Refactor pcscslite.js

- Improve and fix how we parse and handle cardreader strings.

lib/pcsclite.js

@@ -8,54 +8,57 @@ var CardReader = bindings.CardReader;
 inherits(PCSCLite, events.EventEmitter);
 inherits(CardReader, events.EventEmitter);
 
+var parse_readers_string = function(readers_str) {
+    var pos;
+    var readers = [];
+    var ini = 0;
+    while ((pos = readers_str.slice(ini).indexOf('\0')) > 0) {
+        readers.push(readers_str.slice(ini, ini + pos).toString());
+        ini += pos + 1;
+    }
+
+    return readers;
+};
+
 module.exports = function() {
 
     var readers = [];
     var p = new PCSCLite();
     process.nextTick(function() {
-        p.start(function(e, data) {
-            if (e) {
-                p.emit('error', e);
-            } else {
-                /* parse data buffer to get the card reader name, and get the reader */
-                var readers_aux = [];
-                var ini = 0;
-                var pos = 0;
-                while((pos = data.slice(ini).indexOf('\0')) > 0) {
-                    var name = data.slice(ini, ini + pos).toString();
-                    var is_old = false;
-                    for (var i = 0; i < readers.length; ++i) {
-                        if (readers[i].name === name) {
-                            readers_aux.push(readers[i]);
-                            is_old = true;
-                            break;
-                        }
-                    }
-
-                    if (!is_old) {
-                        var r = new CardReader(name);
-                        readers_aux.push(r);
-                        p.emit('reader', r);
-                        r.get_status(function(e, state, atr) {
-                            if (e) {
-                                r.emit('error', e);
-                            } else {
-                                var status = { state : state };
-                                if (atr) {
-                                    status.atr = atr;
-                                }
-
-                                r.emit('status', status);
-                                r.state = state;
-                            }
-                        });
-                    }
-
-                    ini += pos + 1;
-                }
-
-                readers = readers_aux;
+        p.start(function(err, data) {
+            if (err) {
+                return p.emit('error', err);
             }
+
+            var readers_aux = [];
+            var names = parse_readers_string(data);
+            var new_names = names.filter(function(name) {
+                return !readers.some(function(reader) {
+                    return reader.name !== name;
+                });
+            });
+
+            new_names.forEach(function(name) {
+                var r = new CardReader(name);
+                readers_aux.push(r);
+                r.get_status(function(err, state, atr) {
+                    if (err) {
+                        return r.emit('error', e);
+                    }
+
+                    var status = { state : state };
+                    if (atr) {
+                        status.atr = atr;
+                    }
+
+                    r.emit('status', status);
+                    r.state = state;
+                });
+
+                p.emit('reader', r);
+            });
+
+            readers = readers_aux;
         });
     });