Refactor: replace dependency on sql_crdt with crdt

This version introduces a major refactor which results in multiple breaking changes in line with `crdt` 5.0.0.

This package is now compatible with [crdt_sync](https://github.com/cachapa/crdt_sync), thereby abstracting the communication protocol and network management for real-time remote synchronization.

Changes:
- Removed direct interaction with the `Record` and `Hlc` classes
- Added multiple table support

Author: cachapa

CHANGELOG.md

@@ -1,3 +1,12 @@
+## 3.0.0
+This version introduces a major refactor which results in multiple breaking changes in line with `crdt` 5.0.0.
+
+This package is now compatible with [crdt_sync](https://github.com/cachapa/crdt_sync), thereby abstracting the communication protocol and network management for real-time remote synchronization.
+
+Changes:
+- Removed direct interaction with the `Record` and `Hlc` classes
+- Added multiple table support
+
 ## 2.0.4
 - Avoid repeated records when generating changesets using `since`
 

README.md

@@ -1,22 +1,41 @@
-# hive_crdt
+Conflict-free Replicated Data Types (CRDTs) using by [Hive](https://pub.dev/packages/hive) stores for data persistence.
 
-A CRDT backed by a [Hive](https://pub.dev/packages/hive) store.
-
-Depends on the [crdt](https://pub.dev/packages/crdt) package.
+This package implements [crdt](https://github.com/cachapa/crdt) and is compatible with [crdt_sync](https://github.com/cachapa/crdt_sync).
 
 ## Usage
 
-A simple usage example:
-
 ```dart
-import 'package:hive_crdt/hive_crdt.dart';
+import 'package:hive/hive.dart';
+import 'package:hive_crdt/src/hive_adapters.dart';
+import 'package:hive_crdt/src/hive_crdt.dart';
+
+Future<void> main() async {
+  // Initialize Hive
+  Hive
+    ..init('test_store')
+    ..registerAdapter(RecordAdapter(42));
+
+  var crdt1 = await HiveCrdt.open(prefix: 'crdt1', ['table']);
+  var crdt2 = await HiveCrdt.open(prefix: 'crdt2', ['table']);
+
+  print('Inserting 2 records in crdt1…');
+  await crdt1.put('table', 'a', 1);
+  await crdt1.put('table', 'b', 1);
 
-// TODO: Generate id on first launch
-const nodeId = 'random_id';
+  print('crdt1: ${crdt1.getMap('table')}');
 
-main() async {
-  var crdt = await HiveCrdt.open('test', nodeId);
-  crdt.put('x', 1);
-  crdt.get('x');  // 1
+  print('\nInserting a conflicting record in crdt2…');
+  await crdt2.put('table', 'a', 2);
+
+  print('crdt2: ${crdt2.getMap('table')}');
+
+  print('\nMerging crdt2 into crdt1…');
+  await crdt1.merge(crdt2.getChangeset());
+
+  print('crdt1: ${crdt1.getMap('table')}');
 }
 ```
+
+## Features and bugs
+
+Please file feature requests and bugs at the [issue tracker](https://github.com/cachapa/hive_crdt/issues).

example/example.dart

@@ -0,0 +1,29 @@
+import 'package:hive/hive.dart';
+import 'package:hive_crdt/src/hive_adapters.dart';
+import 'package:hive_crdt/src/hive_crdt.dart';
+
+Future<void> main() async {
+  // Initialize Hive
+  Hive
+    ..init('test_store')
+    ..registerAdapter(RecordAdapter(42));
+
+  var crdt1 = await HiveCrdt.open(prefix: 'crdt1', ['table']);
+  var crdt2 = await HiveCrdt.open(prefix: 'crdt2', ['table']);
+
+  print('Inserting 2 records in crdt1…');
+  await crdt1.put('table', 'a', 1);
+  await crdt1.put('table', 'b', 1);
+
+  print('crdt1: ${crdt1.getMap('table')}');
+
+  print('\nInserting a conflicting record in crdt2…');
+  await crdt2.put('table', 'a', 2);
+
+  print('crdt2: ${crdt2.getMap('table')}');
+
+  print('\nMerging crdt2 into crdt1…');
+  await crdt1.merge(crdt2.getChangeset());
+
+  print('crdt1: ${crdt1.getMap('table')}');
+}

example/hive_crdt_example.dart

@@ -1,54 +1,4 @@
-import 'package:crdt/crdt.dart';
-import 'package:hive/hive.dart';
+library hive_crdt;
 
-export 'package:crdt/crdt.dart';
-
-class HiveCrdt<K, V> extends Crdt<K, V> {
-  @override
-  final String nodeId;
-  final Box<Record> _box;
-
-  HiveCrdt(Box<Record> box, this.nodeId) : _box = box;
-
-  static Future<HiveCrdt<K, V>> open<K, V>(String name, String nodeId,
-      {String? path}) async {
-    final box = await Hive.openBox<Record>(name, path: path);
-    return HiveCrdt<K, V>(box, nodeId);
-  }
-
-  @override
-  bool containsKey(K key) => _box.containsKey(_encode(key));
-
-  @override
-  Record<V>? getRecord(K key) => _box.get(_encode(key)) as Record<V>?;
-
-  @override
-  void putRecord(K key, Record<V> value) => _box.put(_encode(key), value);
-
-  @override
-  void putRecords(Map<K, Record<V>> recordMap) => _box.putAll(recordMap);
-
-  @override
-  Map<K, Record<V>> recordMap({Hlc? modifiedSince}) => (_box.toMap()
-        ..removeWhere((_, record) =>
-            record.modified.logicalTime <= (modifiedSince?.logicalTime ?? 0)))
-      .map((key, value) => MapEntry(_decode(key), value as Record<V>));
-
-  @override
-  Stream<MapEntry<K, V?>> watch({K? key}) => _box
-      .watch(key: key)
-      .map((event) => MapEntry<K, V?>(event.key, event.value?.value));
-
-  @override
-  void purge() => _box.clear();
-
-  Future<void> close() => _box.close();
-
-  /// Permanently deletes the store from disk. Useful for testing.
-  Future<void> deleteStore() => _box.deleteFromDisk();
-
-  dynamic _encode(K key) =>
-      key is DateTime ? key.toUtc().toIso8601String() : key;
-
-  K _decode(dynamic key) => K == DateTime ? DateTime.parse(key) : key;
-}
+export 'src/hive_adapters.dart';
+export 'src/hive_crdt.dart';

lib/hive_adapters.dart

@@ -0,0 +1,27 @@
+import 'package:crdt/crdt.dart';
+import 'package:crdt/map_crdt.dart';
+import 'package:hive/hive.dart';
+
+class RecordAdapter extends TypeAdapter<Record> {
+  @override
+  final int typeId;
+
+  RecordAdapter(this.typeId);
+
+  @override
+  Record read(BinaryReader reader) {
+    final value = reader.read();
+    final isDeleted = reader.readBool();
+    final hlc = reader.readString().toHlc;
+    final modified = reader.readString().toHlc;
+    return Record(value, isDeleted, hlc, modified);
+  }
+
+  @override
+  void write(BinaryWriter writer, Record obj) {
+    writer.write(obj.value);
+    writer.writeBool(obj.isDeleted);
+    writer.writeString(obj.hlc.toString());
+    writer.writeString(obj.modified.toString());
+  }
+}

lib/hive_crdt.dart

@@ -0,0 +1,67 @@
+import 'dart:async';
+
+import 'package:crdt/map_crdt.dart';
+import 'package:hive/hive.dart';
+
+export 'package:crdt/crdt.dart';
+
+class HiveCrdt extends MapCrdtBase {
+  final Map<String, Box<Record>> _boxes;
+
+  @override
+  bool get isEmpty => _boxes.values.fold(true, (p, e) => p && e.isEmpty);
+
+  @override
+  bool get isNotEmpty => !isEmpty;
+
+  HiveCrdt._(super.tables, this._boxes);
+
+  /// Create or open tables and store them in [path].
+  /// Table names are used as file names.
+  /// Use [prefix] to prepend the filename, otherwise Hive will prevent opening
+  /// multiple boxes with the same tables. Useful for testing.
+  static Future<HiveCrdt> open(Iterable<String> tables,
+      {String? path, String? prefix}) async {
+    assert(tables.isNotEmpty);
+    assert(tables.length == tables.toSet().length);
+
+    final boxes = {
+      for (final table in tables)
+        table: await Hive.openBox<Record>('${prefix ?? ''}_$table', path: path)
+    };
+
+    final crdt = HiveCrdt._(tables, boxes);
+    return crdt;
+  }
+
+  /// Closes all tables
+  Future<void> close() => Future.wait(_boxes.values.map((e) => e.close()));
+
+  /// Deletes all data from every table
+  Future<void> purge() => Future.wait(_boxes.values.map((e) => e.clear()));
+
+  /// Deletes all tables from disk
+  Future<void> delete() =>
+      Future.wait(_boxes.values.map((e) => e.deleteFromDisk()));
+
+  @override
+  Record? getRecord(String table, String key) => _boxes[table]!.get(key);
+
+  @override
+  Map<String, Record> getRecords(String table) =>
+      _boxes[table]!.toMap().cast<String, Record>();
+
+  @override
+  Future<void> putRecords(Map<String, Map<String, Record>> dataset) async {
+    for (final entry in dataset.entries) {
+      await _boxes[entry.key]!.putAll(entry.value);
+    }
+  }
+
+  Stream<(String key, dynamic value)> watch(String table, {String? key}) {
+    if (!tables.contains(table)) throw 'Unknown table: $table';
+    return _boxes[table]!
+        .watch(key: key)
+        .map((event) => (event.key, event.value?.value));
+  }
+}

lib/src/hive_adapters.dart

@@ -1,6 +1,6 @@
 name: hive_crdt
 description: Dart implementation of Conflict-free Replicated Data Types (CRDTs), backed by a Hive store.
-version: 2.0.4
+version: 3.0.0
 homepage: https://github.com/cachapa/hive_crdt
 repository: https://github.com/cachapa/hive_crdt
 issue_tracker: https://github.com/cachapa/hive_crdt/issues
@@ -9,9 +9,11 @@ environment:
   sdk: '>=3.0.0 <4.0.0'
 
 dependencies:
-  crdt: ^4.0.3
+  crdt: ^5.0.0
+#    path: ../crdt
   hive: ^2.2.3
 
 dev_dependencies:
   lints: any
   test: any
+  uuid: any