Issue 4231 - Fix unstable FilterEngineTest.testSetRemoveFilterChangeCallback

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

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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 org.adblockplus.libadblockplus.AdblockPlusException;
 import org.adblockplus.libadblockplus.FileSystem;
 import org.adblockplus.libadblockplus.FileSystemUtils;
 
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 
 /**
  * AndroidFileSystem is inefficient for production files routines
  * as C++ streams can't pass JNI layer and be converted into Java streams and vice versa.
  *
  * So in case of any stream routines full stream content is read in either C++ or Java side
- * and it's being passed as string though JNI layer
+ * and it's being passed as bytes array though JNI layer
  *
  * AndroidFileSystem is meant to be used in tests mostly
+ *
+ * All paths are considered relative to the base path, or to be absolute
+ * (see `resolve(String path)`) if no base path is set (see `AndroidFileSystem(File basePath)`)
  */
 public class AndroidFileSystem extends FileSystem
 {
   private File basePath;
 
   public File getBasePath()
   {
     return basePath;
   }
 
   public AndroidFileSystem()
   {
   }
 
   /*
    * Sets the base path, all paths are considered relative to it.
    * @param basePath base path
    */
   public AndroidFileSystem(File basePath)
   {
     this();
     this.basePath = basePath;
   }
 
-  private File buildFullPath(String path)
+  @Override
+  public byte[] read(String path)
   {
-    return basePath != null
-      ? new File(basePath, path)
-      : new File(path);
-  }
-
-  @Override
-  public String read(String path)
-  {
-    File file = buildFullPath(path);
+    File file = new File(path);

[anton, 2017/05/29 11:30:03]

Warning: it does not do resolve() just like in DefaultFileSystem.cpp. This is
going to be updated as soon as it's changed in c++

     if (!file.exists())
     {
       return null;
     }
 
     try
     {
       return FileSystemUtils.readFile(file);
     }
-    catch (FileNotFoundException e)
+    catch (IOException e)
     {
       throw new AdblockPlusException(e);
     }
   }
 
   @Override
-  public void write(String path, String data)
+  public void write(String path, byte[] data)
   {
-    File file = buildFullPath(path);
+    File file = new File(path);

[anton, 2017/05/29 11:30:02]

Warning: it does not do resolve() just like in DefaultFileSystem.cpp. This is
going to be updated as soon as it's changed in c++

     if (file.exists())
     {
       file.delete();
     }
 
     try
     {
       FileSystemUtils.writeFile(file, data);
     }
     catch (IOException e)
     {
       throw new AdblockPlusException(e);
     }
   }
 
   @Override
   public void move(String fromPath, String toPath)
   {
-    File fullFromFile = buildFullPath(fromPath);
-    try
+    File fromFile = new File(fromPath);
+    if (!fromFile.exists())
+      throw new AdblockPlusException("File does not exist: " + fromPath);
+
+    File toFile = new File(toPath);
+    if (!fromFile.renameTo(toFile))
     {
-      String data = FileSystemUtils.readFile(fullFromFile);
-      write(toPath, data);
-      remove(fromPath);
-    }
-    catch (FileNotFoundException e)
-    {
-      throw new AdblockPlusException(e);
+      throw new AdblockPlusException("Failed to move " + fromPath + " to " + toFile);
     }
   }
 
   @Override
   public void remove(String path)
   {
-    File file = buildFullPath(path);
+    File file = new File(path);
     if (file.exists())
     {
       file.delete();
     }
   }
 
   @Override
   public StatResult stat(String path)
   {
-    File file = buildFullPath(path);
+    File file = new File(path);
     return new StatResult(
       file.exists(),
       file.isDirectory(),
       file.isFile(),
       file.lastModified());
   }
 
   @Override
   public String resolve(String path)
   {
-    String fullPath = buildFullPath(path).getAbsolutePath();
-    return basePath != null
-      ? fullPath.substring(basePath.getAbsolutePath().length())
-      : fullPath;
+    return (basePath != null ? new File(basePath, path).getAbsolutePath() : path);
   }
 }