/**
* Licensed to Cloudera, Inc. under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Cloudera, Inc. licenses this file
* to you 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.
*/
package org.arabidopsis.ahocorasick;
import java.util.ArrayList;
/**
* Quick-and-dirty queue class. Essentially uses two lists to represent a queue.
*/
class Queue<T> {
ArrayList<State<T>> l1;
ArrayList<State<T>> l2;
public Queue() {
l1 = new ArrayList<State<T>>();
l2 = new ArrayList<State<T>>();
}
public void add(State<T> s) {
l2.add(s);
}
public boolean isEmpty() {
return l1.isEmpty() && l2.isEmpty();
}
public State<T> pop() {
if (isEmpty())
throw new IllegalStateException();
if (l1.isEmpty()) {
for (int i = l2.size() - 1; i >= 0; i--)
l1.add(l2.remove(i));
assert l2.isEmpty();
assert !l1.isEmpty();
}
return l1.remove(l1.size() - 1);
}
}