golang框架性能优化中如何进行代码重构？

package main

import (
    "context"
    "database/sql"
    "fmt"
    "log"
    "net/http"
    "time"

    "github.com/go-redis/redis/v8"
)

var db *sql.DB
var cache *redis.Client

func main() {
    var err error

    // 初始化数据库连接
    db, err = sql.Open("mysql", "...")
    if err != nil {
        log.Fatal(err)
    }

    // 初始化缓存连接
    cache = redis.NewClient(&redis.Options{
        Addr:     "...",
        Password: "...",
        DB:       0,
    })

    // 启动 HTTP 服务器
    http.HandleFunc("/", handler)
    log.Fatal(http.ListenAndServe(":8080", nil))
}

func handler(w http.ResponseWriter, r *http.Request) {
    key := fmt.Sprintf("query-%s", r.URL.Path)

    // 从缓存中获取结果
    result, err := cache.Get(context.Background(), key).Result()
    if err == redis.Nil {
        // 如果缓存未命中，从数据库获取结果
        result, err = getFromDB(r.URL.Path)
        if err != nil {
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
            return
        }

        // 将结果存储到缓存中，并设置 60 秒失效时间
        if err := cache.Set(context.Background(), key, result, 60*time.Second).Err(); err != nil {
            http.Error(w, "Internal Server Error", http.StatusInternalServerError)
            return
        }
    } else if err != nil {
        http.Error(w, "Internal Server Error", http.StatusInternalServerError)
        return
    }

    w.Write([]byte(result))
}

func getFromDB(path string) (string, error) {
    var result string
    row := db.QueryRow(fmt.Sprintf("SELECT data FROM my_table WHERE path = '%s'", path))
    if err := row.Scan(&result); err != nil {
        return "", err
    }

    return result, nil
}