我怎样才能更好地优化这些数据库查询/functionstream？

我已经把我的手从游戏开发转移到写支持后端。 到目前为止，一切似乎都奏效了，但是当我写一个朋友系统的时候，我碰到了这个对我来说看起来很脏的functionstream程。 而且我确定我只是在这一点上一起黑客攻击。 任何node.js向导都会告诉我如何改进？

相当肯定我应该在Redis中caching玩家查询。

acceptfriend: function(req, res){ //Find our user User.findById( req.decoded._id, function(err, user){ //error occured if(err){ return res.status(401).send(err); } //no user found if(!user){ return res.status(401).json({ succes: false, message: 'no user found with that id' } ); } //Does the request exist? if( !_.any( user.social.friendRequests, {id: req.params.id} ) ){ return res.status(401).json( { succes: false, message: 'friend request not found' } ); } //find the user that belongs to the request User.findById( req.params.id, function(err, friend){ //error occured if(err){ return res.send(err); } //user doesnt exist if(!friend){ return res.status(401).json({ succes: false, message: 'no user found with that id' } ); } //Pull the request from the friendRequests array user.social.friendRequests.pull( req.params.id ); //Add the friend user.social.friends.addToSet( { user_id: friend._id, name: friend.username, corp: 'n/a' } ); //Add the user to the friends list as well friend.social.friends.addToSet({ user_id: user._id, name: user.username, corp: 'n/a' }); //save the docs user.save(); friend.save(); } ); //return success return res.status(200).json({ success: true, message: 'friend succesfully added' }); } ); } 

Answer 1

1-首先，你有一个很大的function。 你必须把它分成一些function。 这样做，您可以使用任何testing框架来testing它们。

2-将错误响应的句柄委托给控制器。

 from -> return res.status(401).send(err); to (with Promises)-> deferred.reject(err); to (normal way) -> throw new Error(err); 

3-您可以使用Promises来pipe理节点的asynchronous行为以清除代码。 我创build了一个例子，也许是在第一次不工作，随时修复不相关的引用。 User ref，'acceptfriend'方法…

要点： https ： //gist.github.com/aitoraznar/b7099ad88ead0cdab256

 var Promise = require('bluebird'); var _ = require('lodash'); //var User = app.models.User; var ERRORS = { userNotFoundError: { code: 401, success: false, message: 'no user found with that id' }, friendRequestNotFoundError: { code: 401, success: false, message: 'friend request not found' }, friendNotFoundError: { code: 401, success: false, message: 'no friend found with that id' } } var SUCCESS_MESSAGES= { friendAddedSuccessfully: { success: true, message: 'friend succesfully added' } }; var userDAO = { /* * */ getUserById: function(id) { var deferred = Promise.pending(); User.findById(id, function(err, user) { //error occured if (err) { err.code = 401; return deferred.reject(err); } //no user found if (!user) { return deferred.reject(ERRORS.userNotFoundError); } deferred.resolve(user); }); return deferred.promise; }, /* * Does the request exist? */ checkFriendRequest: function(user, friendId) { var deferred = Promise.pending(); if (userDAO.haveFriendRequestFrom(user, friendId)) { deferred.resolve(user, friendId); } else { return deferred.reject(ERRORS.friendRequestNotFoundError); } return deferred.promise; }, /* * */ haveFriendRequestFrom: function(user, friendId) { return _.any(user.social.friendRequests, {id: friendId }); }, /* * */ getFriend: function(user, friendId) { var deferred = Promise.pending(); userDAO.getUserById(friendId) .then(function(friend) { deferred.resolve(user, friend); }, function(error) { if (error === ERRORS.userNotFoundError) { // Then the error is friend not found // Override the error error = ERRORS.friendNotFoundError; } return deferred.reject(error); }); return deferred.promise; }, /* * */ makeFriendship: function(user, friend) { var deferred = Promise.pending(); //Pull the request from the friendRequests array user.social.friendRequests.pull(friend._id); //Add the friend user.social.friends.addToSet( { user_id: friend._id, name: friend.username, corp: 'n/a' } ); //Add the user to the friends list as well friend.social.friends.addToSet({ user_id: user._id, name: user.username, corp: 'n/a' }); //save the docs user.save(); friend.save(); // Return the new friendship var friendship = { user: user, friend:friend }; deferred.resolve(friendship); return deferred.promise; }, /* * */ friendRequestError: function(err) { var deferred = Promise.pending(); // Propagate de error deferred.reject(err); return deferred.promise; }, /* * */ friendRequest: function(userId, friendId) { var deferred = Promise.pending(); // Get user by ID userDAO.getUserById(userId) // Check if the user is able to add the friend .then(userDAO.checkFriendRequest, userDAO.friendRequestError) // Get the friend to add .then(userDAO.getFriend, userDAO.friendRequestError) // Make the friendship .then(userDAO.makeFriendship, userDAO.friendRequestError) // Response to the controller .then( function(friendship) { // Resolve with new friendship // This goes to 'success' function in controller deferred.resolve(friendship); }, function(error) { // This goes to 'error' function in controller deferred.reject(error); }) return deferred.promise; } }; // Controller var acceptfriend = function(req, res, next) { var userId = req.decoded._id; var friendId = req.params.id; userDAO.friendRequest(userId, friendId) .then(function(friendRequest) { console.log('---> SUCCESS'); //return success return res.status(200) .json(SUCCESS_MESSAGES.friendAddedSuccessfully); }, function(error) { console.error('---> ERROR', error); return res.status(error.code).json(error); }); }