无法将获取的数据发送到我的 socket.io 流？

Question

我正在尝试从单个 mysql-queries 切换到 mysql-pool 连接，以便用户可以共享一个 mysql-connection，但我不熟悉这一点（也是 nodejs/socket.io 的新内容）。

以下代码是我到目前为止所做的每秒向数组中的套接字发送数据的代码：

var 
port                = process.env.OPENSHIFT_NODEJS_PORT || 8000,
ip                  = process.env.OPENSHIFT_NODEJS_IP || '127.0.0.1',
app                 = require('http').createServer(handler),
fs                  = require('fs'),
request             = require('request'),
mysql               = require('mysql'),
moment              = require('moment'),
tz                  = require('moment-timezone'),
pool                = mysql.createPool({
connectionLimit:    100,
host:               'xxx',
user:               'xxx',
password:           'xxx',
database:           'xxx',
debug:              false,
port:               3306}),
socketArray         = [],
POLLING_INTERVAL    = 1000,
pollingTimer;
moment.tz.setDefault("Europe/Berlin");

var io = require('socket.io').listen(app);
io.set('origins', '*:*');

function time()
{
output = new Date();
output = moment().format('(H:mm:ss.SS) ');
return output;
}

function handler(req,res) 
    {
    res.setHeader("Access-Control-Allow-Origin", "*");
    res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    res.statusCode = 200;
    res.connection.setTimeout(0);
    res.end();
}
app.listen(port,ip);

function pollingLoop () {
    if (socketArray.length === 0) {
        // no connections, wait and try again
        setTimeout(pollingLoop, POLLING_INTERVAL);
        return; // continue without sending mysql query
    }
    pool.getConnection(function(err,connection){ 
    if (err) { console.log({"code" : 100, "status" : "connection-db error"}); return; }   
    console.log('connected as id ' + connection.threadId);
    console.log('socketArray length: ' + socketArray.length);

    var selection = 
        "SELECT\
        a.`id`,a.`product_id` AS pid,a.`random` AS nr,a.`price`,a.`price_end` AS pe,\
        TIMESTAMPDIFF(SECOND,NOW(),a.`datetime`) AS duration,\
        ABS(TIMESTAMPDIFF(SECOND,NOW(),b.`date`)) AS hb\
        FROM `auctions` AS a\
        LEFT JOIN `auctions_bids` AS b ON b.`auction_id` = a.`id`\
        WHERE TIMESTAMPDIFF(SECOND,NOW(),a.`datetime`) > '-1'\
        GROUP BY a.`id`\
        ORDER BY `duration` DESC,`id` DESC LIMIT 15";   
    var streamArray = [], lg = '';                      

    var query = connection.query(selection, function(err, results, rows){
    lg += ('id: '+results[0].id+' ('+results[0].duration+') ');         

    if 
    (
    ((results[0].duration < 2 || results[0].duration <= results[0].nr) && (results[0].price <= results[0].pe)) 
    ||
    ((results[0].duration < 2 || results[0].duration <= results[0].nr) && (results[0].hb > 0 && results[0].hb < 30))
    )   
    {
    min = 3;
    max = 5;
    rand = Math.floor(Math.random()*(max-min+1)+min);
    price = results[0].price+0.01;
    price = price.toFixed(2);

    pool.query('UPDATE `auctions` SET `random` = ?,`price` = ?, `datetime` = DATE_ADD(`datetime`,INTERVAL(17-TIMESTAMPDIFF(SECOND,NOW(),`datetime`))SECOND) WHERE `id` = ?',[rand, price, results[0].id]);  
    console.log(time()+'UPDATED id '+results[0].id+': random ('+rand+') price ('+price+'€)');   
    }       
    streamArray.push(results[0]);        

    updateSockets({ streamArray: streamArray });    
    console.log("auctions pushed: " + streamArray); 
    connection.release();
    setTimeout(pollingLoop, POLLING_INTERVAL);  
    });
    console.log(time()+lg+' C: '+socketArray.length);
}); 
}
pollingLoop();

io.sockets.on('connection', function(socket) {  
    socket.on('disconnect', function() {
    clearTimeout(pollingTimer);
    var socketIndex = socketArray.indexOf(socket);
    console.log(time()+'SOCKET-ID = %s DISCONNECTED', socketIndex);
    if (~socketIndex) { socketArray.splice(socketIndex, 1); }
    });  
    console.log(time()+'NEW SOCKET CONNECTED!');
    socketArray.push(socket);
}); 

var updateSockets = function(data) {
    socketArray.forEach(function(tmpSocket) { tmpSocket.volatile.emit('stream', data); });
};

console.log(time()+'server.js executed\n');

但这不会向我发送任何数据到 WebSocket。这种方法（代码结构）是否正确？以前我使用 query.on('results') 来获取这样的数据：

var selection = "SELECT * FROM auctions";            
var query = mysql.query(selection), auctions = []; 
query.on('result', function(auction) {
console.log('id: '+auction.id+' ('+auction.duration+') ');
});

使用 auction.row 显示数据效果很好，但如何在我的 mysql 池连接中执行此操作？

同样在几秒钟后我得到一个错误 release() 甚至没有定义，但它列在 mysql-module 文档中......所以我认为我的整个逻辑过程有点不正确。

我应该使用 connection.end() 和 .release() 吗？因为
连接永远不会结束。
我还要用setInterval(function () { mysql.query('SELECT<br> 1'); }, 5000); 作为另一个 Whosebug 问题的回答这里的联系还活着吗？ (nodejs mysql Error: Connection lost The server closed the connection)

（感谢任何提示或对我的一些问题的回答！比 none 更好的一些答案，因为我发现这个主题根本没有得到太多回答。）

编辑： 更新了我的整个代码（见上文）。现在输出如下所示：http://s21.postimg.org/avsxa87rb/output.jpg

所以流获取了数据，但在 console.log 中什么也没有，而且有这个 javascript 错误？

Answer 1

您应该创建一个池，并在该池上使用 getConnection。然后，当您完成连接后，释放它。此外，您不需要为每个连接停止或启动轮询循环，一个循环就足够了。

我不明白带条件的if语句，所以我省略了它。它可能需要去别的地方。

var socketArr = [];

function handler(req, res) {
    res.statusCode = 200;
    res.connection.setTimeout(0);
    res.end();
}
app.listen(port, ip);
var pool = mysql.createPool({
    host     : 'example.org',
    user     : 'bob',
    password : 'secret'
});

function pollingLoop () {
    if (socketArr.length === 0) {
        // no connections, wait and try again
        setTimeout(pollingLoop, 1000);
        return; // continue without sending mysql query
    }
    pool.getConnection(function (err, connection) {
        if (err) {
            console.log({
                "code": 100,
                "status": "Error in connection database"
            });
            return;
        }
        console.log('connected as id ' + connection.threadId);
        var selection = "SELECT * FROM auctions";
        var streamArray = [],
            lg = '';
        var query = connection.query(selection, function (err, results, fields, rows) {
            lg += ('id: ' + results[0].id + ' (' + results[0].duration + ') ');
            /*if (conditions) {
                var query_update = connection.query('UPDATE `auctions` SET `price` = ? WHERE `id` = ?', [price, auction.id]);
                console.log(time() + 'UPDATED id ' + auction.id + ': price (' + price + '€)');
            }*/
            streamArray.push(results);
            updateSockets({
                streamArray: streamArray
            });
            console.log("auctions pushed: " + streamArray);
            connection.release();
            setTimeout(pollingLoop, 1000);
        });
        console.log(time() + lg + ' C: ' + socketArr.length);
    });
}
// start loop
pollingLoop();

io.sockets.on('connection', function (socket) {
    socket.on('disconnect', function () {
        var socketIndex = socketArr.indexOf(socket);
        console.log(time() + 'SOCKET-ID = %s DISCONNECTED', socketIndex);
        if (~socketIndex) {
            socketArr.splice(socketIndex, 1);
        }
    });
    console.log(time() + 'NEW SOCKET CONNECTED!');
    socketArr.push(socket);
});
var updateSockets = function (data) {
    socketArr.forEach(function (tmpSocket) {
        tmpSocket.volatile.emit('stream', data);
    });
};

无法将获取的数据发送到我的 socket.io 流？

Can't send fetched data to my socket.io stream?

javascript

mysql

websocket

node.js

socket.io