我正在尝试使用以下代码通过 node.js 从 redis 获取一些数据:
var moment = require("moment");
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var crypto = require('crypto');
var redis = require('redis');
var bluebird = require("bluebird");
bluebird.promisifyAll(redis.RedisClient.prototype);
bluebird.promisifyAll(redis.Multi.prototype);
const uuidv4 = require('uuid/v4');
var KEY_USERS = "auction:users";
var KEY_ADMIN_TOKENS = KEY_USERS + ":admin_tokens";
var KEY_USER_TOKENS = KEY_USERS + ":user_tokens";
var SERVER_PORT = 12251;
var redis_client = bluebird.promisifyAll(redis.createClient({
host: '127.0.0.1',
no_ready_check: true,
auth_pass: '****',
}));
redis_client.on('connect', function () {
console.log('Redis client connected');
});
redis_client.on('error', function (err) {
console.log('Something went wrong with Redis Connection ' + err);
});
server.listen(SERVER_PORT);
console.log('1');
(async () => {
var response = await isAdminUser('c169024a-8902-4310-8955-ff46516e8703');
console.log("From Async " + response);
})()
console.log('2');
// Promise.resolve()
// .then(() => isAdminUser('c169024a-8902-4310-8955-ff46516e8703'))
// .then(() => console.log('3'));
console.log("Server Connected and redis initialized.");
async function isAdminUser(token) {
return new Promise((resolve, reject) => {
redis_client.hmget(KEY_ADMIN_TOKENS, [token, token], function (error, result) {
if (error) {
console.log(error);
throw error;
}
console.log("Token Result : " + result);
resolve(result);
});
});
}
现在的问题是,node 正在等待 redis 查询完成并前进到下一行代码。
控制台输出:
1
2
Server Connected and redis initialized.
Redis client connected
Token Result : "my result"
From Async "my result"
期望的输出:
1
2
Redis client connected
Token Result : "my result"
From Async "my result"
Server Connected and redis initialized.
我错过了什么/做错了什么?我已经阅读了很多建议相同的教程/文章。
最佳答案
异步函数只不过是返回 promise 的函数的语法糖,只有在函数中使用 await
时才使函数异步才有意义。
您的函数 isAdminUser
不使用 await
,因此它不需要 async
。它实际上并没有在那里做任何事情。
此外,您正在将您的 redis_client
传递给 promisifyAll
,但要使其生效,您需要使用 async
中的方法客户。
我稍微重构了你的代码,将客户端初始化转移到一个 promise 中:
const initializeRedisClient = () => new Promise((resolve, reject) => {
const redis_client = bluebird.promisifyAll(redis.createClient({
host: '127.0.0.1',
no_ready_check: true,
auth_pass: '****',
}));
redis_client.on('connect', function () {
console.log('Redis client connected');
resolve(redis_client);
});
redis_client.on('error', function (err) {
console.log('Something went wrong with Redis Connection ' + err);
reject(err);
});
});
(async () => {
const redis_client = await initializeRedisClient();
const response = await isAdminUser(redis_client, 'c169024a-8902-4310-8955-ff46516e8703');
console.log("From Async " + response);
console.log("Server Connected and redis initialized.");
})()
console.log('2');
async function isAdminUser(redis_client, token) {
const result = redis_client.hmgetAsync(KEY_ADMIN_TOKENS, [token, token]);
console.log("Token Result : " + result);
return result;
}
关于javascript - redis hmget node.js 异步/等待不工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56717228/