cvs2svn_lib/cvs_item_database.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 a database that can store arbitrary CVSItems."""
  18
  19
  20 import re
  21 import cPickle
  22
  23 from cvs2svn_lib.cvs_item import CVSRevisionAdd
  24 from cvs2svn_lib.cvs_item import CVSRevisionChange
  25 from cvs2svn_lib.cvs_item import CVSRevisionDelete
  26 from cvs2svn_lib.cvs_item import CVSRevisionNoop
  27 from cvs2svn_lib.cvs_item import CVSBranch
  28 from cvs2svn_lib.cvs_item import CVSBranchNoop
  29 from cvs2svn_lib.cvs_item import CVSTag
  30 from cvs2svn_lib.cvs_item import CVSTagNoop
  31 from cvs2svn_lib.cvs_file_items import CVSFileItems
  32 from cvs2svn_lib.serializer import Serializer
  33 from cvs2svn_lib.serializer import PrimedPickleSerializer
  34 from cvs2svn_lib.indexed_database import IndexedStore
  35
  36
  37 cvs_item_primer = (
  38     CVSRevisionAdd, CVSRevisionChange,
  39     CVSRevisionDelete, CVSRevisionNoop,
  40     CVSBranch, CVSBranchNoop,
  41     CVSTag, CVSTagNoop,
  42     )
  43
  44
  45 class NewCVSItemStore:
  46   """A file of sequential CVSItems, grouped by CVSFile.
  47
  48   The file consists of a sequence of pickles.  The zeroth one is a
  49   Serializer as described in the serializer module.  Subsequent ones
  50   are pickled lists of CVSItems, each list containing all of the
  51   CVSItems for a single file.
  52
  53   We don't use a single pickler for all items because the memo would
  54   grow too large."""
  55
  56   def __init__(self, filename):
  57     """Initialize an instance, creating the file and writing the primer."""
  58
  59     self.f = open(filename, 'wb')
  60
  61     self.serializer = PrimedPickleSerializer(
  62         cvs_item_primer + (CVSFileItems,)
  63         )
  64     cPickle.dump(self.serializer, self.f, -1)
  65
  66   def add(self, cvs_file_items):
  67     """Write CVS_FILE_ITEMS into the database."""
  68
  69     self.serializer.dumpf(self.f, cvs_file_items)
  70
  71   def close(self):
  72     self.f.close()
  73     self.f = None
  74
  75
  76 class OldCVSItemStore:
  77   """Read a file created by NewCVSItemStore.
  78
  79   The file must be read sequentially, one CVSFileItems instance at a
  80   time."""
  81
  82   def __init__(self, filename):
  83     self.f = open(filename, 'rb')
  84
  85     # Read the memo from the first pickle:
  86     self.serializer = cPickle.load(self.f)
  87
  88   def iter_cvs_file_items(self):
  89     """Iterate through the CVSFileItems instances, one file at a time.
  90
  91     Each time yield a CVSFileItems instance for one CVSFile."""
  92
  93     try:
  94       while True:
  95         yield self.serializer.loadf(self.f)
  96     except EOFError:
  97       return
  98
  99   def close(self):
 100     self.f.close()
 101     self.f = None
 102
 103
 104 class LinewiseSerializer(Serializer):
 105   """A serializer that writes exactly one line for each object.
 106
 107   The actual serialization is done by a wrapped serializer; this class
 108   only escapes any newlines in the serialized data then appends a
 109   single newline."""
 110
 111   def __init__(self, wrapee):
 112     self.wrapee = wrapee
 113
 114   @staticmethod
 115   def _encode_newlines(s):
 116     """Return s with newlines and backslashes encoded.
 117
 118     The string is returned with the following character transformations:
 119
 120       LF -> \n
 121       CR -> \r
 122       ^Z -> \z (needed for Windows)
 123       \ -> \\
 124
 125     """
 126
 127     return s.replace('\\', '\\\\') \
 128             .replace('\n', '\\n') \
 129             .replace('\r', '\\r') \
 130             .replace('\x1a', '\\z')
 131
 132   _escape_re = re.compile(r'(\\\\|\\n|\\r|\\z)')
 133   _subst = {'\\n' : '\n', '\\r' : '\r', '\\z' : '\x1a', '\\\\' : '\\'}
 134
 135   @staticmethod
 136   def _decode_newlines(s):
 137     """Return s with newlines and backslashes decoded.
 138
 139     This function reverses the encoding of _encode_newlines().
 140
 141     """
 142
 143     def repl(m):
 144       return LinewiseSerializer._subst[m.group(1)]
 145
 146     return LinewiseSerializer._escape_re.sub(repl, s)
 147
 148   def dumpf(self, f, object):
 149     f.write(self.dumps(object))
 150
 151   def dumps(self, object):
 152     return self._encode_newlines(self.wrapee.dumps(object)) + '\n'
 153
 154   def loadf(self, f):
 155     return self.loads(f.readline())
 156
 157   def loads(self, s):
 158     return self.wrapee.loads(self._decode_newlines(s[:-1]))
 159
 160
 161 class NewSortableCVSRevisionDatabase(object):
 162   """A serially-accessible, sortable file for holding CVSRevisions.
 163
 164   This class creates such files."""
 165
 166   def __init__(self, filename, serializer):
 167     self.f = open(filename, 'w')
 168     self.serializer = LinewiseSerializer(serializer)
 169
 170   def add(self, cvs_rev):
 171     self.f.write(
 172         '%x %08x %s' % (
 173             cvs_rev.metadata_id, cvs_rev.timestamp,
 174             self.serializer.dumps(cvs_rev),
 175             )
 176         )
 177
 178   def close(self):
 179     self.f.close()
 180     self.f = None
 181
 182
 183 class OldSortableCVSRevisionDatabase(object):
 184   """A serially-accessible, sortable file for holding CVSRevisions.
 185
 186   This class reads such files."""
 187
 188   def __init__(self, filename, serializer):
 189     self.filename = filename
 190     self.serializer = LinewiseSerializer(serializer)
 191
 192   def __iter__(self):
 193     f = open(self.filename, 'r')
 194     for l in f:
 195       s = l.split(' ', 2)[-1]
 196       yield self.serializer.loads(s)
 197     f.close()
 198
 199   def close(self):
 200     pass
 201
 202
 203 class NewSortableCVSSymbolDatabase(object):
 204   """A serially-accessible, sortable file for holding CVSSymbols.
 205
 206   This class creates such files."""
 207
 208   def __init__(self, filename, serializer):
 209     self.f = open(filename, 'w')
 210     self.serializer = LinewiseSerializer(serializer)
 211
 212   def add(self, cvs_symbol):
 213     self.f.write(
 214         '%x %s' % (cvs_symbol.symbol.id, self.serializer.dumps(cvs_symbol))
 215         )
 216
 217   def close(self):
 218     self.f.close()
 219     self.f = None
 220
 221
 222 class OldSortableCVSSymbolDatabase(object):
 223   """A serially-accessible, sortable file for holding CVSSymbols.
 224
 225   This class reads such files."""
 226
 227   def __init__(self, filename, serializer):
 228     self.filename = filename
 229     self.serializer = LinewiseSerializer(serializer)
 230
 231   def __iter__(self):
 232     f = open(self.filename, 'r')
 233     for l in f:
 234       s = l.split(' ', 1)[-1]
 235       yield self.serializer.loads(s)
 236     f.close()
 237
 238   def close(self):
 239     pass
 240
 241
 242 def IndexedCVSItemStore(filename, index_filename, mode):
 243   return IndexedStore(
 244       filename, index_filename, mode,
 245       PrimedPickleSerializer(cvs_item_primer)
 246       )
 247
 248