subprojects/viatra-runtime/src/main/java/tools/refinery/viatra/runtime/matchers/util/EclipseCollectionsDeltaBag.java


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

/*******************************************************************************
 * Copyright (c) 2010-2017, Gabor Bergmann, IncQueryLabs Ltd.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-v20.html.
 * 
 * SPDX-License-Identifier: EPL-2.0
 *******************************************************************************/
package tools.refinery.viatra.runtime.matchers.util;

/**
 * @author Gabor Bergmann
 * @since 1.7
 */
public class EclipseCollectionsDeltaBag<T> extends EclipseCollectionsBagMemory<T> implements IDeltaBag<T> {
    
    @Override
    public boolean addOne(T value) {
        return addSigned(value, +1);
    }
    
    @Override
    public boolean addSigned(T value, int count) {
        int oldCount = super.getIfAbsent(value, 0);
        int newCount = oldCount + count;
        
        boolean becomesZero = newCount == 0;
        if (becomesZero)
            super.removeKey(value);
        else 
            super.put(value, newCount);
       
        return becomesZero || oldCount == 0;
    }
    
    
    @Override
    public boolean removeOne(T value) {
        return addSigned(value, -1);
    }
}