def _unzipIterChunkyTest(self, compression, chunksize, lower, upper):
        """
        unzipIterChunky should unzip the given number of bytes per iteration.
        """
        junk = ' '.join([str(random.random()) for n in xrange(1000)])
        junkmd5 = md5(junk).hexdigest()

        tempdir = filepath.FilePath(self.mktemp())
        tempdir.makedirs()
        zfpath = tempdir.child('bigfile.zip').path
        self._makebigfile(zfpath, compression, junk)
        uziter = zipstream.unzipIterChunky(zfpath, tempdir.path,
                                           chunksize=chunksize)
        r = uziter.next()
        # test that the number of chunks is in the right ballpark;
        # this could theoretically be any number but statistically it
        # should always be in this range
        approx = lower < r < upper
        self.failUnless(approx)
        for r in uziter:
            pass
        self.assertEqual(r, 0)
        newmd5 = md5(
            tempdir.child("zipstreamjunk").open().read()).hexdigest()
        self.assertEqual(newmd5, junkmd5)
    def test_unzipIterChunky(self):
        """
        L{twisted.python.zipstream.unzipIterChunky} returns an iterator which
        must be exhausted to completely unzip the input archive.
        """
        numfiles = 10
        contents = ['This is test file %d!' % i for i in range(numfiles)]
        zpfilename = self.makeZipFile(contents)
        list(zipstream.unzipIterChunky(zpfilename, self.unzipdir.path))
        self.assertEquals(
            set(self.unzipdir.listdir()),
            set(map(str, range(numfiles))))

        for child in self.unzipdir.children():
            num = int(child.basename())
            self.assertEquals(child.getContent(), contents[num])
    def test_unzipIterChunkyDirectory(self):
        """
        The path to which a file is extracted by L{zipstream.unzipIterChunky}
        is determined by joining the C{directory} argument to C{unzip} with the
        path within the archive of the file being extracted.
        """
        numfiles = 10
        contents = ['This is test file %d!' % i for i in range(numfiles)]
        zpfilename = self.makeZipFile(contents, 'foo')
        list(zipstream.unzipIterChunky(zpfilename, self.unzipdir.path))
        self.assertEquals(
            set(self.unzipdir.child('foo').listdir()),
            set(map(str, range(numfiles))))

        for child in self.unzipdir.child('foo').children():
            num = int(child.basename())
            self.assertEquals(child.getContent(), contents[num])