Issue 303 - Don't load element hiding rules

src/org/adblockplus/android/AndroidWebRequest.java

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2014 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.android;
 
-import java.io.InputStream;
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.List;
+import java.util.Locale;
 
 import org.adblockplus.libadblockplus.AdblockPlusException;
 import org.adblockplus.libadblockplus.HeaderEntry;
 import org.adblockplus.libadblockplus.ServerResponse;
+import org.adblockplus.libadblockplus.ServerResponse.NsStatus;
 import org.adblockplus.libadblockplus.WebRequest;
-import org.adblockplus.libadblockplus.ServerResponse.NsStatus;
+import org.apache.commons.lang.StringUtils;
 
 import android.util.Log;
 
 public class AndroidWebRequest extends WebRequest
 {
-  public final String TAG = Utils.getTag(WebRequest.class);
+  public final static String TAG = Utils.getTag(WebRequest.class);
 
-  private static final int INITIAL_BUFFER_SIZE = 65536;
-  private static final int BUFFER_GROWTH_DELTA = 65536;
+  private static boolean mightBeFilterList(URL url)
+  {
+    final String filename = url.getPath();
+
+    return StringUtils.isNotEmpty(filename) && filename.toLowerCase(Locale.US).trim().endsWith(".txt");
+  }
 
   @Override
   public ServerResponse httpGET(final String urlStr, final List<HeaderEntry> headers)
   {
     try
     {
       final URL url = new URL(urlStr);
-      Log.d(this.TAG, "Downloading from: " + url);
+      Log.d(TAG, "Downloading from: " + url);
+
+      final boolean mightBeFilterList = mightBeFilterList(url);
 
       final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
       connection.setRequestMethod("GET");
       connection.connect();
 
       final ServerResponse response = new ServerResponse();
       response.setResponseStatus(connection.getResponseCode());
 
       if (response.getResponseStatus() == 200)
       {
-        final InputStream in = connection.getInputStream();
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
+        final StringBuilder sb = new StringBuilder();
 
-        final byte[] buffer = new byte[4096];
+        if (mightBeFilterList)
+        {
+          String line;
+          while ((line = reader.readLine()) != null)
+          {
+            // We're only appending non-element-hiding filters here.
+            // See: https://issues.adblockplus.org/ticket/303
+            if (line.indexOf('#') == -1)
+            {
+              sb.append(line);
+              sb.append('\n');
+            }
+          }
+        }
+        else
+        {
+          int character;
 
-        byte[] out = new byte[INITIAL_BUFFER_SIZE];
-
-        int pos = 0;
-        for (;;)
-        {
-          final int read = in.read(buffer);
-          if (read < 0)
+          while ((character = reader.read()) != -1)
           {
-            break;
+            sb.append((char) character);
           }
-          if (pos + read > out.length)
-          {
-            final byte[] old = out;
-            out = new byte[out.length + BUFFER_GROWTH_DELTA];
-            System.arraycopy(old, 0, out, 0, pos);
-          }
-          System.arraycopy(buffer, 0, out, pos, read);
-          pos += read;
         }
 
         connection.disconnect();
 
         response.setStatus(NsStatus.OK);
-        response.setResponse(new String(out, 0, pos, "utf-8"));
+        response.setResponse(sb.toString());
       }
       else
       {
         response.setStatus(NsStatus.ERROR_FAILURE);
       }
       return response;
     }
     catch (final Throwable t)
     {
       throw new AdblockPlusException("WebRequest failed", t);
     }
   }
 }