lib/mudpy/data.py

   1 # -*- coding: utf-8 -*-
   2 """Data interface functions for the mudpy engine."""
   3
   4 # Copyright (c) 2004-2014 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 import codecs
   9 import configparser
  10 import os
  11 import re
  12 import stat
  13 import sys
  14
  15 import mudpy
  16
  17
  18 class DataFile:
  19
  20     """A file containing universe elements."""
  21
  22     def __init__(self, filename, universe):
  23         self.filename = filename
  24         self.universe = universe
  25         self.load()
  26
  27     def load(self):
  28         """Read a file and create elements accordingly."""
  29         self.data = configparser.RawConfigParser()
  30         self.modified = False
  31         if os.access(self.filename, os.R_OK):
  32             self.data.read(self.filename)
  33         if not hasattr(self.universe, "files"):
  34             self.universe.files = {}
  35         self.universe.files[self.filename] = self
  36         includes = []
  37         if self.data.has_option("__control__", "include_files"):
  38             for included in makelist(
  39                 self.data.get("__control__", "include_files")
  40             ):
  41                 included = find_file(
  42                     included,
  43                     relative=self.filename,
  44                     universe=self.universe
  45                 )
  46                 if included not in includes:
  47                     includes.append(included)
  48         if self.data.has_option("__control__", "include_dirs"):
  49             for included in [
  50                 os.path.join(x, "__init__.mpy") for x in makelist(
  51                     self.data.get("__control__", "include_dirs")
  52                 )
  53             ]:
  54                 included = find_file(
  55                     included,
  56                     relative=self.filename,
  57                     universe=self.universe
  58                 )
  59                 if included not in includes:
  60                     includes.append(included)
  61         if self.data.has_option("__control__", "default_files"):
  62             origins = makedict(
  63                 self.data.get("__control__", "default_files")
  64             )
  65             for key in origins.keys():
  66                 origins[key] = find_file(
  67                     origins[key],
  68                     relative=self.filename,
  69                     universe=self.universe
  70                 )
  71                 if origins[key] not in includes:
  72                     includes.append(origins[key])
  73                 self.universe.default_origins[key] = origins[key]
  74                 if key not in self.universe.categories:
  75                     self.universe.categories[key] = {}
  76         if self.data.has_option("__control__", "private_files"):
  77             for item in makelist(
  78                 self.data.get("__control__", "private_files")
  79             ):
  80                 item = find_file(
  81                     item,
  82                     relative=self.filename,
  83                     universe=self.universe
  84                 )
  85                 if item not in includes:
  86                     includes.append(item)
  87                 if item not in self.universe.private_files:
  88                     self.universe.private_files.append(item)
  89         for section in self.data.sections():
  90             if section != "__control__":
  91                 mudpy.misc.Element(section, self.universe, self.filename)
  92         for include_file in includes:
  93             if not os.path.isabs(include_file):
  94                 include_file = find_file(
  95                     include_file,
  96                     relative=self.filename,
  97                     universe=self.universe
  98                 )
  99             if (include_file not in self.universe.files or not
 100                     self.universe.files[include_file].is_writeable()):
 101                 DataFile(include_file, self.universe)
 102
 103     def save(self):
 104         """Write the data, if necessary."""
 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("__control__", "backup_count"):
 117                 max_count = self.data.has_option(
 118                     "__control__", "backup_count")
 119             else:
 120                 max_count = self.universe.categories[
 121                     "internal"
 122                 ][
 123                     "limits"
 124                 ].getint("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                        """\.\d+$""", candidate
 131                        ):
 132                         backups.append(int(candidate.split(".")[-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 + "." + old_backup)
 138                     elif not os.path.exists(
 139                         self.filename + "." + old_backup + 1
 140                     ):
 141                         os.rename(
 142                             self.filename + "." + old_backup,
 143                             self.filename + "." + old_backup + 1
 144                         )
 145                 if not os.path.exists(self.filename + ".0"):
 146                     os.rename(self.filename, self.filename + ".0")
 147
 148             # our data file
 149             file_descriptor = codecs.open(self.filename, "w", "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                ) != 0o0600:
 155                 os.chmod(self.filename, 0o0600)
 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("[" + section + "]\n")
 162                 options = self.data.options(section)
 163                 options.sort()
 164                 for option in options:
 165                     file_descriptor.write(
 166                         option + " = " +
 167                         self.data.get(section, option) + "\n"
 168                     )
 169                 file_descriptor.write("\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         """Returns True if the __control__ read_only is False."""
 180         return not self.data.has_option(
 181             "__control__", "read_only"
 182         ) or not self.data.getboolean(
 183             "__control__", "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     """Return an absolute file path based on configuration."""
 196
 197     # make sure to get rid of any surrounding quotes first thing
 198     if file_name:
 199         file_name = file_name.strip("\"'")
 200
 201     # this is all unnecessary if it's already absolute
 202     if file_name and os.path.isabs(file_name):
 203         return os.path.realpath(file_name)
 204
 205     # when no file name is specified, look for <argv[0]>.conf
 206     elif not file_name:
 207         file_name = os.path.basename(sys.argv[0]) + ".conf"
 208
 209     # if a universe was provided, try to get some defaults from there
 210     if universe:
 211
 212         if hasattr(
 213            universe,
 214            "contents"
 215            ) and "internal:storage" in universe.contents:
 216             storage = universe.categories["internal"]["storage"]
 217             if not root_path:
 218                 root_path = storage.get("root_path").strip("\"'")
 219             if not search_path:
 220                 search_path = storage.getlist("search_path")
 221             if not default_dir:
 222                 default_dir = storage.get("default_dir").strip("\"'")
 223
 224         # if there's only one file loaded, try to work around a chicken<egg
 225         elif hasattr(universe, "files") and len(
 226             universe.files
 227         ) == 1 and not universe.files[
 228                 list(universe.files.keys())[0]].is_writeable():
 229             data_file = universe.files[list(universe.files.keys())[0]].data
 230
 231             # try for a fallback default directory
 232             if not default_dir and data_file.has_option(
 233                "internal:storage",
 234                "default_dir"
 235                ):
 236                 default_dir = data_file.get(
 237                     "internal:storage",
 238                     "default_dir"
 239                 ).strip("\"'")
 240
 241             # try for a fallback root path
 242             if not root_path and data_file.has_option(
 243                "internal:storage",
 244                "root_path"
 245                ):
 246                 root_path = data_file.get(
 247                     "internal:storage",
 248                     "root_path"
 249                 ).strip("\"'")
 250
 251             # try for a fallback search path
 252             if not search_path and data_file.has_option(
 253                "internal:storage",
 254                "search_path"
 255                ):
 256                 search_path = makelist(
 257                     data_file.get("internal:storage",
 258                                   "search_path").strip("\"'")
 259                 )
 260
 261         # another fallback root path, this time from the universe startdir
 262         if not root_path and hasattr(universe, "startdir"):
 263             root_path = universe.startdir
 264
 265     # when no root path is specified, assume the current working directory
 266     if not root_path:
 267         root_path = os.getcwd()
 268
 269     # otherwise, make sure it's absolute
 270     elif not os.path.isabs(root_path):
 271         root_path = os.path.realpath(root_path)
 272
 273     # if there's no search path, just use the root path and etc
 274     if not search_path:
 275         search_path = [root_path, "etc"]
 276
 277     # work on a copy of the search path, to avoid modifying the caller's
 278     else:
 279         search_path = search_path[:]
 280
 281     # if there's no default path, use the last element of the search path
 282     if not default_dir:
 283         default_dir = search_path[-1]
 284
 285     # if an existing file or directory reference was supplied, prepend it
 286     if relative:
 287         relative = relative.strip("\"'")
 288         if os.path.isdir(relative):
 289             search_path = [relative] + search_path
 290         else:
 291             search_path = [os.path.dirname(relative)] + search_path
 292
 293     # make the search path entries absolute and throw away any dupes
 294     clean_search_path = []
 295     for each_path in search_path:
 296         each_path = each_path.strip("\"'")
 297         if not os.path.isabs(each_path):
 298             each_path = os.path.realpath(os.path.join(root_path, each_path))
 299         if each_path not in clean_search_path:
 300             clean_search_path.append(each_path)
 301
 302     # start hunting for the file now
 303     for each_path in clean_search_path:
 304
 305         # if the file exists and is readable, we're done
 306         if os.path.isfile(os.path.join(each_path, file_name)):
 307             file_name = os.path.realpath(os.path.join(each_path, file_name))
 308             break
 309
 310     # it didn't exist after all, so use the default path instead
 311     if not os.path.isabs(file_name):
 312         file_name = os.path.join(default_dir, file_name)
 313     if not os.path.isabs(file_name):
 314         file_name = os.path.join(root_path, file_name)
 315
 316     # and normalize it last thing before returning
 317     file_name = os.path.realpath(file_name)
 318
 319     # normalize the resulting file path and hand it back
 320     return file_name
 321
 322
 323 def makelist(value):
 324     """Turn string into list type."""
 325     if value[0] + value[-1] == "[]":
 326         return eval(value)
 327     elif value[0] + value[-1] == "\"\"":
 328         return [value[1:-1]]
 329     else:
 330         return [value]
 331
 332
 333 def makedict(value):
 334     """Turn string into dict type."""
 335     if value[0] + value[-1] == "{}":
 336         return eval(value)
 337     elif value.find(":") > 0:
 338         return eval("{" + value + "}")
 339     else:
 340         return {value: None}