Question

Firebase REST端点。我在启动时获得了很多NULL返回。通过其他问题，我认为这是一个Coldstart。我相信问题是我使用的回调在firebase有机会返回数据集之前返回。我从@puf - frank-van-puffelen那里读到了关于callabcks的评论消化冷启动。所以我试图重写作为承诺。这段代码通常可以工作，但仍然可以获得冷启动NULL数据集。我怎么做这个承诺？

var functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

//=================================================================================================
//  KeysFromAccountGet01
//=================================================================================================
// This function is not working correctly because it often returns a NULL set. probably 
// because I am using callbacks instead of promises, and the callback returns before firebase 
// can return a query.  Usually it works.
// But I am fairly sure that I should be using PROMICES so as to wait for the data to arrive.
// that said, I can not figure out how to do a promise.  Everythign I have tried returns nothing.
// some sugestions on how to do promises for this would be appreciated. 
//curl 'https://us-central1-test.cloudfunctions.net/KeysFromAccountGet01?account=dporras8'
//curl 'https://us-central1-test.cloudfunctions.net/KeysFromAccountGet01?account='
//firebase deploy --only functions:KeysFromAccountGet01
exports.KeysFromAccountGet01 = functions.https.onRequest((req, res) =>{
  var arr =[];
  arr.push("1====+++starting");
  arr.push("acount = "+ req.query.account);
 admin.database().ref('/newacctok/'+req.query.account+'/tok3/').on('value', function(snapshot){
        snapshot.forEach(function(miniSnapShot){
        var tt = miniSnapShot.val();
             var json = ({ 
                    "key":miniSnapShot.key,
                    "account":req.query.account,
                     "uuid":tt.uuid,
                     "ts2":tt.ts2,
                     "token":tt.token
             }); 
       arr.push(json);
 })
    .then(res.status(200).send(arr));
});

//===================================

Answer 1

我不确定这些更改是否会对您的Null返回有所帮助。请注意，我将on()更改为once()，而exports.KeysFromAccountGet01 = functions.https.onRequest((req, res) => { var arr =[]; arr.push("1====+++starting"); arr.push("acount = "+ req.query.account); // note change from on() to once() admin.database().ref('/newacctok/'+req.query.account+'/tok3/').once('value') .then(snapshot => { snapshot.forEach(miniSnapShot => { var tt = miniSnapShot.val(); var json = ({ "key":miniSnapShot.key, "account":req.query.account, "uuid":tt.uuid, "ts2":tt.ts2, "token":tt.token }); arr.push(json); }); res.status(200).send(arr) }); });将附加了侦听器。此外，我还看到了Frank van Puffelen的回答，提醒他们不要在HTTPS请求函数中执行异步处理。我会尝试找到他的答案/评论并添加它们。

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firebase功能端点冷启动

1 个答案: