🐼Bamboo-WebSocket🌿

• This is a lightweight WebSocket server implemented entirely in Nim.
• Our goal is to create a clean and elegant implementation, inspired by the simplicity of splitting bamboo.
• This project aims to simplify the creation of chat and gaming servers.
• [TODO] Detailed documentation about Bamboo and its usage will be provided in the wiki.
• The latest release is 0.3.3.
• README in Japanese.

🖥Dependency

requires "nim >= 1.4.8"

👩‍💻Setup

nimble install bamboowebsocket@0.3.3

🤔Description

• It is intended to be used with asynchttpserver, which is provided in the Nim standard.

🤙Usage

🐥Echo Server

• The following is a server that echoes messages received from clients.
• The following code can be found in the bamboowebsocket/example/echo_example directory.

# echo_server.nim

import asyncdispatch,
       asynchttpserver,
       asyncnet,
       httpcore,
       nativesockets,
       net,
       strutils,
       uri

from bamboo_websocket/websocket import WebSocket, ConnectionStatus, OpCode
from bamboo_websocket/bamboo_websocket import loadServerSetting, openWebSocket, receiveMessage, sendMessage

proc callBack(request: Request) {.async, gcsafe.} =
  var ws: WebSocket
  var setting = loadServerSetting()

  if request.url.path == "/":
    let headers = {"Content-type": "text/html; charset=utf-8"}
    let content = readFile("./echo_client.html")
    await request.respond(Http200, content, headers.newHttpHeaders())

  if request.url.path == "/chat":
    try:
      ws = await openWebSocket(request, setting)
    except:
      let message = getCurrentException()

    while ws.status == ConnectionStatus.OPEN:
      try:
        let receive = await ws.receiveMessage()

        if receive[0] == OpCode.TEXT:
          echo("ID: ", ws.id, " echo back.")
          await ws.sendMessage(receive[1], 0x1, 3000, true)

        if receive[0] == OpCode.CLOSE:
          echo("ID: ", ws.id, " has Closed.")
          break

      except:
        ws.status = ConnectionStatus.CLOSED
        ws.socket.close()

    ws.socket.close()

if isMainModule:
  var server = newAsyncHttpServer()
  waitFor server.serve(Port(9001), callBack)

• A json file describing the configuration file for the server must be placed in the same location as the server file (e.g. ehco_server.nim)。

{
  "websocket_version": "13",
  "upgrade": "websocket",
  "connection": "upgrade",
  "websocket_key": "dGhlIHNhbXBsZSBub25jZQ==",
  "magic_strings": "258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
  "mask_key_seeder": "514902776"
}

• Run echo_server.nim after compilation.

nim c -r echo_server.nim

😏Advanced Usage

🐄Chat Server

• The following code is a server that enables chatting between each client.
• The following code can be found in the bamboowebsocket/example/chat_example directory.

# chat_server.nim

import asyncdispatch,
       asynchttpserver,
       asyncnet,
       httpcore,
       json,
       nativesockets,
       net,
       strutils,
       tables,
       uri

from bamboo_websocket/websocket import WebSocket, ConnectionStatus, OpCode
from bamboo_websocket/bamboo_websocket import loadServerSetting, openWebSocket, receiveMessage, sendMessage

var WebSockets: seq[WebSocket] = newSeq[WebSocket]()

proc callBack(request: Request) {.async, gcsafe.} =

  var ws = WebSocket()
  var setting = loadServerSetting()

  if request.url.path == "/":
    let headers = {"Content-type": "text/html; charset=utf-8"}
    let content = readFile("./chat_client.html")
    await request.respond(Http200, content, headers.newHttpHeaders())

  if request.url.path == "/chat":
    try:
      ws = await openWebSocket(request, setting)

      # SubProtocol Proc（名前を取得、さらにURI decode処理を追加）
      var sub_protocol = decodeUrl(request.headers["sec-websocket-protocol", 0])
      ws.optional_data["name"] = $(sub_protocol)

      WebSockets.add(ws)
      echo("ID: ", ws.id, ", Tag: ", ws.optional_data["name"], " has Opened.")
    except:
      let message = getCurrentException()
      echo(message.msg)

      ws.status = ConnectionStatus.INITIAl

    while ws.status == ConnectionStatus.OPEN:
      try:
        let receive = await ws.receiveMessage()
        if receive[0] == OpCode.TEXT:
          var message: string = $(%* [{"name": ws.optional_data["name"], "message": receive[1]}])
          for websocket in WebSockets:
            if websocket.id != ws.id:
              echo("$# => $#" % [$(ws.id), $(websocket.id)])
              await websocket.sendMessage(message, 0x1)

        if receive[0] == OpCode.CLOSE:
          echo("ID: ", ws.id, " has Closed.")
          break

      except:
        ws.status = ConnectionStatus.CLOSED
        ws.socket.close()

    if WebSockets.find(ws) != -1:
      WebSockets.delete(WebSockets.find(ws))

    if ws.status == ConnectionStatus.OPEN:
      ws.socket.close()

if isMainModule:
  var server = newAsyncHttpServer()
  waitFor server.serve(Port(9001), callBack)

• A json file（setting.json） describing the configuration file for the server must be placed in the same location as the server file (e.g. chat_server.nim)。

{
  "websocket_version": "13",
  "upgrade": "websocket",
  "connection": "upgrade",
  "websocket_key": "dGhlIHNhbXBsZSBub25jZQ==",
  "magic_strings": "258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
  "mask_key_seeder": "514902776"
}

• Run chat_server.nim after compilation.

nim c -r chat_server.nim

🐭Game Server

[TODO]

📝Author

• obemaru4012

📖References

• RFC 6455 - The WebSocket Protocol （日本語訳）
• WebSocket サーバーの記述 - Web API | MDN
• WebSocket クライアントアプリケーションの記述 - Web API | MDN
• Nim Package Directory