@j-o-r/cache NPM

@j-o-r/cache

Introduction

The @j-o-r/cache class is a utility for creating a key-value storage system that respects typed arrays. It provides methods for writing, reading, and managing cache entries.

Usage

To use the Cache class, create an instance by passing in the cache folder path and optionally the file extension. The default extension is json (uft8).

const cache = new Cache('storage/tmp', true, 'log', 'ascii');

Methods

`list()`

Returns an array of all keys in the cache folder.

`write(key, value)`

Writes a value to the cache with the given key. If the value is not a string and the extension is not json or ndjson, it throws an error.

`append(key, value)`

Append a value to the cache with the given key. If the value is not a string or the extension is json, it throws an error.

`read(key)`

Reads a value from the cache with the given key. If the file does not exist, it returns undefined.

`file(key)`

Returns a CacheFile object with the file path, encoding, and existence status.

`delete(key)`

Deletes a file from the cache with the given key.

`empty()`

Empties the cache folder by deleting all files.

`expire(time)`

Delete the cache folder files where the keys are older then time (in MS) const time = new Date('1972-12-31').getTime();

Example

const cache = new Cache('storage/tmp', true);

cache.write('key', 'value');
const value = cache.read('key');
cache.delete('key');
cache.empty();

Encryption Example

To enable encryption for the cache content, set a secret key using the secret property:

const cache = new Cache('storage/tmp', true);

// Set a secret key for encryption
cache.secret = 'mySecretKey';

// Write encrypted data
cache.write('key', 'sensitive data');

// Read and decrypt data
const decryptedValue = cache.read('key');
console.log(decryptedValue); // Outputs: 'sensitive data'

Features

Supports typed arrays (Float32Array, Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array, Uint32Array, Float64Array, BigInt64Array, BigUint64Array) when stored as JSON.
Allows for custom file extensions.
Provides methods for listing, writing, reading, and deleting cache entries.