Firebase 云功能非常慢 - Firebase cloud functions is very slow

问题：

We're working on an application that uses the new firebase cloud functions.我们正在开发一个使用新的 firebase 云功能的应用程序。 What currently is happening is that a transaction is put in the queue node.当前发生的是将事务放入队列节点。 And then the function removes that node and puts it in the correct node.然后该函数删除该节点并将其放入正确的节点中。 This has been implemented because of the ability to work offline.由于能够脱机工作，因此已实施。

Our current problem is the speed of the function.我们当前的问题是函数的速度。 The function itself takes about 400ms, so that's alright.该函数本身大约需要 400 毫秒，所以没关系。 But sometimes the functions take a very long time (around 8 seconds), while the entry was already added to the queue.但有时函数需要很长时间（大约 8 秒），而条目已经添加到队列中。

We suspect that the server takes time to boot up, because when we do the action once more after the first.我们怀疑服务器需要时间来启动，因为当我们在第一次之后再次执行操作时。 It takes way less time.它需要更少的时间。

Is there any way to fix this problem?有没有办法解决这个问题？ Down here i added the code of our function.在这里，我添加了我们函数的代码。 We suspect there's nothing wrong with it, but we added it just in case.我们怀疑它没有任何问题，但我们添加了它以防万一。

const functions = require('firebase-functions');
const admin = require('firebase-admin');
const database = admin.database();

exports.insertTransaction = functions.database
    .ref('/userPlacePromotionTransactionsQueue/{userKey}/{placeKey}/{promotionKey}/{transactionKey}')
    .onWrite(event => {
        if (event.data.val() == null) return null;

        // get keys
        const userKey = event.params.userKey;
        const placeKey = event.params.placeKey;
        const promotionKey = event.params.promotionKey;
        const transactionKey = event.params.transactionKey;

        // init update object
        const data = {};

        // get the transaction
        const transaction = event.data.val();

        // transfer transaction
        saveTransaction(data, transaction, userKey, placeKey, promotionKey, transactionKey);
        // remove from queue
        data[`/userPlacePromotionTransactionsQueue/${userKey}/${placeKey}/${promotionKey}/${transactionKey}`] = null;

        // fetch promotion
        database.ref(`promotions/${promotionKey}`).once('value', (snapshot) => {
            // Check if the promotion exists.
            if (!snapshot.exists()) {
                return null;
            }

            const promotion = snapshot.val();

            // fetch the current stamp count
            database.ref(`userPromotionStampCount/${userKey}/${promotionKey}`).once('value', (snapshot) => {
                let currentStampCount = 0;
                if (snapshot.exists()) currentStampCount = parseInt(snapshot.val());

                data[`userPromotionStampCount/${userKey}/${promotionKey}`] = currentStampCount + transaction.amount;

                // determines if there are new full cards
                const currentFullcards = Math.floor(currentStampCount > 0 ? currentStampCount / promotion.stamps : 0);
                const newStamps = currentStampCount + transaction.amount;
                const newFullcards = Math.floor(newStamps / promotion.stamps);

                if (newFullcards > currentFullcards) {
                    for (let i = 0; i < (newFullcards - currentFullcards); i++) {
                        const cardTransaction = {
                            action: "pending",
                            promotion_id: promotionKey,
                            user_id: userKey,
                            amount: 0,
                            type: "stamp",
                            date: transaction.date,
                            is_reversed: false
                        };

                        saveTransaction(data, cardTransaction, userKey, placeKey, promotionKey);

                        const completedPromotion = {
                            promotion_id: promotionKey,
                            user_id: userKey,
                            has_used: false,
                            date: admin.database.ServerValue.TIMESTAMP
                        };

                        const promotionPushKey = database
                            .ref()
                            .child(`userPlaceCompletedPromotions/${userKey}/${placeKey}`)
                            .push()
                            .key;

                        data[`userPlaceCompletedPromotions/${userKey}/${placeKey}/${promotionPushKey}`] = completedPromotion;
                        data[`userCompletedPromotions/${userKey}/${promotionPushKey}`] = completedPromotion;
                    }
                }

                return database.ref().update(data);
            }, (error) => {
                // Log to the console if an error happened.
                console.log('The read failed: ' + error.code);
                return null;
            });

        }, (error) => {
            // Log to the console if an error happened.
            console.log('The read failed: ' + error.code);
            return null;
        });
    });

function saveTransaction(data, transaction, userKey, placeKey, promotionKey, transactionKey) {
    if (!transactionKey) {
        transactionKey = database.ref('transactions').push().key;
    }

    data[`transactions/${transactionKey}`] = transaction;
    data[`placeTransactions/${placeKey}/${transactionKey}`] = transaction;
    data[`userPlacePromotionTransactions/${userKey}/${placeKey}/${promotionKey}/${transactionKey}`] = transaction;
}

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解决方案：

参考一： https://en.stackoom.com/question/2tHD4
参考二： https://stackoom.com/question/2tHD4