com.google.errorprone.apply.DiffApplier.java Source code

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Here is the source code for com.google.errorprone.apply.DiffApplier.java

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/*
 * Copyright 2011 Google Inc. 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.errorprone.apply;

import com.google.common.base.Preconditions;
import com.google.common.base.Stopwatch;
import com.google.common.collect.Iterables;
import com.google.common.collect.Sets;
import com.google.common.util.concurrent.AbstractService;
import java.io.IOException;
import java.util.Set;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentSkipListSet;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Applier of diffs to Java source code
 *
 * @author alexeagle@google.com (Alex Eagle)
 * @author sjnickerson@google.com (Simon Nickerson)
 */
public class DiffApplier extends AbstractService {
    private static final Logger logger = Logger.getLogger(DiffApplier.class.getName());
    private final ExecutorService workerService;
    private final Set<String> refactoredPaths;
    private final Set<String> diffsFailedPaths;
    private final FileSource source;
    private final FileDestination destination;
    private final AtomicInteger completedFiles;
    private final Stopwatch stopwatch;

    // the number of diffs in flight, plus 1 if the service is in the RUNNING state
    private final AtomicInteger runState = new AtomicInteger();

    public DiffApplier(int diffParallelism, FileSource source, FileDestination destination) {
        Preconditions.checkNotNull(source);
        Preconditions.checkNotNull(destination);
        this.diffsFailedPaths = new ConcurrentSkipListSet<>();
        this.refactoredPaths = Sets.newConcurrentHashSet();
        this.source = source;
        this.destination = destination;
        this.completedFiles = new AtomicInteger(0);
        this.stopwatch = Stopwatch.createUnstarted();
        // configure a bounded queue and a rejectedexecutionpolicy.
        // In this case CallerRuns may be appropriate.
        this.workerService = new ThreadPoolExecutor(0, diffParallelism, 5, TimeUnit.SECONDS,
                new ArrayBlockingQueue<Runnable>(50), new ThreadPoolExecutor.CallerRunsPolicy());
    }

    @Override
    protected void doStart() {
        stopwatch.start();
        runState.incrementAndGet();
        notifyStarted();
    }

    @Override
    protected void doStop() {
        decrementTasks(); // matches the increment in doStart();
    }

    private final void decrementTasks() {
        if (runState.decrementAndGet() == 0) {
            workerService.shutdown();
            try {
                destination.flush();
                notifyStopped();
            } catch (Exception e) {
                notifyFailed(e);
            }
            logger.log(Level.INFO, String.format("Completed %d files in %s", completedFiles.get(), stopwatch));
            if (!diffsFailedPaths.isEmpty()) {
                logger.log(Level.SEVERE, String.format("Diffs failed to apply to %d files: %s",
                        diffsFailedPaths.size(), Iterables.limit(diffsFailedPaths, 30)));
            }
        }
    }

    private final class Task implements Runnable {
        private final Diff diff;

        Task(Diff diff) {
            this.diff = diff;
        }

        @Override
        public void run() {
            try {
                SourceFile file = source.readFile(diff.getRelevantFileName());
                diff.applyDifferences(file);
                destination.writeFile(file);

                int completed = completedFiles.incrementAndGet();
                if (completed % 100 == 0) {
                    logger.log(Level.INFO, String.format("Completed %d files in %s", completed, stopwatch));
                }
            } catch (IOException | DiffNotApplicableException e) {
                logger.log(Level.WARNING, "Failed to apply diff to file " + diff.getRelevantFileName(), e);
                diffsFailedPaths.add(diff.getRelevantFileName());
            } finally {
                decrementTasks();
            }
        }
    }

    public Future<?> put(Diff diff) {
        if (refactoredPaths.add(diff.getRelevantFileName())) {
            runState.incrementAndGet();
            return workerService.submit(new Task(diff));
        }
        return null;
    }
}