From edf47a7a07c1085ad96441f8d2859b170e74cfa4 Mon Sep 17 00:00:00 2001
From: Arthur Britto <ahbritto@gmail.com>
Date: Wed, 17 Oct 2012 13:26:31 -0700
Subject: [PATCH] JS: Automatically maintain connection.

---
 js/amount.js           |   2 +-
 js/remote.js           | 363 ++++++++++++++++++++++++-----------------
 test/remote-test.js    |  26 +--
 test/websocket-test.js |  20 ++-
 4 files changed, 235 insertions(+), 176 deletions(-)

diff --git a/js/amount.js b/js/amount.js
index 51e18a5630..652e8438ff 100644
--- a/js/amount.js
+++ b/js/amount.js
@@ -1,4 +1,4 @@
-// Represent Newcoin amounts and currencies.
+// Represent Ripple amounts and currencies.
 // - Numbers in hex are big-endian.
 
 var utils   = require('./utils.js');
diff --git a/js/remote.js b/js/remote.js
index bed251dd7c..1f300b569e 100644
--- a/js/remote.js
+++ b/js/remote.js
@@ -94,6 +94,18 @@ Request.prototype.transaction = function (t) {
   return this;
 };
 
+//
+// Remote - access to a remote Ripple server via websocket.
+//
+// Events:
+// 'connectted'
+// 'disconnected'
+// 'state':
+// - 'online' : connectted and subscribed
+// - 'offline' : not subscribed or not connectted.
+// 'ledger_closed'
+//
+
 // --> trusted: truthy, if remote is trusted
 var Remote = function (trusted, websocket_ip, websocket_port, config, trace) {
   this.trusted              = trusted;
@@ -105,6 +117,11 @@ var Remote = function (trusted, websocket_ip, websocket_port, config, trace) {
   this.ledger_closed        = undefined;
   this.ledger_current_index = undefined;
   this.stand_alone          = undefined;
+  this.online_target	    = false;
+  this.online_state	    = 'closed';	  // 'open', 'closed', 'connecting', 'closing'
+  this.state	  	    = 'offline';  // 'online', 'offline'
+  this.retry_timer	    = undefined;
+  this.retry		    = undefined;
   
   // Cache information for accounts.
   this.accounts = {
@@ -159,186 +176,232 @@ var fees = {
   'offer'	    : Amount.from_json("100"),
 };
 
-Remote.prototype.connect_helper = function () {
+// Set the emited state: 'online' or 'offline'
+Remote.prototype._set_state = function (state) {
+  if (this.trace) console.log("remote: set_state: %s", state);
+
+  if (this.state !== state) {
+    this.state = state;
+
+    this.emit('state', state);
+    switch (state) {
+      case 'online':
+	this.online_state	= 'open';
+	this.emit('connected');
+	break;
+      case 'offline':
+	this.online_state	= 'closed';
+	this.emit('disconnected');
+	break;
+    }
+  }
+};
+
+// Set the target online state. Defaults to false.
+Remote.prototype.connect = function (online) {
+  var target  = undefined === online || online;
+
+  if (this.online_target != target) {
+    this.online_target  = target;
+
+    // If we were in a stable state, go dynamic.
+    switch (this.online_state) {
+      case 'open':
+	if (!target) this._connect_stop();
+	break;
+
+      case 'closed':
+	if (target) this._connect_retry();
+	break;
+    }
+  }
+
+  return this;
+};
+
+// Stop from open state.
+Remote.prototype._connect_stop = function () {
+  delete this.ws.onerror;
+  delete this.ws.onclose;
+
+  this.ws.terminate();
+  delete this.ws;
+
+  this._set_state('offline');
+};
+
+// Implictly we are not connected.
+Remote.prototype._connect_retry = function () {
+  var self  = this;
+
+  if (!self.online_target) {
+    // Do not continue trying to connect.
+    this._set_state('offline');
+  }
+  else if ('connecting' !== this.online_state) {
+    // New to connecting state.
+    this.online_state = 'connecting';
+    this.retry	      = 0;
+ 
+    this._connect_start();
+  }
+  else
+  {
+    // Delay and retry.
+    this.retry	      += 1;
+    this.retry_timer  =  setTimeout(function () {
+	if (self.trace) console.log("remote: retry");
+
+	if (self.online_target) {
+	  self._connect_start();
+	}
+	else {
+	  self._connect_retry();
+	}
+      }, this.retry < 40 ? 1000/20 : 1000); // 20 times per second for 2 seconds then once per second.
+  }
+};
+
+Remote.prototype._connect_start = function () {
+  // Note: as a browser client can't make encrypted connections to random ips
+  // with self-signed certs as the user must have pre-approved the self-signed certs.
+
   var self = this;
+  var url  = util.format("ws://%s:%s", this.websocket_ip, this.websocket_port);
   
-  if (this.trace) console.log("remote: connect: %s", this.url);
+  if (this.trace) console.log("remote: connect: %s", url);
   
-  var ws = this.ws = new WebSocket(this.url);;
+  var ws = this.ws = new WebSocket(url);
   
   ws.response = {};
   
   ws.onopen = function () {
-    if (self.trace) console.log("remote: onopen: %s", ws.readyState);
+    if (self.trace) console.log("remote: onopen: %s: online_target=%s", ws.readyState, self.online_target);
     
-    ws.onclose = undefined;
-    ws.onerror = undefined;
-    
-    clearTimeout(self.connect_timer); delete self.connect_timer;
-    clearTimeout(self.retry_timer); delete self.retry_timer;
+    ws.onerror = function () {
+      if (self.trace) console.log("remote: onerror: %s", ws.readyState);
 
-    self.done(ws.readyState);
+      delete ws.onclose;
+
+      self._connect_retry();
+    };
+
+    ws.onclose = function () {
+      if (self.trace) console.log("remote: onclose: %s", ws.readyState);
+
+      delete ws.onerror;
+
+      self._connect_retry();
+    };
+ 
+    if (self.online_target) {
+    if (self.trace) console.log("remote: onopen: %s: online_target2=%s", ws.readyState, self.online_target);
+      self._set_state('online');
+    }
+    else {
+    if (self.trace) console.log("remote: onopen: %s: online_target3=%s", ws.readyState, self.online_target);
+      self._connect_stop();
+    }
   };
   
   ws.onerror = function () {
     if (self.trace) console.log("remote: onerror: %s", ws.readyState);
+ 
+    delete ws.onclose;
     
-    ws.onclose = undefined;
-    
-    if (self.expire) {
-      if (self.trace) console.log("remote: was expired");
-
-      ws.onerror = undefined;
-      self.done(ws.readyState);
-
-    } else {
-      // Delay and retry.
-
-      clearTimeout(self.retry_timer);
-      self.retry_timer  =  setTimeout(function () {
-	  if (self.trace) console.log("remote: retry");
-
-	  self.connect_helper();
-	}, 50); // Retry rate 50ms.
-    }
+    self._connect_retry();
   };
-  
-  // Covers failure to open.
+
+  // Failure to open.
   ws.onclose = function () {
     if (self.trace) console.log("remote: onclose: %s", ws.readyState);
 
-    ws.onerror = undefined;
+    delete ws.onerror;
 
-    clearTimeout(self.retry_timer);
-    delete self.retry_timer;
-
-    self.done(ws.readyState);
+    self._connect_retry();
   };
   
   // Node's ws module doesn't pass arguments to onmessage.
   ws.on('message', function (json, flags) {
-    var message	    = JSON.parse(json);
-    var	unexpected  = false;
-    var request;
-
-    if ('object' !== typeof message) {
-      unexpected  = true;
-    }
-    else {
-      switch (message.type) {
-	case 'response':
-	  {
-	    request	  = ws.response[message.id];
-
-	    if (!request) {
-	      unexpected  = true;
-	    }
-	    else if ('success' === message.result) {
-	      if (self.trace) console.log("message: %s", json);
-
-	      request.emit('success', message);
-	    }
-	    else if (message.error) {
-	      if (self.trace) console.log("message: %s", json);
-
-	      request.emit('error', {
-		  'error'		: 'remoteError',
-		  'error_message' : 'Remote reported an error.',
-		  'remote'        : message,
-		});
-	    }
-	  }
-	  break;
-
-	case 'ledgerClosed':
-	  // XXX If not trusted, need to verify we consider ledger closed.
-	  // XXX Also need to consider a slow server or out of order response.
-	  // XXX Be more defensive fields could be missing or of wrong type.
-	  // YYY Might want to do some cache management.
-
-	  self.ledger_closed	    = message.ledger_closed;
-	  self.ledger_current_index = message.ledger_closed_index + 1;
-
-	  self.emit('ledger_closed', self.ledger_closed, self.ledger_closed_index);
-	  break;
-	
-	default:
-	  unexpected  = true;
-	  break;
-      }
-    }
-
-    if (!unexpected) {
-    }
-    // Unexpected response from remote.
-    // XXX This isn't so robust. Hard fails should probably only happen in a debugging scenairo.
-    else if (self.trusted) {
-      // Remote is trusted, report an error.
-      console.log("unexpected message from trusted remote: %s", json);
-
-      (request || self).emit('error', {
-	  'error' : 'remoteUnexpected',
-	  'error_message' : 'Unexpected response from remote.'
-	});
-    }
-    else {
-      // Treat as a disconnect.
-      if (self.trace) console.log("unexpected message from untrusted remote: %s", json);
-
-      // XXX All pending request need this treatment and need to actionally disconnect.
-      (request || self).emit('error', {
-	  'error' : 'remoteDisconnected',
-	  'error_message' : 'Remote disconnected.'
-	});
-    }
-  });
+      self._connect_message(json, flags);
+    });
 };
 
-// Target state is connectted.
-// XXX Get rid of 'done' use event model.
-// done(readyState):
-// --> readyState: OPEN, CLOSED
-Remote.prototype.connect = function (done, timeout) {
-  var self = this;
-  
-  this.url  = util.format("ws://%s:%s", this.websocket_ip, this.websocket_port);
-  this.done = done;
-  
-  if (timeout) {
-    if (this.trace) console.log("remote: expire: false");
-    
-    this.expire		= false;
+Remote.prototype._connect_message = function (json, flags) {
+  var message	  = JSON.parse(json);
+  var unexpected  = false;
+  var request;
 
-    this.connect_timer	= setTimeout(function () {
-	if (self.trace) console.log("remote: expire: timeout");
-
-	delete self.connect_timer;
-	self.expire = true;
-      }, timeout);
-
-  } else {
-    if (this.trace) console.log("remote: expire: false");
-    this.expire = true;
+  if ('object' !== typeof message) {
+    unexpected  = true;
   }
-  
-  this.connect_helper();
-};
+  else {
+    switch (message.type) {
+      case 'response':
+	{
+	  request	  = this.ws.response[message.id];
 
-// Target stated is disconnected.
-// Note: if exiting or other side is going away, don't need to disconnect.
-Remote.prototype.disconnect = function (done) {
-  var self  = this;
-  var ws    = this.ws;
+	  if (!request) {
+	    unexpected  = true;
+	  }
+	  else if ('success' === message.result) {
+	    if (this.trace) console.log("message: %s", json);
 
-  if (this.trace) console.log("remote: disconnect");
-  
-  ws.onclose = function () {
-    if (self.trace) console.log("remote: onclose: %s", ws.readyState);
-    done(ws.readyState);
-  };
+	    request.emit('success', message);
+	  }
+	  else if (message.error) {
+	    if (this.trace) console.log("message: %s", json);
 
-  // ws package has a hard coded 30 second timeout.
-  ws.close();
+	    request.emit('error', {
+		'error'		: 'remoteError',
+		'error_message' : 'Remote reported an error.',
+		'remote'        : message,
+	      });
+	  }
+	}
+	break;
+
+      case 'ledgerClosed':
+	// XXX If not trusted, need to verify we consider ledger closed.
+	// XXX Also need to consider a slow server or out of order response.
+	// XXX Be more defensive fields could be missing or of wrong type.
+	// YYY Might want to do some cache management.
+
+	this.ledger_closed	  = message.ledger_closed;
+	this.ledger_current_index = message.ledger_closed_index + 1;
+
+	this.emit('ledger_closed', this.ledger_closed, this.ledger_closed_index);
+	break;
+      
+      default:
+	unexpected  = true;
+	break;
+    }
+  }
+
+  if (!unexpected) {
+  }
+  // Unexpected response from remote.
+  // XXX This isn't so robust. Hard fails should probably only happen in a debugging scenairo.
+  else if (this.trusted) {
+    // Remote is trusted, report an error.
+    console.log("unexpected message from trusted remote: %s", json);
+
+    (request || this).emit('error', {
+	'error' : 'remoteUnexpected',
+	'error_message' : 'Unexpected response from remote.'
+      });
+  }
+  else {
+    // Treat as a disconnect.
+    if (this.trace) console.log("unexpected message from untrusted remote: %s", json);
+
+    // XXX All pending request need this treatment and need to actionally disconnect.
+    (request || this).emit('error', {
+	'error' : 'remoteDisconnected',
+	'error_message' : 'Remote disconnected.'
+      });
+  }
 };
 
 // Send a request.
diff --git a/test/remote-test.js b/test/remote-test.js
index b45f1a62ab..ebcdf731b5 100644
--- a/test/remote-test.js
+++ b/test/remote-test.js
@@ -10,7 +10,7 @@ var Amount  = amount.Amount;
 var fastTearDown  = true;
 
 // How long to wait for server to start.
-var serverDelay = 1500;
+var serverDelay = 1500;	  // XXX Not implemented.
 
 buster.testRunner.timeout = 5000;
  
@@ -23,32 +23,22 @@ buster.testCase("Remote functions", {
 
 	  alpha   = remote.remoteConfig(config, "alpha");
 
-	  alpha.connect(function (stat) {
-	      buster.assert(1 == stat);	      // OPEN
-	      done();
-	    }, serverDelay);
+	  alpha
+	    .on('connected', done)
+	    .connect();
       });
     },
 
   'tearDown' :
     function (done) {
-      if (fastTearDown) {
-	// Fast tearDown
-	server.stop("alpha", function (e) {
-	  buster.refute(e);
-	  done();
-	});
-      }
-      else {
-	alpha.disconnect(function (stat) {
-	    buster.assert(3 == stat);		// CLOSED
-
+      alpha
+	.on('disconnected', function () {
 	    server.stop("alpha", function (e) {
 	      buster.refute(e);
 	      done();
 	    });
-	  });
-      }
+	  })
+	.connect(false);
     },
 
   'request_ledger_current' :
diff --git a/test/websocket-test.js b/test/websocket-test.js
index 9e6e872614..055a0aab23 100644
--- a/test/websocket-test.js
+++ b/test/websocket-test.js
@@ -32,14 +32,20 @@ buster.testCase("WebSocket connection", {
     function (done) {
       var alpha	= remote.remoteConfig(config, "alpha", 'TRACE');
 
-      alpha.connect(function (stat) {
-	buster.assert.equals(stat, 1);	    // OPEN
+      alpha
+	.on('connected', function () {
+	    // OPEN
+	    buster.assert(true);
 
-	alpha.disconnect(function (stat) {
-	    buster.assert.equals(stat, 3);  // CLOSED
-	    done();
-	  });
-	}, serverDelay);
+	    alpha
+	      .on('disconnected', function () {
+		  // CLOSED
+		  buster.assert(true);
+		  done();
+		})
+	      .connect(false);
+	  })
+	.connect();
     },
 });