1 files changed, 107 insertions, 0 deletions
diff --git a/chromium/extensions/renderer/request_sender.h b/chromium/extensions/renderer/request_sender.h
new file mode 100644
index 00000000000..245c0feb67e
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+++ b/chromium/extensions/renderer/request_sender.h
@@ -0,0 +1,107 @@
+// Copyright 2014 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 EXTENSIONS_RENDERER_REQUEST_SENDER_H_
+#define EXTENSIONS_RENDERER_REQUEST_SENDER_H_
+
+#include <map>
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/linked_ptr.h"
+#include "v8/include/v8.h"
+
+namespace base {
+class ListValue;
+}
+
+namespace extensions {
+class Dispatcher;
+class ScriptContext;
+
+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 ScriptContext* GetContext() = 0;
+    virtual void OnResponseReceived(const std::string& name,
+                                    int request_id,
+                                    bool success,
+                                    const base::ListValue& response,
+                                    const std::string& error) = 0;
+  };
+
+  // Helper class to (re)set the |source_tab_id_| below.
+  class ScopedTabID {
+   public:
+    ScopedTabID(RequestSender* request_sender, int tab_id);
+    ~ScopedTabID();
+
+   private:
+    RequestSender* const request_sender_;
+    const int tab_id_;
+    const int previous_tab_id_;
+
+    DISALLOW_COPY_AND_ASSIGN(ScopedTabID);
+  };
+
+  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(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 request source is no longer valid.
+  // TODO(kalman): Do this in a generic/safe way.
+  void InvalidateSource(Source* source);
+
+ private:
+  friend class ScopedTabID;
+  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_;
+
+  int source_tab_id_;  // Id of the tab sending the request, or -1 if no tab.
+
+  DISALLOW_COPY_AND_ASSIGN(RequestSender);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_RENDERER_REQUEST_SENDER_H_