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1 // Copyright 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_SERIAL_SERIAL_CONNECTION_H_
6 #define CHROME_BROWSER_EXTENSIONS_API_SERIAL_SERIAL_CONNECTION_H_
7 
8 #include <set>
9 #include <string>
10 
11 #include "base/callback.h"
12 #include "base/files/file.h"
13 #include "base/memory/ref_counted.h"
14 #include "base/memory/weak_ptr.h"
15 #include "base/message_loop/message_loop.h"
16 #include "base/time/time.h"
17 #include "chrome/browser/extensions/api/serial/serial_io_handler.h"
18 #include "chrome/common/extensions/api/serial.h"
19 #include "content/public/browser/browser_thread.h"
20 #include "extensions/browser/api/api_resource.h"
21 #include "extensions/browser/api/api_resource_manager.h"
22 #include "net/base/file_stream.h"
23 
24 using content::BrowserThread;
25 
26 namespace extensions {
27 
28 // Encapsulates an open serial port. Platform-specific implementations are in
29 // _win and _posix versions of the the .cc file.
30 // NOTE: Instances of this object should only be constructed on the IO thread,
31 // and all methods should only be called on the IO thread unless otherwise
32 // noted.
33 class SerialConnection : public ApiResource,
34                          public base::SupportsWeakPtr<SerialConnection> {
35  public:
36   typedef base::Callback<void(bool success)> OpenCompleteCallback;
37 
38   // This is the callback type expected by Receive. Note that an error result
39   // does not necessarily imply an empty |data| string, since a receive may
40   // complete partially before being interrupted by an error condition.
41   typedef base::Callback<
42       void(const std::string& data, api::serial::ReceiveError error)>
43       ReceiveCompleteCallback;
44 
45   // This is the callback type expected by Send. Note that an error result
46   // does not necessarily imply 0 bytes sent, since a send may complete
47   // partially before being interrupted by an error condition.
48   typedef base::Callback<void(int bytes_sent, api::serial::SendError error)>
49       SendCompleteCallback;
50 
51   SerialConnection(const std::string& port,
52                    const std::string& owner_extension_id);
53   virtual ~SerialConnection();
54 
55   // ApiResource override.
56   virtual bool IsPersistent() const OVERRIDE;
57 
set_persistent(bool persistent)58   void set_persistent(bool persistent) { persistent_ = persistent; }
persistent()59   bool persistent() const { return persistent_; }
60 
set_name(const std::string & name)61   void set_name(const std::string& name) { name_ = name; }
name()62   const std::string& name() const { return name_; }
63 
64   void set_buffer_size(int buffer_size);
buffer_size()65   int buffer_size() const { return buffer_size_; }
66 
67   void set_receive_timeout(int receive_timeout);
receive_timeout()68   int receive_timeout() const { return receive_timeout_; }
69 
70   void set_send_timeout(int send_timeout);
send_timeout()71   int send_timeout() const { return send_timeout_; }
72 
73   void set_paused(bool paused);
paused()74   bool paused() const { return paused_; }
75 
76   // Initiates an asynchronous Open of the device. It is the caller's
77   // responsibility to ensure that this SerialConnection stays alive
78   // until |callback| is run.
79   virtual void Open(const OpenCompleteCallback& callback);
80 
81   // Initiate a Close of the device. The SerialConnection instance will
82   // have its internal state reset synchronously upon calling this, but
83   // the underlying OS handle will be closed asynchronously.
84   virtual void Close();
85 
86   // Begins an asynchronous receive operation. Calling this while a Receive
87   // is already pending is a no-op and returns |false| without calling
88   // |callback|.
89   virtual bool Receive(const ReceiveCompleteCallback& callback);
90 
91   // Begins an asynchronous send operation. Calling this while a Send
92   // is already pending is a no-op and returns |false| without calling
93   // |callback|.
94   virtual bool Send(const std::string& data,
95                     const SendCompleteCallback& callback);
96 
97   // Flushes input and output buffers.
98   virtual bool Flush() const;
99 
100   // Configures some subset of port options for this connection.
101   // Omitted options are unchanged. Returns |true| iff the configuration
102   // changes were successful.
103   virtual bool Configure(const api::serial::ConnectionOptions& options);
104 
105   // Connection configuration query. Fills values in an existing
106   // ConnectionInfo. Returns |true| iff the connection's information
107   // was successfully retrieved.
108   virtual bool GetInfo(api::serial::ConnectionInfo* info) const;
109 
110   // Reads current control signals (DCD, CTS, etc.) into an existing
111   // DeviceControlSignals structure. Returns |true| iff the signals were
112   // successfully read.
113   virtual bool GetControlSignals(
114       api::serial::DeviceControlSignals* control_signals) const;
115 
116   // Sets one or more control signals (DTR and/or RTS). Returns |true| iff
117   // the signals were successfully set. Unininitialized flags in the
118   // HostControlSignals structure are left unchanged.
119   virtual bool SetControlSignals(
120       const api::serial::HostControlSignals& control_signals);
121 
122   static const BrowserThread::ID kThreadId = BrowserThread::IO;
123 
124  protected:
125   // Overrides |io_handler_| for testing.
126   virtual void SetIoHandlerForTest(scoped_refptr<SerialIoHandler> handler);
127 
128   // Performs platform-specific, one-time port configuration on open.
129   bool PostOpen();
130 
131   // Performs platform-specific port configuration. Returns |true| iff
132   // configuration was successful.
133   bool ConfigurePort(const api::serial::ConnectionOptions& options);
134 
135   // Performs a platform-specific port configuration query. Fills values in an
136   // existing ConnectionInfo. Returns |true| iff port configuration was
137   // successfully retrieved.
138   bool GetPortInfo(api::serial::ConnectionInfo* info) const;
139 
140   // Possibly fixes up a serial port path name in a platform-specific manner.
141   static std::string MaybeFixUpPortName(const std::string& port_name);
142 
143  private:
144   friend class ApiResourceManager<SerialConnection>;
service_name()145   static const char* service_name() { return "SerialConnectionManager"; }
146 
147   // Encapsulates a cancelable, delayed timeout task. Posts a delayed
148   // task upon construction and implicitly cancels the task upon
149   // destruction if it hasn't run yet.
150   class TimeoutTask {
151    public:
152     TimeoutTask(const base::Closure& closure, const base::TimeDelta& delay);
153     ~TimeoutTask();
154 
155    private:
156     void Run() const;
157 
158     base::WeakPtrFactory<TimeoutTask> weak_factory_;
159     base::Closure closure_;
160     base::TimeDelta delay_;
161   };
162 
163   // Continues an Open operation on the FILE thread.
164   void StartOpen();
165 
166   // Finalizes an Open operation (continued from StartOpen) on the IO thread.
167   void FinishOpen(base::File file);
168 
169   // Continues a Close operation on the FILE thread.
170   static void DoClose(base::File port);
171 
172   // Handles a receive timeout.
173   void OnReceiveTimeout();
174 
175   // Handles a send timeout.
176   void OnSendTimeout();
177 
178   // Receives read completion notification from the |io_handler_|.
179   void OnAsyncReadComplete(const std::string& data,
180                            api::serial::ReceiveError error);
181 
182   // Receives write completion notification from the |io_handler_|.
183   void OnAsyncWriteComplete(int bytes_sent, api::serial::SendError error);
184 
185   // The pathname of the serial device.
186   std::string port_;
187 
188   // File for the opened serial device. This value is only modified from the IO
189   // thread.
190   base::File file_;
191 
192   // Flag indicating whether or not the connection should persist when
193   // its host app is suspended.
194   bool persistent_;
195 
196   // User-specified connection name.
197   std::string name_;
198 
199   // Size of the receive buffer.
200   int buffer_size_;
201 
202   // Amount of time (in ms) to wait for a Read to succeed before triggering a
203   // timeout response via onReceiveError.
204   int receive_timeout_;
205 
206   // Amount of time (in ms) to wait for a Write to succeed before triggering
207   // a timeout response.
208   int send_timeout_;
209 
210   // Flag indicating that the connection is paused. A paused connection will not
211   // raise new onReceive events.
212   bool paused_;
213 
214   // Callback to handle the completion of a pending Open() request.
215   OpenCompleteCallback open_complete_;
216 
217   // Callback to handle the completion of a pending Receive() request.
218   ReceiveCompleteCallback receive_complete_;
219 
220   // Callback to handle the completion of a pending Send() request.
221   SendCompleteCallback send_complete_;
222 
223   // Closure which will trigger a receive timeout unless cancelled. Reset on
224   // initialization and after every successful Receive().
225   scoped_ptr<TimeoutTask> receive_timeout_task_;
226 
227   // Write timeout closure. Reset on initialization and after every successful
228   // Send().
229   scoped_ptr<TimeoutTask> send_timeout_task_;
230 
231   // Asynchronous I/O handler.
232   scoped_refptr<SerialIoHandler> io_handler_;
233 };
234 
235 }  // namespace extensions
236 
237 #endif  // CHROME_BROWSER_EXTENSIONS_API_SERIAL_SERIAL_CONNECTION_H_
238