perf: faster remembered entities

server/traits/informed.trait.js

@@ -25,7 +25,8 @@ export class Informed extends decorate(Trait) {
   constructor(entity, params, state) {
     super(entity, params, state);
     this._packer = new Packer();
-    this._rememberedEntities = {};
+    this._rememberedEntities = [];
+    this._rememberedUuids = [];
     this._socket = undefined;
     this._state = I.Map();
   }
@@ -35,7 +36,8 @@ export class Informed extends decorate(Trait) {
       delete this._socket.entity;
       delete this._socket;
     }
-    this._rememberedEntities = {};
+    this._rememberedEntities = [];
+    this._rememberedUuids = [];
     this._state = this._state.clear();
   }
 
@@ -103,16 +105,17 @@ export class Informed extends decorate(Trait) {
     steps = steps.withMutations((steps) => {
       const iterator = adds.values();
       for (const add of iterator) {
-        // Remember the entity.
+        // Entity we remember?.
         const parts = add.get('parts');
         const layerId = parts[3];
         const uuid = parts[5];
-        if (!(uuid in this._rememberedEntities)) {
+        const index = this._rememberedUuids.indexOf(uuid);
+        if (-1 === index) {
           continue;
         }
-        const rememberedEntity = this._rememberedEntities[uuid].entity;
+        const rememberedEntity = this._rememberedEntities[index].entity;
         // Reset remembrance timeout.
-        this._rememberedEntities[uuid].rememberFor = 60;
+        this._rememberedEntities[index].rememberFor = 60;
         // Take a diff from what the client remembers to now.
         const currentState = state.getIn(
           ['room', 'layers', layerId, 'entityList', uuid]
@@ -142,13 +145,16 @@ export class Informed extends decorate(Trait) {
       }
       const parts = step.get('parts');
       const uuid = parts[5];
-      return !(uuid in this._rememberedEntities);
+      const index = this._rememberedUuids.indexOf(uuid);
+      return -1 === index;
     });
     // Forget all remembered entities.
     adds.forEach((step) => {
       const parts = step.get('parts');
       const uuid = parts[5];
-      delete this._rememberedEntities[uuid];
+      const index = this._rememberedUuids.indexOf(uuid);
+      this._rememberedEntities.splice(index, 1);
+      this._rememberedUuids.splice(index, 1);
     });
     return steps;
   }
@@ -172,11 +178,12 @@ export class Informed extends decorate(Trait) {
         if (!remembered) {
           return;
         }
-        this._rememberedEntities[uuid] = {
+        this._rememberedUuids.push(uuid);
+        this._rememberedEntities.push({
           entity: remembered,
           // Remember entities for one minute.
           rememeberFor: 60,
-        };
+        });
         // Add overrides.
         const overrides = this.entityOverrides(
           removal.get('path'),
@@ -194,7 +201,8 @@ export class Informed extends decorate(Trait) {
       }
       const parts = step.get('parts');
       const uuid = parts[5];
-      return !(uuid in this._rememberedEntities);
+      const index = this._rememberedUuids.indexOf(uuid);
+      return -1 === index;
     });
   }
 
@@ -269,13 +277,19 @@ export class Informed extends decorate(Trait) {
   }
 
   tick(elapsed) {
-    const rememberedEntities = this._rememberedEntities;
-    for (const uuid in rememberedEntities) {
-      const rememberFor = rememberedEntities[uuid].rememberFor -= elapsed;
-      if (rememberFor <= 0) {
-        delete rememberedEntities[uuid];
+    const removeUuids = [];
+    for (let i = 0; i < this._rememberedEntities.length; i++) {
+      this._rememberedEntities[i].rememberFor -= elapsed;
+      if (this._rememberedEntities[i].rememberFor <= 0) {
+        removeUuids.push(this._rememberedUuids[i]);
       }
     }
+    for (let i = 0; i < removeUuids.length; i++) {
+      const uuid = removeUuids[i];
+      const index = this._rememberedUuids.indexOf(uuid);
+      this._rememberedEntities.splice(index, 1);
+      this._rememberedUuids.splice(index, 1);
+    }
   }
 
 }