com.bigdata.btree.proc

Class BatchLookup

java.lang.Object

com.bigdata.btree.proc.AbstractIndexProcedure<T>

com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>

com.bigdata.btree.proc.BatchLookup

All Implemented Interfaces:

IIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>, IKeyArrayIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>, IParallelizableIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>, IReadOnly, Externalizable, Serializable

public class BatchLookup
extends AbstractKeyArrayIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>
implements IParallelizableIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>

Batch lookup operation.

Author:

Bryan Thompson

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BatchLookup.BatchLookupConstructor Factory for BatchLookup procedures.

Nested classes/interfaces inherited from class com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure

AbstractKeyArrayIndexProcedure.ResultBitBuffer, AbstractKeyArrayIndexProcedure.ResultBitBufferCounter, AbstractKeyArrayIndexProcedure.ResultBitBufferHandler, AbstractKeyArrayIndexProcedure.ResultBuffer, AbstractKeyArrayIndexProcedure.ResultBufferHandler

Constructor Summary

Constructors

Modifier	Constructor and Description
	BatchLookup() De-serialization ctor.
protected	BatchLookup(IRabaCoder keysCoder, IRabaCoder valsCoder, int fromIndex, int toIndex, byte[][] keys) Create a batch lookup operation.

Method Summary

Methods

Modifier and Type	Method and Description
AbstractKeyArrayIndexProcedure.ResultBuffer	applyOnce(IIndex ndx, IRaba keys, IRaba vals) Apply the procedure to the specified key range of the index.
boolean	isReadOnly() Return true iff the procedure asserts that it will not write on the index.
protected IResultHandler<AbstractKeyArrayIndexProcedure.ResultBuffer,AbstractKeyArrayIndexProcedure.ResultBuffer>	newAggregator() Return an IResultHandler that will be used to combine the results if the index procedure is parallelized against a local index (including a scale-out shard).

Methods inherited from class com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure

apply, getKeys, getKeysCoder, getValues, getValuesCoder, readExternal, readMetadata, writeExternal, writeMetadata

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.btree.proc.IIndexProcedure

apply

Constructor Detail

BatchLookup

public BatchLookup()

De-serialization ctor.

BatchLookup

protected BatchLookup(IRabaCoder keysCoder,
           IRabaCoder valsCoder,
           int fromIndex,
           int toIndex,
           byte[][] keys)

Create a batch lookup operation.

Parameters:

keys - The array of keys (one key per tuple).

See Also:

BatchLookup.BatchLookupConstructor

Method Detail

isReadOnly

public final boolean isReadOnly()

Description copied from interface: IReadOnly

Return true iff the procedure asserts that it will not write on the index. When true, the procedure may be run against a view of the index that is read-only or which allows concurrent processes to read on the same index object. When false the procedure will be run against a mutable view of the index (assuming that the procedure is executed in a context that has access to a mutable index view).

Specified by:

isReadOnly in interface IReadOnly

applyOnce

public AbstractKeyArrayIndexProcedure.ResultBuffer applyOnce(IIndex ndx,
                                                    IRaba keys,
                                                    IRaba vals)

Description copied from class: AbstractKeyArrayIndexProcedure

Apply the procedure to the specified key range of the index.

Specified by:

applyOnce in class AbstractKeyArrayIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>

Parameters:

ndx - The index.

Returns:

AbstractKeyArrayIndexProcedure.ResultBuffer

newAggregator

protected IResultHandler<AbstractKeyArrayIndexProcedure.ResultBuffer,AbstractKeyArrayIndexProcedure.ResultBuffer> newAggregator()

Description copied from class: AbstractKeyArrayIndexProcedure

Return an IResultHandler that will be used to combine the results if the index procedure is parallelized against a local index (including a scale-out shard). If a null is returned, then the index procedure WILL NOT be parallelized against the local index. To parallelize index procedures that do not return anything against a local index, just use NopAggregator. A non-null value will permit both index local parallelization of the index procedure and (in scale-out) parallelization of the index procedure across the shards as well. In order to be parallelized, the index procedure must also be marked as IParallelizableIndexProcedure.

Specified by:

newAggregator in class AbstractKeyArrayIndexProcedure<AbstractKeyArrayIndexProcedure.ResultBuffer>

Returns:

The IResultHandler -or- null

See Also:

NopAggregator, IParallelizableIndexProcedure, (Schedule more IOs when loading data)