Core/PacketIO: Reduce size of SMSG_UPDATE_OBJECT by trimming trailing zeros in values updatemask

src/server/game/Entities/DynamicObject/DynamicObject.cpp

@@ -176,8 +176,7 @@ void DynamicObject::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player
         return;
 
     ByteBuffer fieldBuffer;
-    UpdateMask updateMask;
-    updateMask.SetCount(m_valuesCount);
+    UpdateMaskPacketBuilder updateMask(m_valuesCount);
 
     uint32* flags = nullptr;
     uint32 visibleFlag = GetUpdateFieldData(target, flags);
@@ -214,7 +213,6 @@ void DynamicObject::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player
         }
     }
 
-    *data << uint8(updateMask.GetBlockCount());
     updateMask.AppendToPacket(data);
     data->append(fieldBuffer);
 }

src/server/game/Entities/GameObject/GameObject.cpp

@@ -2524,8 +2524,7 @@ void GameObject::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* t
 
     ByteBuffer fieldBuffer;
 
-    UpdateMask updateMask;
-    updateMask.SetCount(m_valuesCount);
+    UpdateMaskPacketBuilder updateMask(m_valuesCount);
 
     uint32* flags = GameObjectUpdateFieldFlags;
     uint32 visibleFlag = UF_FLAG_PUBLIC;
@@ -2593,7 +2592,6 @@ void GameObject::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* t
         }
     }
 
-    *data << uint8(updateMask.GetBlockCount());
     updateMask.AppendToPacket(data);
     data->append(fieldBuffer);
 }

src/server/game/Entities/Object/Object.cpp

@@ -665,8 +665,7 @@ void Object::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* targe
         return;
 
     ByteBuffer fieldBuffer;
-    UpdateMask updateMask;
-    updateMask.SetCount(m_valuesCount);
+    UpdateMaskPacketBuilder updateMask(m_valuesCount);
 
     uint32* flags = nullptr;
     uint32 visibleFlag = GetUpdateFieldData(target, flags);
@@ -682,7 +681,6 @@ void Object::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* targe
         }
     }
 
-    *data << uint8(updateMask.GetBlockCount());
     updateMask.AppendToPacket(data);
     data->append(fieldBuffer);
 }

src/server/game/Entities/Object/Updates/UpdateMask.h

@@ -24,101 +24,92 @@
 
 class UpdateMask
 {
-    public:
-        /// Type representing how client reads update mask
-        typedef uint32 ClientUpdateMaskType;
+public:
+    UpdateMask() : _bits(nullptr), _fieldCount(0) { }
 
-        enum UpdateMaskCount
-        {
-            CLIENT_UPDATE_MASK_BITS = sizeof(ClientUpdateMaskType) * 8,
-        };
+    void SetBit(uint32 index)
+    {
+        _bits[index] = 1;
+    }
 
-        UpdateMask() : _fieldCount(0), _blockCount(0), _bits(nullptr) { }
+    void UnsetBit(uint32 index)
+    {
+        _bits[index] = 0;
+    }
 
-        UpdateMask(UpdateMask const& right) : _bits(nullptr)
-        {
-            SetCount(right.GetCount());
-            memcpy(_bits, right._bits, sizeof(uint8) * _blockCount * 32);
-        }
+    bool GetBit(uint32 index) const
+    {
+        return _bits[index] != 0;
+    }
 
-        ~UpdateMask() { delete[] _bits; }
+    void SetCount(uint32 valuesCount)
+    {
+        _bits = std::make_unique<uint8[]>(valuesCount);
+        std::uninitialized_fill_n(&_bits[0], valuesCount, 0);
+        _fieldCount = valuesCount;
+    }
 
-        void SetBit(uint32 index) { _bits[index] = 1; }
-        void UnsetBit(uint32 index) { _bits[index] = 0; }
-        bool GetBit(uint32 index) const { return _bits[index] != 0; }
+    void Clear()
+    {
+        if (_bits)
+            std::fill_n(&_bits[0], _fieldCount, 0);
+    }
 
-        void AppendToPacket(ByteBuffer* data)
-        {
-            for (uint32 i = 0; i < GetBlockCount(); ++i)
-            {
-                ClientUpdateMaskType maskPart = 0;
-                for (uint32 j = 0; j < CLIENT_UPDATE_MASK_BITS; ++j)
-                    if (_bits[CLIENT_UPDATE_MASK_BITS * i + j])
-                        maskPart |= 1 << j;
+private:
+    std::unique_ptr<uint8[]> _bits;
+    uint32 _fieldCount;
+};
 
-                *data << maskPart;
-            }
-        }
+class UpdateMaskPacketBuilder
+{
+public:
+    /// Type representing how client reads update mask
+    using ClientUpdateMaskType = uint32;
 
-        uint32 GetBlockCount() const { return _blockCount; }
-        uint32 GetCount() const { return _fieldCount; }
+    enum UpdateMaskCount
+    {
+        CLIENT_UPDATE_MASK_BITS = sizeof(ClientUpdateMaskType) * 8,
+    };
 
-        void SetCount(uint32 valuesCount)
-        {
-            delete[] _bits;
+    explicit UpdateMaskPacketBuilder(uint32 valuesCount) : _lastSetBit(0)
+    {
+        std::size_t blockCount = CalculateBlockCount(valuesCount);
+        _mask = std::make_unique<ClientUpdateMaskType[]>(blockCount);
+        std::uninitialized_fill_n(&_mask[0], blockCount, 0);
+    }
 
-            _fieldCount = valuesCount;
-            _blockCount = (valuesCount + CLIENT_UPDATE_MASK_BITS - 1) / CLIENT_UPDATE_MASK_BITS;
+    void SetBit(uint32 bit)
+    {
+        _mask[GetBlockIndex(bit)] |= GetBlockFlag(bit);
+        _lastSetBit = bit;
+    }
 
-            _bits = new uint8[_blockCount * CLIENT_UPDATE_MASK_BITS];
-            memset(_bits, 0, sizeof(uint8) * _blockCount * CLIENT_UPDATE_MASK_BITS);
-        }
+    void AppendToPacket(ByteBuffer* data)
+    {
+        uint8 blockCount = CalculateBlockCount(_lastSetBit + 1);
+        *data << uint8(blockCount);
+        if (blockCount)
+            data->append(&_mask[0], blockCount);
+    }
 
-        void Clear()
-        {
-            if (_bits)
-                memset(_bits, 0, sizeof(uint8) * _blockCount * CLIENT_UPDATE_MASK_BITS);
-        }
+private:
+    static constexpr uint8 CalculateBlockCount(uint32 fieldCount)
+    {
+        return (fieldCount + CLIENT_UPDATE_MASK_BITS - 1) / CLIENT_UPDATE_MASK_BITS;
+    }
 
-        UpdateMask& operator=(UpdateMask const& right)
-        {
-            if (this == &right)
-                return *this;
+    static constexpr std::size_t GetBlockIndex(uint32 bit)
+    {
+        return bit / 32;
+    }
 
-            SetCount(right.GetCount());
-            memcpy(_bits, right._bits, sizeof(uint8) * _blockCount * CLIENT_UPDATE_MASK_BITS);
-            return *this;
-        }
+    static constexpr uint32 GetBlockFlag(uint32 bit)
+    {
+        return 1u << (bit % 32);
+    }
 
-        UpdateMask& operator&=(UpdateMask const& right)
-        {
-            ASSERT(right.GetCount() <= GetCount());
-            for (uint32 i = 0; i < _fieldCount; ++i)
-                _bits[i] &= right._bits[i];
-
-            return *this;
-        }
-
-        UpdateMask& operator|=(UpdateMask const& right)
-        {
-            ASSERT(right.GetCount() <= GetCount());
-            for (uint32 i = 0; i < _fieldCount; ++i)
-                _bits[i] |= right._bits[i];
-
-            return *this;
-        }
-
-        UpdateMask operator|(UpdateMask const& right)
-        {
-            UpdateMask ret(*this);
-            ret |= right;
-            return ret;
-        }
-
-    private:
-        uint32 _fieldCount;
-        uint32 _blockCount;
-        uint8* _bits;
+    std::unique_ptr<ClientUpdateMaskType[]> _mask;
+    uint32 _lastSetBit;
 };
 
 #endif

src/server/game/Entities/Unit/Unit.cpp

@@ -14204,7 +14204,6 @@ void Unit::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* target)
         return;
 
     ByteBuffer fieldBuffer;
-    UpdateMask updateMask;
 
     uint32 valCount = m_valuesCount;
 
@@ -14216,7 +14215,7 @@ void Unit::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* target)
     else if (GetTypeId() == TYPEID_PLAYER)
         valCount = PLAYER_END_NOT_SELF;
 
-    updateMask.SetCount(valCount);
+    UpdateMaskPacketBuilder updateMask(valCount);
 
     Player* plr = GetCharmerOrOwnerPlayerOrPlayerItself();
     if (GetOwnerGUID() == target->GetGUID())
@@ -14365,7 +14364,6 @@ void Unit::BuildValuesUpdate(uint8 updateType, ByteBuffer* data, Player* target)
         }
     }
 
-    *data << uint8(updateMask.GetBlockCount());
     updateMask.AppendToPacket(data);
     data->append(fieldBuffer);
 }