com.path.android.jobqueue.CopyOnWriteGroupSet Maven / Gradle / Ivy

Go to download
package com.path.android.jobqueue;

import java.util.ArrayList;
import java.util.Collection;
import java.util.TreeSet;

/**
 * a util class that holds running jobs sorted by name and uniq.
 * it behaves like CopyOnWriteLists
 */
public class CopyOnWriteGroupSet {
    private ArrayList publicClone;
    private final TreeSet internalSet;

    public CopyOnWriteGroupSet() {
        internalSet = new TreeSet();
    }

    public synchronized Collection getSafe() {
        if(publicClone == null) {
            publicClone = new ArrayList(internalSet);
        }
        return publicClone;
    }

    public synchronized void add(String group) {
        if(internalSet.add(group)) {
            publicClone = null;//invalidate
        }
    }

    public synchronized void remove(String group) {
        if(internalSet.remove(group)) {
            publicClone = null;
        }
    }

    public synchronized void clear() {
        internalSet.clear();
        publicClone = null;
    }
}