add new wrapper for iterzipfile instead of mod'ing the python modules

directly...  make use of this..

[git-p4: depot-paths = "//depot/": change = 811]

ZipStorage.py

@@ -8,7 +8,8 @@ import itertools
 import os.path
 import sets
 import time
-import zipfile
+import iterzipfile
+zipfile = iterzipfile
 
 import FileDIDL
 from DIDLLite import StorageFolder, Item, VideoItem, AudioItem, TextItem, ImageItem, Resource

iterzipfile.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+
+import binascii
+import os
+import zipfile
+from zipfile import *
+try:
+	import zlib # We may need its compression method
+except ImportError:
+	zlib = None
+
+__all__ = zipfile.__all__
+
+def dupfile(fp):
+	if not hasattr(fp, 'fileno'):
+		raise ValueError, 'must be operating on real file'
+	newfp = os.fdopen(os.dup(fp.fileno()))
+	return newfp
+
+class ZipFile(ZipFile):
+	def readiter(self, name, blksize=16384):
+		"""Return file bytes (as a string) for name."""
+
+		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)
+		fp = dupfile(self.fp)
+		fp.seek(zinfo.file_offset, 0)
+		if zinfo.compress_type == ZIP_STORED:
+			assert zinfo.file_size == zinfo.compress_size
+			i = 0
+			while i < zinfo.file_size:
+				yield fp.read(min(blksize, zinfo.file_size - i))
+		elif zinfo.compress_type == ZIP_DEFLATED:
+			if not zlib:
+				raise RuntimeError, "De-compression requires " \
+				    "the (missing) zlib module"
+			# zlib compress/decompress code by Jeremy Hylton of CNRI
+			uncomp = 0
+			comp = 0
+			dc = zlib.decompressobj(-15)
+			crc = None
+			doflush = False
+			while uncomp < zinfo.file_size:
+				if not dc.unconsumed_tail:
+					compread = min(blksize,
+					    zinfo.compress_size - comp)
+					bytes = fp.read(compread)
+					comp += compread
+					if compread == 0:
+						doflush = True
+				else:
+					bytes = dc.unconsumed_tail
+				if doflush:
+					# need to feed in unused pad byte so
+					# that zlib won't choke
+					bytes = dc.decompress('Z') + dc.flush()
+				else:
+					bytes = dc.decompress(bytes, blksize)
+				yield bytes
+				uncomp += len(bytes)
+				if crc is None:
+					crc = binascii.crc32(bytes)
+				else:
+					crc = binascii.crc32(bytes, crc)
+			if crc != zinfo.CRC:
+				raise BadZipfile, "Bad CRC-32 for file %s" % \
+				    name
+		else:
+			raise BadZipfile, "Unsupported compression method " \
+			    "%d for file %s" % (zinfo.compress_type, name)