Store: add debugLogs, improved attach fail msg

Author: greenrobot

objectbox/lib/src/native/store.dart

@@ -9,6 +9,7 @@ import 'dart:typed_data';
 
 import 'package:ffi/ffi.dart';
 import 'package:meta/meta.dart';
+import 'package:objectbox/src/native/version.dart';
 import 'package:path/path.dart' as path;
 
 import '../common.dart';
@@ -30,6 +31,10 @@ class Store {
   /// Path of the default directory, currently 'objectbox'.
   static const String defaultDirectoryPath = 'objectbox';
 
+  /// Enables a couple of debug logs.
+  /// This meant for tests only; do not enable for releases!
+  static bool debugLogs = false;
+
   late final Pointer<OBX_store> _cStore;
   HashMap<int, Type>? _entityTypeById;
   final _boxes = HashMap<Type, Box>();
@@ -130,6 +135,11 @@ class Store {
         C.opt_free(opt);
         rethrow;
       }
+      if (debugLogs) {
+        print('Opening store (C lib V${libraryVersion()})... path=$directory'
+            ' isOpen=${isOpen(directory)}');
+      }
+
       _cStore = C.store_open(opt);
 
       _checkStorePointer(_cStore);
@@ -233,12 +243,17 @@ class Store {
       final path = _safeDirectoryPath(directoryPath);
       final pathCStr = path.toNativeUtf8();
       try {
+        if (debugLogs) {
+          final isOpen = C.store_is_open(pathCStr.cast());
+          print('Attaching to store... path=$path isOpen=$isOpen');
+        }
         _cStore = C.store_attach(pathCStr.cast());
       } finally {
         malloc.free(pathCStr);
       }
 
-      _checkStorePointer(_cStore);
+      checkObxPtr(_cStore,
+          'could not attach to the store at given path - please ensure it was opened before');
 
       // Not setting reference as this is a replacement for obtaining a store
       // via reference.

objectbox/test/isolates_test.dart

@@ -56,6 +56,7 @@ void main() {
   /// Work with a single store across multiple isolates using
   /// the directory path to attach to an existing store.
   test('single store using attach', () async {
+    Store.debugLogs = true;
     await testUsingStoreFromIsolate(storeCreatorAttach, (env) => env.dir.path);
   });
 }
@@ -64,8 +65,10 @@ void main() {
 Store storeCreatorFromRef(dynamic msg) =>
     Store.fromReference(getObjectBoxModel(), msg as ByteData);
 
-Store storeCreatorAttach(dynamic msg) =>
-    Store.attach(getObjectBoxModel(), msg as String);
+Store storeCreatorAttach(dynamic msg) {
+  Store.debugLogs = true;
+  return Store.attach(getObjectBoxModel(), msg as String);
+}
 
 class IsolateInitMessage {
   SendPort sendPort;
@@ -105,6 +108,8 @@ Future<void> testUsingStoreFromIsolate(Store Function(dynamic) storeCreator,
 
   // Pass the store to the isolate
   final env = TestEnv('isolates');
+  expect(Store.isOpen('testdata-isolates'), true);
+
   expect(await call(storeRefGetter(env)), equals('store set'));
 
   {