lib/mudpy/data.py

   1 # -*- coding: utf-8 -*-
   2 """Data interface functions for the mudpy engine."""
   3
   4 # Copyright (c) 2004-2013 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 os
  10 import re
  11 import stat
  12 import sys
  13
  14 # TODO: remove this check after the switch to py3k
  15 try:
  16     import configparser
  17 except ImportError:
  18     import ConfigParser as configparser
  19
  20 import mudpy
  21
  22
  23 class DataFile:
  24
  25     """A file containing universe elements."""
  26
  27     def __init__(self, filename, universe):
  28         self.filename = filename
  29         self.universe = universe
  30         self.load()
  31
  32     def load(self):
  33         """Read a file and create elements accordingly."""
  34         self.data = configparser.RawConfigParser()
  35         self.modified = False
  36         if os.access(self.filename, os.R_OK):
  37             self.data.read(self.filename)
  38         if not hasattr(self.universe, "files"):
  39             self.universe.files = {}
  40         self.universe.files[self.filename] = self
  41         includes = []
  42         if self.data.has_option("__control__", "include_files"):
  43             for included in makelist(
  44                 self.data.get("__control__", "include_files")
  45             ):
  46                 included = find_file(
  47                     included,
  48                     relative=self.filename,
  49                     universe=self.universe
  50                 )
  51                 if included not in includes:
  52                     includes.append(included)
  53         if self.data.has_option("__control__", "include_dirs"):
  54             for included in [
  55                 os.path.join(x, "__init__.mpy") for x in makelist(
  56                     self.data.get("__control__", "include_dirs")
  57                 )
  58             ]:
  59                 included = find_file(
  60                     included,
  61                     relative=self.filename,
  62                     universe=self.universe
  63                 )
  64                 if included not in includes:
  65                     includes.append(included)
  66         if self.data.has_option("__control__", "default_files"):
  67             origins = makedict(
  68                 self.data.get("__control__", "default_files")
  69             )
  70             for key in origins.keys():
  71                 origins[key] = find_file(
  72                     origins[key],
  73                     relative=self.filename,
  74                     universe=self.universe
  75                 )
  76                 if origins[key] not in includes:
  77                     includes.append(origins[key])
  78                 self.universe.default_origins[key] = origins[key]
  79                 if key not in self.universe.categories:
  80                     self.universe.categories[key] = {}
  81         if self.data.has_option("__control__", "private_files"):
  82             for item in makelist(
  83                 self.data.get("__control__", "private_files")
  84             ):
  85                 item = find_file(
  86                     item,
  87                     relative=self.filename,
  88                     universe=self.universe
  89                 )
  90                 if item not in includes:
  91                     includes.append(item)
  92                 if item not in self.universe.private_files:
  93                     self.universe.private_files.append(item)
  94         for section in self.data.sections():
  95             if section != "__control__":
  96                 mudpy.misc.Element(section, self.universe, self.filename)
  97         for include_file in includes:
  98             if not os.path.isabs(include_file):
  99                 include_file = find_file(
 100                     include_file,
 101                     relative=self.filename,
 102                     universe=self.universe
 103                 )
 104             if (include_file not in self.universe.files or not
 105                     self.universe.files[include_file].is_writeable()):
 106                 DataFile(include_file, self.universe)
 107
 108     def save(self):
 109         """Write the data, if necessary."""
 110
 111         # when modified, writeable and has content or the file exists
 112         if self.modified and self.is_writeable() and (
 113            self.data.sections() or os.path.exists(self.filename)
 114            ):
 115
 116             # make parent directories if necessary
 117             if not os.path.exists(os.path.dirname(self.filename)):
 118                 os.makedirs(os.path.dirname(self.filename))
 119
 120             # backup the file
 121             if self.data.has_option("__control__", "backup_count"):
 122                 max_count = self.data.has_option(
 123                     "__control__", "backup_count")
 124             else:
 125                 max_count = self.universe.categories[
 126                     "internal"
 127                 ][
 128                     "limits"
 129                 ].getint("default_backup_count")
 130             if os.path.exists(self.filename) and max_count:
 131                 backups = []
 132                 for candidate in os.listdir(os.path.dirname(self.filename)):
 133                     if re.match(
 134                        os.path.basename(self.filename) +
 135                        """\.\d+$""", candidate
 136                        ):
 137                         backups.append(int(candidate.split(".")[-1]))
 138                 backups.sort()
 139                 backups.reverse()
 140                 for old_backup in backups:
 141                     if old_backup >= max_count - 1:
 142                         os.remove(self.filename + "." + old_backup)
 143                     elif not os.path.exists(
 144                         self.filename + "." + old_backup + 1
 145                     ):
 146                         os.rename(
 147                             self.filename + "." + old_backup,
 148                             self.filename + "." + old_backup + 1
 149                         )
 150                 if not os.path.exists(self.filename + ".0"):
 151                     os.rename(self.filename, self.filename + ".0")
 152
 153             # our data file
 154             file_descriptor = codecs.open(self.filename, "w", "utf-8")
 155
 156             # if it's marked private, chmod it appropriately
 157             if self.filename in self.universe.private_files and oct(
 158                stat.S_IMODE(os.stat(self.filename)[stat.ST_MODE])
 159                ) != 0o0600:
 160                 os.chmod(self.filename, 0o0600)
 161
 162             # write it back sorted, instead of using configparser
 163             sections = self.data.sections()
 164             sections.sort()
 165             for section in sections:
 166                 file_descriptor.write("[" + section + "]\n")
 167                 options = self.data.options(section)
 168                 options.sort()
 169                 for option in options:
 170                     file_descriptor.write(
 171                         option + " = " +
 172                         self.data.get(section, option) + "\n"
 173                     )
 174                 file_descriptor.write("\n")
 175
 176             # flush and close the file
 177             file_descriptor.flush()
 178             file_descriptor.close()
 179
 180             # unset the modified flag
 181             self.modified = False
 182
 183     def is_writeable(self):
 184         """Returns True if the __control__ read_only is False."""
 185         return not self.data.has_option(
 186             "__control__", "read_only"
 187         ) or not self.data.getboolean(
 188             "__control__", "read_only"
 189         )
 190
 191
 192 def find_file(
 193     file_name=None,
 194     root_path=None,
 195     search_path=None,
 196     default_dir=None,
 197     relative=None,
 198     universe=None
 199 ):
 200     """Return an absolute file path based on configuration."""
 201
 202     # make sure to get rid of any surrounding quotes first thing
 203     if file_name:
 204         file_name = file_name.strip("\"'")
 205
 206     # this is all unnecessary if it's already absolute
 207     if file_name and os.path.isabs(file_name):
 208         return os.path.realpath(file_name)
 209
 210     # when no file name is specified, look for <argv[0]>.conf
 211     elif not file_name:
 212         file_name = os.path.basename(sys.argv[0]) + ".conf"
 213
 214     # if a universe was provided, try to get some defaults from there
 215     if universe:
 216
 217         if hasattr(
 218            universe,
 219            "contents"
 220            ) and "internal:storage" in universe.contents:
 221             storage = universe.categories["internal"]["storage"]
 222             if not root_path:
 223                 root_path = storage.get("root_path").strip("\"'")
 224             if not search_path:
 225                 search_path = storage.getlist("search_path")
 226             if not default_dir:
 227                 default_dir = storage.get("default_dir").strip("\"'")
 228
 229         # if there's only one file loaded, try to work around a chicken<egg
 230         elif hasattr(universe, "files") and len(
 231             universe.files
 232         ) == 1 and not universe.files[
 233                 list(universe.files.keys())[0]].is_writeable():
 234             data_file = universe.files[list(universe.files.keys())[0]].data
 235
 236             # try for a fallback default directory
 237             if not default_dir and data_file.has_option(
 238                "internal:storage",
 239                "default_dir"
 240                ):
 241                 default_dir = data_file.get(
 242                     "internal:storage",
 243                     "default_dir"
 244                 ).strip("\"'")
 245
 246             # try for a fallback root path
 247             if not root_path and data_file.has_option(
 248                "internal:storage",
 249                "root_path"
 250                ):
 251                 root_path = data_file.get(
 252                     "internal:storage",
 253                     "root_path"
 254                 ).strip("\"'")
 255
 256             # try for a fallback search path
 257             if not search_path and data_file.has_option(
 258                "internal:storage",
 259                "search_path"
 260                ):
 261                 search_path = makelist(
 262                     data_file.get("internal:storage",
 263                                   "search_path").strip("\"'")
 264                 )
 265
 266         # another fallback root path, this time from the universe startdir
 267         if not root_path and hasattr(universe, "startdir"):
 268             root_path = universe.startdir
 269
 270     # when no root path is specified, assume the current working directory
 271     if not root_path:
 272         root_path = os.getcwd()
 273
 274     # otherwise, make sure it's absolute
 275     elif not os.path.isabs(root_path):
 276         root_path = os.path.realpath(root_path)
 277
 278     # if there's no search path, just use the root path and etc
 279     if not search_path:
 280         search_path = [root_path, "etc"]
 281
 282     # work on a copy of the search path, to avoid modifying the caller's
 283     else:
 284         search_path = search_path[:]
 285
 286     # if there's no default path, use the last element of the search path
 287     if not default_dir:
 288         default_dir = search_path[-1]
 289
 290     # if an existing file or directory reference was supplied, prepend it
 291     if relative:
 292         relative = relative.strip("\"'")
 293         if os.path.isdir(relative):
 294             search_path = [relative] + search_path
 295         else:
 296             search_path = [os.path.dirname(relative)] + search_path
 297
 298     # make the search path entries absolute and throw away any dupes
 299     clean_search_path = []
 300     for each_path in search_path:
 301         each_path = each_path.strip("\"'")
 302         if not os.path.isabs(each_path):
 303             each_path = os.path.realpath(os.path.join(root_path, each_path))
 304         if each_path not in clean_search_path:
 305             clean_search_path.append(each_path)
 306
 307     # start hunting for the file now
 308     for each_path in clean_search_path:
 309
 310         # if the file exists and is readable, we're done
 311         if os.path.isfile(os.path.join(each_path, file_name)):
 312             file_name = os.path.realpath(os.path.join(each_path, file_name))
 313             break
 314
 315     # it didn't exist after all, so use the default path instead
 316     if not os.path.isabs(file_name):
 317         file_name = os.path.join(default_dir, file_name)
 318     if not os.path.isabs(file_name):
 319         file_name = os.path.join(root_path, file_name)
 320
 321     # and normalize it last thing before returning
 322     file_name = os.path.realpath(file_name)
 323
 324     # normalize the resulting file path and hand it back
 325     return file_name
 326
 327
 328 def makelist(value):
 329     """Turn string into list type."""
 330     if value[0] + value[-1] == "[]":
 331         return eval(value)
 332     elif value[0] + value[-1] == "\"\"":
 333         return [value[1:-1]]
 334     else:
 335         return [value]
 336
 337
 338 def makedict(value):
 339     """Turn string into dict type."""
 340     if value[0] + value[-1] == "{}":
 341         return eval(value)
 342     elif value.find(":") > 0:
 343         return eval("{" + value + "}")
 344     else:
 345         return {value: None}