minor fixes:

- better perf for short DCS without params (8 times faster)
- test perf for class and string based interfaces of OSC and DCS
  separately
- undo wrong commit on parser

src/common/parser/DcsParser.ts

@@ -100,19 +100,27 @@ export class DcsParser implements IDcsParser {
   }
 }
 
+// predefine empty params as [0] (ZDM)
+const EMPTY_PARAMS = new Params();
+EMPTY_PARAMS.addParam(0);
+
 /**
  * Convenient class to create a DCS handler from a single callback function.
  * Note: The payload is currently limited to 50 MB (hardcoded).
  */
 export class DcsHandler implements IDcsHandler {
   private _data = '';
-  private _params: IParams | undefined;
+  private _params: IParams = EMPTY_PARAMS;
   private _hitLimit: boolean = false;
 
   constructor(private _handler: (data: string, params: IParams) => boolean) {}
 
   public hook(params: IParams): void {
-    this._params = params.clone();
+    // since we need to preserve params until `unhook`, we have to clone it
+    // (only borrowed from parser and spans multiple parser states)
+    // perf optimization:
+    // clone only, if we have non empty params, otherwise stick with default
+    this._params = (params.length > 1 || params.params[0]) ? params.clone() : EMPTY_PARAMS;
     this._data = '';
     this._hitLimit = false;
   }
@@ -133,9 +141,9 @@ export class DcsHandler implements IDcsHandler {
     if (this._hitLimit) {
       ret = false;
     } else if (success) {
-      ret = this._handler(this._data, this._params || new Params());
+      ret = this._handler(this._data, this._params);
     }
-    this._params = undefined;
+    this._params = EMPTY_PARAMS;
     this._data = '';
     this._hitLimit = false;
     return ret;