Add children indexer map for fast getChildByTag & getChildByName support

cocos/2d/CCNode.cpp

@@ -34,6 +34,7 @@ THE SOFTWARE.
 #include <string>
 #include <regex>
 
+#include "xxhash.h"
 #include "base/CCDirector.h"
 #include "base/CCScheduler.h"
 #include "base/CCEventDispatcher.h"
@@ -53,6 +54,10 @@ THE SOFTWARE.
 #define RENDER_IN_SUBPIXEL(__ARGS__) (ceil(__ARGS__))
 #endif
 
+/*
+* 4.5x faster than std::hash in release mode
+*/
+#define CC_HASH_NODE_NAME(name) (!name.empty() ? XXH3_64bits(name.c_str(), name.length()) : 0)
 
 NS_CC_BEGIN
 
@@ -84,13 +89,14 @@ Node::Node()
 , _additionalTransformDirty(false)
 , _transformUpdated(true)
 // children (lazy allocs)
+, _childrenIndexer(nullptr)
 // lazy alloc
 , _localZOrder$Arrival(0LL)
 , _globalZOrder(0)
 , _parent(nullptr)
 // "whole screen" objects. like Scenes and Layers, should set _ignoreAnchorPointForPosition to true
 , _tag(Node::INVALID_TAG)
-, _name("")
+, _name()
 , _hashOfName(0)
 // userData is always inited as nil
 , _userData(nullptr)
@@ -149,6 +155,8 @@ Node * Node::create()
 Node::~Node()
 {
     CCLOGINFO( "deallocing Node: %p - tag: %i", this, _tag );
+
+    CC_SAFE_DELETE(_childrenIndexer);
     
 #if CC_ENABLE_SCRIPT_BINDING
     if (_updateScriptHandler)
@@ -680,7 +688,15 @@ int Node::getTag() const
 /// tag setter
 void Node::setTag(int tag)
 {
-    _tag = tag ;
+    auto parentChildrenIndexer = getParentChildrenIndexer();
+    if (parentChildrenIndexer)
+    {
+        if (_tag != tag)
+            parentChildrenIndexer->erase(_tag);
+        (*parentChildrenIndexer)[tag] = this;
+    }
+
+    _tag        = tag;
 }
 
 const std::string& Node::getName() const
@@ -690,9 +706,30 @@ const std::string& Node::getName() const
 
 void Node::setName(const std::string& name)
 {
+    uint64_t newHash           = CC_HASH_NODE_NAME(name);
+    auto parentChildrenIndexer = getParentChildrenIndexer();
+    if (parentChildrenIndexer)
+    {
+        auto oldHash = CC_HASH_NODE_NAME(_name);
+        if (oldHash != newHash)
+            parentChildrenIndexer->erase(oldHash);
+        (*parentChildrenIndexer)[newHash] = this;
+    }
+
     _name = name;
-    std::hash<std::string> h;
-    _hashOfName = h(name);
+    _hashOfName = newHash;
+}
+
+NodeIndexerMap_t* Node::getParentChildrenIndexer()
+{
+    if (!_director->isChildrenIndexerEnabled())
+        return nullptr;
+    auto parent = getParent();
+
+    NodeIndexerMap_t* indexer = nullptr;
+    if (parent && !parent->_childrenIndexer)
+        indexer = parent->_childrenIndexer = new NodeIndexerMap_t();
+    return indexer;
 }
 
 /// userData setter
@@ -750,26 +787,41 @@ Node* Node::getChildByTag(int tag) const
 {
     CCASSERT(tag != Node::INVALID_TAG, "Invalid tag");
 
-    for (const auto child : _children)
+    if (_childrenIndexer)
     {
-        if(child && child->_tag == tag)
-            return child;
+        auto it = _childrenIndexer->find(tag);
+        if (it != _childrenIndexer->end())
+            return it->second;
+    }
+    else
+    {
+        for (const auto child : _children)
+        {
+            if (child && child->_tag == tag)
+                return child;
+        }
     }
     return nullptr;
 }
 
 Node* Node::getChildByName(const std::string& name) const
 {
-    CCASSERT(!name.empty(), "Invalid name");
-    
-    std::hash<std::string> h;
-    size_t hash = h(name);
-    
-    for (const auto& child : _children)
+    // CCASSERT(!name.empty(), "Invalid name");
+    auto hash = CC_HASH_NODE_NAME(name);
+    if (_childrenIndexer)
     {
-        // Different strings may have the same hash code, but can use it to compare first for speed
-        if(child->_hashOfName == hash && child->_name.compare(name) == 0)
-            return child;
+        auto it = _childrenIndexer->find(hash);
+        if (it != _childrenIndexer->end())
+            return it->second;
+    }
+    else
+    {
+        for (const auto& child : _children)
+        {
+            // Different strings may have the same hash code, but can use it to compare first for speed
+            if (child->_hashOfName == hash && child->_name.compare(name) == 0)
+                return child;
+        }
     }
     return nullptr;
 }
@@ -937,14 +989,14 @@ void Node::addChildHelper(Node* child, int localZOrder, int tag, const std::stri
     }
     
     this->insertChild(child, localZOrder);
-    
+
+    child->setParent(this);
+
     if (setTag)
         child->setTag(tag);
     else
         child->setName(name);
     
-    child->setParent(this);
-
     child->updateOrderOfArrival();
 
     if( _running )
@@ -1056,6 +1108,7 @@ void Node::removeAllChildrenWithCleanup(bool cleanup)
     }
     
     _children.clear();
+    CC_SAFE_DELETE(_childrenIndexer);
 }
 
 void Node::resetChild(Node* child, bool cleanup)

cocos/2d/CCNode.h

@@ -82,6 +82,8 @@ enum {
 
 class EventListener;
 
+typedef std::map<uint64_t, Node*> NodeIndexerMap_t;
+
 /** @class Node
 * @brief Node is the base element of the Scene Graph. Elements of the Scene Graph must be Node objects or subclasses of it.
  The most common Node objects are: Scene, Layer, Sprite, Menu, Label.
@@ -1841,6 +1843,8 @@ protected:
 private:
     void addChildHelper(Node* child, int localZOrder, int tag, const std::string &name, bool setTag);
     
+    NodeIndexerMap_t* getParentChildrenIndexer();
+
 protected:
 
     float _rotationX;               ///< rotation on the X-axis
@@ -1897,6 +1901,7 @@ protected:
     static std::uint32_t s_globalOrderOfArrival;
 
     Vector<Node*> _children;        ///< array of children nodes
+    NodeIndexerMap_t* _childrenIndexer;  ///< The children indexer for fast find child
     Node *_parent;                  ///< weak reference to parent node
     Director* _director;            //cached director pointer to improve rendering performance
     int _tag;                       ///< a tag. Can be any number you assigned just to identify this node

cocos/base/CCDirector.h

@@ -4,8 +4,9 @@
  Copyright (c) 2011      Zynga Inc.
  Copyright (c) 2013-2016 Chukong Technologies Inc.
  Copyright (c) 2017-2019 Xiamen Yaji Software Co., Ltd.
+ Copyright (c) 2021 Bytedance Inc.
 
-http://www.cocos2d-x.org
+https://adxe.org
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -502,6 +503,9 @@ public:
      */
     const std::thread::id& getCocos2dThreadId() const { return _cocos2d_thread_id; }
 
+    void setChildrenIndexerEnabled(bool enable) { _childrenIndexerEnabled = enable; }
+    bool isChildrenIndexerEnabled() const { return _childrenIndexerEnabled; }
+
     /**
      * returns whether or not the Director is in a valid state
      */
@@ -638,12 +642,14 @@ protected:
 
     bool _isStatusLabelUpdated = true;
 
-    /* cocos2d thread id */
-    std::thread::id _cocos2d_thread_id;
-
     /* whether or not the director is in a valid state */
     bool _invalid = false;
 
+    bool _childrenIndexerEnabled = false;
+
+    /* cocos2d thread id */
+    std::thread::id _cocos2d_thread_id;
+
     // GLView will recreate stats labels to fit visible rect
     friend class GLView;
 };