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 import yaml
  17
  18
  19 class DataFile:
  20
  21     """A file containing universe elements."""
  22
  23     def __init__(self, filename, universe):
  24         self.filename = filename
  25         self.universe = universe
  26         self.data = {}
  27         self.load()
  28
  29     def load(self):
  30         """Read a file and create elements accordingly."""
  31         # TODO(fungi): remove this indirection after the YAML transition
  32         if self.filename.endswith('.yaml'):
  33             self.load_yaml()
  34         else:
  35             self.load_mpy()
  36
  37     def load_yaml(self):
  38         """Read a file and create elements accordingly."""
  39         # TODO(fungi): remove this parameter after the YAML transition
  40         self._format = 'yaml'
  41         self.modified = False
  42         try:
  43             self.data = yaml.load(open(self.filename))
  44         except FileNotFoundError:
  45             # it's normal if the file is one which doesn't exist yet
  46             try:
  47                 mudpy.misc.log("Couldn't read %s file." % self.filename, 6)
  48             except NameError:
  49                 # happens when we're not far enough along in the init process
  50                 pass
  51         if not hasattr(self.universe, "files"):
  52             self.universe.files = {}
  53         self.universe.files[self.filename] = self
  54         includes = []
  55         if "__control__" in self.data:
  56             if "include_files" in self.data["__control__"]:
  57                 for included in makelist(
  58                         self.data["__control__"]["include_files"]):
  59                     included = find_file(
  60                         included,
  61                         relative=self.filename,
  62                         universe=self.universe)
  63                     if included not in includes:
  64                         includes.append(included)
  65             if "include_dirs" in self.data["__control__"]:
  66                 for included in [
  67                     os.path.join(x, "__init__.mpy") for x in makelist(
  68                         self.data["__control__"]["include_dirs"]
  69                     )
  70                 ]:
  71                     included = find_file(
  72                         included,
  73                         relative=self.filename,
  74                         universe=self.universe
  75                     )
  76                     if included not in includes:
  77                         includes.append(included)
  78             if "default_files" in self.data["__control__"]:
  79                 origins = makedict(
  80                     self.data["__control__"]["default_files"]
  81                 )
  82                 for key in origins.keys():
  83                     origins[key] = find_file(
  84                         origins[key],
  85                         relative=self.filename,
  86                         universe=self.universe
  87                     )
  88                     if origins[key] not in includes:
  89                         includes.append(origins[key])
  90                     self.universe.default_origins[key] = origins[key]
  91                     if key not in self.universe.categories:
  92                         self.universe.categories[key] = {}
  93             if "private_files" in self.data["__control__"]:
  94                 for item in makelist(
  95                     self.data["__control__"]["private_files"]
  96                 ):
  97                     item = find_file(
  98                         item,
  99                         relative=self.filename,
 100                         universe=self.universe
 101                     )
 102                     if item not in includes:
 103                         includes.append(item)
 104                     if item not in self.universe.private_files:
 105                         self.universe.private_files.append(item)
 106         for element in self.data:
 107             if element != "__control__":
 108                 mudpy.misc.Element(element, self.universe, self.filename)
 109         for include_file in includes:
 110             if not os.path.isabs(include_file):
 111                 include_file = find_file(
 112                     include_file,
 113                     relative=self.filename,
 114                     universe=self.universe
 115                 )
 116             if (include_file not in self.universe.files or not
 117                     self.universe.files[include_file].is_writeable()):
 118                 DataFile(include_file, self.universe)
 119
 120     # TODO(fungi): remove this method after the YAML transition
 121     def load_mpy(self):
 122         """Read a file and create elements accordingly."""
 123         self._format = 'mpy'
 124         self.modified = False
 125         self.data = configparser.RawConfigParser()
 126         if os.access(self.filename, os.R_OK):
 127             self.data.read(self.filename)
 128         if not hasattr(self.universe, "files"):
 129             self.universe.files = {}
 130         self.universe.files[self.filename] = self
 131         includes = []
 132         if self.data.has_option("__control__", "include_files"):
 133             for included in makelist(
 134                 self.data.get("__control__", "include_files")
 135             ):
 136                 included = find_file(
 137                     included,
 138                     relative=self.filename,
 139                     universe=self.universe
 140                 )
 141                 if included not in includes:
 142                     includes.append(included)
 143         if self.data.has_option("__control__", "include_dirs"):
 144             for included in [
 145                 os.path.join(x, "__init__.mpy") for x in makelist(
 146                     self.data.get("__control__", "include_dirs")
 147                 )
 148             ]:
 149                 included = find_file(
 150                     included,
 151                     relative=self.filename,
 152                     universe=self.universe
 153                 )
 154                 if included not in includes:
 155                     includes.append(included)
 156         if self.data.has_option("__control__", "default_files"):
 157             origins = makedict(
 158                 self.data.get("__control__", "default_files")
 159             )
 160             for key in origins.keys():
 161                 origins[key] = find_file(
 162                     origins[key],
 163                     relative=self.filename,
 164                     universe=self.universe
 165                 )
 166                 if origins[key] not in includes:
 167                     includes.append(origins[key])
 168                 self.universe.default_origins[key] = origins[key]
 169                 if key not in self.universe.categories:
 170                     self.universe.categories[key] = {}
 171         if self.data.has_option("__control__", "private_files"):
 172             for item in makelist(
 173                 self.data.get("__control__", "private_files")
 174             ):
 175                 item = find_file(
 176                     item,
 177                     relative=self.filename,
 178                     universe=self.universe
 179                 )
 180                 if item not in includes:
 181                     includes.append(item)
 182                 if item not in self.universe.private_files:
 183                     self.universe.private_files.append(item)
 184         for section in self.data.sections():
 185             if section != "__control__":
 186                 mudpy.misc.Element(section, self.universe, self.filename)
 187         for include_file in includes:
 188             if not os.path.isabs(include_file):
 189                 include_file = find_file(
 190                     include_file,
 191                     relative=self.filename,
 192                     universe=self.universe
 193                 )
 194             if (include_file not in self.universe.files or not
 195                     self.universe.files[include_file].is_writeable()):
 196                 DataFile(include_file, self.universe)
 197
 198     # TODO(fungi): this should support writing YAML
 199     def save(self):
 200         """Write the data, if necessary."""
 201
 202         # when modified, writeable and has content or the file exists
 203         if self.modified and self.is_writeable() and (
 204            self.data.sections() or os.path.exists(self.filename)
 205            ):
 206
 207             # make parent directories if necessary
 208             if not os.path.exists(os.path.dirname(self.filename)):
 209                 os.makedirs(os.path.dirname(self.filename))
 210
 211             # backup the file
 212             if self.data.has_option("__control__", "backup_count"):
 213                 max_count = self.data.has_option(
 214                     "__control__", "backup_count")
 215             else:
 216                 max_count = self.universe.categories[
 217                     "internal"
 218                 ][
 219                     "limits"
 220                 ].getint("default_backup_count")
 221             if os.path.exists(self.filename) and max_count:
 222                 backups = []
 223                 for candidate in os.listdir(os.path.dirname(self.filename)):
 224                     if re.match(
 225                        os.path.basename(self.filename) +
 226                        """\.\d+$""", candidate
 227                        ):
 228                         backups.append(int(candidate.split(".")[-1]))
 229                 backups.sort()
 230                 backups.reverse()
 231                 for old_backup in backups:
 232                     if old_backup >= max_count - 1:
 233                         os.remove(self.filename + "." + old_backup)
 234                     elif not os.path.exists(
 235                         self.filename + "." + old_backup + 1
 236                     ):
 237                         os.rename(
 238                             self.filename + "." + old_backup,
 239                             self.filename + "." + old_backup + 1
 240                         )
 241                 if not os.path.exists(self.filename + ".0"):
 242                     os.rename(self.filename, self.filename + ".0")
 243
 244             # our data file
 245             file_descriptor = codecs.open(self.filename, "w", "utf-8")
 246
 247             # if it's marked private, chmod it appropriately
 248             if self.filename in self.universe.private_files and oct(
 249                stat.S_IMODE(os.stat(self.filename)[stat.ST_MODE])
 250                ) != 0o0600:
 251                 os.chmod(self.filename, 0o0600)
 252
 253             # write it back sorted, instead of using configparser
 254             sections = self.data.sections()
 255             sections.sort()
 256             for section in sections:
 257                 file_descriptor.write("[" + section + "]\n")
 258                 options = self.data.options(section)
 259                 options.sort()
 260                 for option in options:
 261                     file_descriptor.write(
 262                         option + " = " +
 263                         self.data.get(section, option) + "\n"
 264                     )
 265                 file_descriptor.write("\n")
 266
 267             # flush and close the file
 268             file_descriptor.flush()
 269             file_descriptor.close()
 270
 271             # unset the modified flag
 272             self.modified = False
 273
 274     def is_writeable(self):
 275         """Returns True if the __control__ read_only is False."""
 276         # TODO(fungi): remove this indirection after the YAML transition
 277         if self._format == "yaml":
 278             try:
 279                 return not self.data["__control__"].get("read_only", False)
 280             except KeyError:
 281                 return True
 282         else:
 283             return not self.data.has_option(
 284                 "__control__", "read_only"
 285             ) or not self.data.getboolean(
 286                 "__control__", "read_only"
 287             )
 288
 289
 290 def find_file(
 291     file_name=None,
 292     root_path=None,
 293     search_path=None,
 294     default_dir=None,
 295     relative=None,
 296     universe=None
 297 ):
 298     """Return an absolute file path based on configuration."""
 299
 300     # make sure to get rid of any surrounding quotes first thing
 301     if file_name:
 302         file_name = file_name.strip("\"'")
 303
 304     # this is all unnecessary if it's already absolute
 305     if file_name and os.path.isabs(file_name):
 306         return os.path.realpath(file_name)
 307
 308     # when no file name is specified, look for <argv[0]>.conf
 309     elif not file_name:
 310         file_name = os.path.basename(sys.argv[0]) + ".conf"
 311
 312     # if a universe was provided, try to get some defaults from there
 313     if universe:
 314
 315         if hasattr(
 316            universe,
 317            "contents"
 318            ) and "internal:storage" in universe.contents:
 319             storage = universe.categories["internal"]["storage"]
 320             if not root_path:
 321                 root_path = storage.get("root_path").strip("\"'")
 322             if not search_path:
 323                 search_path = storage.getlist("search_path")
 324             if not default_dir:
 325                 default_dir = storage.get("default_dir").strip("\"'")
 326
 327         # if there's only one file loaded, try to work around a chicken<egg
 328         elif hasattr(universe, "files") and len(
 329             universe.files
 330         ) == 1 and not universe.files[
 331                 list(universe.files.keys())[0]].is_writeable():
 332             data_file = universe.files[list(universe.files.keys())[0]].data
 333
 334             # try for a fallback default directory
 335             if not default_dir and data_file.has_option(
 336                "internal:storage",
 337                "default_dir"
 338                ):
 339                 default_dir = data_file.get(
 340                     "internal:storage",
 341                     "default_dir"
 342                 ).strip("\"'")
 343
 344             # try for a fallback root path
 345             if not root_path and data_file.has_option(
 346                "internal:storage",
 347                "root_path"
 348                ):
 349                 root_path = data_file.get(
 350                     "internal:storage",
 351                     "root_path"
 352                 ).strip("\"'")
 353
 354             # try for a fallback search path
 355             if not search_path and data_file.has_option(
 356                "internal:storage",
 357                "search_path"
 358                ):
 359                 search_path = makelist(
 360                     data_file.get("internal:storage",
 361                                   "search_path").strip("\"'")
 362                 )
 363
 364         # another fallback root path, this time from the universe startdir
 365         if not root_path and hasattr(universe, "startdir"):
 366             root_path = universe.startdir
 367
 368     # when no root path is specified, assume the current working directory
 369     if not root_path:
 370         root_path = os.getcwd()
 371
 372     # otherwise, make sure it's absolute
 373     elif not os.path.isabs(root_path):
 374         root_path = os.path.realpath(root_path)
 375
 376     # if there's no search path, just use the root path and etc
 377     if not search_path:
 378         search_path = [root_path, "etc"]
 379
 380     # work on a copy of the search path, to avoid modifying the caller's
 381     else:
 382         search_path = search_path[:]
 383
 384     # if there's no default path, use the last element of the search path
 385     if not default_dir:
 386         default_dir = search_path[-1]
 387
 388     # if an existing file or directory reference was supplied, prepend it
 389     if relative:
 390         relative = relative.strip("\"'")
 391         if os.path.isdir(relative):
 392             search_path = [relative] + search_path
 393         else:
 394             search_path = [os.path.dirname(relative)] + search_path
 395
 396     # make the search path entries absolute and throw away any dupes
 397     clean_search_path = []
 398     for each_path in search_path:
 399         each_path = each_path.strip("\"'")
 400         if not os.path.isabs(each_path):
 401             each_path = os.path.realpath(os.path.join(root_path, each_path))
 402         if each_path not in clean_search_path:
 403             clean_search_path.append(each_path)
 404
 405     # start hunting for the file now
 406     for each_path in clean_search_path:
 407
 408         # if the file exists and is readable, we're done
 409         if os.path.isfile(os.path.join(each_path, file_name)):
 410             file_name = os.path.realpath(os.path.join(each_path, file_name))
 411             break
 412
 413     # it didn't exist after all, so use the default path instead
 414     if not os.path.isabs(file_name):
 415         file_name = os.path.join(default_dir, file_name)
 416     if not os.path.isabs(file_name):
 417         file_name = os.path.join(root_path, file_name)
 418
 419     # and normalize it last thing before returning
 420     file_name = os.path.realpath(file_name)
 421
 422     # normalize the resulting file path and hand it back
 423     return file_name
 424
 425
 426 def makelist(value):
 427     """Turn string into list type."""
 428     if value[0] + value[-1] == "[]":
 429         return eval(value)
 430     elif value[0] + value[-1] == "\"\"":
 431         return [value[1:-1]]
 432     else:
 433         return [value]
 434
 435
 436 def makedict(value):
 437     """Turn string into dict type."""
 438     if value[0] + value[-1] == "{}":
 439         return eval(value)
 440     elif value.find(":") > 0:
 441         return eval("{" + value + "}")
 442     else:
 443         return {value: None}