Hive is a lightweight and blazing fast key-value database written in pure Dart. Inspired by Bitcask.
Consider using Isar, a Flutter database by the author of Hive that is superior in every way!
- 🚀 Cross platform: mobile, desktop, browser
- ⚡ Great performance (see benchmark)
- ❤️ Simple, powerful, & intuitive API
- 🔒 Strong encryption built in
- 🎈 NO native dependencies
- 🔋 Batteries included
Check out the Quick Start documentation to get started.
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 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 collectionfinal collection =awaitBoxCollection.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 inawait 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 valuesfinal cats =await catsBox.getAll(['loki', 'fluffy']);
print(cats);
// Returns a List<String> of all keysfinal allCatKeys =await catsBox.getAllKeys();
print(allCatKeys);
// Returns a Map<String, Map> with all keys and entriesfinal catMap =await catsBox.getAllValues();
print(catMap);
// delete one or more entriesawait catsBox.delete('loki');
await catsBox.deleteAll(['loki', 'fluffy']);
// ...or clear the whole box at onceawait catsBox.clear();
// Speed up write actions with transactionsawait 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,
);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)
classPersonextendsHiveObject {
@HiveField(0)
String name;
@HiveField(1)
int age;
}Extending HiveObject is optional but it provides handy methods like save() and delete().
var box =awaitHive.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 - 30Hive 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';
classSettingsPageextendsStatelessWidget {
@overrideWidgetbuild(BuildContext context) {
returnValueListenableBuilder(
valueListenable:Hive.box('settings').listenable(),
builder: (context, box, widget) {
returnSwitch(
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.
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';
voidmain() {
// Enable Flutter cryptographyFlutterCryptography.enable();
// ....
}| 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.
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.