reduce memory allocation in label ids (use numbers instead of strings)

tangrams · Mar 6, 2019 · af89f8e · af89f8e
1 parent 9d772cd
commit af89f8e
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/labels/label.js b/src/labels/label.js
@@ -130,10 +130,11 @@ Label.add = function (label, bboxes) {
 };
 
 Label.id = 0;
-Label.id_prefix = ''; // id prefix scoped to worker thread
+Label.id_prefix = 0; // id prefix scoped to worker thread
+Label.id_multiplier = 0; // multiplier to keep label ids distinct across threads
 
 Label.nextLabelId = function () {
-    return Label.id_prefix + '/' + (Label.id++);
+    return Label.id_prefix + ((Label.id++) * Label.id_multiplier);
 };
 
 Label.epsilon = 0.9999; // tolerance around collision boxes, prevent perfectly adjacent objects from colliding

diff --git a/src/scene/scene_worker.js b/src/scene/scene_worker.js
@@ -39,6 +39,7 @@ const SceneWorker = Object.assign(self, {
         this.style_manager = new StyleManager();
         this.importExternalScripts(external_scripts);
         Label.id_prefix = worker_id;
+        Label.id_multiplier = num_workers;
         return worker_id;
     },