new version hash listeners tree which is faster in most case

benchmark/hash-listener-tree.js

@@ -1,50 +1,51 @@
 /* eslint-disable */
-import { stringifyPath } from '../src/utils';
-function pathify(p) {
-  if (Array.isArray(p)) p = stringifyPath(p);
-  return '$$_' + p; // prepend special symbols to avoid name conflict with protos
-}
-function keyify(path, listener) {
-  return path + '//' + listener;
-}
+let count = 1;
 class ListenTree {
   constructor() {
-    this._listeners = [];
-    this._count = 1;
+    this._listeners = Object.create(null);
     this._listened = {};
   }
 
   on(p, listener) {
-    const path = pathify(p);
+    const path = `!_${ p.join('#')}`;
     if (!listener.$id) {
-      listener.$id = this._count++;
+      listener.$id = count++;
     }
-    const key = keyify(path, listener.$id);
+    const key = path + '//' + listener.$id;
     if (this._listened[key]) return;
     if (!this._listeners[path]) this._listeners[path] = [];
     this._listeners[path].push(listener);
     this._listened[key] = true;
   }
 
   off(p, listener) {
-    const path = pathify(p);
+    const path = `!_${ p.join('#')}`;
     const listeners = this._listeners[path];
-    if (!listeners || !listeners.length) return;
-    listeners.splice(listeners.indexOf(listener), 1);
-    this._listened[keyify(path, listener)] = false;
+    if (!listeners) return;
+    var i = 0;
+    while (listeners[i] && listener != listeners[i]) i++;
+    while (listeners[i] = listeners[i + 1]) i++;
+    listeners.length = i;
+    this._listened[path + '//' + listener.$id] = false;
   }
 
   emit(p) {
-    const path = pathify(p);
-    const listeners = {};
-    Object.keys(this._listeners).forEach(p2 => {
-      if (path !== '' && p2 !== ''
-        && p2.indexOf(path) !== 0 && path.indexOf(p2) !== 0) return;
-      (this._listeners[p2] || []).forEach(listener => {
-        listeners[listener.$id] = listener;
-      });
-    });
-    Object.keys(listeners).forEach(k => listeners[k]());
+    const path = `!_${ p.join('#')}`;
+    const listeners = this._listeners;
+    const len1 = path.length;
+    const called = {};
+    for (let p2 in listeners) {
+      const len2 = p2.length;
+      if (len2 >= len1 && p2.slice(0, len1) !== path) continue;
+      if (len2 < len1 && path.slice(0, len2) !== p2) continue;
+      const subListeners = listeners[p2];
+      var i = 0, listener;
+      while (listener = subListeners[i++]) {
+        if (called[listener.$id]) continue;
+        called[listener.$id] = true;
+        listener();
+      }
+    }
   }
 }