StoreIT

Pub Version License: MIT Flutter

StoreIT is a high-performance, SQLite-backed caching engine for Flutter, architected with the same philosophy of simplicity and power that defines Redis. It provides a robust key-value store that handles complex data types with native TTL support and background maintenance.

Design Philosophy

StoreIT is built for developers who need more than basic preferences but less than a full relational database.

  1. Redis-Inspired: Familiar command patterns for Strings, Lists, and Hashes (JSON).
  2. Predictable Performance: SQLite indexing ensures O(1) or O(log N) lookups even with large datasets.
  3. Automatic Expiration: Native Time-To-Live (TTL) management at the database level.
  4. Zero UI Blocking: Maintenance tasks like purging expired keys are offloaded to a background isolate.

Installation

Add the package to your pubspec.yaml:

dependencies:
  store_it: ^1.0.0

Introduction to StoreIT

Before executing commands, initialize the store. This establishes the SQLite connection and starts the background maintenance worker.

import 'package:store_it/store_it.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await StoreIT.init();
  runApp(MyApp());
}

Data Types

StoreIT supports three primary data types, each with specialized commands:

  • Strings: The most basic data type, capable of storing any text data.
  • Lists: Ordered collections of strings, supporting append and removal operations.
  • JSON (Hashes): Maps of fields and values, allowing for atomic partial updates (merges).

Command Reference

Generic Commands

Command Description
exists(key) Returns true if the key exists and has not expired.
typeOf(key) Returns the type of value stored at the key.
ttl(key) Returns the remaining time to live in seconds.
expire(key, ttl) Updates the expiration time for an existing key.
keys(prefix) Returns all keys matching the given prefix.
delete(key) Removes the specified key.
deleteByPrefix(prefix) Removes all keys matching the given prefix.
flush() Removes all keys from the database.

String Commands

Command Description
set(key, value, {ttl}) Sets the string value of a key with optional TTL.
get(key) Returns the string value of a key.
update(key, value) Updates the value of an existing key.

List Commands

Command Description
listSet(key, list) Sets a list of strings at the specified key.
listGet(key) Returns the list of strings at the specified key.
listAppend(key, items) Appends items to the end of the list.
listRemove(key, items) Removes specified items from the list.

JSON (Hash) Commands

Command Description
jsonSet(key, object) Stores a JSON-encodable Map or List.
jsonGet(key) Returns the decoded JSON object.
jsonMerge(key, patch) Merges a Map into an existing JSON object (HSET-like).

Examples

1. Basic Caching with Expiration

Similar to the Redis SETEX command, you can cache data with an automatic expiration.

// Cache API response for 5 minutes (300 seconds)
await StoreIT.set('api:user:123', jsonResponse, ttlSeconds: 300);

// Later, retrieve the data
String? cachedData = await StoreIT.get('api:user:123');
if (cachedData == null) {
  // The data has either expired or never existed
}

2. Activity Logging with Lists

Use Lists to store ordered logs or recent search terms.

// Log user actions
await StoreIT.listAppend('logs:user:42', ['login_success']);
await StoreIT.listAppend('logs:user:42', ['view_dashboard']);

// Retrieve the full activity log
List<String>? logs = await StoreIT.listGet('logs:user:42');

3. Partial Updates for Complex Objects

Atomic merging allows you to update specific fields in a JSON object without fetching and rewriting the entire object.

// Initial state
await StoreIT.jsonSet('config:ui', {
  'theme': 'light',
  'compact_mode': true,
  'font_size': 12
});

// Update only the theme
await StoreIT.jsonMerge('config:ui', {'theme': 'dark'});

4. Bulk Key Management

Manage groups of keys efficiently using prefixes.

// Find all session-related keys
List<String> sessions = await StoreIT.keys(prefix: 'auth:session:');

// Delete all temporary cache entries at once
await StoreIT.deleteByPrefix('temp:');

Persistence and Maintenance

Background Isolate

StoreIT maintains a lean storage footprint by purging expired keys. To ensure this doesn't impact UI frames, the purge logic runs in a separate Dart Isolate.

You can observe background activity through the onPurge hook:

StoreIT.onPurge = (count) {
  print('StoreIT Purge: $count keys evicted.');
};

Manual Purging

While the background worker is automatic, you can force a purge of expired records:

int evicted = await StoreIT.purgeExpired();

License

StoreIT is released under the MIT License. See the LICENSE file for details.

Libraries

store_it