import config from "config"; import redis from "redis"; import mongoose from "mongoose"; import CoreClass from "../../core"; // Lightweight / convenience wrapper around redis module for our needs const pubs = {}; const subs = {}; let CacheModule; class _CacheModule extends CoreClass { // eslint-disable-next-line require-jsdoc constructor() { super("cache"); CacheModule = this; } /** * Initialises the cache/redis module * * @returns {Promise} - returns promise (reject, resolve) */ async initialize() { const importSchema = schemaName => new Promise(resolve => { import(`./schemas/${schemaName}`).then(schema => resolve(schema.default)); }); this.schemas = { session: await importSchema("session"), station: await importSchema("station"), playlist: await importSchema("playlist"), officialPlaylist: await importSchema("officialPlaylist"), song: await importSchema("song"), punishment: await importSchema("punishment"), recentActivity: await importSchema("recentActivity") }; return new Promise((resolve, reject) => { this.url = config.get("redis").url; this.password = config.get("redis").password; this.log("INFO", "Connecting..."); this.client = redis.createClient({ url: this.url, password: this.password, retry_strategy: options => { if (this.getStatus() === "LOCKDOWN") return; if (this.getStatus() !== "RECONNECTING") this.setStatus("RECONNECTING"); this.log("INFO", `Attempting to reconnect.`); if (options.attempt >= 10) { this.log("ERROR", `Stopped trying to reconnect.`); this.setStatus("FAILED"); } } }); this.client.on("error", err => { if (this.getStatus() === "INITIALIZING") reject(err); if (this.getStatus() === "LOCKDOWN") return; this.log("ERROR", `Error ${err.message}.`); }); this.client.on("connect", () => { this.log("INFO", "Connected succesfully."); if (this.getStatus() === "INITIALIZING") resolve(); else if (this.getStatus() === "FAILED" || this.getStatus() === "RECONNECTING") this.setStatus("READY"); }); }); } /** * Quits redis client * * @returns {Promise} - returns promise (reject, resolve) */ QUIT() { return new Promise(resolve => { if (CacheModule.client.connected) { CacheModule.client.quit(); Object.keys(pubs).forEach(channel => pubs[channel].quit()); Object.keys(subs).forEach(channel => subs[channel].client.quit()); } resolve(); }); } /** * Sets a single value in a table * * @param {object} payload - object containing payload * @param {string} payload.table - name of the table we want to set a key of (table === redis hash) * @param {string} payload.key - name of the key to set * @param {*} payload.value - the value we want to set * @param {boolean} [payload.stringifyJson=true] - stringify 'value' if it's an Object or Array * @returns {Promise} - returns a promise (resolve, reject) */ HSET(payload) { return new Promise((resolve, reject) => { let { key } = payload; let { value } = payload; if (mongoose.Types.ObjectId.isValid(key)) key = key.toString(); // automatically stringify objects and arrays into JSON if (["object", "array"].includes(typeof value)) value = JSON.stringify(value); CacheModule.client.hset(payload.table, key, value, err => { if (err) return reject(new Error(err)); return resolve(JSON.parse(value)); }); }); } /** * Gets a single value from a table * * @param {object} payload - object containing payload * @param {string} payload.table - name of the table to get the value from (table === redis hash) * @param {string} payload.key - name of the key to fetch * @param {boolean} [payload.parseJson=true] - attempt to parse returned data as JSON * @returns {Promise} - returns a promise (resolve, reject) */ HGET(payload) { return new Promise((resolve, reject) => { let { key } = payload; if (!key) return reject(new Error("Invalid key!")); if (!payload.table) return reject(new Error("Invalid table!")); if (mongoose.Types.ObjectId.isValid(key)) key = key.toString(); return CacheModule.client.hget(payload.table, key, (err, value) => { if (err) return reject(new Error(err)); try { value = JSON.parse(value); } catch (e) { return reject(err); } return resolve(value); }); }); } /** * Deletes a single value from a table * * @param {object} payload - object containing payload * @param {string} payload.table - name of the table to delete the value from (table === redis hash) * @param {string} payload.key - name of the key to delete * @returns {Promise} - returns a promise (resolve, reject) */ HDEL(payload) { return new Promise((resolve, reject) => { let { key } = payload; if (!payload.table) return reject(new Error("Invalid table!")); if (!key) return reject(new Error("Invalid key!")); if (mongoose.Types.ObjectId.isValid(key)) key = key.toString(); return CacheModule.client.hdel(payload.table, key, err => { if (err) return reject(new Error(err)); return resolve(); }); }); } /** * Returns all the keys for a table * * @param {object} payload - object containing payload * @param {string} payload.table - name of the table to get the values from (table === redis hash) * @param {boolean} [payload.parseJson=true] - attempts to parse all values as JSON by default * @returns {Promise} - returns a promise (resolve, reject) */ HGETALL(payload) { return new Promise((resolve, reject) => { if (!payload.table) return reject(new Error("Invalid table!")); return CacheModule.client.hgetall(payload.table, (err, obj) => { if (err) return reject(new Error(err)); if (obj) Object.keys(obj).forEach(key => { obj[key] = JSON.parse(obj[key]); }); else if (!obj) obj = []; return resolve(obj); }); }); } /** * Publish a message to a channel, caches the redis client connection * * @param {object} payload - object containing payload * @param {string} payload.channel - the name of the channel we want to publish a message to * @param {*} payload.value - the value we want to send * @param {boolean} [payload.stringifyJson=true] - stringify 'value' if it's an Object or Array * @returns {Promise} - returns a promise (resolve, reject) */ PUB(payload) { return new Promise((resolve, reject) => { let { value } = payload; if (!payload.channel) return reject(new Error("Invalid channel!")); if (!value) return reject(new Error("Invalid value!")); if (["object", "array"].includes(typeof value)) value = JSON.stringify(value); return CacheModule.client.publish(payload.channel, value, err => { if (err) reject(err); else resolve(); }); }); } /** * Subscribe to a channel, caches the redis client connection * * @param {object} payload - object containing payload * @param {string} payload.channel - name of the channel to subscribe to * @param {boolean} [payload.parseJson=true] - parse the message as JSON * @returns {Promise} - returns a promise (resolve, reject) */ SUB(payload) { return new Promise((resolve, reject) => { if (!payload.channel) return reject(new Error("Invalid channel!")); if (subs[payload.channel] === undefined) { subs[payload.channel] = { client: redis.createClient({ url: CacheModule.url, password: CacheModule.password }), cbs: [] }; subs[payload.channel].client.on("message", (channel, message) => { if (message.startsWith("[") || message.startsWith("{")) try { message = JSON.parse(message); } catch (err) { console.error(err); } else if (message.startsWith('"') && message.endsWith('"')) message = message.substring(1).substring(0, message.length - 2); return subs[channel].cbs.forEach(cb => cb(message)); }); subs[payload.channel].client.subscribe(payload.channel); } subs[payload.channel].cbs.push(payload.cb); return resolve(); }); } /** * Returns a redis schema * * @param {object} payload - object containing the payload * @param {string} payload.schemaName - the name of the schema to get * @returns {Promise} - returns promise (reject, resolve) */ GET_SCHEMA(payload) { return new Promise(resolve => { resolve(CacheModule.schemas[payload.schemaName]); }); } } export default new _CacheModule();