Question

我正在使用Unity创建一个简单的2D多人游戏，我选择使用Firebase作为后端。尝试使用Firebase Cloud功能填充房间时，我遇到了一些问题。我计划如何工作如下：

玩家点击“加入房间” - 按钮
在“搜索房间的玩家”下将唯一设备ID发送到实时数据库，并将事件侦听器添加到该ID
当'onWrite'事件发生时，将触发云功能。然后函数将检查房间阵列是否为空。如果房间阵列为空，则Cloud功能会将新房间推送到实时数据库。
云功能会将“房间ID”推送到“玩家搜索房间”
因为玩家已经在“玩家搜索房间”下收听了他自己的ID，所以当房间ID按照他自己的ID推送时，将运行一个功能。这将告诉玩家Cloud功能为他成功找到了一个房间。

以下是云功能：

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

// Create and Deploy Your First Cloud Functions
// https://firebase.google.com/docs/functions/write-firebase-functions

var room = [];

// ID for the room we are filling at the moment
var room_currentID;

// This functions triggers each time something is added or deleted to "Players Searching For Room"

exports.findRoom = functions.database
    .ref('/Players Searching For Room/{pushId}')
    .onWrite(event => {

        // Check if data exists (if not, this was triggered by delete -> return)

        if(!event.data.exists())
        {
            return;
        } 

        // If this player already has a room, we want to return
        if(event.data.val().inRoom != "none")
            return;

        // Store data under changed pushId (if player was added to waiting players then data is -> "size" : 4)
        const data = event.data.val();
        // Name of the player. We get this from the pushId of the item we pushed ("container" for data pushed).
        var name = event.params.pushId;
        // Size of the room the player wants to join
        var size = data.size;

        // With IF-statements check which room_size_n object array we want to loop through

        console.log("Player called " + name + " is waiting for room that has maxium of " + size + " players")

        // We can push the user to the room array since it can never be full 
        // (we clear the array before allowing next guy to join)
        room.push(name);

        // If this was the first guy
        // we need to create new room
        if(room.length == 1) 
        {
            admin.database().ref('/Rooms').push({
                onGoing: false // We need to set something, might aswell set something usefull
            }).then(snapshot => {
                // because this function is triggered by changes in firebase realtime database
                // we can't return anything to the player. BUT we can inform player about the room
                // he's been attached to by adding roomID to the playername in the "Players Searching For Room"
                // then players device will handle removing 

                // Store ID of the room so that we can send it to later joiners in this room
                room_currentID = snapshot.key;

                data.inRoom = room_currentID;

                return event.data.ref.set(data);
            });
        }
        // If there already exists a suitable room with space on it
        else if(room.length > 1)
        {
            // We can attach the stored roomID to the player so he knows which rooms onGoing flag to watch for.
            data.inRoom = room_currentID;

            // Attach roomID to the player and then check if room is full
            // waiting roomID to attach to player before setting onGoing TRUE
            // prevents other player to get a head start
            event.data.ref.set(data).then(snapshot => {
                // If roomId was attached to the player we can check the room size
                if(room.length == size)
                {
                    // ...and if the room became full we need to set onGoing to true
                    admin.database().ref('/Rooms/'+room_currentID).set({
                        onGoing: true
                    }).then(snapshot => {
                        room = [];
                    });
                }
            });
        }
    });

问题是，如果多个用户在短时间内点击Join Game-button，则会导致系统混乱。在“玩家搜索房间”下添加玩家ID似乎每次都有效，但有时云功能从不将房间ID附加到玩家ID，有时云功能会创建比应有的更多的房间。我只是通过在每次单击时在“Players Searching For Room”下附加随机ID的按钮来测试这个。然后我快速点击该按钮10次。这应该为这10个随机ID附加5个不同的房间ID，并生成5个新房间。相反，它生成了7个房间，并且只为8个随机ID添加了房间ID，而不是10个。

问题是，我认为：

Abe点击12.00.00
云功能启动（执行需要5秒）
Rob点击12.00.02
云功能在完成Abe的请求之前再次触发
Eveything变得混乱

是否可以使用firebase来改变这一点，以便如果Rob在Abe的请求完成之前触发Cloud功能，Rob将在Abe完成时被搁置。当安倍晋三完成而不是罗伯的回合。唉，非常长的解释希望有人会读到这个：）

Answer 1

在Google I / O 2017上，我发表了关于在后端仅使用Firebase构建多人游戏的演讲。云功能几乎实现了游戏的所有逻辑。它还具有简单的匹配功能，您可以扩展该方案以执行更复杂的操作。您可以观看演讲here，该项目的源代码即将推出。

阻止多个用户同时访问相同的云功能

1 个答案: