@duell10111/react-native-cache

LRU cache built on top of the React Native communities' AsyncStorage v2 (or included MemoryStore) and automatic pruning of least recently used items.

Based on timfpark's version.

Additionally a sync version is included to use it on top of the React Native MMKV package.

Installation

• Run the following command.

npm install --save @duell10111/react-native-cache
or
yarn add @duell10111/react-native-cache

• Import the library.

import { Cache } from "@duell10111/react-native-cache"; //Async version

import { SyncCache } from "@duell10111/react-native-cache"; //Sync version

Usage

You initialize a cache using the following.

const cache = new Cache({
    namespace: "myapp",
    policy: {
        maxEntries: 50000, // if unspecified, it can have unlimited entries
        stdTTL: 0 // the standard ttl as number in seconds, default: 0 (unlimited)
    },
    backend: AsyncStorage,
    prunecallback: (keys) => {console.log(keys)} //prunecallback called if a key gets removed
});

Multiple caches can be mantained in an application by instantiating caches with different namespaces.

Setting a key's value in the cache

await cache.set("hello", "world");
// key 'hello' is now set to 'world' in namespace 'myapp'

Get an item in the cache

const value = await cache.get("key1");
console.log(value);
// 'hello'
});

Getting an item from the cache also moves it to the end of the LRU list: it will be evicted from the cache last.

Delete an item from the cache

await cache.remove("key1");
// 'key1' is no more.

Peeking at an item in the cache

You can also peek at an item in the cache without updating its position in the LRU list:

const value = await cache.peek("key1");
// value is retrieved but LRU value is unchanged.

Getting all of the elements in the cache

You can look at all of the elements in the cache without updating its position in the LRU list:

const entries = await cache.getAll();
console.dir(entries);
// {
//     "key1": { "value": 42 }
//     "key2": { "value": 2 }
//     ...
// }

Clearing all of the elements in the cache

You can also clear all of the items in the cache with:

await cache.clearAll();

For more usage examples, see the tests.