multiple template set

[fedy85]

The library ignores template sets with multiple templates and merges all of them into the first one it finds in byte buffer.
I've made a fix. Could you merge it into the master ?

/ipfix_node/lib/ipfix_packet_elements/template_set/record.js

--- record.js.backup    2023-06-20 22:56:54.323450660 +0200
+++ record.js   2023-06-21 11:09:49.482162620 +0200
@@ -4,20 +4,31 @@
     this.templateId = undefined;
     this.numberFields = undefined;
     this.FieldSpecifiers = []
+
+    this.isLast = false;
+    this.newBuffer = null;
+
     var _construct = function() {
-        var i = 0;
-        self.setId = buffer.readUInt16BE(i)
-        self.sizeInBytes = buffer.readUInt16BE(i += 2);
-        self.templateId = buffer.readUInt16BE(i += 2);
-        self.numberFields = buffer.readUInt16BE(i += 2);
-        buffer = buffer.slice(i += 2);
+        var byte = 0;
+        self.setId = buffer.readUInt16BE(byte)
+        self.sizeInBytes = buffer.readUInt16BE(byte += 2);
+        self.templateId = buffer.readUInt16BE(byte += 2);
+        self.numberFields = buffer.readUInt16BE(byte += 2);
+
+        var headerBuffer = buffer.slice(0, 4);
+        var setBuffer = buffer.slice(byte += 2);

-        while (i < self.sizeInBytes) {
-            var FreshSpecifier = new TemplateRecordFieldSpecifier(buffer);
+        var i = 0;
+        while (i < self.numberFields) {
+            var FreshSpecifier = new TemplateRecordFieldSpecifier(setBuffer);
             self.FieldSpecifiers.push(FreshSpecifier);
-            buffer = buffer.slice(4);
-            i += 4;
+            setBuffer = setBuffer.slice(4);
+            i++;
         }
+
+        self.isLast = (setBuffer.byteLength == 0) ? true : false;
+        self.newBuffer = Buffer.concat([headerBuffer, setBuffer]);
+
         return this;
     }

and

/ipfix_node/lib/ipfix_packet_elements/ipfix_packet.js

--- ipfix_packet.js.backup      2023-06-21 11:19:55.764359997 +0200
+++ ipfix_packet.js     2023-06-21 11:10:10.354236553 +0200
@@ -22,10 +22,16 @@
             var setType = getSetType(setId);
             var sizeInBytes = buffer.readUInt16BE(2);
             if (setType == 'DataTemplate') {
-                var TemplateSet = new TemplateRecord(buffer);
+                var isLast = false;
+                while (!isLast) {
+                    var TemplateSet = new TemplateRecord(buffer);

-                storeTemplate(TemplateSet);
-                self.TemplateSets.push(TemplateSet);
+                    buffer = TemplateSet.newBuffer;
+                    isLast = TemplateSet.isLast;
+
+                    storeTemplate(TemplateSet);
+                    self.TemplateSets.push(TemplateSet);
+                }
             } else if (setType == 'OptionTemplate') {
                 var OptionsTemplateSet = new OptionsTemplateRecord(buffer);
                 storeTemplate(OptionsTemplateSet);