decreaso allocs for fn class

1 files changed, 43 insertions, 47 deletions

diff --git a/src/util/callback.h b/src/util/callback.h
index df93b59..a2c9477 100644
--- a/src/util/callback.h
+++ b/src/util/callback.h
@@ -3,86 +3,82 @@
 
 template <typename T>
 struct FN;
-
+// voodoo
 template <typename RET, typename... ARGS>
 struct FN<RET(ARGS...)> {
-  // voodoo
   template <typename T> struct __strip_ref { using type = T; };
   template <typename T> struct __strip_ref<T&> { using type = T; };
   template <typename T> struct __strip_ref<T&&> { using type = T; };
   template <typename R, typename... A> struct __strip_ref<R(A...)> { using type = R(*)(A...); };
   template <typename R, typename... A> struct __strip_ref<R(&)(A...)> { using type = R(*)(A...); };
 
+  static const unsigned int BUF_SIZE = 32;
+
+  alignas(8) char buf[BUF_SIZE];
   void* data;
-  U32 size;
   RET( *invoke )( void*, ARGS... );
   void( *destroy )( void* );
-  void*( *clone )( void* );
+  void*( *clone )( void*, char* );
 
   template <typename F>
-  FN( F&& f ) {
+  FN(F&& f) {
     using __stripped = typename __strip_ref<F>::type;
-    data = new __stripped( static_cast<F&&>(f) );
-    size = sizeof( __stripped );
+
+    if constexpr( sizeof(__stripped) <= BUF_SIZE ) {
+      new (buf) __stripped( f );
+      data = buf;
+      destroy = pfn( void* d ) {
+        ( (__stripped*)d )->~__stripped();
+      };
+      clone = pfn( void* d, char* dst ) -> void* {
+        new (dst) __stripped( *(__stripped*)d );
+        return dst;
+      };
+    } else {
+      data = new __stripped( f );
+      destroy = pfn( void* d ) {
+        delete (__stripped*)d;
+      };
+      clone = pfn( void* d, char* dst ) -> void* {
+        return new __stripped( *(__stripped*)d );
+      };
+    }
+
     invoke = pfn( void* d, ARGS... args ) -> RET {
       return ( *(__stripped*)d )( args... );
     };
-    destroy = pfn( void* d ) {
-      delete (__stripped*)d;
-    };
-    clone = pfn( void* data ) {
-      return (void*)new __stripped( *(__stripped*)data );
-    };
-  }
-
-  template <>
-  FN( int&& ) : data( 0 ), invoke( 0 ), destroy( 0 ) {}
-  FN() : data( 0 ), invoke( 0 ), destroy( 0 ) {}
-
-  FN( FN&& other ) : data( other.data ), invoke( other.invoke ), destroy( other.destroy ) {
-    other.data = 0;
-    other.invoke = 0;
-    other.destroy = 0;
-  }
-
-  FN& operator=( FN&& other ) {
-    if( this == &other ) return *this;
-    if( destroy ) destroy( data );
-    data = other.data;
-    invoke = other.invoke;
-    destroy = other.destroy;
-    other.data = 0;
-    other.invoke = 0;
-    other.destroy = 0;
-    return *this;
   }
 
-  FN( const FN& other ) {
-    *this = other;
-  };
+  FN( I32&& ) : data( 0 ), invoke( 0 ), destroy( 0 ), clone( 0 ) {}
+  FN( U32&& ) : data( 0 ), invoke( 0 ), destroy( 0 ), clone( 0 ) {}
+  FN() : data( 0 ), invoke( 0 ), destroy( 0 ), clone( 0 ) {}
 
-  FN& operator=( const FN& other ) {
+  FN( const FN& other ) : invoke( other.invoke ), destroy( other.destroy ), clone( other.clone ) {
     if( !other.data ) {
       data = 0;
-      invoke = 0;
-      destroy = 0;
-      size = 0;
-      return *this;
+      return;
     }
 
-    size = other.size;
-    data = other.clone( other.data );
+    data = other.clone( other.data, buf );
+  }
+
+  FN& operator=( const FN& other ) {
+    if( this == &other ) return *this;
+    if( destroy && data ) destroy( data );
     invoke = other.invoke;
     destroy = other.destroy;
     clone = other.clone;
+    data = other.data ? other.clone( other.data, buf ) : 0;
     return *this;
   }
 
-  ~FN() { if( destroy ) destroy( data ); }
-  operator bool() const { return !!invoke; }
+  ~FN() {
+    if( destroy && data ) destroy( data );
+  }
 
   RET operator()( ARGS... args ) const {
     return invoke( data, args... );
   }
 
+  operator bool() const { return !!invoke; }
 };