pointerFromFunctionImpl<T extends Function> function

Pointer<NativeFunction<T>> pointerFromFunctionImpl<T extends Function>(Function func, WasmTable table, Memory memory)

Implementation

Pointer<NativeFunction<T>> pointerFromFunctionImpl<T extends Function>(
  /* TODO: @DartRepresentationOf('T')  */
  Function func,
  WasmTable table,
  Memory memory,
) {
  // TODO: garbage collect

  return exportedFunctions.putIfAbsent(func, () {
        developer.log('marshal from: ${func.runtimeType} to $T');
        final String dartSignature = func.runtimeType.toString();
        final String argTypes = dartSignature.split('=>').first.trim();
        final List<String> argT = argTypes
            .substring(1, argTypes.length - 1)
            .split(', ');
        developer.log('arg types: $argT');
        final List<Function> marshallers = argTypes
            .substring(1, argTypes.length - 1)
            .split(', ')
            .map((arg) => marshaller(arg))
            .toList();

        final String wasmSignature = _getWasmSignature<T>();

        developer.log('wasm sig: $wasmSignature');

        // ignore: prefer_function_declarations_over_variables
        final Function wrapper1 = (List args) {
          developer.log('wrapper of $T called with $args');
          final marshalledArgs = marshallers
              .mapIndexed((i, m) => m(args[i], memory))
              .toList();
          developer.log('which is $marshalledArgs on $func');
          Function.apply(func, marshalledArgs);
          developer.log('done!');
        };
        final Function wrapper2 = callbackHelpers[argT.length](wrapper1);

        // theFunctions.add(wrapper);

        final wasmFunc = _toWasmFunction(wasmSignature, wrapper2);
        table.grow(1.toJS);
        table.set((table.length.toDartInt - 1).toJS, wasmFunc);
        developer.log(
          'created callback with index ${table.length.toDartInt - 1}',
        );
        return Pointer<NativeFunction<T>>.fromAddress(
          table.length.toDartInt - 1,
          memory,
        );
      })
      as Pointer<NativeFunction<T>>;
}