| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF 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.apache.lucene.index; |
| |
| import static java.lang.System.nanoTime; |
| |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * An implementation of {@link QueryTimeout} that can be used by the {@link ExitableDirectoryReader} |
| * class to time out and exit out when a query takes a long time to rewrite. |
| */ |
| public class QueryTimeoutImpl implements QueryTimeout { |
| |
| /** The local variable to store the time beyond which, the processing should exit. */ |
| private Long timeoutAt; |
| |
| /** |
| * Sets the time at which to time out by adding the given timeAllowed to the current time. |
| * |
| * @param timeAllowed Number of milliseconds after which to time out. Use {@code Long.MAX_VALUE} |
| * to effectively never time out. |
| */ |
| public QueryTimeoutImpl(long timeAllowed) { |
| if (timeAllowed < 0L) { |
| timeAllowed = Long.MAX_VALUE; |
| } |
| timeoutAt = nanoTime() + TimeUnit.NANOSECONDS.convert(timeAllowed, TimeUnit.MILLISECONDS); |
| } |
| |
| /** |
| * Returns time at which to time out, in nanoseconds relative to the (JVM-specific) epoch for |
| * {@link System#nanoTime()}, to compare with the value returned by {@code nanoTime()}. |
| */ |
| public Long getTimeoutAt() { |
| return timeoutAt; |
| } |
| |
| /** |
| * Return true if {@link #reset()} has not been called and the elapsed time has exceeded the time |
| * allowed. |
| */ |
| @Override |
| public boolean shouldExit() { |
| return timeoutAt != null && nanoTime() - timeoutAt > 0; |
| } |
| |
| /** Reset the timeout value. */ |
| public void reset() { |
| timeoutAt = null; |
| } |
| |
| @Override |
| public String toString() { |
| return "timeoutAt: " + timeoutAt + " (System.nanoTime(): " + nanoTime() + ")"; |
| } |
| } |