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 self.universe.files[
  95                include_file
  96                ].is_writeable():
  97                 DataFile(include_file, self.universe)
  98
  99     def save(self):
 100         u"""Write the data, if necessary."""
 101         import codecs
 102         import os
 103         import os.path
 104         import re
 105         import stat
 106
 107         # when modified, writeable and has content or the file exists
 108         if self.modified and self.is_writeable() and (
 109            self.data.sections() or os.path.exists(self.filename)
 110            ):
 111
 112             # make parent directories if necessary
 113             if not os.path.exists(os.path.dirname(self.filename)):
 114                 os.makedirs(os.path.dirname(self.filename))
 115
 116             # backup the file
 117             if self.data.has_option(u"__control__", u"backup_count"):
 118                 max_count = self.data.has_option(
 119                     u"__control__", u"backup_count")
 120             else:
 121                 max_count = self.universe.categories[
 122                     u"internal"
 123                 ][
 124                     u"limits"
 125                 ].getint(u"default_backup_count")
 126             if os.path.exists(self.filename) and max_count:
 127                 backups = []
 128                 for candidate in os.listdir(os.path.dirname(self.filename)):
 129                     if re.match(
 130                        os.path.basename(self.filename) +
 131                        u"""\.\d+$""", candidate
 132                        ):
 133                         backups.append(int(candidate.split(u".")[-1]))
 134                 backups.sort()
 135                 backups.reverse()
 136                 for old_backup in backups:
 137                     if old_backup >= max_count - 1:
 138                         os.remove(self.filename + u"." + unicode(old_backup))
 139                     elif not os.path.exists(
 140                         self.filename + u"." + unicode(old_backup + 1)
 141                     ):
 142                         os.rename(
 143                             self.filename + u"." + unicode(old_backup),
 144                             self.filename + u"." + unicode(old_backup + 1)
 145                         )
 146                 if not os.path.exists(self.filename + u".0"):
 147                     os.rename(self.filename, self.filename + u".0")
 148
 149             # our data file
 150             file_descriptor = codecs.open(self.filename, u"w", u"utf-8")
 151
 152             # if it's marked private, chmod it appropriately
 153             if self.filename in self.universe.private_files and oct(
 154                stat.S_IMODE(os.stat(self.filename)[stat.ST_MODE])
 155                ) != 0600:
 156                 os.chmod(self.filename, 0600)
 157
 158             # write it back sorted, instead of using ConfigParser
 159             sections = self.data.sections()
 160             sections.sort()
 161             for section in sections:
 162                 file_descriptor.write(u"[" + section + u"]\n")
 163                 options = self.data.options(section)
 164                 options.sort()
 165                 for option in options:
 166                     file_descriptor.write(
 167                         option + u" = " +
 168                         self.data.get(section, option) + u"\n"
 169                     )
 170                 file_descriptor.write(u"\n")
 171
 172             # flush and close the file
 173             file_descriptor.flush()
 174             file_descriptor.close()
 175
 176             # unset the modified flag
 177             self.modified = False
 178
 179     def is_writeable(self):
 180         u"""Returns True if the __control__ read_only is False."""
 181         return not self.data.has_option(
 182             u"__control__", u"read_only"
 183         ) or not self.data.getboolean(
 184             u"__control__", u"read_only"
 185         )
 186
 187
 188 def find_file(
 189     file_name=None,
 190     root_path=None,
 191     search_path=None,
 192     default_dir=None,
 193     relative=None,
 194     universe=None
 195 ):
 196     u"""Return an absolute file path based on configuration."""
 197     import os
 198     import os.path
 199     import sys
 200
 201     # make sure to get rid of any surrounding quotes first thing
 202     if file_name:
 203         file_name = file_name.strip(u"\"'")
 204
 205     # this is all unnecessary if it's already absolute
 206     if file_name and os.path.isabs(file_name):
 207         return os.path.realpath(file_name)
 208
 209     # when no file name is specified, look for <argv[0]>.conf
 210     elif not file_name:
 211         file_name = os.path.basename(sys.argv[0]) + u".conf"
 212
 213     # if a universe was provided, try to get some defaults from there
 214     if universe:
 215
 216         if hasattr(
 217            universe,
 218            u"contents"
 219            ) and u"internal:storage" in universe.contents:
 220             storage = universe.categories[u"internal"][u"storage"]
 221             if not root_path:
 222                 root_path = storage.get(u"root_path").strip("\"'")
 223             if not search_path:
 224                 search_path = storage.getlist(u"search_path")
 225             if not default_dir:
 226                 default_dir = storage.get(u"default_dir").strip("\"'")
 227
 228         # if there's only one file loaded, try to work around a chicken<egg
 229         elif hasattr(universe, u"files") and len(
 230             universe.files
 231         ) == 1 and not universe.files[universe.files.keys()[0]].is_writeable():
 232             data_file = universe.files[universe.files.keys()[0]].data
 233
 234             # try for a fallback default directory
 235             if not default_dir and data_file.has_option(
 236                u"internal:storage",
 237                u"default_dir"
 238                ):
 239                 default_dir = data_file.get(
 240                     u"internal:storage",
 241                     u"default_dir"
 242                 ).strip(u"\"'")
 243
 244             # try for a fallback root path
 245             if not root_path and data_file.has_option(
 246                u"internal:storage",
 247                u"root_path"
 248                ):
 249                 root_path = data_file.get(
 250                     u"internal:storage",
 251                     u"root_path"
 252                 ).strip(u"\"'")
 253
 254             # try for a fallback search path
 255             if not search_path and data_file.has_option(
 256                u"internal:storage",
 257                u"search_path"
 258                ):
 259                 search_path = makelist(
 260                     data_file.get(u"internal:storage",
 261                                   u"search_path").strip(u"\"'")
 262                 )
 263
 264         # another fallback root path, this time from the universe startdir
 265         if not root_path and hasattr(universe, "startdir"):
 266             root_path = universe.startdir
 267
 268     # when no root path is specified, assume the current working directory
 269     if not root_path:
 270         root_path = os.getcwd()
 271
 272     # otherwise, make sure it's absolute
 273     elif not os.path.isabs(root_path):
 274         root_path = os.path.realpath(root_path)
 275
 276     # if there's no search path, just use the root path and etc
 277     if not search_path:
 278         search_path = [root_path, u"etc"]
 279
 280     # work on a copy of the search path, to avoid modifying the caller's
 281     else:
 282         search_path = search_path[:]
 283
 284     # if there's no default path, use the last element of the search path
 285     if not default_dir:
 286         default_dir = search_path[-1]
 287
 288     # if an existing file or directory reference was supplied, prepend it
 289     if relative:
 290         relative = relative.strip(u"\"'")
 291         if os.path.isdir(relative):
 292             search_path = [relative] + search_path
 293         else:
 294             search_path = [os.path.dirname(relative)] + search_path
 295
 296     # make the search path entries absolute and throw away any dupes
 297     clean_search_path = []
 298     for each_path in search_path:
 299         each_path = each_path.strip(u"\"'")
 300         if not os.path.isabs(each_path):
 301             each_path = os.path.realpath(os.path.join(root_path, each_path))
 302         if each_path not in clean_search_path:
 303             clean_search_path.append(each_path)
 304
 305     # start hunting for the file now
 306     for each_path in clean_search_path:
 307
 308         # if the file exists and is readable, we're done
 309         if os.path.isfile(os.path.join(each_path, file_name)):
 310             file_name = os.path.realpath(os.path.join(each_path, file_name))
 311             break
 312
 313     # it didn't exist after all, so use the default path instead
 314     if not os.path.isabs(file_name):
 315         file_name = os.path.join(default_dir, file_name)
 316     if not os.path.isabs(file_name):
 317         file_name = os.path.join(root_path, file_name)
 318
 319     # and normalize it last thing before returning
 320     file_name = os.path.realpath(file_name)
 321
 322     # normalize the resulting file path and hand it back
 323     return file_name
 324
 325
 326 def makelist(value):
 327     u"""Turn string into list type."""
 328     if value[0] + value[-1] == u"[]":
 329         return eval(value)
 330     elif value[0] + value[-1] == u"\"\"":
 331         return [value[1:-1]]
 332     else:
 333         return [value]
 334
 335
 336 def makedict(value):
 337     u"""Turn string into dict type."""
 338     if value[0] + value[-1] == u"{}":
 339         return eval(value)
 340     elif value.find(u":") > 0:
 341         return eval(u"{" + value + u"}")
 342     else:
 343         return {value: None}