# Hive Modules

Nitrite provides a persistent storage module based on Hive. Hive is a lightweight and blazing fast, file based key-value store written in pure Dart.

To use Hive module, you need add below dependency to your project:

dart pub add nitrite
dart pub add nitrite_hive_adapter

To use Hive as your persistent storage, you need to load the HiveModule while opening the database. You can also configure the module as per your requirement.

Once the module is loaded, you can use the database as usual. All the data will be persisted in the file you specified.

import 'package:nitrite/nitrite.dart';
import 'package:nitrite_hive_adapter/nitrite_hive_adapter.dart';

// configure the module
var storeModule = HiveModule.withConfig()
            .path(filePath)
            .build();

var db = await Nitrite.builder()
            .loadModule(storeModule)
            .openOrCreate();

You can configure the Hive module as per your requirement. The following configuration options are available:

• path - the file path where the database will be stored. It is a directory path.
• backendPreference - the preference for the backend to use. It takes an enum HiveStorageBackendPreference.
• encryptionCipher - the encryption cipher used to encrypt the database. If not specified, the database will not be encrypted. It takes a HiveCipher instance.
• compactionStrategy - the compaction strategy to use. It takes a function of type CompactionStrategy.
• crashRecovery - if set to true, the database will be recovered from crash. The default value is false.
• addTypeAdapter() - you can add your own type adapter to the Hive database. It takes a TypeAdapter instance.
• addStoreEventListener() - you can add your own store event listener to the Hive database. It takes a StoreEventListener function as argument.

Nitrite provides a builder pattern to configure the module. You can use the HiveModule.withConfig() method to get the builder instance. The builder has a build() method which returns the module instance.

var storeModule = HiveModule.withConfig()
            .path(filePath)
            .backendPreference(HiveStorageBackendPreference.native)
            .encryptionCipher(StandardAESEncryption(password))
            .compactionStrategy((entries, deletedEntries) => true)
            .crashRecovery(true)
            .addTypeAdapter(MyTypeAdapter())
            .addStoreEventListener((event) => print(event))
            .build();

For more details about Hive configuration, please visit Hive Documentation.