hive-nested-adapters: A Dart repository from akmaljon1016

Fast, Enjoyable & Secure NoSQL Database

Hive is a lightweight and blazing fast key-value database written in pure Dart. Inspired by Bitcask.

Documentation & Samples 📖

Before you start

Consider using Isar, a Flutter database by the author of Hive that is superior in every way!

Features

🚀 Cross platform: mobile, desktop, browser
⚡ Great performance (see benchmark)
❤️ Simple, powerful, & intuitive API
🔒 Strong encryption built in
🎈 NO native dependencies
🔋 Batteries included

Getting Started

Check out the Quick Start documentation to get started.

Usage

You can use Hive just like a map. It is not necessary to await Futures.

var box = Hive.box('myBox');

box.put('name', 'David');

var name = box.get('name');

print('Name: $name');

BoxCollections

BoxCollections are a set of boxes which can be similarly used as normal boxes, except of that they dramatically improve speed on web. They support opening and closing all boxes of a collection at once and more efficiently store data in indexed DB on web.

Aside, they also expose Transactions which can be used to speed up tremendous numbers of database transactions on web.

On dart:io platforms, there is no performance gain by BoxCollections or Transactions. Only BoxCollections might be useful for some box hierarchy and development experience.

// Create a box collection
  final collection = await BoxCollection.open(
    'MyFirstFluffyBox', // Name of your database
    {'cats', 'dogs'}, // Names of your boxes
    path: './', // Path where to store your boxes (Only used in Flutter / Dart IO)
    key: HiveCipher(), // Key to encrypt your boxes (Only used in Flutter / Dart IO)
  );

  // Open your boxes. Optional: Give it a type.
  final catsBox = collection.openBox<Map>('cats');

  // Put something in
  await catsBox.put('fluffy', {'name': 'Fluffy', 'age': 4});
  await catsBox.put('loki', {'name': 'Loki', 'age': 2});

  // Get values of type (immutable) Map?
  final loki = await catsBox.get('loki');
  print('Loki is ${loki?['age']} years old.');

  // Returns a List of values
  final cats = await catsBox.getAll(['loki', 'fluffy']);
  print(cats);

  // Returns a List<String> of all keys
  final allCatKeys = await catsBox.getAllKeys();
  print(allCatKeys);

  // Returns a Map<String, Map> with all keys and entries
  final catMap = await catsBox.getAllValues();
  print(catMap);

  // delete one or more entries
  await catsBox.delete('loki');
  await catsBox.deleteAll(['loki', 'fluffy']);

  // ...or clear the whole box at once
  await catsBox.clear();

  // Speed up write actions with transactions
  await collection.transaction(
    () async {
      await catsBox.put('fluffy', {'name': 'Fluffy', 'age': 4});
      await catsBox.put('loki', {'name': 'Loki', 'age': 2});
      // ...
    },
    boxNames: ['cats'], // By default all boxes become blocked.
    readOnly: false,
  );

Store objects

Hive not only supports primitives, lists and maps but also any Dart object you like. You need to generate a type adapter before you can store objects.

@HiveType(typeId: 0)
class Person extends HiveObject {

  @HiveField(0)
  String name;

  @HiveField(1)
  int age;
}

Extending HiveObject is optional but it provides handy methods like save() and delete().

var box = await Hive.openBox('myBox');

var person = Person()
  ..name = 'Dave'
  ..age = 22;
box.add(person);

print(box.getAt(0)); // Dave - 22

person.age = 30;
person.save();

print(box.getAt(0)) // Dave - 30

Hive has limitation 224 (256 - 32 reserved) types limit per type registry. However, you can use Hive.createNestedTypeRegistryAdapter & Hive.registerNestedTypeRegistryAdapter. Pros:

avoid typeIds conflicts if you several libraries with own adapters list and ids conflict
you can use 224*224 type ids
compatible with already exist Hive storages Cons:
slower performance

@HiveType(typeId: 0)
class Person extends HiveObject {
}
@HiveType(typeId: 0)
class Home extends HiveObject {
}
@HiveType(typeId: 1)
class Work extends HiveObject {
}

// 1 is typeId
var nestedAdapter = Hive.createNestedTypeRegistryAdapter(1);
nestedAdapter.registerAdapter(HomeAdapter());
nestedAdapter.registerAdapter(WorkAdapter());
Hive.registerAdapter(PersonAdapter());
Hive.registerAdapter(nestedAdapter);

Another possible issue is required typeId field in @HiveType. Sometimes it is better to specify all ids in one files during registration. You can achieve this via OverrideIdAdapter

Hive.registerAdapter(
  OverrideIdAdapter(
    100,
    PersonAdapter(),
  ),
);

Hive ❤️ Flutter

Hive was written with Flutter in mind. It is a perfect fit if you need a lightweight datastore for your app. After adding the required dependencies and initializing Hive, you can use Hive in your project:

import 'package:hive/hive.dart';
import 'package:hive_flutter/hive_flutter.dart';

class SettingsPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder(
      valueListenable: Hive.box('settings').listenable(),
      builder: (context, box, widget) {
        return Switch(
          value: box.get('darkMode'),
          onChanged: (val) {
            box.put('darkMode', val);
          }
        );
      },
    );
  }
}

Boxes are cached and therefore fast enough to be used directly in the build() method of Flutter widgets.

Native AES crypto implementation

When using Flutter, Hive supports native encryption using package:cryptography and package:cryptography_flutter.

Native AES implementations tremendously speed up operations on encrypted Boxes.

Please follow these steps:

add dependency to pubspec.yaml

dependencies:
  cryptography_flutter: ^2.0.2

enable native implementations

import 'package:cryptography_flutter/cryptography_flutter.dart';

void main() {
  // Enable Flutter cryptography
  FlutterCryptography.enable();

  // ....
}

Benchmark

1000 read iterations	1000 write iterations

SharedPreferences is on par with Hive when it comes to read performance. SQLite performs much worse.	Hive greatly outperforms SQLite and SharedPreferences when it comes to writing or deleting.

The benchmark was performed on a Oneplus 6T with Android Q. You can run the benchmark yourself.

*Take this benchmark with a grain of salt. It is very hard to compare databases objectively since they were made for different purposes.

Licence

Copyright 2019 Simon Leier

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

akmaljon1016/hive-nested-adapters