google-nomulus/java/google/registry/util/RequestStatusCheckerImpl.java
guyben fa70bd272a Add tool to check if other requests are still running
This is needed for the Lock.java enhancement where a lock will be implicitly
released if the request owning it dies.

No matter which solution we want for refactoring the Lock itself, we will need this class.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167600314
2017-09-12 15:51:50 -04:00

83 lines
3.2 KiB
Java

// Copyright 2017 The Nomulus Authors. All Rights Reserved.
//
// 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.
package google.registry.util;
import com.google.appengine.api.log.LogQuery;
import com.google.appengine.api.log.LogService;
import com.google.appengine.api.log.LogServiceFactory;
import com.google.appengine.api.log.RequestLogs;
import com.google.apphosting.api.ApiProxy;
import com.google.apphosting.api.ApiProxy.Environment;
import com.google.common.collect.Iterables;
import java.util.Collections;
import javax.inject.Inject;
/** Implementation of the {@link RequestStatusChecker} interface. */
public class RequestStatusCheckerImpl implements RequestStatusChecker {
private static final long serialVersionUID = -8161977032130865437L;
private static final FormattingLogger logger = FormattingLogger.getLoggerForCallerClass();
/**
* The key to {@link Environment#getAttributes}'s request_log_id value.
*/
private static final String REQUEST_LOG_ID_KEY = "com.google.appengine.runtime.request_log_id";
private static final LogService LOG_SERVICE = LogServiceFactory.getLogService();
@Inject public RequestStatusCheckerImpl() {}
/**
* Returns the unique log identifier of the current request.
*
* <p>May be safely called multiple times, will always return the same result (within the same
* request).
*
* @see <a href="https://cloud.google.com/appengine/docs/standard/java/how-requests-are-handled#request-ids">appengine documentation</a>
*/
@Override
public String getLogId() {
String requestLogId =
ApiProxy.getCurrentEnvironment().getAttributes().get(REQUEST_LOG_ID_KEY).toString();
logger.infofmt("Current requestLogId: %s", requestLogId);
return requestLogId;
}
/**
* Returns true if the given request is currently running.
*
* @see <a href="https://cloud.google.com/appengine/docs/standard/java/javadoc/com/google/appengine/api/log/LogQuery">appengine documentation</a>
*/
@Override
public boolean isRunning(String requestLogId) {
RequestLogs requestLogs =
Iterables.getOnlyElement(
LOG_SERVICE.fetch(
LogQuery.Builder.withRequestIds(
Collections.singletonList(requestLogId))),
null);
// requestLogs will be null if that requestLogId isn't found at all, which also implies it's not
// running.
if (requestLogs == null) {
logger.infofmt(
"Queried an unrecognized requestLogId %s - assume it isn't running", requestLogId);
return false;
}
logger.infofmt(
"Found logs for requestLogId %s - isFinished: %s", requestLogId, requestLogs.isFinished());
return !requestLogs.isFinished();
}
}