pymeds/ZipStorage.py

#!/usr/bin/env python
# Copyright 2006 John-Mark Gurney <gurney_j@resnet.uroegon.edu>
#
# $Id$
#

import os.path
import zipfile

from DIDLLite import StorageFolder, Item, VideoItem, AudioItem, TextItem, ImageItem, Resource
from FSStorage import FSObject, registerklassfun

def isatpath(f, p):
	if f[:len(p)] != p:
		# First part of path doesn't match, it's not
		return False

	slash = f[len(p):].find('/')
	if slash != -1 and slash != len(f) - len(p) + 1:
		# Another path component, skip it, as long as it's not the char
		return False

	# otherwise, it is at this level
	endtrim = len(f)
	if slash:
		endtrip -= 1

	return f[len(p):endtrim]

class ZipChildDir(StorageFolder):
	'''This is to represent a child dir of the zip file.'''

class ZipFile(FSObject, StorageFolder):
	def __init__(self, *args, **kwargs):
		'''If a zip argument is passed it, use that as the zip archive.'''
		path = kwargs['path']
		del kwargs['path']

		StorageFolder.__init__(self, *args, **kwargs)
		FSObject.__init__(self, path)

		# mapping from path to objectID
		self.pathObjmap = {}

	def getdirents(path):
		'''Returns the list of entires for the path, '' is the root path.'''
		lst = self.zip.namelist()
		if path:
			path += '/'

		return filter(lambda x, p = path: isatpath(x, p), lst)

	def doUpdate(self):
		# open the zipfile as necessary.
		self.zip = zipfile.ZipFile(self.FSpath)

		allzipfiles = sets.Set(self.zip.namelist())
		children = sets.Set(getdirents(''))
		for i in self.pathObjmap.keys():
			if i not in children:
				# delete
				self.cd.delItem(self.pathObjmap[i])
				del self.pathObjmap[i]

		for i in children:
			if i in self.pathObjmap:
				continue

			# new object
			if i not in allzipfiles:
				# must be a dir
			else:
				ZipChild(self, i)

def detectzipfile(path, fobj):
	try:
		z = zipfile.ZipFile(fobj)
	except:
		return None, None

	return ZipFile, {}

registerklassfun(detectzipfile)