org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast

Class VectorMapJoinFastBytesHashMultiSetStore

java.lang.Object

org.apache.hadoop.hive.ql.exec.vector.mapjoin.fast.VectorMapJoinFastBytesHashMultiSetStore

All Implemented Interfaces:

MemoryEstimate

public class VectorMapJoinFastBytesHashMultiSetStore
extends Object
implements MemoryEstimate

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	VectorMapJoinFastBytesHashMultiSetStore.HashMultiSetResult A hash multi-set result that can read the set membership count for the key.

Constructor Summary

Constructors

Constructor and Description
VectorMapJoinFastBytesHashMultiSetStore(int writeBuffersSize)

Method Summary

Modifier and Type	Method and Description
long	addFirst(long partialHashCode, byte[] keyBytes, int keyStart, int keyLength) Two 64-bit long result is the key and value reference.
long	bumpCount(long refWord, WriteBuffers.Position unsafeReadPos)
long	getEstimatedMemorySize()
WriteBuffers	getWriteBuffers() A store for a key and set membership count in memory.

Methods inherited from class java.lang.Object

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

Constructor Detail

VectorMapJoinFastBytesHashMultiSetStore

public VectorMapJoinFastBytesHashMultiSetStore(int writeBuffersSize)

Method Detail

getWriteBuffers

public WriteBuffers getWriteBuffers()

A store for a key and set membership count in memory. The memory is a "infinite" byte array as a WriteBuffers object. We give the client (e.g. hash multi-set logic) a 64-bit key and count reference to keep that has the offset within the "infinite" byte array of the key. The 64 bits includes about half of the upper hash code to help during matching. We optimize the common case when the key length is short and store that information in the 64 bit reference. Cases: 1) One element when key and is small (and stored in the reference word): Key and Value Reference | | absoluteOffset | -------------------------------------- | v <4 bytes's for set membership count> <Key Bytes> COUNT KEY NOTE: MultiSetCount.byteLength = 4 2) One element, general: shows optional big key length. Key and Value Reference | | absoluteOffset | ------------------------------------- | v <4 byte's for set membership count> [Big Key Length] <Key Bytes> NEXT (NONE) optional KEY

addFirst

public long addFirst(long partialHashCode,
                     byte[] keyBytes,
                     int keyStart,
                     int keyLength)

Two 64-bit long result is the key and value reference.

Parameters:

partialHashCode -

keyBytes -

keyStart -

keyLength -

bumpCount

public long bumpCount(long refWord,
                      WriteBuffers.Position unsafeReadPos)

Parameters:

refWord -

getEstimatedMemorySize

public long getEstimatedMemorySize()

Specified by:

getEstimatedMemorySize in interface MemoryEstimate