Package org.apache.druid.query.groupby.epinephelinae

Class HashVectorGrouper

java.lang.Object

org.apache.druid.query.groupby.epinephelinae.HashVectorGrouper

All Implemented Interfaces:

Closeable, AutoCloseable, VectorGrouper

public class HashVectorGrouper
extends Object
implements VectorGrouper

An implementation of VectorGrouper backed by a growable MemoryOpenHashTable. Growability is implemented in this class because MemoryOpenHashTable is not innately growable.

Constructor Summary

Constructors

Constructor	Description
HashVectorGrouper(com.google.common.base.Supplier<ByteBuffer> bufferSupplier, int keySize, AggregatorAdapters aggregators, int bufferGrouperMaxSize, float maxLoadFactor, int configuredInitialNumBuckets)

Method Summary

Modifier and Type	Method	Description
AggregateResult	aggregateVector(org.apache.datasketches.memory.Memory keySpace, int startRow, int endRow)	Aggregate the current vector of rows from "startRow" to "endRow" using the provided keys.
void	close()	Close the grouper and release associated resources.
int	getTableStart()
void	initVectorized(int maxVectorSize)	Initialize the grouper.
CloseableIterator<Grouper.Entry<MemoryPointer>>	iterator()	Iterate through entry buckets.
void	reset()	Reset the grouper to its initial state.

Methods inherited from class java.lang.Object

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

Constructor Detail

HashVectorGrouper

public HashVectorGrouper(com.google.common.base.Supplier<ByteBuffer> bufferSupplier,
                         int keySize,
                         AggregatorAdapters aggregators,
                         int bufferGrouperMaxSize,
                         float maxLoadFactor,
                         int configuredInitialNumBuckets)

Method Detail

initVectorized

public void initVectorized(int maxVectorSize)

Description copied from interface: VectorGrouper

Initialize the grouper. This method needs to be called before calling VectorGrouper.aggregateVector(org.apache.datasketches.memory.Memory, int, int).

Specified by:

initVectorized in interface VectorGrouper

aggregateVector

public AggregateResult aggregateVector(org.apache.datasketches.memory.Memory keySpace,
                                       int startRow,
                                       int endRow)

Description copied from interface: VectorGrouper

Aggregate the current vector of rows from "startRow" to "endRow" using the provided keys.

Specified by:

aggregateVector in interface VectorGrouper

Parameters:

keySpace - array holding keys, chunked into ints. First (endRow - startRow) keys must be valid.

startRow - row to start at (inclusive).

endRow - row to end at (exclusive).

Returns:

result that indicates how many keys were aggregated (may be partial due to resource limits)

reset

public void reset()

Description copied from interface: VectorGrouper

Reset the grouper to its initial state.

Specified by:

reset in interface VectorGrouper

iterator

public CloseableIterator<Grouper.Entry<MemoryPointer>> iterator()

Description copied from interface: VectorGrouper

Iterate through entry buckets. Each bucket's key is a MemoryPointer object in native byte order.

After you are done with the iterator returned by this method, you should either call VectorGrouper.close() (if you are done with the VectorGrouper) or VectorGrouper.reset() (if you want to reuse it).

Callers must process and discard the returned Grouper.Entrys immediately, because objects may be reused.

Specified by:

iterator in interface VectorGrouper

Returns:

entry iterator

close

public void close()

Description copied from interface: VectorGrouper

Close the grouper and release associated resources.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface VectorGrouper

getTableStart

public int getTableStart()