archive: Drop decompress function implemented for Python < 2.6

Pisi does not support Python versions before 2.6. It is useless to keep
this function here.

pisi/archive.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2005 - 2007, TUBITAK/UEKAE
+# Copyright (C) 2005-2010, TUBITAK/UEKAE
 #
 # This program is free software; you can redistribute it and/or modify it under
 # the terms of the GNU General Public License as published by the Free
@@ -20,8 +20,6 @@ import tarfile
 import zipfile
 import gzip
 import bz2
-import struct
-import sys
 
 import gettext
 __trans = gettext.translation('pisi', fallback=True)
@@ -251,99 +249,6 @@ class ArchiveTar(ArchiveBase):
                 raise LzmaRuntimeError(err)
 
 
-class MyZipFile(zipfile.ZipFile):
-    def decompressToFile(self, name, outname):
-        import zlib
-        import binascii
-
-        block_size = 1024 * 1024 * 2
-
-        if self.mode not in ("r", "a"):
-            raise RuntimeError, 'read() requires mode "r" or "a"'
-        if not self.fp:
-            raise RuntimeError, \
-                  "Attempt to read ZIP archive that was already closed"
-        zinfo = self.getinfo(name)
-        filepos = self.fp.tell()
-
-        self.fp.seek(zinfo.header_offset, 0)
-
-        # Skip the file header:
-        fheader = self.fp.read(30)
-        if fheader[0:4] != zipfile.stringFileHeader:
-            raise BadZipfile, "Bad magic number for file header"
-
-        fheader = struct.unpack(zipfile.structFileHeader, fheader)
-        fname = self.fp.read(fheader[zipfile._FH_FILENAME_LENGTH])
-        if fheader[zipfile._FH_EXTRA_FIELD_LENGTH]:
-            self.fp.read(fheader[zipfile._FH_EXTRA_FIELD_LENGTH])
-
-        if fname != zinfo.orig_filename:
-            raise zipfile.BadZipfile, \
-                  'File name in directory "%s" and header "%s" differ.' % (
-                zinfo.orig_filename, fname)
-
-        destfile = file(outname, 'wb')
-
-        if zinfo.compress_type == zipfile.ZIP_STORED:
-            total_read = 0
-            crc = None
-            while total_read < zinfo.compress_size:
-                if zinfo.compress_size - total_read < block_size:
-                    block_size = zinfo.compress_size - total_read
-                buff = self.fp.read(block_size)
-                destfile.write(buff)
-                total_read += (block_size)
-                if crc:
-                    crc = binascii.crc32(buff, crc)
-                else:
-                    crc = binascii.crc32(buff)
-            destfile.close()
-            self.fp.seek(filepos, 0)
-            if crc and crc != zinfo.CRC:
-                raise zipfile.BadZipfile, "Bad CRC-32 for file %s" % name
-            return
-        elif zinfo.compress_type != zipfile.ZIP_DEFLATED:
-            raise zipfile.BadZipfile, \
-                  "Unsupported compression method %d for file %s" % \
-            (zinfo.compress_type, name)
-
-        if not zlib:
-            raise RuntimeError, \
-                "De-compression requires the (missing) zlib module"
-        # zlib compress/decompress code by Jeremy Hylton of CNRI
-        dc = zlib.decompressobj(-15)
-
-        total_read = 0
-        crc = None
-        while total_read < zinfo.compress_size:
-            if zinfo.compress_size - total_read < block_size:
-                block_size = zinfo.compress_size - total_read
-            buff = self.fp.read(block_size)
-            dcbuff = dc.decompress(dc.unconsumed_tail + buff)
-            destfile.write(dcbuff)
-            total_read += block_size
-            if crc:
-                crc = binascii.crc32(dcbuff, crc)
-            else:
-                crc = binascii.crc32(dcbuff)
-
-        # need to feed in unused pad byte so that zlib won't choke
-        ex = dc.decompress(dc.unconsumed_tail + 'Z') + dc.flush()
-        if ex:
-            if crc:
-                crc = binascii.crc32(ex, crc)
-            else:
-                crc = binascii.crc32(ex)
-            destfile.write(ex)
-
-        if crc and crc != zinfo.CRC:
-            raise zipfile.BadZipfile, "Bad CRC-32 for file %s" % name
-
-        destfile.close()
-        self.fp.seek(filepos, 0)
-
-
 class ArchiveZip(ArchiveBase):
     """ArchiveZip handles zip archives.
 
@@ -356,7 +261,7 @@ class ArchiveZip(ArchiveBase):
     def __init__(self, file_path, arch_type = "zip", mode = 'r'):
         super(ArchiveZip, self).__init__(file_path, arch_type)
 
-        self.zip_obj = MyZipFile(self.file_path, mode)
+        self.zip_obj = zipfile.ZipFile(self.file_path, mode)
 
     def close(self):
         """Close the zip archive."""
@@ -466,11 +371,8 @@ class ArchiveZip(ArchiveBase):
                     perm >>= 16
                     perm |= 0x00000100
 
-                    if sys.version_info[:2] < (2, 6):
-                        zip_obj.decompressToFile(info.filename, ofile)
-                    else:
-                        info.filename = outpath
-                        zip_obj.extract(info, target_dir)
+                    info.filename = outpath
+                    zip_obj.extract(info, target_dir)
                     os.chmod(ofile, perm)
 
     def unpack_files(self, paths, target_dir):