use property setter in debug mode to map seq num to stack trace

lib/xcore.js

@@ -64,8 +64,26 @@ function XClient(stream, displayNum, screenNum, options)
     this.pack_stream = pack_stream;
 
     this.rsrc_id = 0; // generated for each new resource
-    this.seq_num = 0; // incremented in each request. (even if we don't expect reply)
+    var cli = this;
-    this.seq2stack = {}; // debug: map seq_num to stack at the moment request was issued   
+    if (cli.options.debug) {
+      this.seq_num_ = 0;
+      this.seq2stack = {}; // debug: map seq_num to stack at the moment request was issued   
+      Object.defineProperty(cli, "seq_num", {
+        set : function(v) {
+          cli.seq_num_ = v;
+          var err = new Error();
+          Error.captureStackTrace(err, arguments.callee);
+          err.timestamp = Date.now();
+          cli.seq2stack[client.seq_num] = err;
+        },
+        get: function() {
+	  return cli.seq_num_;
+        }
+      });
+    } else {
+      this.seq_num = 0;
+    }
+
  
     // in/out packets indexed by sequence ID
     this.replies = {};
@@ -83,6 +101,7 @@ function XClient(stream, displayNum, screenNum, options)
     
     this.event_consumers = {}; // maps window id to eventemitter TODO: bad name
     this.eventParsers = {};   
+    this.errorParsers = {};   
 
     this.importRequestsFromTemplates(this, coreRequests);
     
@@ -138,18 +157,6 @@ XClient.prototype.importRequestsFromTemplates = function(target, reqs)
             else
                client.seq_num++;
            
-            // disable long stack trace for the moment, it's too expensive
-            // performance when enabled (travis-ci worker, Xfvb): 70000 requests finished in 52196 ms, 1341.0989347842747 req/sec
-            // without: 70000 requests finished in 14904 ms, 4696.725711218465 req/sec
-            // MBPro, XQuartz: with 3600 req/sec, without 24200 req/sec 
-            if (this.options.debug === true) {
-               var err = new Error();
-               err.name = reqName; //???
-               Error.captureStackTrace(err, arguments.callee);
-               err.timestamp = Date.now();
-               client.seq2stack[client.seq_num] = err;
-            }
-
             // is it fast?
             var args = Array.prototype.slice.call(req_proxy.arguments);
 
@@ -171,7 +178,7 @@ XClient.prototype.importRequestsFromTemplates = function(target, reqs)
                      var value = req_proxy.arguments[1];
                      if (client.atoms[value]) {
                          -- client.seq_num;
-                         return process.nextTick(function() {
+                         return setImmediate(function() {
                              callback(undefined, client.atoms[value]);
                          });
                      } else {
@@ -197,7 +204,7 @@ XClient.prototype.importRequestsFromTemplates = function(target, reqs)
                      var atom = req_proxy.arguments[0];
                      if (client.atom_names[atom]) {
                          -- client.seq_num;
-                         return process.nextTick(function() {
+                         return setImmediate(function() {
                              callback(undefined, client.atom_names[atom]);
                          });
                      } else {
@@ -412,12 +419,22 @@ XClient.prototype.expectReplyHeader = function()
                 error.error = error_code;
                 error.seq = seq_num;
                 error.message = xerrors.errorText[error_code];
-                if (client.options.debug)
+                if (client.options.debug) {
-                    error.stack = client.seq2stack[error.seq]
+                  error.longstack = client.seq2stack[error.seq]
+                  console.log(client.seq2stack[error.seq].stack);
+                }
 
                 // unpack error packet (32 bytes for all error types, 8 of them in CCSL header)
                 client.pack_stream.get(24, function(buf) {
 
+	           var extUnpacker = client.errorParsers[type];
+                   if (extUnpacker) {
+                     var event = extUnpacker(type, seq_num, bad_value, body);
+		     client.emit(error, event);
+                     client.expectReplyHeader();
+		     return;
+                   }
+
                     // TODO: dispatch, use sequence number
                     //TODO: add more generic way to read common values
                     // if (error_code == 14)
@@ -569,26 +586,30 @@ module.exports.createClient = function(options, initCb)
     var client = new XClient(stream, displayNum, screenNum, options);
     if (initCb)
     {
+	var cbCalled = false;
         client.on('connect', function(display) {
-            // Once connected don't call initCb on error, just emit
-            stream.removeListener('error', initCb);
-            stream.on('error', function(err) {
-                client.emit('error', err);
-            });
             // opt-in BigReq
             if (!options.disableBigRequests) {
                 client.require('big-requests', function(BigReq) {
                     BigReq.Enable(function(err, maxLen) {
                         display.max_request_length = maxLen;
+	                cbCalled = true;
                         initCb(undefined, display);
                     });
                 });
             } else {
+	        cbCalled = true;
                 initCb(undefined, display);
             }
         });
-
+        stream.on('error', function(err) {
-        stream.on('error', initCb);
+	  if (cbCalled)
+	    client.emit('error', err);
+	  else {
+	    cbCalled = true;
+            initCb(err);
+	  }
+	});
     }
     return client;
 }