Go语言中http.Transport的请求管道化技巧与应用举例

package main

import (
    "fmt"
    "io/ioutil"
    "net/http"
    "sync"
    "time"
)

type PipelineTransport struct {
    Transport http.Transport
    RWMutex   sync.RWMutex
    Channels  map[string]chan string
}

func (t *PipelineTransport) RoundTrip(req *http.Request) (*http.Response, error) {
    // 获取请求的URL
    url := req.URL.String()

    t.RWMutex.Lock()
    // 如果该URL对应的通道不存在，则新建一个通道
    if _, ok := t.Channels[url]; !ok {
        t.Channels[url] = make(chan string)
    }
    c := t.Channels[url] // 获取通道
    t.RWMutex.Unlock()

    // 向通道发送请求
    go func() {
        resp, err := t.Transport.RoundTrip(req)
        if err != nil {
            c <- err.Error()
            return
        }

        defer resp.Body.Close()
        body, _ := ioutil.ReadAll(resp.Body)
        c <- string(body)
    }()

    return &http.Response{}, nil
}

func main() {
    // 创建一个自定义的http.Transport对象
    transport := PipelineTransport{
        Transport: http.Transport{
            MaxIdleConns:        100,
            MaxIdleConnsPerHost: 100,
            IdleConnTimeout:     30 * time.Second,
        },
        Channels: make(map[string]chan string),
    }

    // 创建一个http.Client对象
    client := http.Client{
        Transport: &transport,
    }

    // 构建并发发送的HTTP请求
    reqs := []*http.Request{
        &http.Request{
            Method: "GET",
            URL:    &url.URL{Scheme: "http", Host: "example.com", Path: "/1"},
        },
        &http.Request{
            Method: "GET",
            URL:    &url.URL{Scheme: "http", Host: "example.com", Path: "/2"},
        },
        &http.Request{
            Method: "GET",
            URL:    &url.URL{Scheme: "http", Host: "example.com", Path: "/3"},
        },
    }

    // 发送并发请求
    var wg sync.WaitGroup
    for _, req := range reqs {
        wg.Add(1)
        go func(r *http.Request) {
            resp, err := client.Do(r)
            if err != nil {
                fmt.Println(err)
                return
            }
            defer resp.Body.Close()

            body, _ := ioutil.ReadAll(resp.Body)
            fmt.Println(string(body))
            wg.Done()
        }(req)
    }

    wg.Wait()
}