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Lua实现http的异步回调

2023-08-13

想用lua实现与http服务器的通信,请求一些数据会回来,默认lua.socket.http是同步的,所以想弄一个异步的方式

测试环境

  • lua 5.1

同步

以下是同步的代码,其中http.request会被阻塞住的

local function send_request()
    local res, code, response_headers = http.request(
        "http://www.lua.org/",
        "POST",
        "name=Lua&age=100",
        {["Content-Type"] = "application/x-www-form-urlencoded"}
    )
    print("code = ", code)
end
send_request();

输出结果:

F:\study\lua\fragmentary> lua "f:\study\lua\fragmentary\socket\client.lua"
code =  200

如果每次执行一次请求,就卡住我们逻辑的Tick,那整个客户端就卡在那里了。所以,我需要非阻塞的用法。也就是执行请求之后,不用等http服务器返回结果,而是继续向下执行。我主动监听,有返回了,再回调我的逻辑。

异步

参考[2],给出了一定的思路,但是我是看到GPT给的结果,代码都详细列出来了,直呼牛皮啊!

    local host = "www.baidu.com"
    local path = "";
    local data = [[name=Lua&age=100]]
    local port = 80;
    local con = assert(socket.connect(host, port))
    self.Conn:settimeout(0)
    
    local request = string.format("POST /%s HTTP/1.0\r\nHost: %s\r\nContent-Type: application/x-www-form-urlencoded\r\nContent-Length: %d\r\n\r\n%s",path, host, #data, data)

    con:send(request)

    local response = ""
    while true do
        local chunk, status, partial = con:receive(1024)
        response = response .. (chunk or partial)
        print("status = ", status);
        if status == "closed" then
            break;
        end
    end

输出:

status =        nil
status =        nil
status =        closed

小结:

  • 1.主要是用tcp连接,用非阻塞的方式去实现
  • 2.自己通过receive接口获取数据

参考

[1]socket.http

[2]Non-Preemptive Multithreading


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