lib/mudpy/data.py

   1 # -*- coding: utf-8 -*-
   2 u"""Data interface functions for the mudpy engine."""
   3
   4 # Copyright (c) 2004-2011 Jeremy Stanley <fungi@yuggoth.org>. Permission
   5 # to use, copy, modify, and distribute this software is granted under
   6 # terms provided in the LICENSE file distributed with this software.
   7
   8
   9 class DataFile:
  10
  11     u"""A file containing universe elements."""
  12
  13     def __init__(self, filename, universe):
  14         self.filename = filename
  15         self.universe = universe
  16         self.load()
  17
  18     def load(self):
  19         u"""Read a file and create elements accordingly."""
  20         import ConfigParser
  21         import misc
  22         import os
  23         import os.path
  24         self.data = ConfigParser.RawConfigParser()
  25         self.modified = False
  26         if os.access(self.filename, os.R_OK):
  27             self.data.read(self.filename)
  28         if not hasattr(self.universe, u"files"):
  29             self.universe.files = {}
  30         self.universe.files[self.filename] = self
  31         includes = []
  32         if self.data.has_option(u"__control__", u"include_files"):
  33             for included in makelist(
  34                 self.data.get(u"__control__", u"include_files")
  35             ):
  36                 included = find_file(
  37                     included,
  38                     relative=self.filename,
  39                     universe=self.universe
  40                 )
  41                 if included not in includes:
  42                     includes.append(included)
  43         if self.data.has_option(u"__control__", u"include_dirs"):
  44             for included in [
  45                 os.path.join(x, u"__init__.mpy") for x in makelist(
  46                     self.data.get(u"__control__", u"include_dirs")
  47                 )
  48             ]:
  49                 included = find_file(
  50                     included,
  51                     relative=self.filename,
  52                     universe=self.universe
  53                 )
  54                 if included not in includes:
  55                     includes.append(included)
  56         if self.data.has_option(u"__control__", u"default_files"):
  57             origins = makedict(
  58                 self.data.get(u"__control__", u"default_files")
  59             )
  60             for key in origins.keys():
  61                 origins[key] = find_file(
  62                     origins[key],
  63                     relative=self.filename,
  64                     universe=self.universe
  65                 )
  66                 if origins[key] not in includes:
  67                     includes.append(origins[key])
  68                 self.universe.default_origins[key] = origins[key]
  69                 if key not in self.universe.categories:
  70                     self.universe.categories[key] = {}
  71         if self.data.has_option(u"__control__", u"private_files"):
  72             for item in makelist(
  73                 self.data.get(u"__control__", u"private_files")
  74             ):
  75                 item = find_file(
  76                     item,
  77                     relative=self.filename,
  78                     universe=self.universe
  79                 )
  80                 if item not in includes:
  81                     includes.append(item)
  82                 if item not in self.universe.private_files:
  83                     self.universe.private_files.append(item)
  84         for section in self.data.sections():
  85             if section != u"__control__":
  86                 misc.Element(section, self.universe, self.filename)
  87         for include_file in includes:
  88             if not os.path.isabs(include_file):
  89                 include_file = find_file(
  90                     include_file,
  91                     relative=self.filename,
  92                     universe=self.universe
  93                 )
  94             if (include_file not in self.universe.files or not
  95                     self.universe.files[include_file].is_writeable()):
  96                 DataFile(include_file, self.universe)
  97
  98     def save(self):
  99         u"""Write the data, if necessary."""
 100         import codecs
 101         import os
 102         import os.path
 103         import re
 104         import stat
 105
 106         # when modified, writeable and has content or the file exists
 107         if self.modified and self.is_writeable() and (
 108            self.data.sections() or os.path.exists(self.filename)
 109            ):
 110
 111             # make parent directories if necessary
 112             if not os.path.exists(os.path.dirname(self.filename)):
 113                 os.makedirs(os.path.dirname(self.filename))
 114
 115             # backup the file
 116             if self.data.has_option(u"__control__", u"backup_count"):
 117                 max_count = self.data.has_option(
 118                     u"__control__", u"backup_count")
 119             else:
 120                 max_count = self.universe.categories[
 121                     u"internal"
 122                 ][
 123                     u"limits"
 124                 ].getint(u"default_backup_count")
 125             if os.path.exists(self.filename) and max_count:
 126                 backups = []
 127                 for candidate in os.listdir(os.path.dirname(self.filename)):
 128                     if re.match(
 129                        os.path.basename(self.filename) +
 130                        u"""\.\d+$""", candidate
 131                        ):
 132                         backups.append(int(candidate.split(u".")[-1]))
 133                 backups.sort()
 134                 backups.reverse()
 135                 for old_backup in backups:
 136                     if old_backup >= max_count - 1:
 137                         os.remove(self.filename + u"." + unicode(old_backup))
 138                     elif not os.path.exists(
 139                         self.filename + u"." + unicode(old_backup + 1)
 140                     ):
 141                         os.rename(
 142                             self.filename + u"." + unicode(old_backup),
 143                             self.filename + u"." + unicode(old_backup + 1)
 144                         )
 145                 if not os.path.exists(self.filename + u".0"):
 146                     os.rename(self.filename, self.filename + u".0")
 147
 148             # our data file
 149             file_descriptor = codecs.open(self.filename, u"w", u"utf-8")
 150
 151             # if it's marked private, chmod it appropriately
 152             if self.filename in self.universe.private_files and oct(
 153                stat.S_IMODE(os.stat(self.filename)[stat.ST_MODE])
 154                ) != 0600:
 155                 os.chmod(self.filename, 0600)
 156
 157             # write it back sorted, instead of using ConfigParser
 158             sections = self.data.sections()
 159             sections.sort()
 160             for section in sections:
 161                 file_descriptor.write(u"[" + section + u"]\n")
 162                 options = self.data.options(section)
 163                 options.sort()
 164                 for option in options:
 165                     file_descriptor.write(
 166                         option + u" = " +
 167                         self.data.get(section, option) + u"\n"
 168                     )
 169                 file_descriptor.write(u"\n")
 170
 171             # flush and close the file
 172             file_descriptor.flush()
 173             file_descriptor.close()
 174
 175             # unset the modified flag
 176             self.modified = False
 177
 178     def is_writeable(self):
 179         u"""Returns True if the __control__ read_only is False."""
 180         return not self.data.has_option(
 181             u"__control__", u"read_only"
 182         ) or not self.data.getboolean(
 183             u"__control__", u"read_only"
 184         )
 185
 186
 187 def find_file(
 188     file_name=None,
 189     root_path=None,
 190     search_path=None,
 191     default_dir=None,
 192     relative=None,
 193     universe=None
 194 ):
 195     u"""Return an absolute file path based on configuration."""
 196     import os
 197     import os.path
 198     import sys
 199
 200     # make sure to get rid of any surrounding quotes first thing
 201     if file_name:
 202         file_name = file_name.strip(u"\"'")
 203
 204     # this is all unnecessary if it's already absolute
 205     if file_name and os.path.isabs(file_name):
 206         return os.path.realpath(file_name)
 207
 208     # when no file name is specified, look for <argv[0]>.conf
 209     elif not file_name:
 210         file_name = os.path.basename(sys.argv[0]) + u".conf"
 211
 212     # if a universe was provided, try to get some defaults from there
 213     if universe:
 214
 215         if hasattr(
 216            universe,
 217            u"contents"
 218            ) and u"internal:storage" in universe.contents:
 219             storage = universe.categories[u"internal"][u"storage"]
 220             if not root_path:
 221                 root_path = storage.get(u"root_path").strip("\"'")
 222             if not search_path:
 223                 search_path = storage.getlist(u"search_path")
 224             if not default_dir:
 225                 default_dir = storage.get(u"default_dir").strip("\"'")
 226
 227         # if there's only one file loaded, try to work around a chicken<egg
 228         elif hasattr(universe, u"files") and len(
 229             universe.files
 230         ) == 1 and not universe.files[universe.files.keys()[0]].is_writeable():
 231             data_file = universe.files[universe.files.keys()[0]].data
 232
 233             # try for a fallback default directory
 234             if not default_dir and data_file.has_option(
 235                u"internal:storage",
 236                u"default_dir"
 237                ):
 238                 default_dir = data_file.get(
 239                     u"internal:storage",
 240                     u"default_dir"
 241                 ).strip(u"\"'")
 242
 243             # try for a fallback root path
 244             if not root_path and data_file.has_option(
 245                u"internal:storage",
 246                u"root_path"
 247                ):
 248                 root_path = data_file.get(
 249                     u"internal:storage",
 250                     u"root_path"
 251                 ).strip(u"\"'")
 252
 253             # try for a fallback search path
 254             if not search_path and data_file.has_option(
 255                u"internal:storage",
 256                u"search_path"
 257                ):
 258                 search_path = makelist(
 259                     data_file.get(u"internal:storage",
 260                                   u"search_path").strip(u"\"'")
 261                 )
 262
 263         # another fallback root path, this time from the universe startdir
 264         if not root_path and hasattr(universe, "startdir"):
 265             root_path = universe.startdir
 266
 267     # when no root path is specified, assume the current working directory
 268     if not root_path:
 269         root_path = os.getcwd()
 270
 271     # otherwise, make sure it's absolute
 272     elif not os.path.isabs(root_path):
 273         root_path = os.path.realpath(root_path)
 274
 275     # if there's no search path, just use the root path and etc
 276     if not search_path:
 277         search_path = [root_path, u"etc"]
 278
 279     # work on a copy of the search path, to avoid modifying the caller's
 280     else:
 281         search_path = search_path[:]
 282
 283     # if there's no default path, use the last element of the search path
 284     if not default_dir:
 285         default_dir = search_path[-1]
 286
 287     # if an existing file or directory reference was supplied, prepend it
 288     if relative:
 289         relative = relative.strip(u"\"'")
 290         if os.path.isdir(relative):
 291             search_path = [relative] + search_path
 292         else:
 293             search_path = [os.path.dirname(relative)] + search_path
 294
 295     # make the search path entries absolute and throw away any dupes
 296     clean_search_path = []
 297     for each_path in search_path:
 298         each_path = each_path.strip(u"\"'")
 299         if not os.path.isabs(each_path):
 300             each_path = os.path.realpath(os.path.join(root_path, each_path))
 301         if each_path not in clean_search_path:
 302             clean_search_path.append(each_path)
 303
 304     # start hunting for the file now
 305     for each_path in clean_search_path:
 306
 307         # if the file exists and is readable, we're done
 308         if os.path.isfile(os.path.join(each_path, file_name)):
 309             file_name = os.path.realpath(os.path.join(each_path, file_name))
 310             break
 311
 312     # it didn't exist after all, so use the default path instead
 313     if not os.path.isabs(file_name):
 314         file_name = os.path.join(default_dir, file_name)
 315     if not os.path.isabs(file_name):
 316         file_name = os.path.join(root_path, file_name)
 317
 318     # and normalize it last thing before returning
 319     file_name = os.path.realpath(file_name)
 320
 321     # normalize the resulting file path and hand it back
 322     return file_name
 323
 324
 325 def makelist(value):
 326     u"""Turn string into list type."""
 327     if value[0] + value[-1] == u"[]":
 328         return eval(value)
 329     elif value[0] + value[-1] == u"\"\"":
 330         return [value[1:-1]]
 331     else:
 332         return [value]
 333
 334
 335 def makedict(value):
 336     u"""Turn string into dict type."""
 337     if value[0] + value[-1] == u"{}":
 338         return eval(value)
 339     elif value.find(u":") > 0:
 340         return eval(u"{" + value + u"}")
 341     else:
 342         return {value: None}