hadoop maptask$ mapoutputbuffer类

Serialize the key, value to intermediate storage.
* When this method returns, kvindex must refer to sufficient unused
* storage to store one METADATA.

将keyvalue序列化为中间存储。 当此方法返回时，kvindex必须引用足够的未使用存储来存储一个METADATA

public synchronized void collect(K key, V value, final int partition
) throws IOException {}