io.opencensus.testing.export.TestHandler Maven / Gradle / Ivy
/*
* Copyright 2017, OpenCensus Authors
*
* 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 io.opencensus.testing.export;
import io.opencensus.trace.export.SpanData;
import io.opencensus.trace.export.SpanExporter;
import java.util.ArrayList;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import javax.annotation.Nullable;
import javax.annotation.concurrent.GuardedBy;
/**
* A {@link SpanExporter.Handler} for testing only.
*
* @since 0.9
*/
public final class TestHandler extends SpanExporter.Handler {
private final Object monitor = new Object();
// TODO: Decide whether to use a different class instead of LinkedList.
@GuardedBy("monitor")
@SuppressWarnings("JdkObsolete")
private final List spanDataList = new LinkedList();
@Override
public void export(Collection spanDataList) {
synchronized (monitor) {
this.spanDataList.addAll(spanDataList);
monitor.notifyAll();
}
}
/**
* Waits until we received numberOfSpans spans to export. Returns the list of exported {@link
* SpanData} objects, otherwise {@code null} if the current thread is interrupted.
*
* @param numberOfSpans the number of minimum spans to be collected.
* @return the list of exported {@link SpanData} objects, otherwise {@code null} if the current
* thread is interrupted.
* @since 0.9
*/
@Nullable
public List waitForExport(int numberOfSpans) {
List ret;
synchronized (monitor) {
while (spanDataList.size() < numberOfSpans) {
try {
monitor.wait();
} catch (InterruptedException e) {
// Preserve the interruption status as per guidance.
Thread.currentThread().interrupt();
return null;
}
}
ret = new ArrayList(spanDataList);
spanDataList.clear();
}
return ret;
}
}