Cloud Function for Firebase 在 60 秒后超时，同时 运行 一堆 Firebase 查询
Cloud Function for Firebase timeout after 60 seconds while running a bunch of Firebase queries
我正在将 Firebase 用于群组协作应用程序（如 Whatsapp），并且我正在使用 Cloud Function 来确定哪些 phone 联系人也在使用我的应用程序（再次类似于 Whatsapp）。 Cloud Function 运行 很好，直到我开始在 Functions Log 中看到一些调用的以下日志。
Function execution took 60023 ms, finished with status: 'timeout'
我做了一些调试，发现对于这个特定的用户，他在 phone 的通讯录上有很多联系人，因此很明显需要做一些工作来找出哪些联系人正在使用应用程序也增加到花费超过 60 秒的时间。下面是云函数的代码
// contactsData is an array of contacts on the user's phone
// Each contact can contain one more phone numbers which are
// present in the phoneNumbers array. So, essentially, we need
// to query over all the phone numbers in the user's contact book
contactsData.forEach((contact) => {
contact.phoneNumbers.forEach((phoneNumber) => {
// Find if user with this phoneNumber is using the app
// Check against mobileNumber and mobileNumberWithCC
promises.push(ref.child('users').orderByChild("mobileNumber").
equalTo(phoneNumber.number).once("value").then(usersSnapshot => {
// usersSnapshot should contain just one entry assuming
// that the phoneNumber will be unique to the user
if(!usersSnapshot.exists()) {
return null
}
var user = null
usersSnapshot.forEach(userSnapshot => {
user = userSnapshot.val()
})
return {
name: contact.name,
mobileNumber: phoneNumber.number,
id: user.id
}
}))
promises.push(ref.child('users').orderByChild("mobileNumberWithCC").
equalTo(phoneNumber.number).once("value").then(usersSnapshot => {
// usersSnapshot should contain just one entry assuming
// that the phoneNumber will be unique to the user
if(!usersSnapshot.exists()) {
return null
}
var user = null
usersSnapshot.forEach(userSnapshot => {
user = userSnapshot.val()
})
return {
name: contact.name,
mobileNumber: phoneNumber.number,
id: user.id
}
}))
});
});
return Promise.all(promises)
}).then(allContacts => {
// allContacts is an array of nulls and contacts using the app
// Get rid of null and any duplicate entries in the returned array
currentContacts = arrayCompact(allContacts)
// Create contactsObj which will the user's contacts that are using the app
currentContacts.forEach(contact => {
contactsObj[contact.id] = contact
})
// Return the currently present contacts
return ref.child('userInfos').child(uid).child('contacts').once('value')
}).then((contactsSnapshot) => {
if(contactsSnapshot.exists()) {
contactsSnapshot.forEach((contactSnapshot) => {
previousContacts.push(contactSnapshot.val())
})
}
// Update the contacts on firease asap after reading the previous contacts
ref.child('userInfos').child(uid).child('contacts').set(contactsObj)
// Figure out the new, deleted and renamed contacts
newContacts = arrayDifferenceWith(currentContacts, previousContacts,
(obj1, obj2) => (obj1.id === obj2.id))
deletedContacts = arrayDifferenceWith(previousContacts, currentContacts,
(obj1, obj2) => (obj1.id === obj2.id))
renamedContacts = arrayIntersectionWith(currentContacts, previousContacts,
(obj1, obj2) => (obj1.id === obj2.id && obj1.name !== obj2.name))
// Create the deletedContactsObj to store on firebase
deletedContacts.forEach((deletedContact) => {
deletedContactsObj[deletedContact.id] = deletedContact
})
// Get the deleted contacts
return ref.child('userInfos').child(uid).child('deletedContacts').once('value')
}).then((deletedContactsSnapshot) => {
if(deletedContactsSnapshot.exists()) {
deletedContactsSnapshot.forEach((deletedContactSnapshot) => {
previouslyDeletedContacts.push(deletedContactSnapshot.val())
})
}
// Contacts that were previously deleted but now added again
restoredContacts = arrayIntersectionWith(newContacts, previouslyDeletedContacts,
(obj1, obj2) => (obj1.id === obj2.id))
// Removed the restored contacts from the deletedContacts
restoredContacts.forEach((restoredContact) => {
deletedContactsObj[restoredContact.id] = null
})
// Update groups using any of the deleted, new or renamed contacts
return ContactsHelper.processContactsData(uid, deletedContacts, newContacts, renamedContacts)
}).then(() => {
// Set after retrieving the previously deletedContacts
return ref.child('userInfos').child(uid).child('deletedContacts').update(deletedContactsObj)
})
下面是一些示例数据
// This is a sample contactsData
[
{
"phoneNumbers": [
{
"number": "12324312321",
"label": "home"
},
{
"number": "2322412132",
"label": "work"
}
],
"givenName": "blah5",
"familyName": "",
"middleName": ""
},
{
"phoneNumbers": [
{
"number": "1231221221",
"label": "mobile"
}
],
"givenName": "blah3",
"familyName": "blah4",
"middleName": ""
},
{
"phoneNumbers": [
{
"number": "1234567890",
"label": "mobile"
}
],
"givenName": "blah1",
"familyName": "blah2",
"middleName": ""
}
]
// This is how users are stored on Firebase. This could a lot of users
"users": {
"id1" : {
"countryCode" : "91",
"id" : "id1",
"mobileNumber" : "1231211232",
"mobileNumberWithCC" : "911231211232",
"name" : "Varun"
},
"id2" : {
"countryCode" : "1",
"id" : "id2",
"mobileNumber" : "2342112133",
"mobileNumberWithCC" : "12342112133",
"name" : "Ashish"
},
"id3" : {
"countryCode" : "1",
"id" : "id3",
"mobileNumber" : "123213421",
"mobileNumberWithCC" : "1123213421",
"name" : "Pradeep Singh"
}
}
在这种特殊情况下，contactsData 包含 1046 个条目，其中一些条目有两个 phoneNumbers。因此，让我们假设我需要检查总共 1500 phone 个数字。我正在创建查询以与数据库中用户的 mobileNumber 和 mobileNumberWithCC 进行比较。因此，在 promise 完成之前，该函数将总共进行 3000 次查询，我猜测完成所有这些查询需要超过 60 秒，因此 Cloud Function 超时。
我的几个问题是：
- 是否所有这些查询都需要超过 60 秒？鉴于它在 Firebase 基础设施中 运行，我期待它完成得更快。
- 有没有办法增加函数的超时限制？我目前正在使用 Blaze 计划。
对于上述功能的任何替代实施建议，我也将不胜感激，以缓解该问题。谢谢！
如果您无法避免查询如此多的数据，您可以使用左侧的 Functions 产品为您的项目更改 Cloud Console 中的函数超时。目前，您必须在每次新部署时重置超时。
问题
您遇到的性能问题来自查询 ref.child('users').orderByChild("mobileNumber").equalTo(phoneNumber.number).once("value")，您在另一个 forEach() 中调用该查询 forEach()。
要分解此查询，您实际上是在要求数据库 迭代 通过 /users 的子项，将键 mobileNumber 与 phoneNumber.number 如果它们匹配，return 一个值。但是，您不仅在 mobileNumber 和 mobileNumberWithCC 上都调用了它，而且在 forEach() 的 每次迭代 上都调用了它。因此，这意味着您正在查看 X 数量的用户，Y 数量的 phone 号码，Z 数量的联系人，因此最多执行 X*Y*Z内部数据库操作。这显然很费力，因此您的查询处理时间超过 60 秒。
潜在修复
我建议在您的数据库上实施一个名为 /phoneNumbers 的索引。 /phoneNumbers 中的每个键都将命名为 n########### 或 c###########，并包含与该 phone 号码关联的 "array" 个用户 ID。
此结构类似于：
"phoneNumbers": {
"n1234567890": { // without CC, be warned of overlap
"userId1": true,
"userId3": true
},
"c011234567890": { // with CC for US
"userId1": true
},
"c611234567890": { // with CC for AU
"userId3": true
},
...
}
备注：
为什么 phone 数字以 n########### 和 c########### 格式存储？
这是因为 Firebase 将数字键视为数组的索引。这对于这个用例没有意义，所以我们在开头添加 n/c 来抑制这种行为。
为什么要同时使用n###########和c###########？
如果所有条目仅使用 n 前缀，则 11 位 phone 号码可能会与添加了国家/地区代码的 10 位 phone 号码重叠。因此，我们对正常的 phone 号码使用 n，对包含国家代码的号码使用 c。
为什么说/phoneNumbers的每个key包含一个"array"个用户ID？
这是因为您应该避免在 Firebase 数据库中使用数字索引数组（以及一般的数组）。假设两个独立的进程想要通过删除用户 ID 来更新 /phoneNumbers/n1234567890。如果一个人要删除位置1的ID，另一个要删除位置2的ID；他们最终会删除位置 1 和 3 的 ID。这可以通过将用户 ID 存储为密钥来克服，这允许您 add/remove 通过 ID 而不是位置。
实施
由于您已经在使用 Cloud Functions，因此实现这样的索引相对简单。此代码可以很容易地适应任何类型的基于用户数据自动生成的索引。
// Initialize functions and admin.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
/**
* Listens to operations on the children of `/users` and updates the `/phoneNumbers` index appropriately.
*/
exports.handleNewUser = functions.database.ref('/users/{userId}')
.onWrite(event => {
var deltaSnapshot = event.data,
userId = event.params.userId,
tasks = []; // for returned promises
if (!deltaSnapshot.exists()) {
// This user has been deleted.
var previousData = deltaSnapshot.previous.val();
if (previousData.number) {
tasks.push(removeUserFromPhoneNumber(userId, previousData.number, false));
}
if (previousData.numberWithCC) {
tasks.push(removeUserFromPhoneNumber(userId, previousData.numberWithCC, true));
}
// Handle other cleanup tasks.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" deleted successfully.');
});
}
var currentData = deltaSnapshot.val();
if (deltaSnapshot.previous.exists()) {
// This is an update to existing data.
var previousData = deltaSnapshot.previous.val();
if (currentData.number != previousData.number) { // Phone number changed.
tasks.push(removeUserFromPhoneNumber(userId, previousData.number, false));
tasks.push(addUserToPhoneNumber(userId, currentData.number, false));
}
if (currentData.numberWithCC != previousData.numberWithCC) { // Phone number changed.
tasks.push(removeUserFromPhoneNumber(userId, previousData.numberWithCC, true));
tasks.push(addUserToPhoneNumber(userId, currentData.numberWithCC, true));
}
// Handle other tasks related to update.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" updated successfully.');
});
}
// If here, this is a new user.
tasks.push(addUserToPhoneNumber(userId, currentData.number, false));
tasks.push(addUserToPhoneNumber(userId, currentData.numberWithCC, true));
// Handle other tasks related to addition of new user.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" created successfully.');
});
);
/* Phone Number Index Helper Functions */
/**
* Returns an array of user IDs linked to the specified phone number.
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - a promise returning an array of user IDs, may be empty.
*/
function lookupUsersByPhoneNumber(number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return lookupIdsByIndex('phoneNumbers', (withCountryCode ? 'c' : 'n') + number);
}
/**
* Adds the user ID under the specified phone number's index.
* @param {String} userId - the user ID
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - the promise returned by transaction()
*/
function addUserToPhoneNumber(userId, number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return addIdToIndex(userId, 'phoneNumbers', (withCountryCode ? 'c' : 'n') + number)
}
/**
* Removes the user ID under the specified phone number's index.
* @param {String} userId - the user ID
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - the promise returned by transaction()
*/
function removeUserFromPhoneNumber(userId, number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return removeIdFromIndex(userId, 'phoneNumbers', (withCountryCode ? 'c' : 'n') + number)
}
/* General Firebase Index CRUD APIs */
/* Credit: @samthecodingman */
/**
* Returns an array of IDs linked to the specified key in the given index.
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function lookupIdsByIndex(indexName, keyName) {
// Error out before corrupting data.
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName).once("value")
.then(snapshot => {
if (!snapshot.exists()) return []; // Use empty array for 'no data'
var idsObject = snapshot.val();
if (idsObject == null) return [];
return Object.keys(idsObject); // return array of IDs
});
}
/**
* Adds the ID to the index under the named key.
* @param {String} id - the entry ID
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function addIdToIndex(id, indexName, keyName) {
// Error out before corrupting data.
if (!id) return Promise.reject(new TypeError('id cannot be falsy.');
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName)
.transaction(function(idsObject) {
idsObject = idsObject || {}; // Create data if it doesn't exist.
if (idsObject.hasOwnProperty(id)) return; // No update needed.
idsObject[id] = true; // Add ID.
return idsObject;
});
}
/**
* Removes the ID from the index under the named key.
* @param {String} id - the entry ID
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function removeIdFromIndex(id, indexName, keyName) {
// Error out before corrupting data.
if (!id) return Promise.reject(new TypeError('id cannot be falsy.');
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName)
.transaction(function(idsObject) {
if (idsObject === null) return; // No data to update.
if (!idsObject.hasOwnProperty(id)) return; // No update needed.
delete idsObject[id]; // Remove ID.
if (Object.keys(idsObject).length === 0) return null; // Delete entire entry.
return idsObject;
});
}
上述代码段中的 handleNewUser 函数不会捕获错误。它只会让 Firebase 处理它们（默认情况下 FB 只会记录错误）。我建议您根据需要实施适当的回退（就像您对任何 Cloud Functions 应该做的那样）。
关于你问题中的源代码，它会变成类似于：
contactsData.forEach((contact) => {
contact.phoneNumbers.forEach((phoneNumber) => {
var tasks = [];
tasks.push(lookupUsersByPhoneNumber(phoneNumber.number, false)); // Lookup without CC
tasks.push(lookupUsersByPhoneNumber(phoneNumber.number, true)); // Lookup with CC
Promise.all(tasks).then(taskResults => {
var i = 0;
// Elements of taskResults are arrays of strings from the lookup functions.
// Flatten and dedupe strings arrays
var userIds = taskResults.reduce((arr, results) => {
for (i=0;i<results.length;i++) {
if (results[i] !== null && ~arr.indexOf(results[i])) {
arr.push(results[i]); // Add if not already added.
}
}
return arr;
}, []);
// Build 'contacts' array (Doesn't need a database lookup!)
return userIds.map(uid => ({
name: contact.name,
phone: phoneNumber.number,
id: uid
}));
}).then(currentContacts => {
currentContacts.forEach(contact => {
contactsObj[contact.id] = contact
});
// do original code from question here.
// I'm not 100% on what it does, so I'll leave it to you.
// It currently uses an array which is a bad implementation (see notes above). Use PUSH to update the contacts rather than deleting and readding them constantly.
});
});
});
关于 Security/Privacy
的注释
出于隐私原因，我强烈建议将 /phoneNumbers 的读写访问限制为仅限云功能服务工作者。这可能还需要根据权限问题将部分程序逻辑移动到服务器。
为此，替换：
admin.initializeApp(functions.config().firebase);
与：
admin.initializeApp(Object.assign({}, functions.config().firebase, {
databaseAuthVariableOverride: {
uid: "cloudfunc-service-worker" // change as desired
}
});
要启用它，您需要按如下方式配置 Firebase 数据库规则：
"rules": {
"phoneNumbers": {
".read": "'cloudfunc-service-worker' === auth.uid",
".write": "'cloudfunc-service-worker' === auth.uid"
}
}
我正在将 Firebase 用于群组协作应用程序（如 Whatsapp），并且我正在使用 Cloud Function 来确定哪些 phone 联系人也在使用我的应用程序（再次类似于 Whatsapp）。 Cloud Function 运行 很好，直到我开始在 Functions Log 中看到一些调用的以下日志。
Function execution took 60023 ms, finished with status: 'timeout'
我做了一些调试，发现对于这个特定的用户，他在 phone 的通讯录上有很多联系人，因此很明显需要做一些工作来找出哪些联系人正在使用应用程序也增加到花费超过 60 秒的时间。下面是云函数的代码
// contactsData is an array of contacts on the user's phone
// Each contact can contain one more phone numbers which are
// present in the phoneNumbers array. So, essentially, we need
// to query over all the phone numbers in the user's contact book
contactsData.forEach((contact) => {
contact.phoneNumbers.forEach((phoneNumber) => {
// Find if user with this phoneNumber is using the app
// Check against mobileNumber and mobileNumberWithCC
promises.push(ref.child('users').orderByChild("mobileNumber").
equalTo(phoneNumber.number).once("value").then(usersSnapshot => {
// usersSnapshot should contain just one entry assuming
// that the phoneNumber will be unique to the user
if(!usersSnapshot.exists()) {
return null
}
var user = null
usersSnapshot.forEach(userSnapshot => {
user = userSnapshot.val()
})
return {
name: contact.name,
mobileNumber: phoneNumber.number,
id: user.id
}
}))
promises.push(ref.child('users').orderByChild("mobileNumberWithCC").
equalTo(phoneNumber.number).once("value").then(usersSnapshot => {
// usersSnapshot should contain just one entry assuming
// that the phoneNumber will be unique to the user
if(!usersSnapshot.exists()) {
return null
}
var user = null
usersSnapshot.forEach(userSnapshot => {
user = userSnapshot.val()
})
return {
name: contact.name,
mobileNumber: phoneNumber.number,
id: user.id
}
}))
});
});
return Promise.all(promises)
}).then(allContacts => {
// allContacts is an array of nulls and contacts using the app
// Get rid of null and any duplicate entries in the returned array
currentContacts = arrayCompact(allContacts)
// Create contactsObj which will the user's contacts that are using the app
currentContacts.forEach(contact => {
contactsObj[contact.id] = contact
})
// Return the currently present contacts
return ref.child('userInfos').child(uid).child('contacts').once('value')
}).then((contactsSnapshot) => {
if(contactsSnapshot.exists()) {
contactsSnapshot.forEach((contactSnapshot) => {
previousContacts.push(contactSnapshot.val())
})
}
// Update the contacts on firease asap after reading the previous contacts
ref.child('userInfos').child(uid).child('contacts').set(contactsObj)
// Figure out the new, deleted and renamed contacts
newContacts = arrayDifferenceWith(currentContacts, previousContacts,
(obj1, obj2) => (obj1.id === obj2.id))
deletedContacts = arrayDifferenceWith(previousContacts, currentContacts,
(obj1, obj2) => (obj1.id === obj2.id))
renamedContacts = arrayIntersectionWith(currentContacts, previousContacts,
(obj1, obj2) => (obj1.id === obj2.id && obj1.name !== obj2.name))
// Create the deletedContactsObj to store on firebase
deletedContacts.forEach((deletedContact) => {
deletedContactsObj[deletedContact.id] = deletedContact
})
// Get the deleted contacts
return ref.child('userInfos').child(uid).child('deletedContacts').once('value')
}).then((deletedContactsSnapshot) => {
if(deletedContactsSnapshot.exists()) {
deletedContactsSnapshot.forEach((deletedContactSnapshot) => {
previouslyDeletedContacts.push(deletedContactSnapshot.val())
})
}
// Contacts that were previously deleted but now added again
restoredContacts = arrayIntersectionWith(newContacts, previouslyDeletedContacts,
(obj1, obj2) => (obj1.id === obj2.id))
// Removed the restored contacts from the deletedContacts
restoredContacts.forEach((restoredContact) => {
deletedContactsObj[restoredContact.id] = null
})
// Update groups using any of the deleted, new or renamed contacts
return ContactsHelper.processContactsData(uid, deletedContacts, newContacts, renamedContacts)
}).then(() => {
// Set after retrieving the previously deletedContacts
return ref.child('userInfos').child(uid).child('deletedContacts').update(deletedContactsObj)
})
下面是一些示例数据
// This is a sample contactsData
[
{
"phoneNumbers": [
{
"number": "12324312321",
"label": "home"
},
{
"number": "2322412132",
"label": "work"
}
],
"givenName": "blah5",
"familyName": "",
"middleName": ""
},
{
"phoneNumbers": [
{
"number": "1231221221",
"label": "mobile"
}
],
"givenName": "blah3",
"familyName": "blah4",
"middleName": ""
},
{
"phoneNumbers": [
{
"number": "1234567890",
"label": "mobile"
}
],
"givenName": "blah1",
"familyName": "blah2",
"middleName": ""
}
]
// This is how users are stored on Firebase. This could a lot of users
"users": {
"id1" : {
"countryCode" : "91",
"id" : "id1",
"mobileNumber" : "1231211232",
"mobileNumberWithCC" : "911231211232",
"name" : "Varun"
},
"id2" : {
"countryCode" : "1",
"id" : "id2",
"mobileNumber" : "2342112133",
"mobileNumberWithCC" : "12342112133",
"name" : "Ashish"
},
"id3" : {
"countryCode" : "1",
"id" : "id3",
"mobileNumber" : "123213421",
"mobileNumberWithCC" : "1123213421",
"name" : "Pradeep Singh"
}
}
在这种特殊情况下，contactsData 包含 1046 个条目，其中一些条目有两个 phoneNumbers。因此，让我们假设我需要检查总共 1500 phone 个数字。我正在创建查询以与数据库中用户的 mobileNumber 和 mobileNumberWithCC 进行比较。因此，在 promise 完成之前，该函数将总共进行 3000 次查询，我猜测完成所有这些查询需要超过 60 秒，因此 Cloud Function 超时。
我的几个问题是：
- 是否所有这些查询都需要超过 60 秒？鉴于它在 Firebase 基础设施中 运行，我期待它完成得更快。
- 有没有办法增加函数的超时限制？我目前正在使用 Blaze 计划。
对于上述功能的任何替代实施建议，我也将不胜感激，以缓解该问题。谢谢！
如果您无法避免查询如此多的数据，您可以使用左侧的 Functions 产品为您的项目更改 Cloud Console 中的函数超时。目前，您必须在每次新部署时重置超时。
问题
您遇到的性能问题来自查询 ref.child('users').orderByChild("mobileNumber").equalTo(phoneNumber.number).once("value")，您在另一个 forEach() 中调用该查询 forEach()。
要分解此查询，您实际上是在要求数据库 迭代 通过 /users 的子项，将键 mobileNumber 与 phoneNumber.number 如果它们匹配，return 一个值。但是，您不仅在 mobileNumber 和 mobileNumberWithCC 上都调用了它，而且在 forEach() 的 每次迭代 上都调用了它。因此，这意味着您正在查看 X 数量的用户，Y 数量的 phone 号码，Z 数量的联系人，因此最多执行 X*Y*Z内部数据库操作。这显然很费力，因此您的查询处理时间超过 60 秒。
潜在修复
我建议在您的数据库上实施一个名为 /phoneNumbers 的索引。 /phoneNumbers 中的每个键都将命名为 n########### 或 c###########，并包含与该 phone 号码关联的 "array" 个用户 ID。
此结构类似于：
"phoneNumbers": {
"n1234567890": { // without CC, be warned of overlap
"userId1": true,
"userId3": true
},
"c011234567890": { // with CC for US
"userId1": true
},
"c611234567890": { // with CC for AU
"userId3": true
},
...
}
备注：
为什么 phone 数字以 n########### 和 c########### 格式存储？
这是因为 Firebase 将数字键视为数组的索引。这对于这个用例没有意义，所以我们在开头添加 n/c 来抑制这种行为。
为什么要同时使用n###########和c###########？
如果所有条目仅使用 n 前缀，则 11 位 phone 号码可能会与添加了国家/地区代码的 10 位 phone 号码重叠。因此，我们对正常的 phone 号码使用 n，对包含国家代码的号码使用 c。
为什么说/phoneNumbers的每个key包含一个"array"个用户ID？
这是因为您应该避免在 Firebase 数据库中使用数字索引数组（以及一般的数组）。假设两个独立的进程想要通过删除用户 ID 来更新 /phoneNumbers/n1234567890。如果一个人要删除位置1的ID，另一个要删除位置2的ID；他们最终会删除位置 1 和 3 的 ID。这可以通过将用户 ID 存储为密钥来克服，这允许您 add/remove 通过 ID 而不是位置。
实施
由于您已经在使用 Cloud Functions，因此实现这样的索引相对简单。此代码可以很容易地适应任何类型的基于用户数据自动生成的索引。
// Initialize functions and admin.
const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);
/**
* Listens to operations on the children of `/users` and updates the `/phoneNumbers` index appropriately.
*/
exports.handleNewUser = functions.database.ref('/users/{userId}')
.onWrite(event => {
var deltaSnapshot = event.data,
userId = event.params.userId,
tasks = []; // for returned promises
if (!deltaSnapshot.exists()) {
// This user has been deleted.
var previousData = deltaSnapshot.previous.val();
if (previousData.number) {
tasks.push(removeUserFromPhoneNumber(userId, previousData.number, false));
}
if (previousData.numberWithCC) {
tasks.push(removeUserFromPhoneNumber(userId, previousData.numberWithCC, true));
}
// Handle other cleanup tasks.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" deleted successfully.');
});
}
var currentData = deltaSnapshot.val();
if (deltaSnapshot.previous.exists()) {
// This is an update to existing data.
var previousData = deltaSnapshot.previous.val();
if (currentData.number != previousData.number) { // Phone number changed.
tasks.push(removeUserFromPhoneNumber(userId, previousData.number, false));
tasks.push(addUserToPhoneNumber(userId, currentData.number, false));
}
if (currentData.numberWithCC != previousData.numberWithCC) { // Phone number changed.
tasks.push(removeUserFromPhoneNumber(userId, previousData.numberWithCC, true));
tasks.push(addUserToPhoneNumber(userId, currentData.numberWithCC, true));
}
// Handle other tasks related to update.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" updated successfully.');
});
}
// If here, this is a new user.
tasks.push(addUserToPhoneNumber(userId, currentData.number, false));
tasks.push(addUserToPhoneNumber(userId, currentData.numberWithCC, true));
// Handle other tasks related to addition of new user.
return Promise.all(tasks).then(() => {
console.log('User "' + userId + '" created successfully.');
});
);
/* Phone Number Index Helper Functions */
/**
* Returns an array of user IDs linked to the specified phone number.
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - a promise returning an array of user IDs, may be empty.
*/
function lookupUsersByPhoneNumber(number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return lookupIdsByIndex('phoneNumbers', (withCountryCode ? 'c' : 'n') + number);
}
/**
* Adds the user ID under the specified phone number's index.
* @param {String} userId - the user ID
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - the promise returned by transaction()
*/
function addUserToPhoneNumber(userId, number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return addIdToIndex(userId, 'phoneNumbers', (withCountryCode ? 'c' : 'n') + number)
}
/**
* Removes the user ID under the specified phone number's index.
* @param {String} userId - the user ID
* @param {String} number - the phone number
* @param {Boolean} withCountryCode - true, if the phone number includes a country code
* @return {Promise} - the promise returned by transaction()
*/
function removeUserFromPhoneNumber(userId, number, withCountryCode) {
// Error out before corrupting data.
if (!number) return Promise.reject(new TypeError('number cannot be falsy.');
return removeIdFromIndex(userId, 'phoneNumbers', (withCountryCode ? 'c' : 'n') + number)
}
/* General Firebase Index CRUD APIs */
/* Credit: @samthecodingman */
/**
* Returns an array of IDs linked to the specified key in the given index.
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function lookupIdsByIndex(indexName, keyName) {
// Error out before corrupting data.
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName).once("value")
.then(snapshot => {
if (!snapshot.exists()) return []; // Use empty array for 'no data'
var idsObject = snapshot.val();
if (idsObject == null) return [];
return Object.keys(idsObject); // return array of IDs
});
}
/**
* Adds the ID to the index under the named key.
* @param {String} id - the entry ID
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function addIdToIndex(id, indexName, keyName) {
// Error out before corrupting data.
if (!id) return Promise.reject(new TypeError('id cannot be falsy.');
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName)
.transaction(function(idsObject) {
idsObject = idsObject || {}; // Create data if it doesn't exist.
if (idsObject.hasOwnProperty(id)) return; // No update needed.
idsObject[id] = true; // Add ID.
return idsObject;
});
}
/**
* Removes the ID from the index under the named key.
* @param {String} id - the entry ID
* @param {String} indexName - the index name
* @param {String} keyName - the key name
* @return {Promise} - the promise returned by transaction()
*/
function removeIdFromIndex(id, indexName, keyName) {
// Error out before corrupting data.
if (!id) return Promise.reject(new TypeError('id cannot be falsy.');
if (!indexName) return Promise.reject(new TypeError('indexName cannot be falsy.');
if (!keyName) return Promise.reject(new TypeError('keyName cannot be falsy.');
return admin.database().ref(indexName).child(keyName)
.transaction(function(idsObject) {
if (idsObject === null) return; // No data to update.
if (!idsObject.hasOwnProperty(id)) return; // No update needed.
delete idsObject[id]; // Remove ID.
if (Object.keys(idsObject).length === 0) return null; // Delete entire entry.
return idsObject;
});
}
上述代码段中的 handleNewUser 函数不会捕获错误。它只会让 Firebase 处理它们（默认情况下 FB 只会记录错误）。我建议您根据需要实施适当的回退（就像您对任何 Cloud Functions 应该做的那样）。
关于你问题中的源代码，它会变成类似于：
contactsData.forEach((contact) => {
contact.phoneNumbers.forEach((phoneNumber) => {
var tasks = [];
tasks.push(lookupUsersByPhoneNumber(phoneNumber.number, false)); // Lookup without CC
tasks.push(lookupUsersByPhoneNumber(phoneNumber.number, true)); // Lookup with CC
Promise.all(tasks).then(taskResults => {
var i = 0;
// Elements of taskResults are arrays of strings from the lookup functions.
// Flatten and dedupe strings arrays
var userIds = taskResults.reduce((arr, results) => {
for (i=0;i<results.length;i++) {
if (results[i] !== null && ~arr.indexOf(results[i])) {
arr.push(results[i]); // Add if not already added.
}
}
return arr;
}, []);
// Build 'contacts' array (Doesn't need a database lookup!)
return userIds.map(uid => ({
name: contact.name,
phone: phoneNumber.number,
id: uid
}));
}).then(currentContacts => {
currentContacts.forEach(contact => {
contactsObj[contact.id] = contact
});
// do original code from question here.
// I'm not 100% on what it does, so I'll leave it to you.
// It currently uses an array which is a bad implementation (see notes above). Use PUSH to update the contacts rather than deleting and readding them constantly.
});
});
});
关于 Security/Privacy
的注释出于隐私原因，我强烈建议将 /phoneNumbers 的读写访问限制为仅限云功能服务工作者。这可能还需要根据权限问题将部分程序逻辑移动到服务器。
为此，替换：
admin.initializeApp(functions.config().firebase);
与：
admin.initializeApp(Object.assign({}, functions.config().firebase, {
databaseAuthVariableOverride: {
uid: "cloudfunc-service-worker" // change as desired
}
});
要启用它，您需要按如下方式配置 Firebase 数据库规则：
"rules": {
"phoneNumbers": {
".read": "'cloudfunc-service-worker' === auth.uid",
".write": "'cloudfunc-service-worker' === auth.uid"
}
}