From 2b04af434937d4cde9a5b6584c19603cc586e6c3 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Mon, 22 Feb 2016 14:03:31 +0800
Subject: [PATCH] No longer need to count the references in webContents

All remote objects are now cached in renderer process, so there is
always only one reference to one remote object for each webContents.
---
 atom/browser/lib/objects-registry.js | 73 +++++++++++-----------------
 atom/browser/lib/rpc-server.js       |  2 +-
 2 files changed, 30 insertions(+), 45 deletions(-)

diff --git a/atom/browser/lib/objects-registry.js b/atom/browser/lib/objects-registry.js
index e9d6d365fa..90d1fe80e5 100644
--- a/atom/browser/lib/objects-registry.js
+++ b/atom/browser/lib/objects-registry.js
@@ -15,70 +15,57 @@ class ObjectsRegistry extends EventEmitter {
     this.storage = {};
 
     // Stores the IDs of objects referenced by WebContents.
-    // (webContentsId) => {(id) => (count)}
+    // (webContentsId) => [id]
     this.owners = {};
   }
 
-  // Register a new object, the object would be kept referenced until you release
-  // it explicitly.
+  // Register a new object and return its assigned ID. If the object is already
+  // registered then the already assigned ID would be returned.
   add(webContentsId, obj) {
-    var base, base1, id;
-    id = this.saveToStorage(obj);
+    // Get or assign an ID to the object.
+    let id = this.saveToStorage(obj);
 
-    // Remember the owner.
-    if ((base = this.owners)[webContentsId] == null) {
-      base[webContentsId] = {};
+    // Add object to the set of referenced objects.
+    let owner = this.owners[webContentsId];
+    if (!owner)
+      owner = this.owners[webContentsId] = new Set();
+    if (!owner.has(id)) {
+      owner.add(id);
+      // Increase reference count if not referenced before.
+      this.storage[id].count++;
     }
-    if ((base1 = this.owners[webContentsId])[id] == null) {
-      base1[id] = 0;
-    }
-    this.owners[webContentsId][id]++;
-
-    // Returns object's id
     return id;
   }
 
   // Get an object according to its ID.
   get(id) {
-    var ref;
-    return (ref = this.storage[id]) != null ? ref.object : void 0;
+    return this.storage[id].object;
   }
 
   // Dereference an object according to its ID.
   remove(webContentsId, id) {
-    var pointer;
-    this.dereference(id, 1);
+    // Dereference from the storage.
+    this.dereference(id);
 
-    // Also reduce the count in owner.
-    pointer = this.owners[webContentsId];
-    if (pointer == null) {
-      return;
-    }
-    --pointer[id];
-    if (pointer[id] === 0) {
-      return delete pointer[id];
-    }
+    // Also remove the reference in owner.
+    this.owners[webContentsId].delete(id);
   }
 
   // Clear all references to objects refrenced by the WebContents.
   clear(webContentsId) {
-    var count, id, ref;
-    this.emit("clear-" + webContentsId);
-    if (this.owners[webContentsId] == null) {
+    this.emit(`clear-${webContentsId}`);
+
+    let owner = this.owners[webContentsId];
+    if (!owner)
       return;
-    }
-    ref = this.owners[webContentsId];
-    for (id in ref) {
-      count = ref[id];
-      this.dereference(id, count);
-    }
-    return delete this.owners[webContentsId];
+    for (let id of owner)
+      this.dereference(id);
+    delete this.owners[webContentsId];
   }
 
   // Private: Saves the object into storage and assigns an ID for it.
   saveToStorage(object) {
-    var id;
-    id = v8Util.getHiddenValue(object, 'atomId');
+    let id = v8Util.getHiddenValue(object, 'atomId');
     if (!id) {
       id = ++this.nextId;
       this.storage[id] = {
@@ -87,18 +74,16 @@ class ObjectsRegistry extends EventEmitter {
       };
       v8Util.setHiddenValue(object, 'atomId', id);
     }
-    ++this.storage[id].count;
     return id;
   }
 
   // Private: Dereference the object from store.
-  dereference(id, count) {
-    var pointer;
-    pointer = this.storage[id];
+  dereference(id) {
+    let pointer = this.storage[id];
     if (pointer == null) {
       return;
     }
-    pointer.count -= count;
+    pointer.count -= 1;
     if (pointer.count === 0) {
       v8Util.deleteHiddenValue(pointer.object, 'atomId');
       return delete this.storage[id];
diff --git a/atom/browser/lib/rpc-server.js b/atom/browser/lib/rpc-server.js
index c3e5159cd9..f366eb43a5 100644
--- a/atom/browser/lib/rpc-server.js
+++ b/atom/browser/lib/rpc-server.js
@@ -145,7 +145,7 @@ var exceptionToMeta = function(error) {
 var unwrapArgs = function(sender, args) {
   var metaToValue;
   metaToValue = function(meta) {
-    var i, len, member, ref, rendererReleased, returnValue;
+    var i, len, member, ref, returnValue;
     switch (meta.type) {
       case 'value':
         return meta.value;