Template out V8 and prepare for other JS engine implementations

include/AdblockPlus/JsEngine.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 26 matching lines @@
 {
   class Isolate;
   class Value;
   class Context;
   template<typename T> class FunctionCallbackInfo;
   typedef void(*FunctionCallback)(const FunctionCallbackInfo<v8::Value>& info);
 }
 
 namespace AdblockPlus
 {
-  class JsEngine;
   class Platform;
+  template <typename T> class JsEngineTemplate;
 
   /**
    * Shared smart pointer to a `JsEngine` instance.
    */
   typedef std::shared_ptr<JsEngine> JsEnginePtr;
 
   /**
    * Provides with isolate. The main aim of this iterface is to delegate a
    * proper initialization and deinitialization of v8::Isolate to an embedder.
    */
   struct IV8IsolateProvider
   {
     virtual ~IV8IsolateProvider() {}
 
     /**
      * Returns v8::Isolate. All subsequent calls of this method should return
      * the same pointer to v8::Isolate as the first call.
      */
     virtual v8::Isolate* Get() = 0;
   };
 
+  template <typename T>
+  struct JsWeakValuesList
+  {
+    ~JsWeakValuesList();
+    std::vector<T> values;
+  };
+  typedef std::list<JsWeakValuesList<v8::Global<v8::Value>>> JsWeakValuesLists;
+
+  /**
+  * An opaque structure representing ID of stored JsValueList.
+  */
+  class JsWeakValuesID
+  {
+    template <typename T> friend class JsEngineTemplate;
+    JsWeakValuesLists::const_iterator iterator;
+  };
+
+
   /**
    * JavaScript engine used by `FilterEngine`, wraps v8.
    */
-  class JsEngine : public std::enable_shared_from_this<JsEngine>
+  template <typename T> class JsEngineTemplate : public std::enable_shared_from_this<JsEngineTemplate<T>>
   {
-    friend class JsValue;
-    friend class JsContext;
+    template <typename T> friend class JsValueTemplate;
+    template <typename T> friend class JsContextTemplate;
 
-    struct JsWeakValuesList
-    {
-      ~JsWeakValuesList();
-      std::vector<v8::Global<v8::Value>> values;
-    };
-    typedef std::list<JsWeakValuesList> JsWeakValuesLists;
   public:
     /**
      * Event callback function.
      */
     typedef std::function<void(JsValueList&& params)> EventCallback;
 
     /**
      * Maps events to callback functions.
      */
     typedef std::map<std::string, EventCallback> EventMap;
 
     /**
-     * An opaque structure representing ID of stored JsValueList.
-     */
-    class JsWeakValuesID
-    {
-      friend class JsEngine;
-      JsWeakValuesLists::const_iterator iterator;
-    };
-
-    /**
      * Creates a new JavaScript engine instance.
      *
      * @param appInfo Information about the app.
      * @param platform AdblockPlus platform providing with necessary
      *        dependencies.
      * @param isolate A provider of v8::Isolate, if the value is nullptr then
      *        a default implementation is used.
      * @return New `JsEngine` instance.
      */
     static JsEnginePtr New(const AppInfo& appInfo, Platform& platform, std::unique_ptr<IV8IsolateProvider> isolate = nullptr);
@@ skipping 64 matching lines @@
      */
     JsValue NewObject();
 
     /**
      * Creates a JavaScript function that invokes a C++ callback.
      * @param callback C++ callback to invoke. The callback receives a
      *        `v8::FunctionCallbackInfo` object and can use `FromArguments()` to retrieve
      *        the current `JsEngine`.
      * @return New `JsValue` instance.
      */
-    JsValue NewCallback(const v8::FunctionCallback& callback);
+    JsValue NewCallback(const typename T::CallbackFunc& callback);
 
     /**
      * Returns a `JsEngine` instance contained in a `v8::FunctionCallbackInfo` object.
      * Use this in callbacks created via `NewCallback()` to retrieve the current
      * `JsEngine`.
      * @param arguments `v8::FunctionCallbackInfo` object containing the `JsEngine`
      *        instance.
      * @return `JsEngine` instance from `v8::FunctionCallbackInfo`.
      */
-    static JsEnginePtr FromArguments(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static JsEnginePtr FromArguments(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Stores `JsValue`s in a way they don't keep a strong reference to
      * `JsEngine` and which are destroyed when `JsEngine` is destroyed. These
      * methods should be used when one needs to carry a JsValue in a callback
      * directly or indirectly passed to `JsEngine`.
      * The method is thread-safe.
      * @param `JsValueList` to store.
      * @return `JsWeakValuesID` of stored values which allows to restore them
      * later.
      */
     JsWeakValuesID StoreJsValues(const JsValueList& values);
 
     /**
      * Extracts and removes from `JsEngine` earlier stored `JsValue`s.
      * The method is thread-safe.
      * @param id `JsWeakValuesID` of values.
      * @return `JsValueList` of stored values.
      */
     JsValueList TakeJsValues(const JsWeakValuesID& id);
 
     /*
      * Private functionality required to implement timers.
      * @param arguments `v8::FunctionCallbackInfo` is the arguments received in C++
      * callback associated for global setTimeout method.
      */
-    static void ScheduleTimer(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static void ScheduleTimer(const typename T::CallbackFuncInfo& arguments);
 
     /*
      * Private functionality required to implement web requests.
      * @param arguments `v8::FunctionCallbackInfo` is the arguments received in C++
      * callback associated for global GET method.
      */
-    static void ScheduleWebRequest(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    static void ScheduleWebRequest(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Converts v8 arguments to `JsValue` objects.
      * @param arguments `v8::FunctionCallbackInfo` object containing the arguments to
      *        convert.
      * @return List of arguments converted to `const JsValue` objects.
      */
-    JsValueList ConvertArguments(const v8::FunctionCallbackInfo<v8::Value>& arguments);
+    JsValueList ConvertArguments(const typename T::CallbackFuncInfo& arguments);
 
     /**
      * Sets a global property that can be accessed by all the scripts.
      * @param name Name of the property to set.
      * @param value Value of the property to set.
      */
     void SetGlobalProperty(const std::string& name, const AdblockPlus::JsValue& value);
 
     /**
      * Returns a pointer to associated v8::Isolate.
      */
-    v8::Isolate* GetIsolate()
+    typename T::Isolate* GetIsolate()
     {
       return isolate->Get();
     }
 
     /**
      * Notifies JS engine about critically low memory what should cause a
      * garbage collection.
      */
     void NotifyLowMemory();
 
     /**
      * Private functionality.
      */
     Platform& GetPlatform()
     {
       return platform;
     }
   private:
     void CallTimerTask(const JsWeakValuesID& timerParamsID);
 
-    explicit JsEngine(Platform& platform, std::unique_ptr<IV8IsolateProvider> isolate);
+    explicit JsEngineTemplate(Platform& platform, std::unique_ptr<IV8IsolateProvider> isolate);
 
     JsValue GetGlobalObject();
 
     Platform& platform;
     /// Isolate must be disposed only after disposing of all objects which are
     /// using it.
     std::unique_ptr<IV8IsolateProvider> isolate;
 
-    std::unique_ptr<v8::Global<v8::Context>> context;
+    std::unique_ptr<typename T::GlobalContext> context;
     EventMap eventCallbacks;
     std::mutex eventCallbacksMutex;
     JsWeakValuesLists jsWeakValuesLists;
     std::mutex jsWeakValuesListsMutex;
   };
 }
 
 #endif