Mongoose synchronousFind

Question

I am trying to build a synchronous mongoose find. I adopted the use of deasync. https://www.npmjs.com/package/deasync

This is currently working for saves but it is not working for queries

exports.synchronousFind = function (instanceModel, query) {
    var ready = false;
    var result = null;
    instanceModel.find(query, function (err, tenantUser) {
        ready = true;
        if (err) {
            console.log(err);
        } else {
            result = tenantUser;
        }
    });

    while (ready === false) {
        require('deasync').runLoopOnce();
    }
    return result;
}

This part of the code

while (ready === false) {
    require('deasync').runLoopOnce();
}

Just hangs forever and eventually it goes through. Does anyone have any ideas?

While loop is like too fast, by the time it reaches there, it would go through a million loops, So basically you are blocking the entire process by a while loop, which is very very wrong. — Ashok Kumar Sahoo, Feb 09 '16 at 07:15
That's what I figured. before using deasync I had a crazy loop that basically blocked everything. The framework is supposed to overcome that — CodeMilian, Feb 09 '16 at 07:17
I changed my code to this just now and it appears to be working require('deasync').loopWhile(function(){return !ready;}); — CodeMilian, Feb 09 '16 at 07:17

score 0 · Answer 1 · answered Feb 09 '16 at 07:20

I changed my code to this and it is now working properly as expected

exports.synchronousFind = function (instanceModel, query) {
    var ready = false;
    var result = null;
    instanceModel.find(query, function (err, tenantUser) {
        ready = true;
        if (err) {
            console.log(err);
        } else {
            result = tenantUser;
        }
    });

    require('deasync').loopWhile(function(){return !ready;});

    /*while (ready === false) {
        require('deasync').runLoopOnce();
    }*/
    return result;
}

score 0 · Answer 2 · edited Dec 20 '18 at 06:14

0

See the below code: Write the while loop in this way

while (!ready) {
    require('deasync').runLoopOnce();
}

This will work properly.

edited Dec 20 '18 at 06:14

Pradeep

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answered Dec 20 '18 at 05:51

Goutam Ghosh

87
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Mongoose synchronousFind

2 Answers2