io.prestosql.operator.aggregation.histogram

Class GroupedTypedHistogram

java.lang.Object

io.prestosql.operator.aggregation.histogram.GroupedTypedHistogram

All Implemented Interfaces:

TypedHistogram

public class GroupedTypedHistogram
extends Object
implements TypedHistogram

implementation that uses groupId in the hash key, so that we may store all groupId x value -> count in one giant map. The value, however, is normalized into a single ValueBuilder. Further, we do not have per-group instances of objects. In order to construct a histogram for a group on demand, a linked list for each group is stored that overlays all virtual nodes (a shared index, i, across parallel arrays).

 eg,
 heads[100] -> 3

 means the first piece of data is (values[valuePositions[3]], counts[3])
 If next[3] is 10, then we look at (values[valuePositions[10]], counts[10])

 and so on to construct the value, count pairs needed. An iterator-style function, readAllValues, exists and the caller may do whatever want with the
 values.

 

Constructor Summary

Constructors

Constructor and Description
GroupedTypedHistogram(long groupId, Block block, Type type, int bucketId) TODO: use RowBlock in the future
GroupedTypedHistogram(Type type, int expectedCount)

Method Summary

Modifier and Type	Method and Description
void	add(int position, Block block, long count)
void	addAll(TypedHistogram other)
void	ensureCapacity(long size)
long	getEstimatedSize()
int	getExpectedSize()
Type	getType()
boolean	isEmpty()
void	readAllValues(HistogramValueReader reader)
void	serialize(BlockBuilder out)
TypedHistogram	setGroupId(long groupId)

Methods inherited from class java.lang.Object

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

Constructor Detail

GroupedTypedHistogram

public GroupedTypedHistogram(Type type,
                             int expectedCount)

GroupedTypedHistogram

public GroupedTypedHistogram(long groupId,
                             Block block,
                             Type type,
                             int bucketId)

TODO: use RowBlock in the future

Parameters:

block - of the form [key1, count1, key2, count2, ...]

Method Detail

ensureCapacity

public void ensureCapacity(long size)

Specified by:

ensureCapacity in interface TypedHistogram

getEstimatedSize

public long getEstimatedSize()

Specified by:

getEstimatedSize in interface TypedHistogram

serialize

public void serialize(BlockBuilder out)

Specified by:

serialize in interface TypedHistogram

addAll

public void addAll(TypedHistogram other)

Specified by:

addAll in interface TypedHistogram

readAllValues

public void readAllValues(HistogramValueReader reader)

Specified by:

readAllValues in interface TypedHistogram

setGroupId

public TypedHistogram setGroupId(long groupId)

Specified by:

setGroupId in interface TypedHistogram

getType

public Type getType()

Specified by:

getType in interface TypedHistogram

getExpectedSize

public int getExpectedSize()

Specified by:

getExpectedSize in interface TypedHistogram

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface TypedHistogram

add

public void add(int position,
                Block block,
                long count)

Specified by:

add in interface TypedHistogram