com.bigdata.bop.engine

Interface IChunkHandler

All Known Implementing Classes:

FederationChunkHandler, ManagedHeapStandloneChunkHandler, NativeHeapStandloneChunkHandler, StandaloneChunkHandler

public interface IChunkHandler

Interface dispatches an IBindingSet[] chunk generated by a running operator task. Each task may produce zero or more such chunks. The chunks may be combined together by the caller in order to have "chunkier" processing by this interface. The interface is responsible for generating the appropriate IChunkMessage(s) for each IBindingSet[] chunk. In standalone there is a one-to-one relationship between input chunks and output messages. In scale-out, we map each IBindingSet over the shard(s) for the next operator, which is a many-to-one mapping.

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
int	handleChunk(IRunningQuery query, int bopId, int sinkId, IBindingSet[] chunk) Take an IBindingSet[] chunk generated by some pass over an operator and make it available to the target operator.

Method Detail

handleChunk

int handleChunk(IRunningQuery query,
              int bopId,
              int sinkId,
              IBindingSet[] chunk)

Take an IBindingSet[] chunk generated by some pass over an operator and make it available to the target operator. How this is done depends on whether the query is running against a standalone database or the scale-out database.

Note: The return value is used as part of the termination criteria for the query which depends on (a) the #of running operator tasks and (b) the #of IChunkMessages generated (available) and consumed. The return value of this method increases the #of IChunkMessages available to the query.

Parameters:

query - The query.

bopId - The operator which wrote on the sink.

sinkId - The identifier of the target operator.

chunk - The intermediate results to be passed to that target operator.

Returns:

The #of IChunkMessage sent. This will always be ONE (1) for scale-up. For scale-out, there will be at least one IChunkMessage per index partition over which the intermediate results were mapped.