AssetDownloader.java

/*
 * This file is part of FTB Launcher.
 *
 * Copyright © 2012-2016, FTB Launcher Contributors <https://github.com/Slowpoke101/FTBLaunch/>
 * FTB Launcher is 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 net.ftb.download.workers;

import static com.google.common.net.HttpHeaders.CACHE_CONTROL;
import static com.google.common.net.HttpHeaders.CONTENT_LENGTH;
import static com.google.common.net.HttpHeaders.CONTENT_MD5;
import static com.google.common.net.HttpHeaders.ETAG;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URLConnection;
import java.util.List;

import javax.swing.ProgressMonitor;
import javax.swing.SwingWorker;

import com.google.common.collect.Lists;

import lombok.Getter;
import net.ftb.download.info.DownloadInfo;
import net.ftb.download.info.DownloadInfo.DLType;
import net.ftb.log.Logger;
import net.ftb.util.DownloadUtils;

public class AssetDownloader extends SwingWorker<Boolean, Void>
{
	private List<DownloadInfo> downloads;
	private final ProgressMonitor monitor;
	private int progressIndex = 0;
	private boolean allDownloaded = true;

	@Getter
	private String status;
	@Getter
	private int ready = 0;

	public AssetDownloader (final ProgressMonitor monitor, List<DownloadInfo> downloads)
	{
		this.downloads = downloads;
		this.monitor = monitor;
	}

	@Override
	protected Boolean doInBackground () throws Exception
	{
		for(DownloadInfo download : downloads)
		{
			if (isCancelled())
			{
				return false;
			}
			doDownload(download);
		}
		setStatus(allDownloaded ? "Success" : "Downloads failed");
		return allDownloaded;
	}

	public synchronized void setReady (int newReady)
	{
		int oldReady = ready;
		ready = newReady;
		firePropertyChange("ready", oldReady, ready);
	}

	public synchronized void setStatus (String newStatus)
	{
		String oldStatus = status;
		status = newStatus;
		firePropertyChange("note", oldStatus, status);
	}

	private void doDownload (DownloadInfo asset)
	{
		byte[] buffer = new byte[24000];
		boolean downloadSuccess = false;
		List<String> remoteHash = asset.hash;
		String hashType;
		int attempt = 0;
		final int attempts = 5;

		while (!downloadSuccess && (attempt < attempts))
		{
			try
			{
				if (remoteHash == null)
				{
					remoteHash = Lists.newArrayList();
				}
				hashType = asset.hashType;
				if (attempt++ > 0)
				{
					Logger.logInfo("Connecting.. Try " + attempt + " of " + attempts + " for: " + asset.url);
				}

				// Will this break something?
				// HTTPURLConnection con = (HttpURLConnection) asset.url.openConnection();
				URLConnection con = asset.url.openConnection();
				if (con instanceof HttpURLConnection)
				{
					con.setRequestProperty(CACHE_CONTROL, "no-cache, no-transform");
					((HttpURLConnection)con).setRequestMethod("HEAD");
					con.connect();
				}

				// gather data for basic checks
				long remoteSize = Long.parseLong(con.getHeaderField(CONTENT_LENGTH));
				if (asset.hash == null && asset.getPrimaryDLType() == DLType.ETag)
				{
					remoteHash.clear();
					remoteHash.add(con.getHeaderField(ETAG).replace("\"", ""));
					hashType = "md5";
				}
				if (asset.hash == null && asset.getPrimaryDLType() == DLType.ContentMD5)
				{
					remoteHash.clear();
					remoteHash.add(con.getHeaderField(CONTENT_MD5).replace("\"", ""));
					hashType = "md5";
				}

				Logger.logDebug(asset.name);
				Logger.logDebug("RemoteSize: " + remoteSize);
				Logger.logDebug("asset.hash: " + asset.hash);
				Logger.logDebug("remoteHash: " + remoteHash);

				// existing file are only added when we want to check file integrity with force update
				if (asset.local.exists())
				{
					long localSize = asset.local.length();
					if (!(con instanceof HttpURLConnection && localSize == remoteSize))
					{
						asset.local.delete();
						Logger.logWarn("Local asset size differs from remote size: " + asset.name + " remote: " + remoteSize + " local: " + localSize);
					}
				}

				if (asset.local.exists())
				{
					doHashCheck(asset, remoteHash);
				}

				if (asset.local.exists())
				{
					downloadSuccess = true;
					progressIndex += 1;
					continue;
				}

				// download if needed
				setProgress(0);
				setStatus("Downloading " + asset.name + "...");
				con = asset.url.openConnection();
				if (con instanceof HttpURLConnection)
				{
					con.setRequestProperty(CACHE_CONTROL, "no-cache, no-transform");
					((HttpURLConnection)con).setRequestMethod("GET");
					con.connect();
				}
				asset.local.getParentFile().mkdirs();
				int readLen;
				int currentSize = 0;
				InputStream input = con.getInputStream();
				FileOutputStream output = new FileOutputStream(asset.local);
				while ((readLen = input.read(buffer, 0, buffer.length)) != -1)
				{
					output.write(buffer, 0, readLen);
					currentSize += readLen;
					int prog = (int)((currentSize / remoteSize) * 100);
					if (prog > 100)
					{
						prog = 100;
					}
					if (prog < 0)
					{
						prog = 0;
					}

					setProgress(prog);

					prog = (progressIndex * 100) + prog;

					setReady(prog);
					// monitor.setProgress(prog);
					// monitor.setNote(status);
				}
				input.close();
				output.close();

				// file downloaded check size
				if (!(con instanceof HttpURLConnection && currentSize > 0 && currentSize == remoteSize))
				{
					asset.local.delete();
					Logger.logWarn("Local asset size differs from remote size: " + asset.name + " remote: " + remoteSize + " local: " + currentSize);
				}

				if (downloadSuccess = doHashCheck(asset, remoteHash))
				{
					progressIndex += 1;
				}
			}
			catch (Exception e)
			{
				downloadSuccess = false;
				Logger.logWarn("Connection failed, trying again", e);
			}
		}
		if (!downloadSuccess)
		{
			allDownloaded = false;
		}
	}

	public boolean doHashCheck (DownloadInfo asset, final List<String> remoteHash) throws IOException
	{
		String hash = DownloadUtils.fileHash(asset.local, asset.hashType).toLowerCase();
		List<String> assetHash = asset.hash;
		boolean good = false;
		if (asset.hash == null)
		{
			if (remoteHash != null)
			{
				assetHash = remoteHash;
			}
			else if (asset.getBackupDLType() == DLType.FTBBackup && DownloadUtils.backupIsValid(asset.local, asset.url.getPath().replace("/FTB2", "")))
			{
				good = true;
			}
		}
		if (good || assetHash != null && assetHash.contains(hash))
		{
			return true;
		}
		Logger.logWarn("Asset hash checking failed: " + asset.name + " " + asset.hashType + " " + hash);// unhashed DL's are not allowed!!!
		asset.local.delete();
		return false;
	}
}