switch manual C-API bindings definition to generated code (ffigen)

Author: Ivan Dlugos

lib/integration_test.dart

@@ -1,7 +1,6 @@
 library integration_test;
 
 import 'package:objectbox/objectbox.dart';
-import './src/bindings/constants.dart';
 import './src/bindings/helpers.dart';
 import './src/bindings/bindings.dart';
 

lib/src/bindings/bindings.dart

@@ -1,7 +1,8 @@
 import 'dart:ffi';
-import 'signatures.dart';
 import 'package:ffi/ffi.dart' show allocate, free;
 
+import 'bindings.dart';
+
 /// This file implements C call forwarding using a trampoline approach.
 ///
 /// When you want to pass a dart callback to a C function you cannot use lambdas and instead the callback must be
@@ -28,21 +29,22 @@ int _lastId = 0;
 final _callbacks = <int, bool Function(Pointer<Uint8> dataPtr, int length)>{};
 
 // called from C, forwards calls to the actual callback registered at the given ID
-int _forwarder(Pointer<Void> callbackId, Pointer<Uint8> dataPtr, int size) {
+int _forwarder(Pointer<Void> callbackId, Pointer<Void> dataPtr, int size) {
   if (callbackId == null || callbackId.address == 0) {
     throw Exception(
         'Data-visitor callback issued with NULL user_data (callback ID)');
   }
 
-  return _callbacks[callbackId.cast<Int64>().value](dataPtr, size) ? 1 : 0;
+  final callback = _callbacks[callbackId.cast<Int64>().value];
+  return callback(dataPtr.cast<Uint8>(), size) ? 1 : 0;
 }
 
 /// A data visitor wrapper/forwarder to be used where obx_data_visitor is expected.
 class DataVisitor {
   int _id;
   Pointer<Int64> _idPtr;
 
-  Pointer<NativeFunction<obx_data_visitor_native_t>> get fn =>
+  Pointer<NativeFunction<obx_data_visitor>> get fn =>
       Pointer.fromFunction(_forwarder, 0);
 
   Pointer<Void> get userData => _idPtr.cast<Void>();

lib/src/bindings/constants.dart

@@ -1,8 +1,9 @@
 import 'dart:ffi';
 import 'dart:typed_data' show Uint8List;
+
 import 'package:flat_buffers/flat_buffers.dart' as fb;
 
-import 'constants.dart';
+import 'bindings.dart';
 import 'structs.dart';
 import '../modelinfo/index.dart';
 

lib/src/bindings/data_visitor.dart

@@ -2,17 +2,16 @@ import 'dart:ffi';
 import 'package:ffi/ffi.dart';
 
 import 'bindings.dart';
-import 'constants.dart';
 import '../common.dart';
 
 void checkObx(int code) {
-  if (code != OBXError.OBX_SUCCESS) {
+  if (code != OBX_SUCCESS) {
     throw latestNativeError(codeIfMissing: code);
   }
 }
 
 bool checkObxSuccess(int code) {
-  if (code == OBXError.OBX_NO_SUCCESS) return false;
+  if (code == OBX_NO_SUCCESS) return false;
   checkObx(code);
   return true;
 }
@@ -39,11 +38,11 @@ ObjectBoxException latestNativeError({String dartMsg, int codeIfMissing}) {
       dartMsg: dartMsg, nativeCode: code, nativeMsg: text);
 }
 
-String cString(Pointer<Utf8> charPtr) {
+String cString(Pointer<Int8> charPtr) {
   // Utf8.fromUtf8 segfaults when called on nullptr
   if (charPtr.address == 0) {
     return '';
   }
 
-  return Utf8.fromUtf8(charPtr);
+  return Utf8.fromUtf8(charPtr.cast<Utf8>());
 }