Question

我尝试制作股票监控应用程序，用户可以在价格变动时Alert。{/ p>

我有Stock文档，我定期从第三方API获取。在Stock更新后，我会获取满足条件的所有Alert，并通过Firebase消息通知用户。

这是我的模特。

/stocks/{stockId}
id: String
price: Number

/alerts/{alertId}
stockId: String
price: Number
condition: [moreThan, lessThan]
uid: String // User who create alert

/users/{userId}
id: String
fcmToken: String

我每5分钟获取一次最新股票价格并更新股票凭证= number of stock写入查询。

function updateStockPrice(): Promise<FirebaseFirestore.WriteResult[]> {
  const db = admin.firestore();

  const options = {
    // Options for stock api
  };

  return client(options)
  .then(function(body) {
    let batch = db.batch()

    for(var stock in body){
      let data = // create data from json response
      let docRef = db.collection("stocks").doc(//id from 3rd party api)
      batch.set(docRef, data)
    }

    return batch.commit()
  });
}

库存写入更新，循环播放警报并从相关用户获取fcm令牌以发送推送通知=（alert query + number of alerts matched condition for user query）x number of stock update

export const onStocksUpdate = functions.firestore.document('stocks/{stockId}').onWrite(function(change, context) {

  const db = admin.firestore()

  const newValue = change.after.data();
  const previousValue = change.before.data();

  const stockId = Number(context.params.stockId)

  let p1 = db.collection("alerts")
      .where("stockId", "==", stockId)
      .where("condition", "==", "moreThan") 
      .where("price", "<=", newValue.lastPrice)
      .get()
      .then(function(querySnapshot) {
        const promises = []
        querySnapshot.forEach(function(doc) {

          let data = doc.data()
          let user = db.collection("users").doc(data.uid).get()

          user.then(function(snapshot) {
            let userData = snapshot.data()

            return userData.fcmToken
          }).then(function(fcmToken) {
            const payload = {
              notification: {
                title: // title,
                body: // body
              },
              token: fcmToken
            }

            return admin.messaging().send(payload)
          }).catch(function(error) {
            console.log(error)
          })

          promises.push(user)
        })

        return Promise.all(promises)
      }).then((response) => {
        // Response is a message ID string.
        console.log('Successfully sent message:', response);
      })
      .catch((error) => {
        console.log('Error sending message:', error);
      });

      return p1
})

总写= number of stock 总读数=（alert query + number of alerts matched condition for user query）x number of stock update

假设我有20个股票，1个用户有3个警报。

每5分钟我将使用20个写查询和（1 + 3）x 20 = 80读

1天= 5760写和23,040读

对于这么小的例子来说，这似乎太多了。这是我应该布置数据结构的正确方法吗？或者有更好的方法吗？

如何优化Firestore读/写操作

0 个答案: