it.unimi.dsi.fastutil.IndirectDoublePriorityQueues Maven / Gradle / Ivy
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package it.unimi.dsi.fastutil;
/*
* Copyright (C) 2003-2017 Sebastiano Vigna
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.util.Comparator;
import java.util.NoSuchElementException;
/** A class providing static methods and objects that do useful things with indirect priority queues.
*
* @see IndirectDoublePriorityQueue
*/
public class IndirectDoublePriorityQueues {
private IndirectDoublePriorityQueues() {}
/** An immutable class representing the empty indirect double priority queue.
*
* This class may be useful to implement your own in case you subclass
* {@link IndirectDoublePriorityQueue}.
*/
public static class EmptyIndirectDoublePriorityQueue extends IndirectPriorityQueues.EmptyIndirectPriorityQueue {
protected EmptyIndirectDoublePriorityQueue() {}
public int secondaryFirst() { throw new NoSuchElementException(); }
public int secondaryLast() { throw new NoSuchElementException(); }
public Comparator secondaryComparator() { return null; }
}
/** An empty indirect double priority queue (immutable).
*/
public final static EmptyIndirectDoublePriorityQueue EMPTY_QUEUE = new EmptyIndirectDoublePriorityQueue();
/** A synchronized wrapper class for indirect double priority queues. */
public static class SynchronizedIndirectDoublePriorityQueue implements IndirectDoublePriorityQueue {
public static final long serialVersionUID = -7046029254386353129L;
final protected IndirectDoublePriorityQueue q;
final protected Object sync;
protected SynchronizedIndirectDoublePriorityQueue( final IndirectDoublePriorityQueue q, final Object sync ) {
this.q = q;
this.sync = sync;
}
protected SynchronizedIndirectDoublePriorityQueue( final IndirectDoublePriorityQueue q ) {
this.q = q;
this.sync = this;
}
public void enqueue( int index ) { synchronized( sync ) { q.enqueue( index ); } }
public int dequeue() { synchronized( sync ) { return q.dequeue(); } }
public int first() { synchronized( sync ) { return q.first(); } }
public int last() { synchronized( sync ) { return q.last(); } }
public boolean contains( final int index ) { synchronized( sync ) { return q.contains( index ); } }
public int secondaryFirst() { synchronized( sync ) { return q.secondaryFirst(); } }
public int secondaryLast() { synchronized( sync ) { return q.secondaryLast(); } }
public boolean isEmpty() { synchronized( sync ) { return q.isEmpty(); } }
public int size() { synchronized( sync ) { return q.size(); } }
public void clear() { synchronized( sync ) { q.clear(); } }
public void changed() { synchronized( sync ) { q.changed(); } }
public void allChanged() { synchronized( sync ) { q.allChanged(); } }
public void changed( int i ) { synchronized( sync ) { q.changed( i ); } }
public boolean remove( int i ) { synchronized( sync ) { return q.remove( i ); } }
public Comparator comparator() { synchronized( sync ) { return q.comparator(); } }
public Comparator secondaryComparator() { synchronized( sync ) { return q.secondaryComparator(); } }
public int secondaryFront( int[] a ) { return q.secondaryFront( a ); }
public int front( int[] a ) { return q.front( a ); }
}
/** Returns a synchronized type-specific indirect double priority queue backed by the specified type-specific indirect double priority queue.
*
* @param q the indirect double priority queue to be wrapped in a synchronized indirect double priority queue.
* @return a synchronized view of the specified indirect double priority queue.
*/
public static IndirectDoublePriorityQueue synchronize( final IndirectDoublePriorityQueue q ) { return new SynchronizedIndirectDoublePriorityQueue( q ); }
/** Returns a synchronized type-specific indirect double priority queue backed by the specified type-specific indirect double priority queue, using an assigned object to synchronize.
*
* @param q the indirect double priority queue to be wrapped in a synchronized indirect double priority queue.
* @param sync an object that will be used to synchronize the access to the indirect double priority queue.
* @return a synchronized view of the specified indirect double priority queue.
*/
public static IndirectDoublePriorityQueue synchronize( final IndirectDoublePriorityQueue q, final Object sync ) { return new SynchronizedIndirectDoublePriorityQueue( q, sync ); }
}