stash_sembast 4.0.1

Sembast storage extension for the stash API. Provides support to store vaults and caches in the local file system in binary format using the msgpack json format

stash_sembast

A stash storage extension for sembast

Overview

This storage extension for stash provides a sembast based storage that relies on a highly performing binary serialization of the cache items through the use of msgpack serialization format.

Getting Started

Add this to your pubspec.yaml (or create it) replacing x.x.x with the latest version of stash_sembast:

dependencies:
    stash_sembast: ^x.x.x

Run the following command to install dependencies:

dart pub get

Finally, to start developing import the library:

import 'package:stash/stash_api.dart';
import 'package:stash_sembast/stash_sembast.dart';

Usage

Vault

The example bellow creates a vault with a sembast storage backend. In this rather simple example the serialization and deserialization of the object is coded by hand but it's more usual to rely on libraries like json_serializable.

import 'dart:io';

import 'package:stash/stash_api.dart';
import 'package:stash_sembast/stash_sembast.dart';

class Task {
  final int id;
  final String title;
  final bool completed;

  Task({required this.id, required this.title, this.completed = false});

  /// Creates a [Task] from json map
  factory Task.fromJson(Map<String, dynamic> json) => Task(
      id: json['id'] as int,
      title: json['title'] as String,
      completed: json['completed'] as bool);

  /// Creates a json map from a [Task]
  Map<String, dynamic> toJson() =>
      <String, dynamic>{'id': id, 'title': title, 'completed': completed};

  @override
  String toString() {
    return 'Task $id, "$title" is ${completed ? "completed" : "not completed"}';
  }
}

void main() async {
  // Temporary path
  final dir = Directory.systemTemp;
  // Temporary database file for a shared store
  final path = '${dir.path}/stash_sembast.sdb';

  // Creates a store
  final store = newSembastLocalVaultStore(
      path: path, fromEncodable: (json) => Task.fromJson(json));

  // Creates a vault from the previously created store
  final vault = store.vault<Task>(
      name: 'vault', eventListenerMode: EventListenerMode.synchronous)
    ..on<VaultEntryCreatedEvent<Task>>().listen(
        (event) => print('Key "${event.entry.key}" added to the vault'));

  // Adds a task with key 'task1' to the vault
  await vault.put(
      'task1', Task(id: 1, title: 'Run vault store example', completed: true));
  // Retrieves the value from the vault
  print(await vault.get('task1'));
}

Cache

The example bellow creates a caches with a sembast storage backend. In this rather simple example the serialization and deserialization of the object is coded by hand but it's more usual to rely on libraries like json_serializable.

import 'dart:io';

import 'package:stash/stash_api.dart';
import 'package:stash_sembast/stash_sembast.dart';

class Task {
  final int id;
  final String title;
  final bool completed;

  Task({required this.id, required this.title, this.completed = false});

  /// Creates a [Task] from json map
  factory Task.fromJson(Map<String, dynamic> json) => Task(
      id: json['id'] as int,
      title: json['title'] as String,
      completed: json['completed'] as bool);

  /// Creates a json map from a [Task]
  Map<String, dynamic> toJson() =>
      <String, dynamic>{'id': id, 'title': title, 'completed': completed};

  @override
  String toString() {
    return 'Task $id, "$title" is ${completed ? "completed" : "not completed"}';
  }
}

void main() async {
  // Temporary path
  final dir = Directory.systemTemp;
  // Temporary database file for a shared store
  final path = '${dir.path}/stash_sembast.sdb';

  // Creates a store
  final store = newSembastLocalCacheStore(
      path: path, fromEncodable: (json) => Task.fromJson(json));

  // Creates a cache with a capacity of 10 from the previously created store
  final cache = store.cache<Task>(
      name: 'cache1',
      maxEntries: 10,
      eventListenerMode: EventListenerMode.synchronous)
    ..on<CacheEntryCreatedEvent<Task>>().listen(
        (event) => print('Key "${event.entry.key}" added to the cache'));

  // Adds a task with key 'task1' to the cache
  await cache.put(
      'task1', Task(id: 1, title: 'Run cache store example', completed: true));
  // Retrieves the value from the cache
  print(await cache.get('task1'));
}

Additional Features

Please take a look at the documentation of stash to gather additional information and to explore the full range of capabilities of the stash library

Features and Bugs

Please file feature requests and bugs at the issue tracker.

License

This project is licensed under the MIT License - see the LICENSE file for details