User Cache

RedisService.js

var redisServer = require('redis');
var RedisService = (function () {
  var instance;
  function init() {
    //6381 for Develop and Test
    //6379 for Production
    var port = 6379;
    var host = "localhost";
    var redis = redisServer.createClient(port,host);

    var expireKey = function(key,cb) {
      redis.expire(key,0,function(err,status) {
        cb(err,status);
      })
    }
    var getKeyTTL = function(key,cb) {
      redis.ttl(key, function (err, ttl) {
        cb(err,ttl);
      });
    }
    var fetchByKey = function(key,cb) {
      redis.get(key,function(err,data){
        cb(err,data)
      })
    }
    var fetchByKeys = function(keys,cb) {
      if (keys.length > 0) {
        redis.mget(keys,function(err,data){
          cb(err,data)
        })
      } else {
        cb(null,'Bad Keys')
      }
    }
    var storeAtKey = function(key,value,ttl,cb) {
      redis.set(key,value,function(err){
        if (err) {
          cb(err)
        } else {
          redis.expire(key,ttl,function(err) {
            cb(null,'ok');
          });
        }
      })
    }
    var clearCache = function(cb) {
      redis.flushdb();
    }
    var listAllKeys = function(cb) {
      redis.keys("*",cb);
    }
    return {
      fetchByKey :fetchByKey,
      fetchByKeys:fetchByKeys,
      storeAtKey :storeAtKey,
      getKeyTTL:getKeyTTL,
      expireKey:expireKey,
      listAllKeys:listAllKeys,
      clearCache:clearCache,

      TTL_ONE_DAY:24*60*60,
      TTL_30_MIN:30*60,
      TTL_01_HOUR:1*60*60,
      TTL_08_HOUR:8*60*60,
      TTL_ZERO:0
    }
  }
  return {
    getInstance: function () {
      if ( !instance ) {
        instance = init();
      }
      return instance;
    }
  };
})();

module.exports = RedisService;

userCache.js

var co = require('co');
var _ = require('lodash');
var moment = require('moment');
const promisify = require("es6-promisify");
var Util = require('./Utilities');
var APIConst = require('./constant.js');
var myRedisService = require('./redisService.js').getInstance();
//User Relation inside user table
module.exports = function(user) {
  var TTL = 60*60;
  //["581965742d145f15b993ea15","581965742d145f15b993ea1c","581965742d145f15b993ea12","581965742d145f15b993ea14","581965742d145f15b993ea16","581965742d145f15b993ea19" ]
  user.getUsersData = function(userIds,format,cb){
    co(function*() {
      var cachedUser = yield promisify(myRedisService.fetchByKeys)(userIds);
      cachedUser  = cachedUser.map(function(ud) {
        return JSON.parse(ud)
      })
      //console.log(cachedUser) 
      cachedUser = cachedUser.filter(function(ud) {
        return ud
      })     
      var cachedIds = cachedUser.map(function(ud) {
        return ud.id
      })
      var leftIds = userIds.filter(function(uid){
        return (cachedIds.indexOf(uid.toString()) === -1 )
      })
      console.log(leftIds)
      var dbUsers = []
      if (leftIds.length > 0) {
        format = format || 'array';
        var orQuery = [];
        var uniqIds = _.uniq(leftIds);
        uniqIds.map(function(uid){
          orQuery.push({id:uid})
        });
        var query = {
          where:{or:orQuery},
          fields:APIConst.TABLE_FIELDS.UserFieldsDefault
        }      
        dbUsers = yield user.find(query);
        var cacheSave = yield dbUsers.map(function(ud) {
          return promisify(myRedisService.storeAtKey)(ud.id.toString(),JSON.stringify(ud),TTL)
        })
      }
      var allUsers = cachedUser.concat(dbUsers);
      if (format === 'dictionary') {
        //In Dictionary Form
        var userDict = {};
        allUsers.map(function(ud) {
          userDict[ud.id] = ud
        })
        cb(null,userDict)
      } else {
        cb(null,allUsers)
      }
    })
    .catch(function(err){
      cb(null,{err:err});
    })
  }  
  user.remoteMethod(
      'getUsersData',
      {
        http: {verb: 'get'},
        accepts: [
          {arg: 'userIds', type: 'array', required: true, description:'userIds'},
          {arg: 'format', type: 'string', description:'array | dictionary'}
        ],
        returns: {arg: 'response', type: 'object'},
        description:'Get userData from userId in an Array'
      }
  ); 
}