Node Cache Manager store for Filesystem


Package to cache key-value pairs in JSON files.

Installation

``sh
npm install cache-manager-fs-hash
`

Features

* Saves anything that is JSON.stringify-able to disk
* Buffers are saved as well (if they reach a certain size they will be stored to separate files)
* Works well with the cluster module

Usage example

Here is an example that demonstrates how to use the filesystem cache store.

`javascript
const { DiskStore } = require('cache-manager-fs-hash');

const diskStore = new DiskStore({
path: 'diskcache', // path for cached files (default: cache)
ttl: 60 60 1000, // time to live in milliseconds
// (default: never expires)
zip: true, // zip files to save disk space (default: false)
hash: false, // keys are hashed to generate filenames (default: true)
// set to false to use plain keys as filenames
});

(async () => {
await diskStore.set('key', 'value');
console.log(await diskStore.get('key')); // "value"

await diskStore.del('key');
console.log(await diskStore.get('key')); // undefined

await diskStore.set('key', 'value', 1000); // with custom TTL
console.log(await diskStore.ttl('key')); // 999 milliseconds

// delete stored files
await diskStore.reset();
})();
`

Here is an example that demonstrates how to use the store with the node-cache-manager module.

`javascript
const cacheManager = require('cache-manager');
const { DiskStore } = require('cache-manager-fs-hash');

const diskCache = cacheManager.createCache(new DiskStore({
path: 'diskcache', // path for cached files
// ... other options
}));


(async () => {

await diskCache.set('key', 'value');
console.log(await diskCache.get('key')); // "value"

console.log(await getUserCached(5)); // {id: 5, name: '...'}
console.log(await getUserCached(5)); // {id: 5, name: '...'}

function getUserCached(userId) {
return diskCache.wrap(userId, function () {
return getUser(userId);
});
}

async function getUser(userId) {
await new Promise(r => setTimeout(r, 100)); // sleep 0.1 seconds
return {id: userId, name: '...' + Math.random()};
}

})();
`

How it works

The library saves each cached item as a separate file under the specified directory. Writes use a .lock file to ensure that multiple instances accessing the same cache file do not interfere with each other.

Tests

`sh
npm test
``

License

cache-manager-fs-hash is licensed under the MIT license.