| // Copyright 2014 The Bazel 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 com.google.devtools.build.lib.events; |
| |
| import java.util.concurrent.atomic.AtomicReference; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Passes through any events, and notes if any of them were errors. It is thread-safe as long as the |
| * target eventHandler is thread-safe. |
| * |
| * <p>Optionally retains the first error event property value associated with a specified class. |
| */ |
| public final class ErrorSensingEventHandler<T> extends DelegatingEventHandler { |
| |
| @Nullable private final Class<T> errorPropertyClass; |
| private final AtomicReference<T> errorProperty = new AtomicReference<>(null); |
| private volatile boolean hasErrors; |
| |
| public ErrorSensingEventHandler( |
| ExtendedEventHandler eventHandler, @Nullable Class<T> errorPropertyClass) { |
| super(eventHandler); |
| this.errorPropertyClass = errorPropertyClass; |
| } |
| |
| public static ErrorSensingEventHandler<Void> withoutPropertyValueTracking( |
| ExtendedEventHandler eventHandler) { |
| return new ErrorSensingEventHandler<>(eventHandler, /*errorPropertyClass=*/ null); |
| } |
| |
| @Override |
| public void handle(Event e) { |
| if (e.getKind() == EventKind.ERROR) { |
| hasErrors = true; |
| if (errorPropertyClass != null) { |
| T propertyValue = e.getProperty(errorPropertyClass); |
| if (propertyValue != null) { |
| errorProperty.compareAndSet(/*expect=*/ null, /*update=*/ propertyValue); |
| } |
| } |
| } |
| super.handle(e); |
| } |
| |
| /** Returns whether any of the events on this objects were errors. */ |
| public boolean hasErrors() { |
| return hasErrors; |
| } |
| |
| /** Returns the retained error event property value, if any. */ |
| @Nullable |
| public T getErrorProperty() { |
| return errorProperty.get(); |
| } |
| } |