misc/zipfileext.py

   1 #!/usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3 #
   4 # Copyright 2004, 2005 Zuza Software Foundation
   5 #
   6 # This file is part of translate.
   7 #
   8 # translate is free software; you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation; either version 2 of the License, or
  11 # (at your option) any later version.
  12 #
  13 # translate is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17 #
  18 # You should have received a copy of the GNU General Public License
  19 # along with translate; if not, write to the Free Software
  20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21
  22 """extensions to zipfile standard module that will hopefully get included in future..."""
  23
  24 from zipfile import ZipFile, struct, structCentralDir, stringCentralDir, structEndArchive, stringEndArchive
  25
  26 class ZipFileExt(ZipFile, object):
  27     """a ZipFile that can handle replacing objects"""
  28     def delete(self, name):
  29         """Delete the file from the archive. If it appears multiple
  30         times only the first instance will be deleted."""
  31         for i in range (0, len(self.filelist)):
  32             if self.filelist[i].filename == name:
  33                 if self.debug:
  34                     print "Removing", name
  35                 deleted_offset = self.filelist[i].header_offset
  36                 deleted_size   = (self.filelist[i].file_offset - self.filelist[i].header_offset) + self.filelist[i].compress_size
  37                 zinfo_size = struct.calcsize(structCentralDir) + len(self.filelist[i].filename) + len(self.filelist[i].extra)
  38                 # Remove the file's data from the archive.
  39                 current_offset = self.fp.tell()
  40                 # go to the end of the archive to calculate the total archive_size
  41                 self.fp.seek(0, 2)
  42                 archive_size = self.fp.tell()
  43                 self.fp.seek(deleted_offset + deleted_size)
  44                 buf = self.fp.read()
  45                 self.fp.seek(deleted_offset)
  46                 self.fp.write(buf)
  47                 self.fp.truncate(archive_size - deleted_size - zinfo_size)
  48                 # go to the end of the archive to calculate the total archive_size
  49                 self.fp.seek(0, 2)
  50                 if self.debug >= 2:
  51                     if self.fp.tell() != archive_size - deleted_size - zinfo_size:
  52                         print "truncation failed: %r != %r" % (self.fp.tell(), archive_size - deleted_size - zinfo_size)
  53                 if current_offset > deleted_offset + deleted_size:
  54                     current_offset -= deleted_size
  55                 elif current_offset > deleted_offset:
  56                     current_offset = deleted_offset
  57                 self.fp.seek(current_offset, 0)
  58                 # Remove file from central directory.
  59                 del self.filelist[i]
  60                 # Adjust the remaining offsets in the central directory.
  61                 for j in range (i, len(self.filelist)):
  62                     if self.filelist[j].header_offset > deleted_offset:
  63                         self.filelist[j].header_offset -= deleted_size
  64                     if self.filelist[j].file_offset > deleted_offset:
  65                         self.filelist[j].file_offset -= deleted_size
  66                 del self.NameToInfo[name]
  67                 return
  68         if self.debug:
  69             print name, "not in archive"
  70
  71     def close(self):
  72         """Close the file, and for mode "w" and "a" write the ending
  73         records."""
  74         if self.fp is None:
  75             return
  76         self.writeendrec()
  77         if not self._filePassed:
  78             self.fp.close()
  79         self.fp = None
  80
  81     def writeendrec(self):
  82         """Write the ending records (without neccessarily closing the file)"""
  83         if self.mode in ("w", "a"):             # write ending records
  84             count = 0
  85             current_offset = self.fp.tell()
  86             pos1 = self.fp.tell()
  87             for zinfo in self.filelist:         # write central directory
  88                 count = count + 1
  89                 dt = zinfo.date_time
  90                 dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
  91                 dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
  92                 centdir = struct.pack(structCentralDir,
  93                   stringCentralDir, zinfo.create_version,
  94                   zinfo.create_system, zinfo.extract_version, zinfo.reserved,
  95                   zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
  96                   zinfo.CRC, zinfo.compress_size, zinfo.file_size,
  97                   len(zinfo.filename), len(zinfo.extra), len(zinfo.comment),
  98                   0, zinfo.internal_attr, zinfo.external_attr,
  99                   zinfo.header_offset)
 100                 self.fp.write(centdir)
 101                 self.fp.write(zinfo.filename)
 102                 self.fp.write(zinfo.extra)
 103                 self.fp.write(zinfo.comment)
 104             pos2 = self.fp.tell()
 105             # Write end-of-zip-archive record
 106             endrec = struct.pack(structEndArchive, stringEndArchive,
 107                      0, 0, count, count, pos2 - pos1, pos1, 0)
 108             self.fp.write(endrec)
 109             self.fp.seek(pos1)
 110