rolandstarke
Node Cache Manager store for Filesystem
Package to cache key-value pairs in JSON files.
Installation
npm install cache-manager-fs-hashFeatures
- 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 implement the Filesystem cache store.
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 life in milliseconds
// (default: never expires)
zip: true, // zip files to save disk space (default: false)
});
(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.
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 filename is determined by the md5 hash of the key. (The key is also saved in the file to detect hash collisions. In this case it will just return a cache miss). Writing is performed with .lock files so that multiple instances of the library (e.g. using the cluster module) do not interfere with one another.
Tests
npm testLicense
cache-manager-fs-hash is licensed under the MIT license.