Package io.prestosql.operator.aggregation.histogram

Class ValueStore

java.lang.Object

io.prestosql.operator.aggregation.histogram.ValueStore

public class ValueStore
extends Object

helper class for GroupedTypedHistogram May be used for other cases that need a simple hash for values

sort of a FlyWeightStore for values--will return unique number for a value. If it exists, you'll get the same number. Class map Value -> number

Note it assumes you're storing # -> Value (Type, Block, position, or the result of the ) somewhere else

Constructor Summary

Constructors

Constructor	Description
ValueStore(Type type, BlockTypeOperators.BlockPositionEqual equalOperator, int expectedSize, BlockBuilder values)

Method Summary

Modifier and Type	Method	Description
int	addAndGetPosition(Block block, int position, long valueHash)	This will add an item if not already in the system.
long	getEstimatedSize()
int	getRehashCount()

Methods inherited from class java.lang.Object

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

Constructor Detail

ValueStore

public ValueStore(Type type,
                  BlockTypeOperators.BlockPositionEqual equalOperator,
                  int expectedSize,
                  BlockBuilder values)

Method Detail

addAndGetPosition

public int addAndGetPosition(Block block,
                             int position,
                             long valueHash)

This will add an item if not already in the system. It returns a pointer that is unique for multiple instances of the value. If item present, returns the pointer into the system

getRehashCount

public int getRehashCount()

getEstimatedSize

public long getEstimatedSize()