Issue 5180 - introduce asynchronous web request

include/AdblockPlus/IWebRequest.h

Index: include/AdblockPlus/IWebRequest.h
diff --git a/include/AdblockPlus/WebRequest.h b/include/AdblockPlus/IWebRequest.h
similarity index 75%
copy from include/AdblockPlus/WebRequest.h
copy to include/AdblockPlus/IWebRequest.h
index 9eae7e4e7d36f6ea96559fac9315acaee5a5ffc9..110d25fdebdbdf2530f568ef547a25595da0c5ac 100644
--- a/include/AdblockPlus/WebRequest.h
+++ b/include/AdblockPlus/IWebRequest.h
@@ -15,20 +15,21 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef ADBLOCK_PLUS_WEB_REQUEST_H
-#define ADBLOCK_PLUS_WEB_REQUEST_H
+#ifndef ADBLOCK_PLUS_IWEB_REQUEST_H
+#define ADBLOCK_PLUS_IWEB_REQUEST_H
 
+#include <cstdint>
+#include <functional>
 #include <memory>
-#include <stdint.h>
-#include <string>
 #include <vector>
+#include <string>
 
 namespace AdblockPlus
 {
   /**
    * List of HTTP headers.
    */
-  typedef std::vector<std::pair<std::string, std::string> > HeaderList;
+  typedef std::vector<std::pair<std::string, std::string>> HeaderList;
 
   /**
    * HTTP response.
@@ -66,15 +67,14 @@ namespace AdblockPlus
   };
 
   /**
-   * Web request interface.
+   * Web request interface used to implement XMLHttpRequest.
    */
-  class WebRequest
+  struct IWebRequest
   {
-  public:
     /**
      * Possible [Mozilla status codes](https://developer.mozilla.org/en/docs/Table_Of_Errors#Network_Errors).
      */
-    enum
+    enum MozillaStatusCode
     {
       NS_OK = 0,
       NS_ERROR_FAILURE = 0x80004005,
@@ -94,21 +94,26 @@ namespace AdblockPlus
       NS_ERROR_NOT_INITIALIZED = 0xc1f30001
     };
 
-    virtual inline ~WebRequest() {};
+    /**
+     * Callback type invoked when the server response is ready.
+     * The parameter is the server response.
+     */
+    typedef std::function<void(const ServerResponse&)> GetCallback;
+    virtual ~IWebRequest() {};
 
     /**
      * Performs a GET request.
      * @param url Request URL.
      * @param requestHeaders Request headers.
-     * @return HTTP response.
+     * @param getCallback to invoke when the server response is ready.
      */
-    virtual ServerResponse GET(const std::string& url, const HeaderList& requestHeaders) const = 0;
+    virtual void GET(const std::string& url, const HeaderList& requestHeaders, const GetCallback& getCallback) = 0;
   };
 
   /**
-   * Shared smart pointer to a `WebRequest` instance.
+   * Unique smart pointer to an instance of `IWebRequest` implementation.
    */
-  typedef std::shared_ptr<WebRequest> WebRequestSharedPtr;
+  typedef std::unique_ptr<IWebRequest> WebRequestPtr;
 }
 
 #endif