com.bigdata.bop.engine

Class StandaloneChunkHandler

java.lang.Object

com.bigdata.bop.engine.StandaloneChunkHandler

All Implemented Interfaces:

IChunkHandler

Direct Known Subclasses:

FederationChunkHandler, ManagedHeapStandloneChunkHandler, NativeHeapStandloneChunkHandler

public class StandaloneChunkHandler
extends Object
implements IChunkHandler

Implementation supports a standalone database. Depending on the specific instance used, either the generated chunk is left on the Java heap or it is migrated onto the native heap using a SolutionSetStream. Either way, it is then handed off synchronously using QueryEngine.acceptChunk(IChunkMessage). That method will queue the chunk for asynchronous processing.

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
static IChunkHandler	MANAGED_HEAP_INSTANCE Instance puts all chunks onto the managed object heap.
static IChunkHandler	NATIVE_HEAP_INSTANCE Instance puts all chunks onto the native heap.
static IChunkHandler	TEST_INSTANCE This instance is explicitly used for several unit tests in the query engine package that are not written to the RDF data model (the native heap version assumes an RDF data model).

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StandaloneChunkHandler(boolean nativeHeap)

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.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NATIVE_HEAP_INSTANCE

public static final IChunkHandler NATIVE_HEAP_INSTANCE

Instance puts all chunks onto the native heap.

See Also:

Vector query engine on native heap.

MANAGED_HEAP_INSTANCE

public static final IChunkHandler MANAGED_HEAP_INSTANCE

Instance puts all chunks onto the managed object heap.

TEST_INSTANCE

public static final IChunkHandler TEST_INSTANCE

This instance is explicitly used for several unit tests in the query engine package that are not written to the RDF data model (the native heap version assumes an RDF data model).

Constructor Detail

StandaloneChunkHandler

protected StandaloneChunkHandler(boolean nativeHeap)

Method Detail

handleChunk

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

Description copied from interface: IChunkHandler

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.

Specified by:

handleChunk in interface IChunkHandler

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.