feat: Add copyIfNeeded flag

packages/react-native-nitro-modules/ios/core/ArrayBufferHolder.swift

@@ -126,16 +126,26 @@ public extension ArrayBufferHolder {
 public extension ArrayBufferHolder {
   /**
    * Wrap this `ArrayBufferHolder` in a `Data` instance, without performing a copy.
+   * - `copyIfNeeded`: If this `ArrayBuffer` is **non-owning**, the foreign
+   *                   data may needs to be copied to be safely used outside of the scope of the caller function.
+   *                   This flag controls that.
    */
-  func toData() -> Data {
-    // 1. Get the std::shared_ptr<ArrayBuffer>
-    var sharedPointer = self.getArrayBuffer()
-    // 2. Create a Data object WRAPPING our pointer
-    return Data(bytesNoCopy: self.data, count: self.size, deallocator: .custom({ buffer, size in
-      // 3. Capture the std::shared_ptr<ArrayBuffer> in the deallocator lambda so it stays alive.
-      //    As soon as this lambda gets called, the `sharedPointer` gets deleted causing the
-      //    underlying `ArrayBuffer` to be freed.
-      sharedPointer.reset()
-    }))
+  func toData(copyIfNeeded: Bool) -> Data {
+    let shouldCopy = copyIfNeeded && !self.isOwner
+    if shouldCopy {
+      // COPY DATA
+      return Data.init(bytes: self.data, count: self.size)
+    } else {
+      // WRAP DATA
+      // 1. Get the std::shared_ptr<ArrayBuffer>
+      var sharedPointer = self.getArrayBuffer()
+      // 2. Create a Data object WRAPPING our pointer
+      return Data(bytesNoCopy: self.data, count: self.size, deallocator: .custom({ buffer, size in
+        // 3. Capture the std::shared_ptr<ArrayBuffer> in the deallocator lambda so it stays alive.
+        //    As soon as this lambda gets called, the `sharedPointer` gets deleted causing the
+        //    underlying `ArrayBuffer` to be freed.
+        sharedPointer.reset()
+      }))
+    }
   }
 }