libbe/upgrade.py

   1 # Copyright (C) 2009 W. Trevor King <wking@drexel.edu>
   2 #
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 2 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License along
  14 # with this program; if not, write to the Free Software Foundation, Inc.,
  15 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16
  17 """
  18 Handle conversion between the various on-disk images.
  19 """
  20
  21 import os, os.path
  22 import sys
  23 import doctest
  24
  25 import encoding
  26 import mapfile
  27 import vcs
  28
  29 # a list of all past versions
  30 BUGDIR_DISK_VERSIONS = ["Bugs Everywhere Tree 1 0",
  31                         "Bugs Everywhere Directory v1.1",
  32                         "Bugs Everywhere Directory v1.2"]
  33
  34 # the current version
  35 BUGDIR_DISK_VERSION = BUGDIR_DISK_VERSIONS[-1]
  36
  37 class Upgrader (object):
  38     "Class for converting "
  39     initial_version = None
  40     final_version = None
  41     def __init__(self, root):
  42         self.root = root
  43         # use the "None" VCS to ensure proper encoding/decoding and
  44         # simplify path construction.
  45         self.vcs = vcs.vcs_by_name("None")
  46         self.vcs.root(self.root)
  47         self.vcs.encoding = encoding.get_encoding()
  48
  49     def get_path(self, *args):
  50         """
  51         Return a path relative to .root.
  52         """
  53         dir = os.path.join(self.root, ".be")
  54         if len(args) == 0:
  55             return dir
  56         assert args[0] in ["version", "settings", "bugs"], str(args)
  57         return os.path.join(dir, *args)
  58
  59     def check_initial_version(self):
  60         path = self.get_path("version")
  61         version = self.vcs.get_file_contents(path).rstrip("\n")
  62         assert version == self.initial_version, version
  63
  64     def set_version(self):
  65         path = self.get_path("version")
  66         self.vcs.set_file_contents(path, self.final_version+"\n")
  67
  68     def upgrade(self):
  69         print >> sys.stderr, "upgrading bugdir from '%s' to '%s'" \
  70             % (self.initial_version, self.final_version)
  71         self.check_initial_version()
  72         self.set_version()
  73         self._upgrade()
  74
  75     def _upgrade(self):
  76         raise NotImplementedError
  77
  78
  79 class Upgrade_1_0_to_1_1 (Upgrader):
  80     initial_version = "Bugs Everywhere Tree 1 0"
  81     final_version = "Bugs Everywhere Directory v1.1"
  82     def _upgrade_mapfile(self, path):
  83         contents = self.vcs.get_file_contents(path)
  84         old_format = False
  85         for line in contents.splitlines():
  86             if len(line.split("=")) == 2:
  87                 old_format = True
  88                 break
  89         if old_format == True:
  90             # translate to YAML.
  91             newlines = []
  92             for line in contents.splitlines():
  93                 line = line.rstrip('\n')
  94                 if len(line) == 0:
  95                     continue
  96                 fields = line.split("=")
  97                 if len(fields) == 2:
  98                     key,value = fields
  99                     newlines.append('%s: "%s"' % (key, value.replace('"','\\"')))
 100                 else:
 101                     newlines.append(line)
 102             contents = '\n'.join(newlines)
 103             # load the YAML and save
 104             map = mapfile.parse(contents)
 105             mapfile.map_save(self.vcs, path, map)
 106
 107     def _upgrade(self):
 108         """
 109         Comment value field "From" -> "Author".
 110         Homegrown mapfile -> YAML.
 111         """
 112         path = self.get_path("settings")
 113         self._upgrade_mapfile(path)
 114         for bug_uuid in os.listdir(self.get_path("bugs")):
 115             path = self.get_path("bugs", bug_uuid, "values")
 116             self._upgrade_mapfile(path)
 117             c_path = ["bugs", bug_uuid, "comments"]
 118             if not os.path.exists(self.get_path(*c_path)):
 119                 continue # no comments for this bug
 120             for comment_uuid in os.listdir(self.get_path(*c_path)):
 121                 path_list = c_path + [comment_uuid, "values"]
 122                 path = self.get_path(*path_list)
 123                 self._upgrade_mapfile(path)
 124                 settings = mapfile.map_load(self.vcs, path)
 125                 if "From" in settings:
 126                     settings["Author"] = settings.pop("From")
 127                     mapfile.map_save(self.vcs, path, settings)
 128
 129
 130 class Upgrade_1_1_to_1_2 (Upgrader):
 131     initial_version = "Bugs Everywhere Directory v1.1"
 132     final_version = "Bugs Everywhere Directory v1.2"
 133     def _upgrade(self):
 134         """
 135         BugDir settings field "rcs_name" -> "vcs_name".
 136         """
 137         path = self.get_path("settings")
 138         settings = mapfile.map_load(self.vcs, path)
 139         if "rcs_name" in settings:
 140             settings["vcs_name"] = settings.pop("rcs_name")
 141             mapfile.map_save(self.vcs, path, settings)
 142
 143
 144 upgraders = [Upgrade_1_0_to_1_1,
 145              Upgrade_1_1_to_1_2]
 146 upgrade_classes = {}
 147 for upgrader in upgraders:
 148     upgrade_classes[(upgrader.initial_version,upgrader.final_version)]=upgrader
 149
 150 def upgrade(path, current_version,
 151             target_version=BUGDIR_DISK_VERSION):
 152     """
 153     Call the appropriate upgrade function to convert current_version
 154     to target_version.  If a direct conversion function does not exist,
 155     use consecutive conversion functions.
 156     """
 157     if current_version not in BUGDIR_DISK_VERSIONS:
 158         raise NotImplementedError, \
 159             "Cannot handle version '%s' yet." % version
 160     if target_version not in BUGDIR_DISK_VERSIONS:
 161         raise NotImplementedError, \
 162             "Cannot handle version '%s' yet." % version
 163
 164     if (current_version, target_version) in upgrade_classes:
 165         # direct conversion
 166         upgrade_class = upgrade_classes[(current_version, target_version)]
 167         u = upgrade_class(path)
 168         u.upgrade()
 169     else:
 170         # consecutive single-step conversion
 171         i = BUGDIR_DISK_VERSIONS.index(current_version)
 172         while True:
 173             version_a = BUGDIR_DISK_VERSIONS[i]
 174             version_b = BUGDIR_DISK_VERSIONS[i+1]
 175             try:
 176                 upgrade_class = upgrade_classes[(version_a, version_b)]
 177             except KeyError:
 178                 raise NotImplementedError, \
 179                     "Cannot convert version '%s' to '%s' yet." \
 180                     % (version_a, version_b)
 181             u = upgrade_class(path)
 182             u.upgrade()
 183             if version_b == target_version:
 184                 break
 185             i += 1
 186
 187 suite = doctest.DocTestSuite()