chore: refactorings for more code reorganizing

src/engine/metal/gpu.rs

@@ -1543,6 +1543,28 @@ impl Buffer {
         )
     }
 
+    pub(super) fn copy_from(
+        &self,
+        destination_offset: u64,
+        source: &Self,
+        source_offset: u64,
+        bytes: u64,
+        operation: &str,
+    ) -> Result<(), String> {
+        call(
+            unsafe {
+                ds4_gpu_tensor_copy(
+                    self.raw(),
+                    destination_offset,
+                    source.raw(),
+                    source_offset,
+                    bytes,
+                )
+            },
+            operation,
+        )
+    }
+
     pub(super) fn raw(&self) -> *mut GpuTensor {
         self.0.as_ptr()
     }