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