTable
  27 from cvs2svn_lib.serializer import PrimedPickleSerializer
  28 from cvs2svn_lib.indexed_database import IndexedDatabase
  29 from cvs2svn_lib.svn_commit import SVNRevisionCommit
  30 from cvs2svn_lib.svn_commit import SVNInitialProjectCommit
  31 from cvs2svn_lib.svn_commit import SVNPrimaryCommit
  32 from cvs2svn_lib.svn_commit import SVNBranchCommit
  33 from cvs2svn_lib.svn_commit import SVNTagCommit
  34 from cvs2svn_lib.svn_commit import SVNPostCommit
  35
  36
  37 class PersistenceManager:
  38   """The PersistenceManager allows us to effectively store SVNCommits
  39   to disk and retrieve them later using only their subversion revision
  40   number as the key.  It also returns the subversion revision number
  41   for a given CVSRevision's unique key.
  42
  43   All information pertinent to each SVNCommit is stored in a series of
  44   on-disk databases so that SVNCommits can be retrieved on-demand.
  45
  46   MODE is one of the constants DB_OPEN_NEW or DB_OPEN_READ.
  47   In 'new' mode, PersistenceManager will initialize a new set of on-disk
  48   databases and be fully-featured.
  49   In 'read' mode, PersistenceManager will open existing on-disk databases
  50   and the set_* methods will be unavailable."""
  51
  52   def __init__(self, mode):
  53     self.mode = mode
  54     if mode not in (DB_OPEN_NEW, DB_OPEN_READ):
  55       raise RuntimeError("Invalid 'mode' argument to PersistenceManager")
  56     primer = (
  57         SVNInitialProjectCommit,
  58         SVNPrimaryCommit,
  59         SVNPostCommit,
  60         SVNBranchCommit,
  61         SVNTagCommit,
  62         )
  63     serializer = PrimedPickleSerializer(primer)
  64     self.svn_commit_db = IndexedDatabase(
  65         artifact_manager.get_temp_file(config.SVN_COMMITS_INDEX_TABLE),
  66         artifact_manager.get_temp_file(config.SVN_COMMITS_STORE),
  67         mode, serializer)
  68     self.cvs2svn_db = RecordTable(
  69         artifact_manager.get_temp_file(config.CVS_REVS_TO_SVN_REVNUMS),
  70         mode, SignedIntegerPacker(SVN_INVALID_REVNUM))
  71
  72   def get_svn_revnum(self, cvs_rev_id):
  73     """Return the Subversion revision number in which CVS_REV_ID was
  74     committed, or SVN_INVALID_REVNUM if there is no mapping for
  75     CVS_REV_ID."""
  76
  77     return self.cvs2svn_db.get(cvs_rev_id, SVN_INVALID_REVNUM)
  78
  79   def get_svn_commit(self, svn_revnum):
  80     """Return an SVNCommit that corresponds to SVN_REVNUM.
  81
  82     If no SVNCommit exists for revnum SVN_REVNUM, then return None."""
  83
  84     return self.svn_commit_db.get(svn_revnum, None)
  85
  86   def put_svn_commit(self, svn_commit):
  87     """Record the bidirectional mapping between SVN_REVNUM and
  88     CVS_REVS and record associated attributes."""
  89
  90     if self.mode == DB_OPEN_READ:
  91       raise RuntimeError(
  92           'Write operation attempted on read-only PersistenceManager'
  93           )
  94
  95     self.svn_commit_db[svn_commit.revnum] = svn_commit
  96
  97     if isinstance(svn_commit, SVNRevisionCommit):
  98       for cvs_rev in svn_commit.cvs_revs:
  99         self.cvs2svn_db[cvs_rev.id] = svn_commit.revnum
 100
 101   def close(self):
 102     self.cvs2svn_db.close()
 103     self.cvs2svn_db = None
 104     self.svn_commit_db.close()
 105     self.svn_commit_db = None
 106
 107