设计说明：

详见:设计文档

编译说明：

make

Running tests

To run tests, call:

    $ make test

It will download kafka's binary tarball during test cases running if you donot have kafka file in testdata. If you already have a running kafka in your enviroment, you can export KAFKA_ADDR and ZOOKEEPER_ADDR before you exec make test. e.g.

	KAFKA_ADDR=localhost:9096 ZOOKEEPER_ADDR=localhost:2181 make test