improve drag performance and not to release global worker pool (#1990)

* use Geometry.translate to improve geometry edit's performance

* never release workerPool

Author: fuzhenn

src/core/worker/Actor.js

@@ -138,7 +138,7 @@ export default class Actor {
         this.workers.forEach(w => {
             w.removeEventListener('message', this.receiveFn, false);
         });
-        this.workerPool.release(this.actorId);
+        // this.workerPool.release(this.actorId);
         delete this.receiveFn;
         delete this.workers;
         delete this.callbacks;

src/core/worker/WorkerPool.js

@@ -86,6 +86,9 @@ export default class WorkerPool {
     }
 
     commit() {
+        if (!this.workers) {
+            return;
+        }
         if (this._messages.length) {
             for (let i = 0; i < this._messages.length; i++) {
                 if (!this._messages[i] || !this._messages[i].length) {

src/geometry/editor/GeometryEditor.js

@@ -300,9 +300,11 @@ class GeometryEditor extends Eventable(Class) {
                 }
             },
             onUp: () => {
-                const geo = shadow || this._geometry;
-                this._update('setCoordinates', Coordinate.toNumberArrays(geo.getCoordinates()));
                 if (shadow) {
+                    const shadowFirst = shadow.getFirstCoordinate();
+                    const first = this._geometry.getFirstCoordinate();
+                    const offset = shadowFirst.sub(first);
+                    this._update('translate', offset);
                     shadow.remove();
                 }
             }

src/geometry/ext/Geometry.Drag.js

@@ -319,15 +319,10 @@ class GeometryDragHandler extends Handler {
         const shadow = this._shadow;
         if (shadow) {
             if (target.options['dragShadow']) {
-                if (target.getGeometries) {
-                    const shadows = shadow.getGeometries();
-                    const geos = target.getGeometries();
-                    shadows.forEach((g, i) => {
-                        geos[i].setCoordinates(shadows[i].getCoordinates());
-                    });
-                } else {
-                    target.setCoordinates(shadow.getCoordinates());
-                }
+                const shadowFirst = shadow.getFirstCoordinate();
+                const first = target.getFirstCoordinate();
+                const offset = shadowFirst.sub(first);
+                target.translate(offset);
             }
             shadow._fireEvent('dragend', eventParam);
             shadow.remove();