如何使用Golang优化大量图片链接替换的性能？

content := `@@##@@</img>@@##@@</img>`

package main

import (
    "bytes"
    "fmt"
    "regexp"
    "strconv"
    "strings"
    "sync"
    "time"

    "github.com/aliyun/aliyun-oss-go-sdk/oss"
)

// ... (阿里云OSS配置: Endpoint, key, AccessKeySecret, BucketName) ...

var (
    ossClient *oss.Client
    once      sync.Once
    imgCache  sync.Map // key: old URL, value: new URL
)

func getOSSClient() *oss.Client {
    once.Do(func() {
        client, err := oss.New(Endpoint, key, AccessKeySecret)
        if err != nil {
            panic(err) // Handle error appropriately in production
        }
        ossClient = client
    })
    return ossClient
}


func Upload(url string) (string, error) {
    client := getOSSClient()
    bucket, err := client.Bucket(BucketName)
    if err != nil {
        return "", err
    }

    t1 := time.Now().Unix()
    long := 0 // Simplified counter, consider a more robust solution
    obj := fmt.Sprintf("article/%d%d.png", t1, long)

    err = bucket.PutObject(obj, bytes.NewReader(ReadImgData(url))) // ReadImgData function assumed to exist
    if err != nil {
        return "", err
    }
    return "https://" + BucketName + "." + Endpoint + "/" + obj, nil
}

func RepImages(htmls string) string {
    var imgRE = regexp.MustCompile(`@@##@@]*src=["']([^"']+)["'][^>]*>`) // Improved regex
    imgs := imgRE.FindAllStringSubmatch(htmls, -1)
    var wg sync.WaitGroup
    resultChan := make(chan string, len(imgs))

    for _, img := range imgs {
        if len(img) > 1 {
            oldURL := img[1]
            if newURL, ok := imgCache.Load(oldURL); ok {
                resultChan <- strings.Replace(htmls, oldURL, newURL.(string), -1)
                continue
            }
            wg.Add(1)
            go func(oldURL string) {
                defer wg.Done()
                newURL, err := Upload(oldURL)
                if err != nil {
                    // Handle error appropriately (e.g., log, retry)
                    fmt.Printf("Error uploading %s: %v\n", oldURL, err)
                    resultChan <- htmls // Keep original string if upload fails
                    return
                }
                imgCache.Store(oldURL, newURL)
                resultChan <- strings.Replace(htmls, oldURL, newURL, -1)
            }(oldURL)
        }
    }

    wg.Wait()
    close(resultChan)

    resHtml := htmls // Default to original if no images found or errors occur.
    for updatedHTML := range resultChan {
        resHtml = updatedHTML
    }

    return resHtml
}

func main() {
    content := `@@##@@</img>@@##@@</img>`
    fmt.Println(RepImages(content))
}

// Placeholder for the actual image reading function
func ReadImgData(url string) []byte {
    // Replace this with your actual image reading logic
    // ...
    return []byte("image data")
}