1 // Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_ 6 #define CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_ 7 8 #include "chrome/browser/extensions/chrome_extension_function.h" 9 #include "content/public/browser/browser_thread.h" 10 11 namespace extensions { 12 13 // Base class for API functions. TODO(miket): there isn't much here anymore 14 // since the removal of ApiResourceEventRouter. Should we promote all its 15 // subclasses to UIThreadExtensionFunctions? 16 class ApiFunction : public ChromeAsyncExtensionFunction { 17 protected: 18 ApiFunction(); 19 virtual ~ApiFunction(); 20 }; 21 22 // AsyncApiFunction provides convenient thread management for APIs that need to 23 // do essentially all their work on a thread other than the UI thread. 24 class AsyncApiFunction : public ApiFunction { 25 protected: 26 AsyncApiFunction(); 27 virtual ~AsyncApiFunction(); 28 29 // Like Prepare(). A useful place to put common work in an ApiFunction 30 // superclass that multiple API functions want to share. 31 virtual bool PrePrepare(); 32 33 // Set up for work (e.g., validate arguments). Guaranteed to happen on UI 34 // thread. 35 virtual bool Prepare() = 0; 36 37 // Do actual work. Guaranteed to happen on the thread specified in 38 // work_thread_id_. 39 virtual void Work(); 40 41 // Start the asynchronous work. Guraranteed to happen on requested thread. 42 virtual void AsyncWorkStart(); 43 44 // Notify AsyncIOApiFunction that the work is completed 45 void AsyncWorkCompleted(); 46 47 // Respond. Guaranteed to happen on UI thread. 48 virtual bool Respond() = 0; 49 50 // ExtensionFunction::RunImpl() 51 virtual bool RunImpl() OVERRIDE; 52 53 protected: set_work_thread_id(content::BrowserThread::ID work_thread_id)54 void set_work_thread_id(content::BrowserThread::ID work_thread_id) { 55 work_thread_id_ = work_thread_id; 56 } 57 58 private: 59 void WorkOnWorkThread(); 60 void RespondOnUIThread(); 61 62 // If you don't want your Work() method to happen on the IO thread, then set 63 // this to the thread that you do want, preferably in Prepare(). 64 content::BrowserThread::ID work_thread_id_; 65 }; 66 67 } // namespace extensions 68 69 #endif // CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_ 70