perf(Stream): improve performance of Observer methods in Stream

staltz · Feb 26, 2016 · 465f22d · 465f22d
1 parent 7ff9fd0
commit 465f22d
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Showing 2 changed files with 22 additions and 10 deletions.
diff --git a/perf/filter-map-reduce.js b/perf/filter-map-reduce.js
@@ -28,6 +28,10 @@ var options = {
 };
 
 suite
+  .add('xstream', function(deferred) {
+    runners.runXStream(deferred,
+      xstream.from(a).filter(even).map(add1).fold(sum, 0).last());
+  }, options)
   .add('most', function(deferred) {
     runners.runMost(deferred, most.from(a).filter(even).map(add1).reduce(sum, 0));
   }, options)
@@ -38,10 +42,6 @@ suite
     runners.runRx5(deferred,
       rxjs.Observable.fromArray(a).filter(even).map(add1).reduce(sum, 0));
   }, options)
-  .add('xstream', function(deferred) {
-    runners.runXStream(deferred,
-      xstream.from(a).filter(even).map(add1).fold(sum, 0).last());
-  }, options)
   .add('kefir', function(deferred) {
     runners.runKefir(deferred, kefirFromArray(a).filter(even).map(add1).scan(sum, 0).last());
   }, options)

diff --git a/src/Stream.ts b/src/Stream.ts
@@ -19,22 +19,34 @@ export class Stream<T> implements Observer<T> {
 
   next(x: T): void {
     const len = this.observers.length;
-    for (let i = len - 1; i >= 0; i--) {
-      this.observers[i].next(x);
+    if (len === 1) {
+      this.observers[0].next(x);
+    } else {
+      for (let i = 0; i < len; i++) {
+        this.observers[i].next(x);
+      }
     }
   }
 
   error(err: any): void {
     const len = this.observers.length;
-    for (let i = len - 1; i >= 0; i--) {
-      this.observers[i].error(err);
+    if (len === 1) {
+      this.observers[0].error(err);
+    } else {
+      for (let i = 0; i < len; i++) {
+        this.observers[i].error(err);
+      }
     }
   }
 
   complete(): void {
     const len = this.observers.length;
-    for (let i = len - 1; i >= 0; i--) {
-      this.observers[i].complete();
+    if (len === 1) {
+      this.observers[0].complete();
+    } else {
+      for (let i = 0; i < len; i++) {
+        this.observers[i].complete();
+      }
     }
   }