Issue 4977 - Request for compressed response in AndroidWebRequest

libadblockplus-android/src/org/adblockplus/libadblockplus/android/AndroidWebRequest.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 package org.adblockplus.libadblockplus.android;
 
 import java.io.BufferedReader;
+import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.zip.GZIPInputStream;
 
 import org.adblockplus.libadblockplus.AdblockPlusException;
 import org.adblockplus.libadblockplus.FilterEngine;
 import org.adblockplus.libadblockplus.HeaderEntry;
 import org.adblockplus.libadblockplus.ServerResponse;
 import org.adblockplus.libadblockplus.ServerResponse.NsStatus;
 import org.adblockplus.libadblockplus.WebRequest;
 
 import android.util.Log;
 
 public class AndroidWebRequest extends WebRequest
 {
+  protected static final String ENCODING_GZIP = "gzip";
+  protected static final String ENCODING_IDENTITY = "identity";
+
   public final static String TAG = Utils.getTag(WebRequest.class);
 
   private final HashSet<String> subscriptionURLs = new HashSet<String>();
   private final boolean elemhideEnabled;
+  private final boolean compressedStream;
 
-  public AndroidWebRequest(boolean enableElemhide)
+  /**
+   * Ctor
+   * @param enableElemhide Enable element hiding?
+   *                       Element hiding requires significantly more memory
+   *                       but allows better ad blocking
+   * @param compressedStream Request for gzip compressed stream from the server
+   */
+  public AndroidWebRequest(boolean enableElemhide, boolean compressedStream)
   {
     this.elemhideEnabled = enableElemhide;
+    this.compressedStream = compressedStream;
   }
 
   public AndroidWebRequest()
   {
-    this(false);
+    this(false, true);
   }
 
   private boolean isListedSubscriptionUrl(final URL url)
   {
     String toCheck = url.toString();
 
     final int idx = toCheck.indexOf('?');
     if (idx != -1)
     {
       toCheck = toCheck.substring(0, idx);
@@ skipping 14 matching lines @@
   @Override
   public ServerResponse httpGET(final String urlStr, final List<HeaderEntry> headers)
   {
     try
     {
       final URL url = new URL(urlStr);
       Log.d(TAG, "Downloading from: " + url);
 
       final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
       connection.setRequestMethod("GET");
+      connection.setRequestProperty("Accept-Encoding",
+        (compressedStream ? ENCODING_GZIP : ENCODING_IDENTITY));
       connection.connect();
 
       final ServerResponse response = new ServerResponse();
       response.setResponseStatus(connection.getResponseCode());
 
       if (response.getResponseStatus() == 200)
       {
-        final BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
+        final InputStream inputStream =
+          (compressedStream && ENCODING_GZIP.equals(connection.getContentEncoding())
+            ? new GZIPInputStream(connection.getInputStream())
+            : connection.getInputStream());
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
         final StringBuilder sb = new StringBuilder();
 
         String line;
         while ((line = reader.readLine()) != null)
         {
           // We're only appending non-element-hiding filters here.
           //
           // See:
           //      https://issues.adblockplus.org/ticket/303
           //
@@ skipping 35 matching lines @@
       Log.d(TAG, "Downloading finished");
       return response;
     }
     catch (final Throwable t)
     {
       Log.e(TAG, "WebRequest failed", t);
       throw new AdblockPlusException("WebRequest failed", t);
     }
   }
 }