Apps V2 in Pepper: Host side implementation of ExntensionsCommon - Part 1.

chrome/renderer/extensions/request_sender.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_EXTENSIONS_REQUEST_SENDER_H_
 #define CHROME_RENDERER_EXTENSIONS_REQUEST_SENDER_H_
 
 #include <string>
 #include <map>
 
 #include "base/memory/linked_ptr.h"
 #include "v8/include/v8.h"
 
 namespace base {
 class ListValue;
 }
 
 namespace extensions {
 class ChromeV8Context;
 class Dispatcher;
 
 struct PendingRequest;
 
 // Responsible for sending requests for named extension API functions to the
 // extension host and routing the responses back to the caller.
 class RequestSender {
  public:
+  // Source represents a user of RequestSender. Every request is associated with
+  // a Source object, which will be notified when the corresponding response
+  // arrives. When a Source object is going away and there are pending requests,
+  // it should call InvalidateSource() to make sure no notifications are sent to
+  // it later.
+  class Source {
+   public:
+    virtual ~Source() {}
+
+    virtual ChromeV8Context* GetContext() = 0;

[asargent_no_longer_on_chrome, 2013/03/28 20:33:26]

Eventually it might be interesting to abstract this specific dependency on the
ChromeV8Context, but this CL overall is good incremental progress so I think
that could wait for future changes.
 

[yzshen1, 2013/03/28 22:25:22]

I will bear that in mind. I think I will touch this part of codebase some more
in near future.

On 2013/03/28 20:33:26, Antony Sargent wrote:

+    virtual void OnResponseReceived(const std::string& name,
+                                    int request_id,
+                                    bool success,
+                                    const base::ListValue& response,
+                                    const std::string& error) = 0;
+  };
+
   explicit RequestSender(Dispatcher* dispatcher);
   ~RequestSender();
 
+  // In order to avoid collision, all |request_id|s passed into StartRequest()
+  // should be generated by this method.
+  int GetNextRequestId() const;
+
   // Makes a call to the API function |name| that is to be handled by the
   // extension host. The response to this request will be received in
   // HandleResponse().
   // TODO(koz): Remove |request_id| and generate that internally.
   //            There are multiple of these per render view though, so we'll
   //            need to vend the IDs centrally.
-  void StartRequest(ChromeV8Context* target_context,
+  void StartRequest(Source* source,
                     const std::string& name,
                     int request_id,
                     bool has_callback,
                     bool for_io_thread,
                     base::ListValue* value_args);
 
   // Handles responses from the extension host to calls made by StartRequest().
   void HandleResponse(int request_id,
                       bool success,
                       const base::ListValue& response,
                       const std::string& error);
 
-  // Notifies this that a context is no longer valid.
+  // Notifies this that a request source is no longer valid.
   // TODO(kalman): Do this in a generic/safe way.
-  void InvalidateContext(ChromeV8Context* context);
+  void InvalidateSource(Source* source);
 
  private:
   typedef std::map<int, linked_ptr<PendingRequest> > PendingRequestMap;
 
   void InsertRequest(int request_id, PendingRequest* pending_request);
   linked_ptr<PendingRequest> RemoveRequest(int request_id);
 
   Dispatcher* dispatcher_;
   PendingRequestMap pending_requests_;
 
   DISALLOW_COPY_AND_ASSIGN(RequestSender);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_REQUEST_SENDER_H_