Improved exception tolerance, added logging to a file, removed old code, simplified handling of common requests.

1 files changed, 40 insertions, 81 deletions

diff --git a/web/main.js b/web/main.js
index 9f06e88..931a550 100644
--- a/web/main.js
+++ b/web/main.js
@@ -4,7 +4,21 @@ var engine = require('engine.io'),
     Promise = require('bluebird'),
     log4js = require('log4js');
 
-var logger = log4js.getLogger(); // TODO: log to a file
+log4js.loadAppender('file');
+log4js.addAppender(log4js.appenders.file('web.log'), 'log');
+var logger = log4js.getLogger('log');
+
+Promise.onPossiblyUnhandledRejection(function (error) {
+    var msg = 'Unhandled promise rejection: ' + error;
+    if ((error instanceof Error) && (typeof error.stack === 'string')) msg += '\n' + error.stack;
+    logger.error(msg);
+});
+
+process.on('uncaughtException', function (error) {
+    var msg = 'Uncaught exception: ' + error;
+    if ((error instanceof Error) && (typeof error.stack === 'string')) msg += '\n' + error.stack;
+    logger.error(msg);
+});
 
 http_server.listen(8083);
 
@@ -41,34 +55,9 @@ var sessions = {
     // sid: sessions description {sid: string, lastActivity: Date.now(), socket: net.Socket}
 };
 
-// GUI action handlers, keyed by the action name, values are functions that take the session and the message
+// GUI action handlers, keyed by the action name, values are functions that take the session and the message, or truthy values
 var guiHandlers = {
-    // TODO: list_problems is outside sessions for now; later it must become session-aware
-    'list_problems': function actionListProblems(session, message) {
-        var tid = message['tid']; // remember any TID that is set
-        delete message['tid']; // delete any TID, we must use an internal one when sending to Python, because it must be unique over all connected sessions
-        logger.debug('Received a list_problems request from GUI');
-        sendDataToPython(message).then(
-            function listProblemsRequestOK(response) {
-                if ((typeof tid !== 'undefined') && (tid !== null)) response['tid'] = tid;
-                else delete response['tid'];
-                session.send(response);
-            },
-            function listProblemsRequestFailed(err) {
-                var response = {
-                        'code': -30
-                    },
-                    reason;
-                logger.debug('Failed to request list_problems from Python');
-                if ((typeof tid !== 'undefined') && (tid !== null)) response['tid'] = tid;
-                if ((typeof err === 'object') && (err !== null)) reason = err.toString();
-                else reason = '' + err;
-                response['message'] = 'List-problems request failed: ' + reason;
-                session.end(response);
-            }
-        ).done();
-    },
-
+    // special-case action handlers
     'login': function actionLogin(session, message) {
         // first-time connect: login
         var tid = message['tid']; // remember any TID that is set
@@ -109,11 +98,6 @@ var guiHandlers = {
         ).done();
     },
 
-    //'resume': function actionResume(session, message) {
-    //    // reconnect: resume the session after unexpected disconnect
-    //
-    //},
-
     'logout': function actionLogout(session, message) {
         // logout, the user quit the app
         logger.debug('Logout GUI');
@@ -122,50 +106,17 @@ var guiHandlers = {
         }).done();
     },
 
-    'activity': function actionActivity(session, message) {
-        logger.debug('Received activity from GUI');
-        sendDataToPython(message).catch(session.end).done();
-    },
-
-    'query': function actionQuery(session, message) {
-        logger.debug('Received query from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'python_exec': function actionPythonExec(session, message) {
-        logger.debug('Received python_exec from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'python_push': function actionPythonPush(session, message) {
-        logger.debug('Received python_push from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'python_stop': function actionPythonStop(session, message) {
-        logger.debug('Received python_stop from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'hint': function actionHint(session, message) {
-        logger.debug('Received hint from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'test': function actionTest(session, message) {
-        logger.debug('Received test from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'get_problem': function actionTest(session, message) {
-        logger.debug('Received get_problem from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    },
-
-    'settings': function actionSettings(session, message) {
-        logger.debug('Received settings from GUI');
-        sendDataToPython(message).then(session.send, session.end).done();
-    }
+    // actions to use default handling should define truthy values that are not functions
+    // (this is to filter out unnecessary traffic before it hits Python)
+    'activity':    true,
+    'query':       true,
+    'python_exec': true,
+    'python_push': true,
+    'python_stop': true,
+    'hint':        true,
+    'test':        true,
+    'get_problem': true,
+    'settings':    true
 };
 
 server.on('connection', function (socket) {
@@ -218,7 +169,7 @@ server.on('connection', function (socket) {
         logger.debug('GUI socket closed: ' + reason);
         if (session.sid !== null) {
             if (sessions[session.sid] === session) delete sessions[session.sid];
-            sendDataToPython({'type': 'unregister', 'sid': session.sid});
+            sendDataToPython({'type': 'unregister', 'sid': session.sid}).done();
         }
     });
 
@@ -291,7 +242,15 @@ server.on('connection', function (socket) {
         }
 
         try {
-            handler(session, m);
+            if (typeof handler === 'function') {
+                // special case processing
+                handler(session, m);
+            }
+            else {
+                // default processing: just proxy it through to Python
+//                logger.debug((session.sid || '[no session]') + ': Received ' + action + ' from GUI');
+                sendDataToPython(m).then(session.send, session.end).done();
+            }
             session.lastTID = tid;
         }
         catch (e) {
@@ -348,7 +307,7 @@ var processPacketFromPython = function processPacketFromPythonFunc(packetString)
             key = m.tid + ':' + m.sid;
             resolver = pythonPromises[key];
             if (!resolver) {
-                key = '' + m.tid
+                key = '' + m.tid;
                 resolver = pythonPromises[key];
             }
         }
@@ -395,7 +354,7 @@ var processPacketFromPython = function processPacketFromPythonFunc(packetString)
 // this is internal function to python connection handler
 var sendPacketToPython = function sendPacketToPythonFunc(packet) {
     if (pythonSaturated || (pythonClient === null)) return false;
-    logger.debug('Attempting to send a packet to Python: ' + packet);
+    logger.debug('Sending to Python: ' + packet);
     try {
         pythonSaturated = !pythonClient.write(packet, 'utf8');
         return true;