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Source Code for Package pyffi.formats.bsa

  1  """ 
  2  :mod:`pyffi.formats.bsa` --- Bethesda Archive (.bsa) 
  3  ==================================================== 
  4   
  5  .. warning:: 
  6   
  7     This module is still a work in progress, 
  8     and is not yet ready for production use. 
  9   
 10  A .bsa file is an archive format used by Bethesda (Morrowind, Oblivion, 
 11  Fallout 3). 
 12   
 13  Implementation 
 14  -------------- 
 15   
 16  .. autoclass:: BsaFormat 
 17     :show-inheritance: 
 18     :members: 
 19   
 20  Regression tests 
 21  ---------------- 
 22   
 23  Read a BSA file 
 24  ^^^^^^^^^^^^^^^ 
 25   
 26  >>> # check and read bsa file 
 27  >>> stream = open('tests/bsa/test.bsa', 'rb') 
 28  >>> data = BsaFormat.Data() 
 29  >>> data.inspect_quick(stream) 
 30  >>> data.version 
 31  103 
 32  >>> data.inspect(stream) 
 33  >>> data.folders_offset 
 34  36 
 35  >>> hex(data.archive_flags.to_int(data)) 
 36  '0x703' 
 37  >>> data.num_folders 
 38  1 
 39  >>> data.num_files 
 40  7 
 41  >>> #data.read(stream) 
 42  >>> # TODO check something else... 
 43   
 44  Parse all BSA files in a directory tree 
 45  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
 46   
 47  >>> for stream, data in BsaFormat.walkData('tests/bsa'): 
 48  ...     print(stream.name) 
 49  tests/bsa/test.bsa 
 50   
 51  Create an BSA file from scratch and write to file 
 52  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 
 53   
 54  >>> data = BsaFormat.Data() 
 55  >>> # TODO store something... 
 56  >>> from tempfile import TemporaryFile 
 57  >>> stream = TemporaryFile() 
 58  >>> #data.write(stream) 
 59  """ 
 60   
 61  # ***** BEGIN LICENSE BLOCK ***** 
 62  # 
 63  # Copyright (c) 2007-2011, Python File Format Interface 
 64  # All rights reserved. 
 65  # 
 66  # Redistribution and use in source and binary forms, with or without 
 67  # modification, are permitted provided that the following conditions 
 68  # are met: 
 69  # 
 70  #    * Redistributions of source code must retain the above copyright 
 71  #      notice, this list of conditions and the following disclaimer. 
 72  # 
 73  #    * Redistributions in binary form must reproduce the above 
 74  #      copyright notice, this list of conditions and the following 
 75  #      disclaimer in the documentation and/or other materials provided 
 76  #      with the distribution. 
 77  # 
 78  #    * Neither the name of the Python File Format Interface 
 79  #      project nor the names of its contributors may be used to endorse 
 80  #      or promote products derived from this software without specific 
 81  #      prior written permission. 
 82  # 
 83  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 84  # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
 85  # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 86  # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
 87  # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 88  # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 89  # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 90  # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
 91  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 92  # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
 93  # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 94  # POSSIBILITY OF SUCH DAMAGE. 
 95  # 
 96  # ***** END LICENSE BLOCK ***** 
 97   
 98  from itertools import izip 
 99  import logging 
100  import struct 
101  import os 
102  import re 
103   
104  import pyffi.object_models.xml 
105  import pyffi.object_models.common 
106  from pyffi.object_models.xml.basic import BasicBase 
107  import pyffi.object_models 
108  from pyffi.utils.graph import EdgeFilter 
109   
110   
111 -class BsaFormat(pyffi.object_models.xml.FileFormat): 
112      """This class implements the BSA format.""" 
113      xml_file_name = 'bsa.xml' 
114      # where to look for bsa.xml and in what order: 
115      # BSAXMLPATH env var, or BsaFormat module directory 
116      xml_file_path = [os.getenv('BSAXMLPATH'), os.path.dirname(__file__)] 
117      # file name regular expression match 
118      RE_FILENAME = re.compile(r'^.*\.bsa$', re.IGNORECASE) 
119   
120      # basic types 
121      UInt32 = pyffi.object_models.common.UInt 
122      ZString = pyffi.object_models.common.ZString 
123   
124      # implementation of bsa-specific basic types 
125   
126 -    class Hash(pyffi.object_models.common.UInt64): 
127   
128 -        def __str__(self): 
129              return "0x%016X" % self._value 
130   
131 -        def get_detail_display(self): 
132              return self.__str__() 
133   
134 -    class BZString(pyffi.object_models.common.SizedString): 
135   
136 -        def get_size(self, data=None): 
137              return 2 + len(self._value) 
138   
139 -        def read(self, stream, data=None): 
140              length, = struct.unpack('<B', stream.read(1)) 
141              self._value = stream.read(length)[:-1] # strip trailing null byte 
142   
143 -        def write(self, stream, data=None): 
144              stream.write(struct.pack('<B', len(self._value))) 
145              stream.write(self._value) 
146              stream.write(struct.pack('<B', 0)) 
147   
148 -    class FileVersion(pyffi.object_models.common.UInt): 
149          """Basic type which implements the header of a BSA file.""" 
150   
151 -        def __init__(self, **kwargs): 
152              BasicBase.__init__(self, **kwargs) 
153   
154 -        def read(self, stream, data): 
155              """Read header string from stream and check it. 
156   
157              :param stream: The stream to read from. 
158              :type stream: file 
159              """ 
160              hdrstr = stream.read(4) 
161              # check if the string is correct 
162              if hdrstr == "\x00\x01\x00\x00".encode("ascii"): 
163                  # morrowind style, set version too! 
164                  self._value = 0 
165              elif hdrstr == "BSA\x00".encode("ascii"): 
166                  # oblivion an up: read version 
167                  self._value, = struct.unpack("<I", stream.read(4)) 
168              else: 
169                  raise ValueError( 
170                      "invalid BSA header:" 
171                      " expected '\\x00\\x01\\x00\\x00' or 'BSA\\x00'" 
172                      " but got '%s'" % hdrstr) 
173   
174 -        def write(self, stream, data): 
175              """Write the header string to stream. 
176   
177              :param stream: The stream to write to. 
178              :type stream: file 
179              """ 
180              if self._value >= 103: 
181                  stream.write("BSA\x00".encode("ascii")) 
182                  stream.write(struct.pack("<I", self._value)) 
183              else: 
184                  stream.write("\x00\x01\x00\x00".encode("ascii")) 
185   
186 -        def get_size(self, data=None): 
187              """Return number of bytes the header string occupies in a file. 
188   
189              :return: Number of bytes. 
190              """ 
191              return 4 
192   
193      @staticmethod 
194 -    def version_number(version_str): 
195          """Converts version string into an integer. 
196   
197          :param version_str: The version string. 
198          :type version_str: str 
199          :return: A version integer. 
200   
201          >>> BsaFormat.version_number('103') 
202          103 
203          >>> BsaFormat.version_number('XXX') 
204          -1 
205          """ 
206          try: 
207              return int(version_str) 
208          except ValueError: 
209              # not supported 
210              return -1 
211   
212 -    class Header(pyffi.object_models.FileFormat.Data): 
213          """A class to contain the actual bsa data.""" 
214   
215 -        def inspect_quick(self, stream): 
216              """Quickly checks if stream contains BSA data, and gets the 
217              version, by looking at the first 8 bytes. 
218   
219              :param stream: The stream to inspect. 
220              :type stream: file 
221              """ 
222              pos = stream.tell() 
223              try: 
224                  self._version_value_.read(stream, data=self) 
225              finally: 
226                  stream.seek(pos) 
227   
228          # overriding pyffi.object_models.FileFormat.Data methods 
229   
230 -        def inspect(self, stream): 
231              """Quickly checks if stream contains BSA data, and reads the 
232              header. 
233   
234              :param stream: The stream to inspect. 
235              :type stream: file 
236              """ 
237              pos = stream.tell() 
238              try: 
239                  self.inspect_quick(stream) 
240                  BsaFormat._Header.read(self, stream, data=self) 
241              finally: 
242                  stream.seek(pos) 
243   
244 -        def read(self, stream): 
245              """Read a bsa file. 
246   
247              :param stream: The stream from which to read. 
248              :type stream: ``file`` 
249              """ 
250              logger = logging.getLogger("pyffi.bsa.data") 
251   
252              # inspect 
253              self.inspect_quick(stream) 
254   
255              # read file 
256              logger.debug("Reading header at 0x%08X." % stream.tell()) 
257              BsaFormat._Header.read(self, stream, data=self) 
258              if self.version == 0: 
259                  # morrowind 
260                  logger.debug("Reading file records at 0x%08X." % stream.tell()) 
261                  self.old_files.read(stream, data=self) 
262                  logger.debug( 
263                      "Reading file name offsets at 0x%08X." % stream.tell()) 
264                  for old_file in self.old_files: 
265                      old_file._name_offset_value_.read(stream, data=self) 
266                  logger.debug("Reading file names at 0x%08X." % stream.tell()) 
267                  for old_file in self.old_files: 
268                      old_file._name_value_.read(stream, data=self) 
269                  logger.debug("Reading file hashes at 0x%08X." % stream.tell()) 
270                  for old_file in self.old_files: 
271                      old_file._name_hash_value_.read(stream, data=self) 
272                  # "read" the files 
273                  logger.debug( 
274                      "Seeking end of raw file data at 0x%08X." % stream.tell()) 
275                  total_num_bytes = 0 
276                  for old_file in self.old_files: 
277                      total_num_bytes += old_file.data_size 
278                  stream.seek(total_num_bytes, os.SEEK_CUR) 
279              else: 
280                  # oblivion and up 
281                  logger.debug( 
282                      "Reading folder records at 0x%08X." % stream.tell()) 
283                  self.folders.read(stream, data=self) 
284                  logger.debug( 
285                      "Reading folder names and file records at 0x%08X." 
286                      % stream.tell()) 
287                  for folder in self.folders: 
288                      folder._name_value_.read(stream, data=self) 
289                      folder._files_value_.read(stream, data=self) 
290                  logger.debug("Reading file names at 0x%08X." % stream.tell()) 
291                  for folder in self.folders: 
292                      for file_ in folder.files: 
293                          file_._name_value_.read(stream, data=self) 
294                  # "read" the files 
295                  logger.debug( 
296                      "Seeking end of raw file data at 0x%08X." % stream.tell()) 
297                  total_num_bytes = 0 
298                  for folder in self.folders: 
299                      for file_ in folder.files: 
300                          total_num_bytes += file_.file_size.num_bytes 
301                  stream.seek(total_num_bytes, os.SEEK_CUR) 
302   
303              # check if we are at the end of the file 
304              if stream.read(1): 
305                  raise ValueError( 
306                      'end of file not reached: corrupt bsa file?') 
307   
308 -        def write(self, stream): 
309              """Write a bsa file. 
310   
311              :param stream: The stream to which to write. 
312              :type stream: ``file`` 
313              """ 
314              # write the file 
315              raise NotImplementedError 
316   
317  if __name__ == '__main__': 
318      import doctest 
319      doctest.testmod() 
320   

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