alexandrajs/amule-rush

"use strict";
/**
 * @author Michał Żaloudik <ponury.kostek@gmail.com>
 */
const Redis = require("ioredis");
const fast = require("fast.js");
const Layer = require("amule").Layer;
const JSONLess = require('json-less');
/**
 *
 * @constructor
 */
class Rush extends Layer {
    /**
     *
     * @param {Object} [options]
     * @param {Redis|Object} [options.client]
     * @param {boolean} [options.cluster=false]
     * @param {string} [options.prefix=""]
     * @param {number} [options.ttl=0]
     */
    constructor(options) {
        super();
        this.options = fast.assign({
            prefix: "",
            cluster: false,
            ttl: 0
        }, options || {});
        if (this.options.client && this.options.client.constructor && this.options.client.constructor.name === "Redis") {
            this.client = this.options.client;
        } else {
            if (this.options.cluster) {
                this.client = new Redis.Cluster(this.options.client);
            } else {
                this.client = new Redis(this.options.client);
            }
        }
    }

    /**
     *
     * @param {string} key
     * @param {string} field
     * @param {function} callback
     */
    _has(key, field, callback) {
        this.client.hget(this.options.prefix + key, field, (err, value) => {
            if (err || typeof value !== "string") {
                return callback(err, false);
            }
            try {
                JSONLess.parse(value);
                callback(err, true);
            } catch (err) {
                callback(err, false);
            }
        });
    };

    /**
     *
     * @param {string} key
     * @param {string} field
     * @param {function} callback
     */
    _get(key, field, callback) {
        this.client.hget(this.options.prefix + key, field, (err, value) => {
            callback(err, typeof value === "string" ? JSONLess.parse(value) : value);
        });
    };

    /**
     *
     * @param {string} key
     * @param {string} field
     * @param value
     * @param {function} callback
     */
    _set(key, field, value, callback) {
        this.client.hset(this.options.prefix + key, field, JSONLess.stringify(value), (err) => {
            if (err || !this.options.ttl) {
                return callback(err);
            }
            this.client.expire(this.options.prefix + key, this.options.ttl, callback);
        });
    };

    /**
     *
     * @param {string} key
     * @param {string} field
     * @param {function} callback
     */
    _delete(key, field, callback) {
        this.client.hdel(this.options.prefix + key, field, callback);
    };

    /**
     * @param {function} callback
     */
    _clear(callback) {
        const stream = this.client.scanStream({match: this.options.prefix + "*"});
        stream.on("data", (keys) => {
            this.client.del(keys.join(" "));
        });
        stream.on("end", () => callback(null, true));
    };
}

module.exports = Rush;