/*
* 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.stanbol.commons.testing.http;
import static org.junit.Assert.fail;
/**
* Convenience class for retrying tests
* until timeout or success.
*/
public class RetryLoop {
private final long timeout;
/**
* Interface for conditions to check, isTrue will be called
* repeatedly until success or timeout
*/
public interface Condition {
/**
* Used in failure messages to describe what was expected
*/
String getDescription();
/**
* If true we stop retrying. The RetryLoop retries on AssertionError,
* so if tests fail in this method they are not reported as
* failures but retried.
*/
boolean isTrue() throws Exception;
}
/**
* Retry Condition c until it returns true or timeout. See {@link Condition}
* for isTrue semantics.
*/
public RetryLoop(Condition c, int timeoutSeconds, int intervalBetweenTriesMsec) {
timeout = System.currentTimeMillis() + timeoutSeconds * 1000L;
while (System.currentTimeMillis() < timeout) {
try {
if (c.isTrue()) {
return;
}
} catch (AssertionError ae) {
// Retry JUnit tests failing in the condition as well
reportException(ae);
} catch (Exception e) {
reportException(e);
}
try {
Thread.sleep(intervalBetweenTriesMsec);
} catch (InterruptedException ignore) {
}
}
onTimeout();
fail("RetryLoop failed, condition is false after " + timeoutSeconds + " seconds: " + c.getDescription());
}
/**
* Can be overridden to report Exceptions that happen in the retry loop
*/
protected void reportException(Throwable t) {
}
/**
* Called if the loop times out without success, just before failing
*/
protected void onTimeout() {
}
protected long getRemainingTimeSeconds() {
return Math.max(0L, (timeout - System.currentTimeMillis()) / 1000L);
}
}