1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef EXTENSIONS_RENDERER_REQUEST_SENDER_H_ 6 #define EXTENSIONS_RENDERER_REQUEST_SENDER_H_ 7 8 #include <map> 9 #include <string> 10 11 #include "base/memory/linked_ptr.h" 12 #include "v8/include/v8.h" 13 14 namespace base { 15 class ListValue; 16 } 17 18 namespace extensions { 19 class Dispatcher; 20 class ScriptContext; 21 22 struct PendingRequest; 23 24 // Responsible for sending requests for named extension API functions to the 25 // extension host and routing the responses back to the caller. 26 class RequestSender { 27 public: 28 // Source represents a user of RequestSender. Every request is associated with 29 // a Source object, which will be notified when the corresponding response 30 // arrives. When a Source object is going away and there are pending requests, 31 // it should call InvalidateSource() to make sure no notifications are sent to 32 // it later. 33 class Source { 34 public: ~Source()35 virtual ~Source() {} 36 37 virtual ScriptContext* GetContext() = 0; 38 virtual void OnResponseReceived(const std::string& name, 39 int request_id, 40 bool success, 41 const base::ListValue& response, 42 const std::string& error) = 0; 43 }; 44 45 // Helper class to (re)set the |source_tab_id_| below. 46 class ScopedTabID { 47 public: 48 ScopedTabID(RequestSender* request_sender, int tab_id); 49 ~ScopedTabID(); 50 51 private: 52 RequestSender* const request_sender_; 53 const int tab_id_; 54 const int previous_tab_id_; 55 56 DISALLOW_COPY_AND_ASSIGN(ScopedTabID); 57 }; 58 59 explicit RequestSender(Dispatcher* dispatcher); 60 ~RequestSender(); 61 62 // In order to avoid collision, all |request_id|s passed into StartRequest() 63 // should be generated by this method. 64 int GetNextRequestId() const; 65 66 // Makes a call to the API function |name| that is to be handled by the 67 // extension host. The response to this request will be received in 68 // HandleResponse(). 69 // TODO(koz): Remove |request_id| and generate that internally. 70 // There are multiple of these per render view though, so we'll 71 // need to vend the IDs centrally. 72 void StartRequest(Source* source, 73 const std::string& name, 74 int request_id, 75 bool has_callback, 76 bool for_io_thread, 77 base::ListValue* value_args); 78 79 // Handles responses from the extension host to calls made by StartRequest(). 80 void HandleResponse(int request_id, 81 bool success, 82 const base::ListValue& response, 83 const std::string& error); 84 85 // Notifies this that a request source is no longer valid. 86 // TODO(kalman): Do this in a generic/safe way. 87 void InvalidateSource(Source* source); 88 89 private: 90 friend class ScopedTabID; 91 typedef std::map<int, linked_ptr<PendingRequest> > PendingRequestMap; 92 93 void InsertRequest(int request_id, PendingRequest* pending_request); 94 linked_ptr<PendingRequest> RemoveRequest(int request_id); 95 96 Dispatcher* dispatcher_; 97 PendingRequestMap pending_requests_; 98 99 int source_tab_id_; // Id of the tab sending the request, or -1 if no tab. 100 101 DISALLOW_COPY_AND_ASSIGN(RequestSender); 102 }; 103 104 } // namespace extensions 105 106 #endif // EXTENSIONS_RENDERER_REQUEST_SENDER_H_ 107