LRU cache built on top of the React Native communities' AsyncStorage v2 (or included MemoryStore) and automatic pruning of least recently used items.
- Run the following command.
npm install --save react-native-cache
- Import the library.
import { Cache } from "react-native-cache";
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
});
Multiple caches can be mantained in an application by instantiating caches with different namespaces.
await cache.set("hello", "world");
// key 'hello' is now set to 'world' in namespace 'myapp'
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.
await cache.remove("key1");
// 'key1' is no more.
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.
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 }
// ...
// }
You can also clear all of the items in the cache with:
await cache.clearAll();
For more usage examples, see the tests.