mudpy/data.py

   1 """Data interface functions for the mudpy engine."""
   2
   3 # Copyright (c) 2004-2016 Jeremy Stanley <fungi@yuggoth.org>. Permission
   4 # to use, copy, modify, and distribute this software is granted under
   5 # terms provided in the LICENSE file distributed with this software.
   6
   7 import os
   8 import re
   9 import stat
  10
  11 import mudpy
  12 import yaml
  13
  14
  15 class DataFile:
  16
  17     """A file containing universe elements and their facets."""
  18
  19     def __init__(self, filename, universe):
  20         self.filename = filename
  21         self.universe = universe
  22         self.data = {}
  23         self.load()
  24
  25     def load(self):
  26         """Read a file, create elements and poplulate facets accordingly."""
  27         self.modified = False
  28         try:
  29             self.data = yaml.safe_load(open(self.filename))
  30         except FileNotFoundError:
  31             # it's normal if the file is one which doesn't exist yet
  32             log_entry = ("File %s is unavailable." % self.filename, 6)
  33             try:
  34                 mudpy.misc.log(*log_entry)
  35             except NameError:
  36                 # happens when we're not far enough along in the init process
  37                 self.universe.setup_loglines.append(log_entry)
  38         if not hasattr(self.universe, "files"):
  39             self.universe.files = {}
  40         self.universe.files[self.filename] = self
  41         includes = []
  42         if "__control__" in self.data:
  43             if "include_files" in self.data["__control__"]:
  44                 for included in self.data["__control__"]["include_files"]:
  45                     included = find_file(
  46                         included,
  47                         relative=self.filename,
  48                         universe=self.universe)
  49                     if included not in includes:
  50                         includes.append(included)
  51             if "include_dirs" in self.data["__control__"]:
  52                 for included in [
  53                     os.path.join(x, "__init__.yaml") for x in
  54                         self.data["__control__"]["include_dirs"]
  55                 ]:
  56                     included = find_file(
  57                         included,
  58                         relative=self.filename,
  59                         universe=self.universe
  60                     )
  61                     if included not in includes:
  62                         includes.append(included)
  63             if "default_files" in self.data["__control__"]:
  64                 origins = self.data["__control__"]["default_files"]
  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 "private_files" in self.data["__control__"]:
  77                 for item in self.data["__control__"]["private_files"]:
  78                     item = find_file(
  79                         item,
  80                         relative=self.filename,
  81                         universe=self.universe
  82                     )
  83                     if item not in includes:
  84                         includes.append(item)
  85                     if item not in self.universe.private_files:
  86                         self.universe.private_files.append(item)
  87         for node in list(self.data):
  88             if node == "__control__":
  89                 continue
  90             facet_pos = node.rfind(".") + 1
  91             if not facet_pos:
  92                 mudpy.misc.Element(node, self.universe, self.filename,
  93                                    old_style=True)
  94             else:
  95                 prefix = node[:facet_pos].strip(".")
  96                 try:
  97                     element = self.universe.contents[prefix]
  98                 except KeyError:
  99                     element = mudpy.misc.Element(prefix, self.universe,
 100                         self.filename)
 101                 element.set(node[facet_pos:], self.data[node])
 102                 if prefix.startswith("mudpy.movement."):
 103                     self.universe.directions.add(
 104                         prefix[prefix.rfind(".") + 1:])
 105         for include_file in includes:
 106             if not os.path.isabs(include_file):
 107                 include_file = find_file(
 108                     include_file,
 109                     relative=self.filename,
 110                     universe=self.universe
 111                 )
 112             if (include_file not in self.universe.files or not
 113                     self.universe.files[include_file].is_writeable()):
 114                 DataFile(include_file, self.universe)
 115
 116     def save(self):
 117         """Write the data, if necessary."""
 118         normal_umask = 0o0022
 119         private_umask = 0o0077
 120         private_file_mode = 0o0600
 121
 122         # when modified, writeable and has content or the file exists
 123         if self.modified and self.is_writeable() and (
 124            self.data or os.path.exists(self.filename)
 125            ):
 126
 127             # make parent directories if necessary
 128             if not os.path.exists(os.path.dirname(self.filename)):
 129                 old_umask = os.umask(normal_umask)
 130                 os.makedirs(os.path.dirname(self.filename))
 131                 os.umask(old_umask)
 132
 133             # backup the file
 134             if "__control__" in self.data and "backup_count" in self.data[
 135                     "__control__"]:
 136                 max_count = self.data["__control__"]["backup_count"]
 137             else:
 138                 max_count = self.universe.contents["mudpy.limit"].get(
 139                     "backups")
 140             if os.path.exists(self.filename) and max_count:
 141                 backups = []
 142                 for candidate in os.listdir(os.path.dirname(self.filename)):
 143                     if re.match(
 144                        os.path.basename(self.filename) +
 145                        """\.\d+$""", candidate
 146                        ):
 147                         backups.append(int(candidate.split(".")[-1]))
 148                 backups.sort()
 149                 backups.reverse()
 150                 for old_backup in backups:
 151                     if old_backup >= max_count - 1:
 152                         os.remove(self.filename + "." + str(old_backup))
 153                     elif not os.path.exists(
 154                         self.filename + "." + str(old_backup + 1)
 155                     ):
 156                         os.rename(
 157                             self.filename + "." + str(old_backup),
 158                             self.filename + "." + str(old_backup + 1)
 159                         )
 160                 if not os.path.exists(self.filename + ".0"):
 161                     os.rename(self.filename, self.filename + ".0")
 162
 163             # our data file
 164             if self.filename in self.universe.private_files:
 165                 old_umask = os.umask(private_umask)
 166                 file_descriptor = open(self.filename, "w")
 167                 if oct(stat.S_IMODE(os.stat(
 168                         self.filename)[stat.ST_MODE])) != private_file_mode:
 169                     # if it's marked private, chmod it appropriately
 170                     os.chmod(self.filename, private_file_mode)
 171             else:
 172                 old_umask = os.umask(normal_umask)
 173                 file_descriptor = open(self.filename, "w")
 174             os.umask(old_umask)
 175
 176             # write and close the file
 177             yaml.safe_dump(self.data, allow_unicode=True,
 178                            default_flow_style=False, stream=file_descriptor)
 179             file_descriptor.close()
 180
 181             # unset the modified flag
 182             self.modified = False
 183
 184     def is_writeable(self):
 185         """Returns True if the __control__ read_only is False."""
 186         try:
 187             return not self.data["__control__"].get("read_only", False)
 188         except KeyError:
 189             return True
 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     # if a universe was provided, try to get some defaults from there
 211     if universe:
 212
 213         if hasattr(
 214            universe,
 215            "contents"
 216            ) and "internal:storage" in universe.contents:
 217             storage = universe.categories["internal"]["storage"]
 218             if not root_path:
 219                 root_path = storage.get("root_path").strip("\"'")
 220             if not search_path:
 221                 search_path = storage.get("search_path")
 222             if not default_dir:
 223                 default_dir = storage.get("default_dir").strip("\"'")
 224
 225         # if there's only one file loaded, try to work around a chicken<egg
 226         elif hasattr(universe, "files") and len(
 227             universe.files
 228         ) == 1 and not universe.files[
 229                 list(universe.files.keys())[0]].is_writeable():
 230             data_file = universe.files[list(universe.files.keys())[0]].data
 231
 232             # try for a fallback default directory
 233             if not default_dir:
 234                 default_dir = data_file.get(
 235                     "internal:storage", "").get("default_dir", "")
 236
 237             # try for a fallback root path
 238             if not root_path:
 239                 root_path = data_file.get(
 240                     "internal:storage", "").get("root_path", "")
 241
 242             # try for a fallback search path
 243             if not search_path:
 244                 search_path = data_file.get(
 245                     "internal:storage", "").get("search_path", "")
 246
 247         # another fallback root path, this time from the universe startdir
 248         if not root_path and hasattr(universe, "startdir"):
 249             root_path = universe.startdir
 250
 251     # when no root path is specified, assume the current working directory
 252     if not root_path:
 253         root_path = os.getcwd()
 254
 255     # otherwise, make sure it's absolute
 256     elif not os.path.isabs(root_path):
 257         root_path = os.path.realpath(root_path)
 258
 259     # if there's no search path, just use the root path and etc
 260     if not search_path:
 261         search_path = [root_path, "etc"]
 262
 263     # work on a copy of the search path, to avoid modifying the caller's
 264     else:
 265         search_path = search_path[:]
 266
 267     # if there's no default path, use the last component of the search path
 268     if not default_dir:
 269         default_dir = search_path[-1]
 270
 271     # if an existing file or directory reference was supplied, prepend it
 272     if relative:
 273         relative = relative.strip("\"'")
 274         if os.path.isdir(relative):
 275             search_path = [relative] + search_path
 276         else:
 277             search_path = [os.path.dirname(relative)] + search_path
 278
 279     # make the search path entries absolute and throw away any dupes
 280     clean_search_path = []
 281     for each_path in search_path:
 282         each_path = each_path.strip("\"'")
 283         if not os.path.isabs(each_path):
 284             each_path = os.path.realpath(os.path.join(root_path, each_path))
 285         if each_path not in clean_search_path:
 286             clean_search_path.append(each_path)
 287
 288     # start hunting for the file now
 289     for each_path in clean_search_path:
 290
 291         # if the file exists and is readable, we're done
 292         if os.path.isfile(os.path.join(each_path, file_name)):
 293             file_name = os.path.realpath(os.path.join(each_path, file_name))
 294             break
 295
 296     # it didn't exist after all, so use the default path instead
 297     if not os.path.isabs(file_name):
 298         file_name = os.path.join(default_dir, file_name)
 299     if not os.path.isabs(file_name):
 300         file_name = os.path.join(root_path, file_name)
 301
 302     # and normalize it last thing before returning
 303     file_name = os.path.realpath(file_name)
 304
 305     # normalize the resulting file path and hand it back
 306     return file_name