模块 roaringbitmap

程序包 org.bitlap.roaringbitmap

类 ParallelAggregation

java.lang.Object

org.bitlap.roaringbitmap.ParallelAggregation

public class ParallelAggregation
extends 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 = ...
       RoaringBitmap[] bitmaps = ...
       // executes on executors threads
       RoaringBitmap result = executor.submit(() -> ParallelAggregation.or(bitmaps)).get();
 
 

嵌套类概要

嵌套类

修饰符和类型	类	说明
static class	ParallelAggregation.ContainerCollector	Collects containers grouped by their key into a RoaringBitmap, applying the supplied aggregation function to each group.
static class	ParallelAggregation.OrCollector	Collects a list of containers into a single container.

构造器概要

构造器

构造器	说明
ParallelAggregation()

方法概要

修饰符和类型	方法	说明
static SortedMap<Character,List<Container>>	groupByKey(RoaringBitmap... bitmaps)	Groups the containers by their keys
static RoaringBitmap	or(RoaringBitmap... bitmaps)	Computes the bitwise union of the input bitmaps
static RoaringBitmap	xor(RoaringBitmap... 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

ParallelAggregation

public ParallelAggregation()

方法详细资料

groupByKey

public static SortedMap<Character,List<Container>> groupByKey(RoaringBitmap... 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 RoaringBitmap or(RoaringBitmap... 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 RoaringBitmap xor(RoaringBitmap... bitmaps)

Computes the bitwise symmetric difference of the input bitmaps

参数:

bitmaps - the input bitmaps

返回:

the symmetric difference of the bitmaps