public boolean next ( K key , TupleWritable value ) throws IOException { if ( jc . flush ( value ) ) { WritableUtils . cloneInto ( key , jc . key ( ) ) ; return true ; } jc . clear ( ) ; K iterkey = createKey ( ) ; final PriorityQueue < ComposableRecordReader < K , ? > > q = getRecordReaderQueue ( ) ; while ( ! q . isEmpty ( ) ) { fillJoinCollector ( iterkey ) ; jc . reset ( iterkey ) ; if ( jc . flush ( value ) ) { WritableUtils . cloneInto ( key , jc . key ( ) ) ; return true ; } jc . clear ( ) ; } return false ; }
Emit the next set of key value pairs as defined by the child RecordReaders and operation associated with this composite RR .