Noissue - Lint adjustments and optimizations

adblockplussbrowser/src/org/adblockplus/sbrowser/contentblocker/engine/Subscription.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
@@ skipping 14 matching lines @@
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.StringReader;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.zip.GZIPInputStream;
 import java.util.zip.GZIPOutputStream;
 
 import android.text.TextUtils;
 import android.text.format.DateUtils;
 import android.util.Log;
 
 /**
  * Simple subscription representation.
  */
 final class Subscription
 {
   private static final String TAG = Subscription.class.getSimpleName();
   public static final String KEY_TITLE = "title";
   public static final String KEY_VERSION = "version";
-  public static final String KEY_FORCED_TITLE = "_title";
   public static final String KEY_HTTP_ETAG = "_etag";
   public static final String KEY_HTTP_LAST_MODIFIED = "_last_modified";
   public static final String KEY_UPDATE_TIMESTAMP = "_update_timestamp";
   public static final String KEY_TRIED_UPDATE_TIMESTAMP = "_tried_update_timestamp";
   public static final String KEY_DOWNLOAD_COUNT = "_download_count";
   public static final String KEY_ENABLED = "_enabled";
-  public static final String KEY_HAS_FILTERS = "_has_filters";
   public static final String KEY_META_HASH = "_meta_hash";
 
   private static final long MINIMAL_DOWNLOAD_INTERVAL = DateUtils.HOUR_IN_MILLIS / 4;
   private static final long DOWNLOAD_RETRY_INTERVAL = DateUtils.HOUR_IN_MILLIS;
 
-  private static final HashSet<String> ALLOWED_META_KEYS = new HashSet<>();
+  /**
+   * List of meta keys that are allowed to import from a downloaded
+   * subscription.
+   */
+  private static final String[] ALLOWED_META_KEYS_ARRAY =
+      {
+          "checksum", KEY_VERSION, KEY_TITLE, "last modified", "expires", "homepage", "licence"
+      };
+  private static final HashSet<String> ALLOWED_META_KEYS =
+      new HashSet<>(Arrays.asList(ALLOWED_META_KEYS_ARRAY));
+
   private static final Locale LOCALE_EN = Locale.ENGLISH;
 
   private final long updateInterval = DateUtils.DAY_IN_MILLIS
       + (long) (DateUtils.HOUR_IN_MILLIS * 8. * Math.random());
-
-  /**
-   * List of meta keys that are allowed to import from a downloaded
-   * subscription.
-   */
-  private static final String[] ALLOWED_META_KEYS_ARRAY =
-  {
-      "checksum", KEY_VERSION, KEY_TITLE, "last modified", "expires", "homepage", "licence"
-  };
 
   private final URL url;
   private final Type type;
   private final HashMap<String, String> meta = new HashMap<>();
   private final HashSet<String> filters = new HashSet<>();
 
   private boolean metaDataValid = true;
   private boolean filtersValid = true;
-
-  static
-  {
-    Collections.addAll(ALLOWED_META_KEYS, ALLOWED_META_KEYS_ARRAY);
-  }
 
   /**
    * Subscription type.
    *
    * @author René Jeschke &lt;rene@adblockplus.org&gt;
    */
   public enum Type
   {
     /**
      * Initiated from an URL, can be automatically downloaded.
@@ skipping 287 matching lines @@
     }
     catch (final NoSuchAlgorithmException e)
     {
       throw new IOException("MD5 is unavailable: " + e.getMessage(), e);
     }
   }
 
   public void serializeMetaData(final File metaFile) throws IOException
   {
     this.putMeta(KEY_META_HASH, createMetaDataHash(this.meta));
     try (final DataOutputStream metaOut = new DataOutputStream(new BufferedOutputStream(

[anton, 2017/06/02 07:39:56]

here and below: what's the purpose of buffering before gzipping?
As for me it seems reasonable to buffer before writing to file to eliminate file
io routines (as it was before).
What am i missing?

[diegocarloslima, 2017/06/02 21:03:42]

Basically, it's because GZIP Streams already hold a buffer inside them, but they
don't expose this buffer. More info here:
https://stackoverflow.com/questions/4438085/seeking-out-the-optimum-size-for-...

         new GZIPOutputStream(new FileOutputStream(metaFile)))))
     {
       metaOut.writeUTF(this.url != null ? this.url.toString() : "");
       metaOut.writeInt(this.meta.size());
       for (final Entry<String, String> e : this.meta.entrySet())
       {
         metaOut.writeUTF(e.getKey());
         metaOut.writeUTF(e.getValue());
       }
     }
@@ skipping 189 matching lines @@
     this.serializeMetaData(metaFile);
     if (filtersChanged)
     {
       this.serializeFilters(filtersFile);
       this.clearFilters();
     }
 
     return filtersChanged;
   }
 }