entity_simple_cache 1.0.2

A simple in memory cache for small/medium size systems

Entity Simple Cache

Small and simple library for caching typed objects and values. It gives few strategies to control expiration of entries in cache. This lib doesn't use any kind soft/weak linking to track objects. It's more like a Map with extra wrapper to control when and how to dispose values from it.

Features

• Read, update, delete and invalidate cache.
• Allows to configure expiration time of entry
• Allows to limit maximum number of entries in cache
• Provides built-in mechanism to periodically remove expired entries
• Provides built-in mechanism to remove expired entries by chosen count of read operations

Getting started

Here is simple listing of cache usage. For more examples and ideas how to use it please refer to test folder.

import 'package:entity_simple_cache/src/cache.dart';

void main() {
  final cache = Cache<String, String>(maxLength: 3);  //constrain cache to 3 elements
  cache.write("A", "This is A");    //add to cache
  cache["B"] = "This is B";         //add to cache
  print(cache.length);              //get approximate size

  cache["C"] = "This is C";         //add to cache
  cache["D"] = "This is D";         //add to cache

  print(cache);                     //dump cache info
  print("cache for key A is: ${cache.read("A")}");  //read from cache
  print("cache for key B is: ${cache["B"]}");       //read from cache
  print("cache for key C is: ${cache["C"]}");       //read from cache
  print("cache for key D is: ${cache["D"]}");       //read from cache
}

Selecting different cache collection

By default proposed cache is using HashMap as a collection to store data, however it allows to choose also SplayTreeMap. Here is show code snippet showing how to use it:

import 'package:entity_simple_cache/src/cache.dart';

void main() {
  final cache = Cache<String, String>(maxLength: 3);            //uses HashMap internally
  final cache2 = SplayTreeCache<String, String>(maxLength: 3);  //uses SplayTreeMap internally
}

If for some reasons different type of collection is needed please refer to source how to do it. Chosen collection must conform to Dart Map interface, here is example how to build CustomCache class which uses LinkedHashMap under the hood:

class CustomCache<K, V> extends TypedCache<K, V> {
  CustomCache({
    super.entriesExpiration = const Duration(minutes: 10),
    super.revalidateHitCount = -1,
    Duration? cleanupDuration,
    super.maxLength = -1,
  }) : super(LinkedHashMap<K, CacheEntry<V>>(), cleanupDuration: cleanupDuration);
}