feat: 缩略图

Author: SugarMGP

.gitignore

@@ -26,4 +26,5 @@ go.work.sum
 /config.yaml
 /.idea
 /logs
-/static
+/static
+/thumbnail_cache

config.example.yaml

@@ -31,6 +31,9 @@ oss:
   limit: 10  # 文件大小限制 单位: MB
   adminKey: ""  # 管理员密钥
   quality: 75  # 图片质量（0-100）
+  thumbnailDir: "./thumbnail_cache"  # 缓存目录
+  thumbnailQuality: 85  # 缩略图质量（0-100）
+  thumbnailLongEdge: 640  # 缩略图长边像素
 
 log:
   disableStacktrace: false # 是否禁用堆栈跟踪

internal/controllers/objectController/get.go

@@ -2,6 +2,7 @@ package objectController
 
 import (
 	"errors"
+	"image"
 	"net/http"
 
 	"cube-go/internal/apiException"
@@ -19,6 +20,7 @@ type getFileListData struct {
 type getFileData struct {
 	Bucket    string `form:"bucket" binding:"required"`
 	ObjectKey string `form:"object_key" binding:"required"`
+	Thumbnail bool   `form:"thumbnail"`
 }
 
 // GetFileList 获取文件列表
@@ -58,27 +60,45 @@ func GetFile(c *gin.Context) {
 		c.AbortWithStatus(http.StatusBadRequest)
 		return
 	}
+	objectKey := objectService.CleanLocation(data.ObjectKey)
 
-	bucket, err := oss.Buckets.GetBucket(data.Bucket)
-	if err != nil {
-		c.AbortWithStatus(http.StatusNotFound)
-		return
-	}
+	if data.Thumbnail {
+		thumbnail, size, err := objectService.GetThumbnail(data.Bucket, objectKey)
+		if errors.Is(err, oss.ErrResourceNotExists) || errors.Is(err, image.ErrFormat) {
+			c.AbortWithStatus(http.StatusNotFound)
+			return
+		}
+		if err != nil {
+			c.AbortWithStatus(http.StatusInternalServerError)
+			return
+		}
+		defer func() {
+			_ = thumbnail.Close()
+		}()
 
-	obj, content, err := bucket.GetObject(data.ObjectKey)
-	if errors.Is(err, oss.ErrResourceNotExists) {
-		c.AbortWithStatus(http.StatusNotFound)
-		return
-	}
-	if err != nil {
-		c.AbortWithStatus(http.StatusInternalServerError)
-		return
-	}
-	defer func() {
-		_ = obj.Close()
-	}()
+		c.DataFromReader(http.StatusOK, size, "image/jpeg", thumbnail, nil)
+	} else {
+		bucket, err := oss.Buckets.GetBucket(data.Bucket)
+		if err != nil {
+			c.AbortWithStatus(http.StatusNotFound)
+			return
+		}
 
-	c.DataFromReader(http.StatusOK, content.ContentLength, content.ContentType, obj, nil)
+		obj, content, err := bucket.GetObject(objectKey)
+		if errors.Is(err, oss.ErrResourceNotExists) {
+			c.AbortWithStatus(http.StatusNotFound)
+			return
+		}
+		if err != nil {
+			c.AbortWithStatus(http.StatusInternalServerError)
+			return
+		}
+		defer func() {
+			_ = obj.Close()
+		}()
+
+		c.DataFromReader(http.StatusOK, content.ContentLength, content.ContentType, obj, nil)
+	}
 }
 
 // GetBucketList 获取存储桶列表

internal/services/objectService/service.go

@@ -4,19 +4,23 @@ import (
 	"bytes"
 	"image"
 	_ "image/gif" // 注册解码器
-	_ "image/jpeg"
-	_ "image/png"
+	"image/jpeg"
+	_ "image/png" // 注册解码器
 	"io"
+	"os"
 	"path"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"sync"
 
 	"cube-go/pkg/config"
+	"cube-go/pkg/oss"
 	"github.com/chai2010/webp"
 	"github.com/dustin/go-humanize"
 	_ "golang.org/x/image/bmp" // 注册解码器
-	_ "golang.org/x/image/tiff"
+	"golang.org/x/image/draw"
+	_ "golang.org/x/image/tiff" // 注册解码器
 	_ "golang.org/x/image/webp"
 )
 
@@ -66,3 +70,78 @@ func ConvertToWebP(reader io.Reader) (*bytes.Reader, error) {
 	}
 	return bytes.NewReader(buf.Bytes()), nil
 }
+
+// GetThumbnail 获取缩略图
+func GetThumbnail(bucket string, objectKey string) (io.ReadCloser, int64, error) {
+	filename := bucket + "-" + objectKey
+	cachePath := filepath.Join(config.Config.GetString("oss.thumbnailDir"), filename+".jpg")
+
+	// 尝试从缓存中读取
+	if stat, err := os.Stat(cachePath); err == nil {
+		file, err := os.Open(cachePath)
+		if err == nil {
+			return file, stat.Size(), nil
+		}
+	}
+
+	// 从 OSS 获取源文件
+	provider, err := oss.Buckets.GetBucket(bucket)
+	if err != nil {
+		return nil, 0, err
+	}
+	object, _, err := provider.GetObject(objectKey)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer func() {
+		_ = object.Close()
+	}()
+
+	// 解码图片
+	img, _, err := image.Decode(object)
+	if err != nil {
+		return nil, 0, err
+	}
+	finalImg := resizeIfNeeded(img, config.Config.GetInt("oss.thumbnailLongEdge"))
+
+	buf, _ := bufferPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer bufferPool.Put(buf)
+
+	err = jpeg.Encode(buf, finalImg, &jpeg.Options{
+		Quality: config.Config.GetInt("oss.thumbnailQuality"),
+	})
+	if err != nil {
+		return nil, 0, err
+	}
+
+	// 写入缓存文件
+	if err := os.MkdirAll(filepath.Dir(cachePath), os.ModePerm); err == nil {
+		_ = os.WriteFile(cachePath, buf.Bytes(), 0644)
+	}
+
+	return io.NopCloser(bytes.NewReader(buf.Bytes())), int64(buf.Len()), nil
+}
+
+func resizeIfNeeded(img image.Image, targetLongSide int) image.Image {
+	b := img.Bounds()
+	w, h := b.Dx(), b.Dy()
+	longSide, shortSide := max(w, h), min(w, h)
+
+	if longSide <= targetLongSide {
+		return img
+	}
+	scale := float64(targetLongSide) / float64(longSide)
+	targetShort := int(float64(shortSide) * scale)
+
+	var tw, th int
+	if w > h {
+		tw, th = targetLongSide, targetShort
+	} else {
+		tw, th = targetShort, targetLongSide
+	}
+
+	dst := image.NewRGBA(image.Rect(0, 0, tw, th))
+	draw.BiLinear.Scale(dst, dst.Rect, img, b, draw.Over, nil)
+	return dst
+}