michael@0: /*
michael@0:  * Copyright (C) 2013 Square, Inc.
michael@0:  *
michael@0:  * Licensed under the Apache License, Version 2.0 (the "License");
michael@0:  * you may not use this file except in compliance with the License.
michael@0:  * You may obtain a copy of the License at
michael@0:  *
michael@0:  *      http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing, software
michael@0:  * distributed under the License is distributed on an "AS IS" BASIS,
michael@0:  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
michael@0:  * See the License for the specific language governing permissions and
michael@0:  * limitations under the License.
michael@0:  */
michael@0: package com.squareup.picasso;
michael@0: 
michael@0: import android.content.Context;
michael@0: import android.net.Uri;
michael@0: import android.net.http.HttpResponseCache;
michael@0: import android.os.Build;
michael@0: import java.io.File;
michael@0: import java.io.IOException;
michael@0: import java.net.HttpURLConnection;
michael@0: import java.net.URL;
michael@0: 
michael@0: import static com.squareup.picasso.Utils.parseResponseSourceHeader;
michael@0: 
michael@0: /**
michael@0:  * A {@link Downloader} which uses {@link HttpURLConnection} to download images. A disk cache of 2%
michael@0:  * of the total available space will be used (capped at 50MB) will automatically be installed in the
michael@0:  * application's cache directory, when available.
michael@0:  */
michael@0: public class UrlConnectionDownloader implements Downloader {
michael@0:   static final String RESPONSE_SOURCE = "X-Android-Response-Source";
michael@0: 
michael@0:   private static final Object lock = new Object();
michael@0:   static volatile Object cache;
michael@0: 
michael@0:   private final Context context;
michael@0: 
michael@0:   public UrlConnectionDownloader(Context context) {
michael@0:     this.context = context.getApplicationContext();
michael@0:   }
michael@0: 
michael@0:   protected HttpURLConnection openConnection(Uri path) throws IOException {
michael@0:     HttpURLConnection connection = (HttpURLConnection) new URL(path.toString()).openConnection();
michael@0:     connection.setConnectTimeout(Utils.DEFAULT_CONNECT_TIMEOUT);
michael@0:     connection.setReadTimeout(Utils.DEFAULT_READ_TIMEOUT);
michael@0:     return connection;
michael@0:   }
michael@0: 
michael@0:   @Override public Response load(Uri uri, boolean localCacheOnly) throws IOException {
michael@0:     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
michael@0:       installCacheIfNeeded(context);
michael@0:     }
michael@0: 
michael@0:     HttpURLConnection connection = openConnection(uri);
michael@0:     connection.setUseCaches(true);
michael@0:     if (localCacheOnly) {
michael@0:       connection.setRequestProperty("Cache-Control", "only-if-cached,max-age=" + Integer.MAX_VALUE);
michael@0:     }
michael@0: 
michael@0:     int responseCode = connection.getResponseCode();
michael@0:     if (responseCode >= 300) {
michael@0:       connection.disconnect();
michael@0:       throw new ResponseException(responseCode + " " + connection.getResponseMessage());
michael@0:     }
michael@0: 
michael@0:     boolean fromCache = parseResponseSourceHeader(connection.getHeaderField(RESPONSE_SOURCE));
michael@0: 
michael@0:     return new Response(connection.getInputStream(), fromCache);
michael@0:   }
michael@0: 
michael@0:   private static void installCacheIfNeeded(Context context) {
michael@0:     // DCL + volatile should be safe after Java 5.
michael@0:     if (cache == null) {
michael@0:       try {
michael@0:         synchronized (lock) {
michael@0:           if (cache == null) {
michael@0:             cache = ResponseCacheIcs.install(context);
michael@0:           }
michael@0:         }
michael@0:       } catch (IOException ignored) {
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   private static class ResponseCacheIcs {
michael@0:     static Object install(Context context) throws IOException {
michael@0:       File cacheDir = Utils.createDefaultCacheDir(context);
michael@0:       HttpResponseCache cache = HttpResponseCache.getInstalled();
michael@0:       if (cache == null) {
michael@0:         long maxSize = Utils.calculateDiskCacheSize(cacheDir);
michael@0:         cache = HttpResponseCache.install(cacheDir, maxSize);
michael@0:       }
michael@0:       return cache;
michael@0:     }
michael@0:   }
michael@0: }