The Tor Browser / file revision

 /*

  * Copyright (C) 2013 Square, Inc.

  *

  * 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.squareup.picasso;

 import android.content.Context;

 import android.net.Uri;

 import android.net.http.HttpResponseCache;

 import android.os.Build;

 import java.io.File;

 import java.io.IOException;

 import java.net.HttpURLConnection;

 import java.net.URL;

 import static com.squareup.picasso.Utils.parseResponseSourceHeader;

 /**

  * A {@link Downloader} which uses {@link HttpURLConnection} to download images. A disk cache of 2%

  * of the total available space will be used (capped at 50MB) will automatically be installed in the

  * application's cache directory, when available.

  */

 public class UrlConnectionDownloader implements Downloader {

   static final String RESPONSE_SOURCE = "X-Android-Response-Source";

   private static final Object lock = new Object();

   static volatile Object cache;

   private final Context context;

   public UrlConnectionDownloader(Context context) {

     this.context = context.getApplicationContext();

   }

   protected HttpURLConnection openConnection(Uri path) throws IOException {

     HttpURLConnection connection = (HttpURLConnection) new URL(path.toString()).openConnection();

     connection.setConnectTimeout(Utils.DEFAULT_CONNECT_TIMEOUT);

     connection.setReadTimeout(Utils.DEFAULT_READ_TIMEOUT);

     return connection;

   }

   @Override public Response load(Uri uri, boolean localCacheOnly) throws IOException {

     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {

       installCacheIfNeeded(context);

     }

     HttpURLConnection connection = openConnection(uri);

     connection.setUseCaches(true);

     if (localCacheOnly) {

       connection.setRequestProperty("Cache-Control", "only-if-cached,max-age=" + Integer.MAX_VALUE);

     }

     int responseCode = connection.getResponseCode();

     if (responseCode >= 300) {

       connection.disconnect();

       throw new ResponseException(responseCode + " " + connection.getResponseMessage());

     }

     boolean fromCache = parseResponseSourceHeader(connection.getHeaderField(RESPONSE_SOURCE));

     return new Response(connection.getInputStream(), fromCache);

   }

   private static void installCacheIfNeeded(Context context) {

     // DCL + volatile should be safe after Java 5.

     if (cache == null) {

       try {

         synchronized (lock) {

           if (cache == null) {

             cache = ResponseCacheIcs.install(context);

           }

         }

       } catch (IOException ignored) {

       }

     }

   }

   private static class ResponseCacheIcs {

     static Object install(Context context) throws IOException {

       File cacheDir = Utils.createDefaultCacheDir(context);

       HttpResponseCache cache = HttpResponseCache.getInstalled();

       if (cache == null) {

         long maxSize = Utils.calculateDiskCacheSize(cacheDir);

         cache = HttpResponseCache.install(cacheDir, maxSize);

       }

       return cache;

     }

   }

 }