com.yahoo.sketches.theta.AnotB Maven / Gradle / Ivy
/*
* Copyright 2015-16, Yahoo! Inc.
* Licensed under the terms of the Apache License 2.0. See LICENSE file at the project root for terms.
*/
package com.yahoo.sketches.theta;
import com.yahoo.memory.WritableMemory;
import com.yahoo.sketches.Family;
/**
* The API for the set difference operation A and not B operations.
* This is a stateless operation. However, to make the API
* more consistent with the other set operations the intended use is:
*
* AnotB aNotB = SetOperationBuilder.buildAnotB();
* aNotB.update(SketchA, SketchB); //Called only once.
* CompactSketch result = aNotB.getResult();
*
*
* Calling the update function a second time essentially clears the internal state and updates
* with the new pair of sketches.
*
*
As an alternative, one can use the aNotB method that returns the result immediately.
*
* @author Lee Rhodes
*/
public abstract class AnotB extends SetOperation {
@Override
public Family getFamily() {
return Family.A_NOT_B;
}
/**
* Gets the result of this operation as an ordered CompactSketch on the Java heap
* @return the result of this operation as an ordered CompactSketch on the Java heap
*/
public abstract CompactSketch getResult();
/**
* Gets the result of this set operation as a CompactSketch of the chosen form
* @param dstOrdered
* See Destination Ordered.
*
* @param dstMem
* See Destination Memory.
*
* @return the result of this set operation as a CompactSketch of the chosen form
*/
public abstract CompactSketch getResult(boolean dstOrdered, WritableMemory dstMem);
/**
* Perform A-and-not-B set operation on the two given sketches.
* A null sketch is interpreted as an empty sketch.
*
* @param a The incoming sketch for the first argument
* @param b The incoming sketch for the second argument
*/
public abstract void update(Sketch a, Sketch b);
/**
* Perform A-and-not-B set operation on the two given sketches and return the result as an
* ordered CompactSketch on the heap.
* @param a The incoming sketch for the first argument
* @param b The incoming sketch for the second argument
* @return an ordered CompactSketch on the heap
*/
public CompactSketch aNotB(final Sketch a, final Sketch b) {
return aNotB(a, b, true, null);
}
/**
* Perform A-and-not-B set operation on the two given sketches and return the result as a
* CompactSketch.
* @param a The incoming sketch for the first argument
* @param b The incoming sketch for the second argument
* @param dstOrdered
* See Destination Ordered.
* @param dstMem
* See Destination Memory.
* @return the result as a CompactSketch.
*/
public abstract CompactSketch aNotB(Sketch a, Sketch b, boolean dstOrdered,
WritableMemory dstMem);
}