Issue 5183 - Provide async interface for FileSystem

include/AdblockPlus/DefaultFileSystem.h

Index: include/AdblockPlus/DefaultFileSystem.h
===================================================================
--- a/include/AdblockPlus/DefaultFileSystem.h
+++ b/include/AdblockPlus/DefaultFileSystem.h
@@ -33,21 +33,34 @@
    * system's file system.
    * All paths are considered relative to the base path, or to the current
    * working directory if no base path is set (see `SetBasePath()`).
    */
   class DefaultFileSystem : public FileSystem

[sergei, 2017/05/26 13:32:04]

I think that there should be a different class implementing asynchronous file
system interface and accepting a smart pointer to synchronous implementation.
The implementation of async interface should run methods of sync interface in
detached threads so far.

   {
   public:
     std::shared_ptr<std::istream> Read(const std::string& path) const;
+    void Read(const std::string& path,
+              const ReadCallback& callback) const;
     void Write(const std::string& path, std::istream& data);
+    void Write(const std::string& path,
+               std::istream& data,
+               const Callback& callback);
     void Move(const std::string& fromPath, const std::string& toPath);
+    void Move(const std::string& fromPath,
+              const std::string& toPath,
+              const Callback& callback);
     void Remove(const std::string& path);
+    void Remove(const std::string& path, const Callback& callback);
     StatResult Stat(const std::string& path) const;
+    void Stat(const std::string& path,
+              const StatCallback& callback) const;
     std::string Resolve(const std::string& path) const;
+    void Resolve(const std::string& path,
+                 const ResolveCallback& callback) const;
 
     /**
      * Sets the base path, all paths are considered relative to it.
      * @param path Base path.
      */
     void SetBasePath(const std::string& path);
 
   protected: