org.gradle.launcher.continuous.TaskInputsWatcher.java Source code

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Here is the source code for org.gradle.launcher.continuous.TaskInputsWatcher.java

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/*
 * Copyright 2015 the original author or 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 org.gradle.launcher.continuous;

import com.google.common.collect.Lists;
import org.gradle.BuildAdapter;
import org.gradle.BuildResult;
import org.gradle.api.Action;
import org.gradle.api.Task;
import org.gradle.api.Transformer;
import org.gradle.api.execution.TaskExecutionGraph;
import org.gradle.api.execution.TaskExecutionGraphListener;
import org.gradle.api.file.FileCollection;
import org.gradle.api.internal.file.FileCollectionInternal;
import org.gradle.api.internal.file.UnionFileCollection;
import org.gradle.api.invocation.Gradle;
import org.gradle.api.logging.Logger;
import org.gradle.api.logging.Logging;
import org.gradle.api.specs.Spec;
import org.gradle.internal.filewatch.FileWatcherEvent;
import org.gradle.internal.filewatch.FileWatcherFactory;
import org.gradle.internal.filewatch.FilteringFileWatcherListener;
import org.gradle.internal.filewatch.StopThenFireFileWatcherListener;
import org.gradle.util.CollectionUtils;

import java.util.Collection;

public class TaskInputsWatcher extends BuildAdapter {
    private final static Logger LOGGER = Logging.getLogger(TaskInputsWatcher.class);
    private final TriggerListener listener;
    private final FileWatcherFactory fileWatcherFactory;
    private final Collection<Task> tasks;

    public TaskInputsWatcher(TriggerListener listener, FileWatcherFactory fileWatcherFactory) {
        this.listener = listener;
        this.fileWatcherFactory = fileWatcherFactory;
        this.tasks = Lists.newLinkedList();
    }

    @Override
    public void buildStarted(Gradle gradle) {
        // Task graph is consumed, so it's empty by the time buildFinished is called
        // Save the list of tasks that will be executed.
        gradle.getTaskGraph().addTaskExecutionGraphListener(new TaskExecutionGraphListener() {
            @Override
            public void graphPopulated(TaskExecutionGraph graph) {
                tasks.addAll(graph.getAllTasks());
            }
        });
    }

    @Override
    public void buildFinished(BuildResult result) {
        final FileCollectionInternal taskInputs = new UnionFileCollection(
                CollectionUtils.collect(tasks, new Transformer<FileCollection, Task>() {
                    public FileCollection transform(Task input) {
                        return input.getInputs().getFiles();
                    }
                }));

        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("Task inputs: {}", taskInputs.getFiles());
        }

        fileWatcherFactory.watch(taskInputs.getFileSystemRoots(), new Action<Throwable>() {
            @Override
            public void execute(Throwable throwable) {
                listener.triggered(
                        new DefaultTriggerDetails(TriggerDetails.Type.STOP, "error " + throwable.getMessage()));
            }
        }, new FilteringFileWatcherListener(new Spec<FileWatcherEvent>() {
            @Override
            public boolean isSatisfiedBy(FileWatcherEvent element) {
                if (LOGGER.isDebugEnabled()) {
                    LOGGER.debug("Received file system event: {}", element);
                }
                return element.getType().equals(FileWatcherEvent.Type.OVERFLOW)
                        || element.getType().equals(FileWatcherEvent.Type.DELETE) // because fileCollection.contains() may not consider files that would be contained if they did exist
                        || taskInputs.contains(element.getFile());
            }
        }, new StopThenFireFileWatcherListener(new Runnable() {
            @Override
            public void run() {
                listener.triggered(new DefaultTriggerDetails(TriggerDetails.Type.REBUILD, "file change"));
            }
        })));
    }
}