CODEWITHSUNDEEP
javascriptfirebasegoogle-cloud-functions
nDD
nDD

Reputation: 11

why my javascript its use to long time to run?

I'm working with Cloud Functions for Firebase, and I get a timeout with some of my functions. I'm pretty new with JavaScript. It looks like I need to put a for inside a promise, and I get some problems. The code actually get off from for too early, and I think he make this in a long time. Do you have some way to improve this code and make the code faster?

exports.firebaseFunctions = functions.database.ref("mess/{pushId}").onUpdate(event => {
    //first i get event val and a object inside a firebase
    const original = event.data.val();
    const users = original.uids; // THIS ITS ALL USERS UIDS!!

    // so fist i get all users uids and put inside a array
    let usersUids = [];
    for (let key in users) {
        usersUids.push(users[key]);
    }

    // so now i gonna make a promise for use all this uids and get token's device 
    //and save them inside a another child in firebase!!
    return new Promise((resolve) => {
            let userTokens = [];
            usersUids.forEach(element => {
                admin.database().ref('users/' + element).child('token').once('value', snapShot => {
                    if (snapShot.val()) { // if token exist put him inside a array
                        userTokens.push(snapShot.val());
                    }
                })
            })
            resolve({
                userTokens
            })
        }) // now i make then here, from get userTokens and save in another child inside a firebase database
        .then((res) => {
            return admin.database().ref("USERS/TOKENS").push({
                userTokens: res,
            })
        })
})

Upvotes: 0

Views: 49

Answers (1)

Luan Nico
Luan Nico

Reputation: 5927

You are making network requests with firebase, so maybe that's why it's slow. You are making one request per user, so if you have 100 ids there, it might as well take a while.

But there's another problem that I notice, that is: you are just resolving to an empty list. To wait for several promises, create an array of promises, and then use Promise.all to create a promise that waits for all of them in parallel.

When you call resolve, you have already done the forEach, and you have started every promise, but they have not been added to the list yet. To make it better, chance it to a map and collect all the returned promises, and then return Promise.all.

Upvotes: 1

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