cvs2svn_lib/symbolings_reader.py

   1 # (Be in -*- python -*- mode.)
   2 #
   3 # ====================================================================
   4 # Copyright (c) 2000-2006 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 database facilities used by cvs2svn."""
  18
  19
  20 from __future__ import generators
  21
  22 from boolean import *
  23 import config
  24 from context import Ctx
  25 from artifact_manager import artifact_manager
  26 import database
  27 from openings_closings import OpeningsClosingsMap
  28 from symbolic_name_filling_guide import SymbolicNameFillingGuide
  29
  30
  31 class SymbolingsReader:
  32   """Provides an interface to the SYMBOL_OPENINGS_CLOSINGS_SORTED file
  33   and the SYMBOL_OFFSETS_DB.  Does the heavy lifting of finding and
  34   returning the correct opening and closing Subversion revision
  35   numbers for a given symbolic name."""
  36
  37   def __init__(self):
  38     """Opens the SYMBOL_OPENINGS_CLOSINGS_SORTED for reading, and
  39     reads the offsets database into memory."""
  40
  41     self.symbolings = open(
  42         artifact_manager.get_temp_file(
  43             config.SYMBOL_OPENINGS_CLOSINGS_SORTED),
  44         'r')
  45     # The offsets_db is really small, and we need to read and write
  46     # from it a fair bit, so suck it into memory
  47     offsets_db = database.Database(
  48         artifact_manager.get_temp_file(config.SYMBOL_OFFSETS_DB),
  49         database.DB_OPEN_READ)
  50     self.offsets = { }
  51     for key in offsets_db:
  52       #print " ZOO:", key, offsets_db[key]
  53       self.offsets[key] = offsets_db[key]
  54
  55   def filling_guide_for_symbol(self, symbolic_name, svn_revnum):
  56     """Given SYMBOLIC_NAME and SVN_REVNUM, return a new
  57     SymbolicNameFillingGuide object.
  58
  59     Note that if we encounter an opening rev in this fill, but the
  60     corresponding closing rev takes place later than SVN_REVNUM, the
  61     closing will not be passed to SymbolicNameFillingGuide in this
  62     fill (and will be discarded when encountered in a later fill).
  63     This is perfectly fine, because we can still do a valid fill
  64     without the closing--we always try to fill what we can as soon as
  65     we can."""
  66
  67     openings_closings_map = OpeningsClosingsMap(symbolic_name)
  68
  69     # It's possible to have a branch start with a file that was added
  70     # on a branch
  71     if self.offsets.has_key(symbolic_name):
  72       # set our read offset for self.symbolings to the offset for
  73       # symbolic_name
  74       self.symbolings.seek(self.offsets[symbolic_name])
  75
  76       while 1:
  77         fpos = self.symbolings.tell()
  78         line = self.symbolings.readline().rstrip()
  79         if not line:
  80           break
  81         name, revnum, type, branch_name, cvs_path = line.split(" ", 4)
  82         if branch_name == '*':
  83           svn_path = Ctx().project.make_trunk_path(cvs_path)
  84         else:
  85           svn_path = Ctx().project.make_branch_path(branch_name, cvs_path)
  86         revnum = int(revnum)
  87         if revnum > svn_revnum or name != symbolic_name:
  88           break
  89         openings_closings_map.register(svn_path, revnum, type)
  90
  91       # get current offset of the read marker and set it to the offset
  92       # for the beginning of the line we just read if we used anything
  93       # we read.
  94       if not openings_closings_map.is_empty():
  95         self.offsets[symbolic_name] = fpos
  96
  97     return SymbolicNameFillingGuide(openings_closings_map)
  98
  99