io.druid.query.groupby.epinephelinae

Class LimitedBufferGrouper<KeyType>

java.lang.Object

io.druid.query.groupby.epinephelinae.AbstractBufferGrouper<KeyType>

io.druid.query.groupby.epinephelinae.LimitedBufferGrouper<KeyType>

All Implemented Interfaces:

Grouper<KeyType>, Closeable, AutoCloseable

public class LimitedBufferGrouper<KeyType>
extends AbstractBufferGrouper<KeyType>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LimitedBufferGrouper.BufferGrouperOffsetHeapIndexUpdater

Nested classes/interfaces inherited from interface io.druid.query.groupby.epinephelinae.Grouper

Grouper.BufferComparator, Grouper.Entry<T>, Grouper.KeySerde<T>, Grouper.KeySerdeFactory<T>

Field Summary

Fields inherited from class io.druid.query.groupby.epinephelinae.AbstractBufferGrouper

aggregatorOffsets, aggregators, bucketSize, bufferGrouperMaxSize, bufferSupplier, HASH_SIZE, hashTable, initialBuckets, keySerde, keySize, log, maxLoadFactor

Constructor Summary

Constructors

Constructor and Description
LimitedBufferGrouper(com.google.common.base.Supplier<ByteBuffer> bufferSupplier, Grouper.KeySerde<KeyType> keySerde, ColumnSelectorFactory columnSelectorFactory, AggregatorFactory[] aggregatorFactories, int bufferGrouperMaxSize, float maxLoadFactor, int initialBuckets, int limit, boolean sortHasNonGroupingFields)

Method Summary

Modifier and Type	Method and Description
void	afterAggregateHook(int bucketOffset) Called after a row is aggregated.
boolean	canSkipAggregate(boolean bucketWasUsed, int bucketOffset) Called to check if it's possible to skip aggregation for a row.
int	getLimit()
void	init() Initialize the grouper.
boolean	isInitialized() Check this grouper is initialized or not.
Iterator<Grouper.Entry<KeyType>>	iterator(boolean sorted) Iterate through entries.
void	newBucketHook(int bucketOffset) Called when a new bucket is used for an entry in the hash table.
void	reset() Reset the grouper to its initial state.

Methods inherited from class io.druid.query.groupby.epinephelinae.AbstractBufferGrouper

aggregate, aggregate, bucketEntryForOffset, close, getBuckets, getGrowthCount, getMaxSize, getSize

Methods inherited from class java.lang.Object

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

Constructor Detail

LimitedBufferGrouper

public LimitedBufferGrouper(com.google.common.base.Supplier<ByteBuffer> bufferSupplier,
                            Grouper.KeySerde<KeyType> keySerde,
                            ColumnSelectorFactory columnSelectorFactory,
                            AggregatorFactory[] aggregatorFactories,
                            int bufferGrouperMaxSize,
                            float maxLoadFactor,
                            int initialBuckets,
                            int limit,
                            boolean sortHasNonGroupingFields)

Method Detail

init

public void init()

Description copied from interface: Grouper

Initialize the grouper. This method needs to be called before calling Grouper.aggregate(Object) and Grouper.aggregate(Object, int).

isInitialized

public boolean isInitialized()

Description copied from interface: Grouper

Check this grouper is initialized or not.

Returns:

true if the grouper is already initialized, otherwise false.

newBucketHook

public void newBucketHook(int bucketOffset)

Description copied from class: AbstractBufferGrouper

Called when a new bucket is used for an entry in the hash table. An implementing BufferGrouper class can use this to update its own state, e.g. tracking bucket offsets in a structure outside of the hash table.

Specified by:

newBucketHook in class AbstractBufferGrouper<KeyType>

Parameters:

bucketOffset - offset of the new bucket, within the buffer returned by hashTable.getTableBuffer()

canSkipAggregate

public boolean canSkipAggregate(boolean bucketWasUsed,
                                int bucketOffset)

Description copied from class: AbstractBufferGrouper

Called to check if it's possible to skip aggregation for a row.

Specified by:

canSkipAggregate in class AbstractBufferGrouper<KeyType>

Parameters:

bucketWasUsed - Was the row a new entry in the hash table?

bucketOffset - Offset of the bucket containing this row's entry in the hash table, within the buffer returned by hashTable.getTableBuffer()

Returns:

true if aggregation can be skipped, false otherwise.

afterAggregateHook

public void afterAggregateHook(int bucketOffset)

Description copied from class: AbstractBufferGrouper

Called after a row is aggregated. An implementing BufferGrouper class can use this to update its own state, e.g. reading the new aggregated values for the row's key and acting on that information.

Specified by:

afterAggregateHook in class AbstractBufferGrouper<KeyType>

Parameters:

bucketOffset - Offset of the bucket containing the row that was aggregated, within the buffer returned by hashTable.getTableBuffer()

reset

public void reset()

Description copied from interface: Grouper

Reset the grouper to its initial state.

iterator

public Iterator<Grouper.Entry<KeyType>> iterator(boolean sorted)

Description copied from interface: Grouper

Iterate through entries. If a comparator is provided, do a sorted iteration.

Once this method is called, writes are no longer safe. After you are done with the iterator returned by this method, you should either call Grouper.close() (if you are done with the Grouper), Grouper.reset() (if you want to reuse it), or Grouper.iterator(boolean) again if you want another iterator.

If "sorted" is true then the iterator will return sorted results. It will use KeyType's natural ordering on deserialized objects, and will use the KeySerde#comparator() on serialized objects. Woe be unto you if these comparators are not equivalent.

Parameters:

sorted - return sorted results

Returns:

entry iterator

getLimit

public int getLimit()