1 /* 2 * Copyright 2017, OpenCensus Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package io.opencensus.testing.export; 18 19 import io.opencensus.trace.export.SpanData; 20 import io.opencensus.trace.export.SpanExporter; 21 import java.util.ArrayList; 22 import java.util.Collection; 23 import java.util.LinkedList; 24 import java.util.List; 25 import javax.annotation.Nullable; 26 import javax.annotation.concurrent.GuardedBy; 27 28 /** 29 * A {@link SpanExporter.Handler} for testing only. 30 * 31 * @since 0.9 32 */ 33 public final class TestHandler extends SpanExporter.Handler { 34 35 private final Object monitor = new Object(); 36 37 // TODO: Decide whether to use a different class instead of LinkedList. 38 @GuardedBy("monitor") 39 @SuppressWarnings("JdkObsolete") 40 private final List<SpanData> spanDataList = new LinkedList<SpanData>(); 41 42 @Override export(Collection<SpanData> spanDataList)43 public void export(Collection<SpanData> spanDataList) { 44 synchronized (monitor) { 45 this.spanDataList.addAll(spanDataList); 46 monitor.notifyAll(); 47 } 48 } 49 50 /** 51 * Waits until we received numberOfSpans spans to export. Returns the list of exported {@link 52 * SpanData} objects, otherwise {@code null} if the current thread is interrupted. 53 * 54 * @param numberOfSpans the number of minimum spans to be collected. 55 * @return the list of exported {@link SpanData} objects, otherwise {@code null} if the current 56 * thread is interrupted. 57 * @since 0.9 58 */ 59 @Nullable waitForExport(int numberOfSpans)60 public List<SpanData> waitForExport(int numberOfSpans) { 61 List<SpanData> ret; 62 synchronized (monitor) { 63 while (spanDataList.size() < numberOfSpans) { 64 try { 65 monitor.wait(); 66 } catch (InterruptedException e) { 67 // Preserve the interruption status as per guidance. 68 Thread.currentThread().interrupt(); 69 return null; 70 } 71 } 72 ret = new ArrayList<SpanData>(spanDataList); 73 spanDataList.clear(); 74 } 75 return ret; 76 } 77 } 78