Incomplete structured setting - slow

temp.js

const kTypedArrayConstructors = {
  i8: Int8Array,
  u8: Uint8Array,
  i16: Int16Array,
  u16: Uint16Array,
  i32: Int32Array,
  u32: Uint32Array,
  f32: Float32Array,
  f64: Float64Array,
  i64: BigInt64Array,
  u64: BigUint64Array,
};

class StructuredAccessorFactory {
  constructor(layout) {
    const typedArraysTypes = [...new Set(Object.values(layout).map(({type}) => type))];
    this.create = function(buffer) {
      const data = Object.fromEntries(typedArraysTypes.map(type => [type, new kTypedArrayConstructors[type](buffer)]));
      const accessor = {};
      Object.defineProperties(accessor, Object.fromEntries(Object.entries(layout).map(([key, {type, byteOffset}]) => {
        const view = data[type];
        const arrayOffset = byteOffset / view.BYTES_PER_ELEMENT;
        return [key, {
          enumerable: true,
          get() {
            return view[arrayOffset];
          },
          set(value) {
            view[arrayOffset] = value; 
          },
        }];
      })));
      return accessor;
    };
  }
}