1 // Copyright 2013 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 REMOTING_HOST_NATIVE_MESSAGING_NATIVE_MESSAGING_READER_H_ 6 #define REMOTING_HOST_NATIVE_MESSAGING_NATIVE_MESSAGING_READER_H_ 7 8 #include "base/basictypes.h" 9 #include "base/callback.h" 10 #include "base/memory/scoped_ptr.h" 11 #include "base/memory/weak_ptr.h" 12 #include "base/platform_file.h" 13 #include "base/threading/thread.h" 14 15 namespace base { 16 class SequencedTaskRunner; 17 class Value; 18 } // namespace base 19 20 namespace net { 21 class FileStream; 22 } // namespace net 23 24 namespace remoting { 25 26 // This class is used for reading messages from the Native Messaging client 27 // webapp. 28 class NativeMessagingReader { 29 public: 30 typedef base::Callback<void(scoped_ptr<base::Value>)> MessageCallback; 31 32 explicit NativeMessagingReader(base::PlatformFile handle); 33 ~NativeMessagingReader(); 34 35 // Begin reading messages from the Native Messaging client webapp, calling 36 // |message_callback| for each received message, or |eof_callback| if 37 // EOF or error is encountered. This method is asynchronous - the callbacks 38 // will be run on the same thread via PostTask. The caller should be prepared 39 // for these callbacks to be invoked right up until this object is destroyed. 40 void Start(MessageCallback message_callback, base::Closure eof_callback); 41 42 private: 43 class Core; 44 friend class Core; 45 46 // Wrappers posted to by the read thread to trigger the message and EOF 47 // callbacks on the caller thread, and have them safely dropped if the reader 48 // has been deleted before they are processed. 49 void InvokeMessageCallback(scoped_ptr<base::Value> message); 50 void InvokeEofCallback(); 51 52 // Holds the information that the read thread needs to access, such as the 53 // FileStream, and the TaskRunner used for posting notifications back to this 54 // class. 55 scoped_ptr<Core> core_; 56 57 // Caller-supplied message and end-of-file callbacks. 58 MessageCallback message_callback_; 59 base::Closure eof_callback_; 60 61 // Separate thread used to read from the stream without blocking the main 62 // thread. net::FileStream's async API cannot be used here because, on 63 // Windows, it requires the file handle to have been opened for overlapped IO. 64 base::Thread reader_thread_; 65 scoped_refptr<base::SequencedTaskRunner> read_task_runner_; 66 67 // Allows the reader to be deleted safely even when tasks may be pending on 68 // it. 69 base::WeakPtrFactory<NativeMessagingReader> weak_factory_; 70 71 DISALLOW_COPY_AND_ASSIGN(NativeMessagingReader); 72 }; 73 74 } // namespace remoting 75 76 #endif // REMOTING_HOST_NATIVE_MESSAGING_NATIVE_MESSAGING_READER_H_ 77