npm-package-resolver/libs/redis-transport.js

An API for Resolving NPM package dependencies

/**
 * Created by Liam Bilich on 07/03/2016.
 *  This is our redis transport module, all comm with redis is done through it.
 */


var redis   = require('redis');
var util = require('util');

var _ = require('underscore');
// logger instance, provide unique id for current logging from this module, as 'redis-transport'
var _config = require('./config.js');


// later assigned to be the current config used, either for dev or production
var config = process.env['NODE_ENV']=="production"?_config.production:_config.development;

// VARIABLES AND CONSTANTS

var redisRetriesBeforeExit = 500;
var redisClientSubscriber;
var redisClientSetter;
var callback;

// wrap properly later on with real logging, such as winston and logstash / logstashUDP


// are we connected or not?
var connected = false;


function retryRedisConnect(){
    if (redisRetriesBeforeExit>0) {
        redisRetriesBeforeExit--;

    } else {
        //sentry.captureMessage('unable to reconnect to Redis, after few retries exiting');
        console.error('unable to reconnect to Redis, after few retries exiting');

    }

}


function connect(messageCallback){

    console.log('connecting to Redis... host :',config.redis.host,' port:',config.redis.port);

    // if server is not found no re-connection will be done
    if (!connected){
        redisClientSetter = redis.createClient(config.redis.port,config.redis.host,{connect_timeout:3600000});
        redisClientSetter.on('error',function(e){
            console.error('error finding redis! will try to reconnect:'+e);
        });

        connected = true;

        if (messageCallback){
            messageCallback();
        }



    } else {
        console.log('redis already connected, skipping')
    }



}


/**
 * save value in redis key
 *
 * @param packageName;
 * @param data
 */
function saveHash(packageName,data){


    var _data;
    //if (util.isString(data)){
    if (typeof(data)=="string"){
        _data = data;

    } else if (typeof(data)=="object"){ // making sure we are s string
        _data = JSON.stringify(data);
    }


    console.log('Saving data to redis',_data);
    redisClientSetter.set(packageName, _data,function (e, reply) {
        if (e){
            console.error('redis error setting',e);
        } else {

            console.log(reply.toString());
        }

    });
}


/**
 * wrapper for redis lpush, using proper convention
 * @param key
 * @param listArray
 * @param callback
 */
function lpush(key,listArray,callback){

    var cloned = _.clone(listArray);
    cloned.unshift(key);
    redisClientSetter.lpush(cloned,function(e,reply){
        if (callback) {
            callback(e,reply);
        }
    })

}



/**
 * save value in redis key
 *
 * @param packageName - name of the package
 * @param depsArray - array of dependencies
 */
function savePackageDeps(packageName,depsArray){

    if (!connected) {
        console.error('redis not connnected, cannot save data');
        return;
    }

    var _data;
    //if (util.isString(data)){
    if (typeof(data)=="string"){
        _data = data;

    } else if (typeof(data)=="object"){ // making sure we are s string
        _data = JSON.stringify(data);
    }


    console.log('Saving data to redis',_data);
    redisClientSetter.lpush(packageName,depsArray)


}


function loadData(packageName,callback){

    if (!connected) {
        console.error('redis not connected, cannot load data');
        return;
    }
    redisClientSetter.get(packageName,callback);
}






module.exports = {
    connect:connect,
    loadData:loadData,
    savePackageDeps:savePackageDeps,
    saveHash:saveHash,
    lpush:lpush

}

Object.defineProperty(module.exports, 'connected', {
    get: function() {
        return connected;
    }
});


// return redis client instance
Object.defineProperty(module.exports, 'client', {
    get: function() {
        return redisClientSetter;
    }
});