GAE Golang中urlfetch超时设置的演进与实践

package main

import (
    "encoding/json"
    "io/ioutil"
    "net/http"
    "strings"
    "time"

    "google.golang.org/appengine"
    "google.golang.org/appengine/urlfetch"
)

// TimeoutDuration 定义了期望的超时时长
var TimeoutDuration time.Duration = time.Second * 30

func CallLegacy(c appengine.Context, address string, allowInvalidServerCertificate bool, method string, id interface{}, params []interface{}) (map[string]interface{}, error) {
    data, err := json.Marshal(map[string]interface{}{
        "method": method,
        "id":     id,
        "params": params,
    })
    if err != nil {
        return nil, err
    }

    req, err := http.NewRequest("POST", address, strings.NewReader(string(data)))
    if err != nil {
        return nil, err
    }

    // 核心问题：TimeoutDuration的设置方式
    // 错误的设置方式可能导致默认5秒超时被忽略
    // tr := &urlfetch.Transport{Context: c, Deadline: TimeoutDuration, AllowInvalidServerCertificate: allowInvalidServerCertificate}

    // 正确的早期设置方式：显式类型转换
    tr := &urlfetch.Transport{Context: c, Deadline: time.Duration(30) * time.Second, AllowInvalidServerCertificate: allowInvalidServerCertificate}

    resp, err := tr.RoundTrip(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        return nil, err
    }
    result := make(map[string]interface{})
    err = json.Unmarshal(body, &result)
    if err != nil {
        return nil, err
    }
    return result, nil
}

package main

import (
    "context" // 导入标准的context包
    "encoding/json"
    "io/ioutil"
    "net/http"
    "strings"
    "time"

    "google.golang.org/appengine" // 新的GAE包
    "google.golang.org/appengine/urlfetch"
    "golang.org/x/oauth2" // 示例中包含，用于说明与http.Client的集成
)

func CallModern(ctx context.Context, address string, allowInvalidServerCertificate bool, method string, id interface{}, params []interface{}) (map[string]interface{}, error) {
    // 1. 使用context.WithTimeout为请求设置超时
    // 这里设置1分钟的超时
    ctxWithDeadline, cancel := context.WithTimeout(ctx, 1*time.Minute)
    defer cancel() // 确保在函数退出时取消上下文，释放资源

    data, err := json.Marshal(map[string]interface{}{
        "method": method,
        "id":     id,
        "params": params,
    })
    if err != nil {
        return nil, err
    }

    req, err := http.NewRequest("POST", address, strings.NewReader(string(data)))
    if err != nil {
        return nil, err
    }

    // 2. 将带有截止时间的context传递给请求
    // 注意：urlfetch.Transport不再直接接收Deadline字段
    tr := &urlfetch.Transport{Context: ctxWithDeadline}

    // 3. 构建http.Client并使用urlfetch.Transport
    // 实际应用中可能需要根据认证方式集成oauth2.Transport等
    client := &http.Client{
        Transport: &oauth2.Transport{ // 示例中包含oauth2.Transport
            Base: tr,
        },
        // 对于不涉及OAuth2的简单情况，可以直接使用：
        // Transport: tr,
    }

    // 4. 发送请求，此时超时由ctxWithDeadline控制
    resp, err := client.Do(req.WithContext(ctxWithDeadline)) // 确保请求也带有该上下文
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    body, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        return nil, err
    }
    result := make(map[string]interface{})
    err = json.Unmarshal(body, &result)
    if err != nil {
        return nil, err
    }
    return result, nil
}