stash_sqlite

Description:

stash sqlite

stash_sqlite #
A stash storage extension for sqlite using the drift package




Overview #
This storage extension for stash provides a storage layer through the drift persistent library and relies on a highly performing binary serialization of the cache items through the use of msgpack serialization format. This storage backend is particularly optimized to support cache features, like expiration and eviction which are highly dependent on the update of control fields on the entries upon user operations. On this storage backend the update of those fields does not cause the update of the whole cache entry as some of the other storage implementations like stash_hive or stash_sembast since they are stored in specific columns on the relational database model.
Getting Started #
Add this to your pubspec.yaml (or create it) replacing x.x.x with the latest version of stash_sqlite:
dependencies:
stash_sqlite: ^x.x.x
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Run the following command to install dependencies:
dart pub get
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Finally, to start developing import the library:
import 'package:stash/stash_api.dart';
import 'package:stash_sqlite/stash_sqlite.dart';
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Usage #
Vault #
The example bellow creates a vault with a shared sqlite 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_sqlite/stash_sqlite.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 directory
final dirPath = Directory.systemTemp;
// Temporary database file for a shared store
final file = File('${dirPath.path}/stash_sqlite.sdb');

// Creates a store
final store = await newSqliteLocalVaultStore(file: file);

// Creates a vault from the previously created store
final vault = await store.vault<Task>(
name: 'vault',
fromEncodable: (json) => Task.fromJson(json),
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'));
// Closes the vault
vault.close();
}
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Cache #
The example bellow creates a cache with a shared sqlite 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_sqlite/stash_sqlite.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 directory
final dirPath = Directory.systemTemp;
// Temporary database file for a shared store
final file = File('${dirPath.path}/stash_sqlite.sdb');

// Creates a store
final store = await newSqliteLocalCacheStore(file: file);

// Creates a cache with a capacity of 10 from the previously created store
final cache = await store.cache<Task>(
name: 'cache1',
fromEncodable: (json) => Task.fromJson(json),
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'));
// Closes the cache
cache.close();
}
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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