cvs2svn_lib/symbol_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 the SymbolDatabase class."""
  18
  19
  20 import cPickle
  21
  22 from cvs2svn_lib import config
  23 from cvs2svn_lib.artifact_manager import artifact_manager
  24
  25
  26 class SymbolDatabase:
  27   """Read-only access to symbol database.
  28
  29   This class allows iteration and lookups id -> symbol, where symbol
  30   is a TypedSymbol instance.  The whole database is read into memory
  31   upon construction."""
  32
  33   def __init__(self):
  34     # A map { id : TypedSymbol }
  35     self._symbols = {}
  36
  37     f = open(artifact_manager.get_temp_file(config.SYMBOL_DB), 'rb')
  38     symbols = cPickle.load(f)
  39     f.close()
  40     for symbol in symbols:
  41       self._symbols[symbol.id] = symbol
  42
  43   def get_symbol(self, id):
  44     """Return the symbol instance with id ID.
  45
  46     Raise KeyError if the symbol is not known."""
  47
  48     return self._symbols[id]
  49
  50   def __iter__(self):
  51     """Iterate over the Symbol instances within this database."""
  52
  53     return self._symbols.itervalues()
  54
  55   def close(self):
  56     self._symbols = None
  57
  58
  59 def create_symbol_database(symbols):
  60   """Create and fill a symbol database.
  61
  62   Record each symbol that is listed in SYMBOLS, which is an iterable
  63   containing Trunk and TypedSymbol objects."""
  64
  65   f = open(artifact_manager.get_temp_file(config.SYMBOL_DB), 'wb')
  66   cPickle.dump(symbols, f, -1)
  67   f.close()
  68