test_zlib.py 文件源码

def test_odd_flush(self):
        # Test for odd flushing bugs noted in 2.0, and hopefully fixed in 2.1
        import random

        if hasattr(zlib, 'Z_SYNC_FLUSH'):
            # Testing on 17K of "random" data

            # Create compressor and decompressor objects
            co = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
            dco = zlib.decompressobj()

            # Try 17K of data
            # generate random data stream
            try:
                # In 2.3 and later, WichmannHill is the RNG of the bug report
                gen = random.WichmannHill()
            except AttributeError:
                try:
                    # 2.2 called it Random
                    gen = random.Random()
                except AttributeError:
                    # others might simply have a single RNG
                    gen = random
            gen.seed(1)
            data = genblock(1, 17 * 1024, generator=gen)

            # compress, sync-flush, and decompress
            first = co.compress(data)
            second = co.flush(zlib.Z_SYNC_FLUSH)
            expanded = dco.decompress(first + second)

            # if decompressed data is different from the input data, choke.
            self.assertEqual(expanded, data, "17K random source doesn't match")