DownloadJob.java

package net.minecraft.launcher.updater.download;

import net.minecraft.launcher.Launcher;

import java.util.*;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.atomic.AtomicInteger;

public class DownloadJob {
    private static final int MAX_ATTEMPTS_PER_FILE = 5;
    private static final int ASSUMED_AVERAGE_FILE_SIZE = 5242880;
    private final Queue<Downloadable> remainingFiles = new ConcurrentLinkedQueue();
    private final List<Downloadable> allFiles = Collections.synchronizedList(new ArrayList());
    private final List<Downloadable> failures = Collections.synchronizedList(new ArrayList());
    private final List<Downloadable> successful = Collections.synchronizedList(new ArrayList());
    private final List<ProgressContainer> progressContainers = Collections.synchronizedList(new ArrayList());
    private final DownloadListener listener;
    private final String name;
    private final boolean ignoreFailures;
    private final AtomicInteger remainingThreads = new AtomicInteger();
    private boolean started;

    public DownloadJob(String name, boolean ignoreFailures, DownloadListener listener, Collection<Downloadable> files) {
        this.name = name;
        this.ignoreFailures = ignoreFailures;
        this.listener = listener;
        if (files != null) addDownloadables(files);
    }

    public DownloadJob(String name, boolean ignoreFailures, DownloadListener listener) {
        this(name, ignoreFailures, listener, null);
    }

    public void addDownloadables(Collection<Downloadable> downloadables) {
        if (this.started) throw new IllegalStateException("Cannot add to download job that has already started");

        this.allFiles.addAll(downloadables);
        this.remainingFiles.addAll(downloadables);

        for (Downloadable downloadable : downloadables) {
            this.progressContainers.add(downloadable.getMonitor());
            if (downloadable.getExpectedSize() == 0L)
                downloadable.getMonitor().setTotal(5242880L);
            else {
                downloadable.getMonitor().setTotal(downloadable.getExpectedSize());
            }
            downloadable.getMonitor().setJob(this);
        }
    }

    public void addDownloadables(Downloadable[] downloadables) {
        if (this.started) throw new IllegalStateException("Cannot add to download job that has already started");

        for (Downloadable downloadable : downloadables) {
            this.allFiles.add(downloadable);
            this.remainingFiles.add(downloadable);
            this.progressContainers.add(downloadable.getMonitor());
            if (downloadable.getExpectedSize() == 0L)
                downloadable.getMonitor().setTotal(5242880L);
            else {
                downloadable.getMonitor().setTotal(downloadable.getExpectedSize());
            }
            downloadable.getMonitor().setJob(this);
        }
    }

    public void startDownloading(ThreadPoolExecutor executorService) {
        if (this.started) throw new IllegalStateException("Cannot start download job that has already started");
        this.started = true;

        if (this.allFiles.isEmpty()) {
            Launcher.getInstance().println("Download job '" + this.name + "' skipped as there are no files to download");
            this.listener.onDownloadJobFinished(this);
        } else {
            int threads = executorService.getMaximumPoolSize();
            this.remainingThreads.set(threads);
            Launcher.getInstance().println("Download job '" + this.name + "' started (" + threads + " threads, " + this.allFiles.size() + " files)");
            for (int i = 0; i < threads; i++)
                executorService.submit(new Runnable() {
                    public void run() {
                        DownloadJob.this.popAndDownload();
                    }
                });
        }
    }

    private void popAndDownload() {
        Downloadable downloadable;
        while ((downloadable = (Downloadable) this.remainingFiles.poll()) != null) {
            if (downloadable.getNumAttempts() > 5) {
                if (!this.ignoreFailures) this.failures.add(downloadable);
                Launcher.getInstance().println("Gave up trying to download " + downloadable.getUrl() + " for job '" + this.name + "'");
            } else {
                try {
                    String result = downloadable.download();
                    this.successful.add(downloadable);
                    Launcher.getInstance().println("Finished downloading " + downloadable.getTarget() + " for job '" + this.name + "'" + ": " + result);
                } catch (Throwable t) {
                    Launcher.getInstance().println("Couldn't download " + downloadable.getUrl() + " for job '" + this.name + "'", t);
                    this.remainingFiles.add(downloadable);
                }
            }
        }
        if (this.remainingThreads.decrementAndGet() <= 0)
            this.listener.onDownloadJobFinished(this);
    }

    public boolean shouldIgnoreFailures() {
        return this.ignoreFailures;
    }

    public boolean isStarted() {
        return this.started;
    }

    public boolean isComplete() {
        return (this.started) && (this.remainingFiles.isEmpty()) && (this.remainingThreads.get() == 0);
    }

    public int getFailures() {
        return this.failures.size();
    }

    public int getSuccessful() {
        return this.successful.size();
    }

    public String getName() {
        return this.name;
    }

    public void updateProgress() {
        this.listener.onDownloadJobProgressChanged(this);
    }

    public float getProgress() {
        float current = 0.0F;
        float total = 0.0F;

        synchronized (this.progressContainers) {
            for (ProgressContainer progress : this.progressContainers) {
                total += (float) progress.getTotal();
                current += (float) progress.getCurrent();
            }
        }

        float result = -1.0F;
        if (total > 0.0F) result = current / total;
        return result;
    }
}