118 lines
2.9 KiB
Go
118 lines
2.9 KiB
Go
package utils
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import (
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"bytes"
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"encoding/base64"
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"errors"
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"fmt"
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"image"
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_ "image/jpeg" // 引入 jpeg 解码器
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_ "image/png" // 引入 png 解码器
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"io"
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"regexp"
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"strings"
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"sync"
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)
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var wg sync.WaitGroup
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// GetMimeType 获取 MIME 类型
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func GetMimeType(data []byte) string {
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if len(data) < 4 {
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return "application/octet-stream" // 默认类型
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}
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// 判断 JPEG
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if data[0] == 0xFF && data[1] == 0xD8 {
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return "image/jpeg"
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}
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// 判断 PNG
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if len(data) >= 8 && data[0] == 0x89 && data[1] == 0x50 && data[2] == 0x4E && data[3] == 0x47 &&
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data[4] == 0x0D && data[5] == 0x0A && data[6] == 0x1A && data[7] == 0x0A {
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return "image/png"
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}
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// 判断 GIF
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if len(data) >= 6 && data[0] == 'G' && data[1] == 'I' && data[2] == 'F' {
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return "image/gif"
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}
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// 判断 WEBP
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if len(data) >= 12 && data[0] == 0x52 && data[1] == 0x49 && data[2] == 0x46 && data[3] == 0x46 &&
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data[8] == 0x57 && data[9] == 0x45 && data[10] == 0x42 && data[11] == 0x50 {
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return "image/webp"
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}
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// 判断svg
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if len(data) >= 4 && data[0] == '<' && data[1] == '?' && data[2] == 'x' && data[3] == 'm' {
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return "image/svg+xml"
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}
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// 判断JPG
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if len(data) >= 3 && data[0] == 0xFF && data[1] == 0xD8 && data[2] == 0xFF {
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return "image/jpeg"
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}
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return "application/octet-stream" // 默认类型
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}
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// ProcessImages 处理图片，将 base64 字符串转换为字节数组
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func ProcessImages(images []string) ([][]byte, error) {
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var imagesData [][]byte
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dataChan := make(chan []byte, len(images))
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re := regexp.MustCompile(`^data:image/\w+;base64,`)
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for _, img := range images {
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wg.Add(1)
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go func(img string) {
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defer wg.Done()
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imgWithoutPrefix := re.ReplaceAllString(img, "")
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data, err := Base64ToBytes(imgWithoutPrefix)
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if err != nil {
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return // 出错时直接返回
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}
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dataChan <- data
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}(img)
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}
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wg.Wait()
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close(dataChan)
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for data := range dataChan {
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imagesData = append(imagesData, data)
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}
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return imagesData, nil
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}
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// Base64ToBytes 将base64字符串转换为字节数组
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func Base64ToBytes(base64Str string) ([]byte, error) {
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reader := base64.NewDecoder(base64.StdEncoding, strings.NewReader(base64Str))
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data, err := io.ReadAll(reader)
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if err != nil {
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return nil, errors.New("failed to decode base64 string")
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}
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return data, nil
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}
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// Base64ToImage 将 Base64 字符串转换为 image.Image 格式
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func Base64ToImage(base64Str string) (image.Image, error) {
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// 使用正则表达式去除前缀
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re := regexp.MustCompile(`^data:image/([a-zA-Z]*);base64,`)
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// 去除前缀部分
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base64Str = re.ReplaceAllString(base64Str, "")
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// 解码 Base64 字符串
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data, err := base64.StdEncoding.DecodeString(base64Str)
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if err != nil {
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return nil, fmt.Errorf("failed to decode base64 string: %v", err)
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}
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// 使用 image.Decode 解码字节数据
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img, _, err := image.Decode(bytes.NewReader(data))
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if err != nil {
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return nil, fmt.Errorf("failed to decode image: %v", err)
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}
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return img, nil
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}
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