53 lines
1.2 KiB
JavaScript
53 lines
1.2 KiB
JavaScript
const redis = require("redis")
|
|
const client = redis.createClient()
|
|
|
|
class Cache {
|
|
/**
|
|
* Retrieve an unexpired cache entry by key.
|
|
* @param {String} key of the cache entry
|
|
* @returns {Promise}
|
|
*/
|
|
get(key) {
|
|
return new Promise((resolve, reject) => {
|
|
client.get(key, (error, reply) => {
|
|
if (reply == null) {
|
|
return reject();
|
|
}
|
|
|
|
resolve(JSON.parse(reply));
|
|
});
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Insert cache entry with key and value.
|
|
* @param {String} key of the cache entry
|
|
* @param {String} value of the cache entry
|
|
* @param {Number} timeToLive the number of seconds before entry expires
|
|
* @returns {Object}
|
|
*/
|
|
set(key, value, timeToLive = 10800) {
|
|
if (value == null || key == null) return null;
|
|
|
|
const json = JSON.stringify(value);
|
|
client.set(key, json, (error, reply) => {
|
|
if (reply == "OK") {
|
|
// successfully set value with key, now set TTL for key
|
|
client.expire(key, timeToLive, e => {
|
|
if (e)
|
|
console.error(
|
|
"Unexpected error while setting expiration for key:",
|
|
key,
|
|
". Error:",
|
|
error
|
|
);
|
|
});
|
|
}
|
|
});
|
|
|
|
return value;
|
|
}
|
|
}
|
|
|
|
module.exports = Cache;
|