Game Server
This is a "simple" game server. Main functionalities are matching and establishing a connection between players
How to Run?
run the server first
go run ./cmd/server/server.go
and run as many client as you want (kidding, go easy :) ).
go run ./cmd/client/client.go
Folder Structure and Packages:
| Package | Folder | Description |
|---|---|---|
| server | /server | Server is main package of this project it contains the code for matching (TCP) and connection(UDP) |
| client | /client | Client is an abstract representation of player. |
| config | /config | Config package holds the server configurations such as connection information, game size etc. |
| frame | /frame | Frame package is a data frame package. It designed and developed just for this project and It is a serializer for a game events. A detailed frame information is in below. frame contains 3 section.first is the header, it holds the important information about this frame such as gameID, clientID and number of event.second section is events. Event is a basic information packets. it holds a eventID and a data part.last section is for time stamp. |
| simulator | /simulator | Simulator simulates a pseudo client events and it listens for certain events like game over. |
| test | /simulator | There is only one test in this project and it controls the frame marshal and unmarshal functions. |
| utils | /utils | utils has general utility functions and the most important part is encoding and decoding functions. they are crucial for frame package. |
| cmd | /cmd | cmd folder has 2 subfolder named server and client. Those packages can run by themselves to simulate a game server/client environment. there is a demonstration of client and server. |
Frame in Detail
|------------------------------------|-----------------------------------------|-----------|
| header | events... | time |
|------------------------------------|------------------------------------------------------
|clientID | gameID | number of event | eventID | data | eventID | data |...| timeStamp |
|------------------------------------|------------------------------------------------------
| 2byte | 2byte | 1byte | 1byte | 4byte | 1byte | 4byte |...| 8byte |
| 16bit | 16bit | 8bit | 8bit | 32bit | 8bit | 32bit |...| 64bit |
|------------------------------------|-----------------------------------------|-----------|
Server and client communication demonstration
Server Work Flow
Game Matcher
Mather is using TCP connections to receive game requests.
After a game request has arrived matcher is adding that user to a queue. if there are enough participant in the queue, matcher groups them under a gameID and attaches this group to the gameList.
After adding group to the gameList it removes players from the gameQueue and closes their TCP connections.
*Game size can be change from /config directory.
Game Routine
Game routine listens UDP packets. First it needs a register request from client. And receives a response with gameID and clientID.
When register arrive game routine start to reads and process incoming data and send back to clients.
*Game routine is schedules a dummy game over routine to test if games are lasting properly. Max and min game times are configurable from /config directory.
Client Game Request
Client sends an initial message that contains a "token" if token is valid (and there are enough participant to create a game of course) server responds it with a gameID and clientID.
Client uses those information to send a initial UDP register message.
Client waits for game started event and send a pseudo random events to the server.
When game over event has arrived client ends its process.
*event sending and receiving functions are not serial functions. they are running concurrently
Flow charts
Notes
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To avoid ip:port collision event, all clients opens their UDP listen port differently. for example client 3's UDP port is 9093(9090+3)
-
There is also a dummy non-functional authentication system. it is like a placeholder for better authentication and authorization systems.
-
There is an easy interrupt handle for client and server. If client receives an interrupt (SIGINT, SIGTERN or SIGQUIT) it sends a disconnected event to server and server broadcasts a game over event to all players. Likewise If server interrupted it send the same game over event to all players in all games.
