Implement the client side of Serial I/O on data pipe.

extensions/renderer/resources/serial_service.js

 // 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.
 
 define('serial_service', [
     'content/public/renderer/service_provider',
+    'data_receiver',
+    'data_sender',
     'device/serial/serial.mojom',
     'mojo/public/js/bindings/core',
     'mojo/public/js/bindings/router',
-], function(serviceProvider, serialMojom, core, routerModule) {
+], function(serviceProvider,
+            dataReceiver,
+            dataSender,
+            serialMojom,
+            core,
+            routerModule) {
   /**
    * A Javascript client for the serial service and connection Mojo services.
    *
    * This provides a thick client around the Mojo services, exposing a JS-style
    * interface to serial connections and information about serial devices. This
    * converts parameters and result between the Apps serial API types and the
    * Mojo types.
    */
 
   var service = new serialMojom.SerialServiceProxy(new routerModule.Router(
@@ skipping 31 matching lines @@
     undefined: serialMojom.StopBits.NONE,
     'one': serialMojom.StopBits.ONE,
     'two': serialMojom.StopBits.TWO,
   };
   var PARITY_BIT_TO_MOJO = {
     undefined: serialMojom.ParityBit.NONE,
     'no': serialMojom.ParityBit.NO,
     'odd': serialMojom.ParityBit.ODD,
     'even': serialMojom.ParityBit.EVEN,
   };
+  var SEND_ERROR_TO_MOJO = {
+    undefined: serialMojom.SendError.NONE,
+    'disconnected': serialMojom.SendError.DISCONNECTED,
+    'pending': serialMojom.SendError.PENDING,
+    'timeout': serialMojom.SendError.TIMEOUT,
+    'system_error': serialMojom.SendError.SYSTEM_ERROR,
+  };
+  var RECEIVE_ERROR_TO_MOJO = {
+    undefined: serialMojom.ReceiveError.NONE,
+    'disconnected': serialMojom.ReceiveError.DISCONNECTED,
+    'device_lost': serialMojom.ReceiveError.DEVICE_LOST,
+    'timeout': serialMojom.ReceiveError.TIMEOUT,
+    'system_error': serialMojom.ReceiveError.SYSTEM_ERROR,
+  };
 
   function invertMap(input) {
     var output = {};
     for (var key in input) {
       if (key == 'undefined')
         output[input[key]] = undefined;
       else
         output[input[key]] = key;
     }
     return output;
   }
   var DATA_BITS_FROM_MOJO = invertMap(DATA_BITS_TO_MOJO);
   var STOP_BITS_FROM_MOJO = invertMap(STOP_BITS_TO_MOJO);
   var PARITY_BIT_FROM_MOJO = invertMap(PARITY_BIT_TO_MOJO);
+  var SEND_ERROR_FROM_MOJO = invertMap(SEND_ERROR_TO_MOJO);
+  var RECEIVE_ERROR_FROM_MOJO = invertMap(RECEIVE_ERROR_TO_MOJO);
 
   function getServiceOptions(options) {
     var out = {};
     if (options.dataBits)
       out.data_bits = DATA_BITS_TO_MOJO[options.dataBits];
     if (options.stopBits)
       out.stop_bits = STOP_BITS_TO_MOJO[options.stopBits];
     if (options.parityBit)
       out.parity_bit = PARITY_BIT_TO_MOJO[options.parityBit];
     if ('ctsFlowControl' in options) {
@@ skipping 10 matching lines @@
       throw new Error('Failed to get ConnectionInfo.');
     return {
       ctsFlowControl: !!result.info.cts_flow_control,
       bitrate: result.info.bitrate || undefined,
       dataBits: DATA_BITS_FROM_MOJO[result.info.data_bits],
       stopBits: STOP_BITS_FROM_MOJO[result.info.stop_bits],
       parityBit: PARITY_BIT_FROM_MOJO[result.info.parity_bit],
     };
   }
 
-  function Connection(remoteConnection, router, id, options) {
+  function Connection(
+      remoteConnection, router, receivePipe, sendPipe, id, options) {
     this.remoteConnection_ = remoteConnection;
     this.router_ = router;
+    this.options_ = {};
+    for (var key in DEFAULT_CLIENT_OPTIONS) {
+      this.options_[key] = DEFAULT_CLIENT_OPTIONS[key];
+    }
+    this.setClientOptions_(options);
+    this.receivePipe_ =
+        new dataReceiver.DataReceiver(receivePipe,
+                                      this.options_.bufferSize,
+                                      serialMojom.ReceiveError.DISCONNECTED);
+    this.sendPipe_ = new dataSender.DataSender(
+        sendPipe, this.options_.bufferSize, serialMojom.SendError.DISCONNECTED);
     this.id_ = id;
     getConnections().then(function(connections) {
       connections[this.id_] = this;
     }.bind(this));
     this.paused_ = false;
-    this.options_ = {};
-    for (var key in DEFAULT_CLIENT_OPTIONS) {
-      this.options_[key] = DEFAULT_CLIENT_OPTIONS[key];
-    }
-    this.setClientOptions_(options);
+    this.sendInProgress_ = false;
+    this.pendingReceive_ = null;
+    this.pendingError_ = null;
+    this.startReceive_();
   }
 
   Connection.create = function(path, options) {
     options = options || {};
     var serviceOptions = getServiceOptions(options);
     var pipe = core.createMessagePipe();
-    // Note: These two are created and closed because the service implementation
-    // requires that we provide valid message pipes for the data source and
-    // sink. Currently the client handles are immediately closed; the real
-    // implementation will come later.
     var sendPipe = core.createMessagePipe();
     var receivePipe = core.createMessagePipe();
     service.connect(path,
                     serviceOptions,
                     pipe.handle0,
                     sendPipe.handle0,
                     receivePipe.handle0);
-    core.close(sendPipe.handle1);
-    core.close(receivePipe.handle1);
     var router = new routerModule.Router(pipe.handle1);
     var connection = new serialMojom.ConnectionProxy(router);
-    return connection.getInfo().then(convertServiceInfo).then(
-        function(info) {
+    return connection.getInfo().then(convertServiceInfo).then(function(info) {
       return Promise.all([info, allocateConnectionId()]);
     }).catch(function(e) {
       router.close();
+      core.close(sendPipe.handle1);
+      core.close(receivePipe.handle1);
       throw e;
     }).then(function(results) {
       var info = results[0];
       var id = results[1];
-      var serialConnectionClient = new Connection(
-          connection, router, id, options);
+      var serialConnectionClient = new Connection(connection,
+                                                  router,
+                                                  receivePipe.handle1,
+                                                  sendPipe.handle1,
+                                                  id,
+                                                  options);
       var clientInfo = serialConnectionClient.getClientInfo_();
       for (var key in clientInfo) {
         info[key] = clientInfo[key];
       }
       return {
         connection: serialConnectionClient,
         info: info,
       };
     });
   };
 
   Connection.prototype.close = function() {
     this.router_.close();
+    this.receivePipe_.close();
+    this.sendPipe_.close();
+    clearTimeout(this.receiveTimeoutId_);
+    clearTimeout(this.sendTimeoutId_);
     return getConnections().then(function(connections) {
-      delete connections[this.id_]
+      delete connections[this.id_];
       return true;
     }.bind(this));
   };
 
   Connection.prototype.getClientInfo_ = function() {
     var info = {
       connectionId: this.id_,
       paused: this.paused_,
-    }
+    };
     for (var key in this.options_) {
       info[key] = this.options_[key];
     }
     return info;
   };
 
   Connection.prototype.getInfo = function() {
     var info = this.getClientInfo_();
     return this.remoteConnection_.getInfo().then(convertServiceInfo).then(
         function(result) {
@@ skipping 61 matching lines @@
   };
 
   Connection.prototype.flush = function() {
     return this.remoteConnection_.flush().then(function(result) {
       return !!result.success;
     });
   };
 
   Connection.prototype.setPaused = function(paused) {
     this.paused_ = paused;
+    if (paused) {
+      clearTimeout(this.receiveTimeoutId_);
+      this.receiveTimeoutId_ = null;
+      return;
+    }

[raymes, 2014/08/29 06:07:16]

Using if/else here probably makes this slightly clearer (to say: if paused do
this otherwise do this)

[Sam McNally, 2014/09/01 06:35:17]

Done.

+    if (!this.receiveInProgress_)
+      this.startReceive_();
+  };
+
+  Connection.prototype.send = function(data) {
+    if (this.sendInProgress_)
+      return Promise.resolve({bytesSent: 0, error: 'pending'});
+
+    if (this.options_.sendTimeout) {
+      this.sendTimeoutId_ = setTimeout(function() {
+        this.sendPipe_.cancel(serialMojom.SendError.TIMEOUT);
+      }.bind(this), this.options_.sendTimeout);
+    }
+    this.sendInProgress_ = true;
+    return this.sendPipe_.send(data).then(function(bytesSent) {
+      return {bytesSent: bytesSent};
+    }).catch(function(e) {
+      return {
+        bytesSent: e.bytesSent || 0,
+        error: SEND_ERROR_FROM_MOJO[e.error] || 'system_error',

[raymes, 2014/08/29 06:07:15]

In what case will it return 'system_error'?

[Sam McNally, 2014/09/01 06:35:18]

It shouldn't hit that case.

+      };
+    }).then(function(result) {
+      if (this.sendTimeoutId_)
+        clearTimeout(this.sendTimeoutId_);
+      this.sendTimeoutId_ = null;
+      this.sendInProgress_ = false;
+      return result;
+    }.bind(this));
+  };
+
+  Connection.prototype.startReceive_ = function() {
+    this.receiveInProgress_ = true;
+    var receivePromise = null;
+    if (this.pendingReceive_) {

[raymes, 2014/08/29 06:07:15]

Some comments describing how pendingReceive_/pendingError_ is used only if we
receive some data while we are paused would be helpful for a reader.

More comments in general in this file would be helpful, sorry that's been the
theme of my feedback hasn't it! But I'll leave it to you at this point.

[Sam McNally, 2014/09/01 06:35:17]

Done.

+      receivePromise = Promise.resolve(this.pendingReceive_);
+      this.pendingReceive_ = null;
+    } else if (this.pendingError_) {
+      receivePromise = Promise.reject(this.pendingError_);
+      this.pendingError_ = null;
+    } else {
+      receivePromise = this.receivePipe_.receive();
+    }
+    receivePromise.then(this.onDataReceived_.bind(this)).catch(
+        this.onReceiveError_.bind(this));
+    this.startReceiveTimeoutTimer_();
+  };
+
+  Connection.prototype.onDataReceived_ = function(data) {
+    this.startReceiveTimeoutTimer_();
+    this.receiveInProgress_ = false;
+    if (this.paused_) {
+      this.pendingReceive_ = data;
+      return;
+    }
+    if (this.onData) {
+      this.onData(data);
+    }
+    if (!this.paused_) {
+      this.startReceive_();
+    }
+  };
+
+  Connection.prototype.onReceiveError_ = function(e) {
+    clearTimeout(this.receiveTimeoutId_);
+    this.receiveInProgress_ = false;
+    if (this.paused_) {
+      this.pendingError_ = e;
+      return;
+    }
+    var error = e.error || serialMojom.ReceiveError.SYSTEM_ERROR;
+    this.paused_ = true;
+    if (this.onError)
+      this.onError(RECEIVE_ERROR_FROM_MOJO[error]);
+  };
+
+  Connection.prototype.startReceiveTimeoutTimer_ = function() {
+    clearTimeout(this.receiveTimeoutId_);
+    if (this.options_.receiveTimeout && !this.paused_) {
+      this.receiveTimeoutId_ = setTimeout(this.onReceiveTimeout_.bind(this),
+                                          this.options_.receiveTimeout);
+    }
+  };
+
+  Connection.prototype.onReceiveTimeout_ = function() {
+    if (this.onError)
+      this.onError('timeout');
+    this.startReceiveTimeoutTimer_();
   };
 
   var connections_ = {};
   var nextConnectionId_ = 0;
 
   // Wrap all access to |connections_| through getConnections to avoid adding
   // any synchronous dependencies on it. This will likely be important when
   // supporting persistent connections by stashing them.
   function getConnections() {
     return Promise.resolve(connections_);
   }
 
   function getConnection(id) {
     return getConnections().then(function(connections) {
       if (!connections[id])
-        throw new Error ('Serial connection not found.');
+        throw new Error('Serial connection not found.');
       return connections[id];
     });
   }
 
   function allocateConnectionId() {
     return Promise.resolve(nextConnectionId_++);
   }
 
   return {
     getDevices: getDevices,
     createConnection: Connection.create,
     getConnection: getConnection,
     getConnections: getConnections,
+    // For testing.
+    Connection: Connection,
   };
 });