org.bitlap.roaringbitmap.buffer

类 BufferParallelAggregation

java.lang.Object

org.bitlap.roaringbitmap.buffer.BufferParallelAggregation

public class BufferParallelAggregation
extends java.lang.Object

These utility methods provide parallel implementations of logical aggregation operators. AND is not implemented because it is unlikely to be profitable. There is a temporary memory overhead in using these methods, since a materialisation of the rotated containers grouped by key is created in each case. Each method executes on the default fork join pool by default. If this is undesirable (it usually is) wrap the call inside a submission of a runnable to your own thread pool.

 

       //...

       ExecutorService executor = ...
       ImmutableRoaringBitmap[] bitmaps = ...
       // executes on executors threads
       MutableRoaringBitmap result = executor.submit(
            () -> BufferParallelAggregation.or(bitmaps)).get();
 
 

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	BufferParallelAggregation.ContainerCollector Collects containers grouped by their key into a RoaringBitmap, applying the supplied aggregation function to each group.
static class	BufferParallelAggregation.OrCollector Collects a list of containers into a single container.

构造器概要

构造器

构造器和说明
BufferParallelAggregation()

方法概要

限定符和类型	方法和说明
static java.util.SortedMap<java.lang.Character,java.util.List<MappeableContainer>>	groupByKey(ImmutableRoaringBitmap... bitmaps) Groups the containers by their keys
static MutableRoaringBitmap	or(ImmutableRoaringBitmap... bitmaps) Computes the bitwise union of the input bitmaps
static MutableRoaringBitmap	xor(ImmutableRoaringBitmap... bitmaps) Computes the bitwise symmetric difference of the input bitmaps

从类继承的方法 java.lang.Object

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

构造器详细资料

BufferParallelAggregation

public BufferParallelAggregation()

方法详细资料

groupByKey

public static java.util.SortedMap<java.lang.Character,java.util.List<MappeableContainer>> groupByKey(ImmutableRoaringBitmap... bitmaps)

Groups the containers by their keys

参数:

bitmaps - input bitmaps

返回:

The containers from the bitmaps grouped by key

or

public static MutableRoaringBitmap or(ImmutableRoaringBitmap... bitmaps)

Computes the bitwise union of the input bitmaps

参数:

bitmaps - the input bitmaps

返回:

the union of the bitmaps

xor

public static MutableRoaringBitmap xor(ImmutableRoaringBitmap... bitmaps)

Computes the bitwise symmetric difference of the input bitmaps

参数:

bitmaps - the input bitmaps

返回:

the symmetric difference of the bitmaps