refactor(layout): consolidate backend codebase into backend/ package and clean root directory

- Moved cmd/, core/, plugins/, pkg/, downstream/, and main.go into backend/ directory - Batch updated all Go source files to import github.com/Rain-kl/Wavelet/backend/... - Updated Makefile, scripts/swagger.sh, architecture guards, and platform skills - Passed all quality gates (100% tests, 0 lint issues, clean build)
2026-10-10 17:26:38 +08:00 · 2026-08-28 12:56:02 +08:00
parent 33b38f8687
commit 43dc97e48c
319 changed files with 912 additions and 1031 deletions
@@ -0,0 +1,322 @@
+// Copyright 2025 linux.do
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+// Package filesrv serves uploaded files with access control and image compression.
+package filesrv
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/Rain-kl/Wavelet/backend/core/contracts"
+	"github.com/Rain-kl/Wavelet/backend/pkg/response"
+	pkgutil "github.com/Rain-kl/Wavelet/backend/pkg/util"
+	"github.com/Rain-kl/Wavelet/backend/plugins/domain/auth"
+	"github.com/Rain-kl/Wavelet/backend/plugins/domain/upload/cache"
+	"github.com/Rain-kl/Wavelet/backend/plugins/domain/upload/models"
+	"github.com/Rain-kl/Wavelet/backend/plugins/domain/upload/shared"
+	uploadstorage "github.com/Rain-kl/Wavelet/backend/plugins/domain/upload/storage"
+	"github.com/Rain-kl/Wavelet/backend/plugins/domain/upload/util"
+	"github.com/Rain-kl/Wavelet/backend/plugins/infra/storage/diskcache"
+
+	"github.com/Rain-kl/Wavelet/backend/pkg/logger"
+	"github.com/gin-gonic/gin"
+	"golang.org/x/sync/singleflight"
+	"gorm.io/gorm"
+)
+
+var compressedImageFlight singleflight.Group
+
+type compressedImageCacheResult struct {
+	bytes  []byte
+	cached bool
+	err    error
+}
+
+type fileTypeCategory string
+
+const (
+	fileTypeImage fileTypeCategory = "image"
+	fileTypeVideo fileTypeCategory = "video"
+	fileTypeAudio fileTypeCategory = "audio"
+	fileTypeOther fileTypeCategory = "other"
+)
+
+// ServeFileByID 根据 ID 获取并提供已上传的文件
+// @Summary 获取已上传文件
+// @Description 根据文件 ID 获取并提供已上传的临时或正式文件，若配置了缓存则优先走本地缓存，否则从 S3 等后端存储读取并流式返回
+// @Tags upload
+// @Produce octet-stream
+// @Param id path string true "文件 ID"
+// @Param quality query string false "图片质量 (low, medium, high, origin)，默认为 origin"
+// @Success 200 {file} file "成功获取文件内容"
+// @Failure 400 {object} response.Any "文件 ID 格式错误"
+// @Failure 401 {object} response.Any "未登录"
+// @Failure 404 {object} response.Any "文件未找到"
+// @Failure 500 {object} response.Any "服务内部错误"
+// @Router /f/{id} [get]
+func ServeFileByID(c *gin.Context) {
+	upload, err := GetUploadRecordByID(c)
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			response.AbortNotFound(c, "文件记录未找到")
+			return
+		}
+		if _, ok := err.(*strconv.NumError); ok {
+			response.AbortBadRequest(c, "无效的上传ID")
+			return
+		}
+		response.AbortInternal(c, "服务器内部错误")
+		return
+	}
+
+	if err := CheckFileAccessPermission(c, upload); err != nil {
+		response.AbortUnauthorized(c, shared.ErrUnauthorized)
+		return
+	}
+
+	ServeUpload(c, upload)
+}
+
+// GetUploadRecordByID 从请求路径参数中解析文件 ID 并从数据库中检索处于 Pending 或 Used 状态的上传记录。
+func GetUploadRecordByID(c *gin.Context) (*models.Upload, error) {
+	c.Header("X-Content-Type-Options", "nosniff")
+	c.Header("Content-Security-Policy", "sandbox")
+
+	idStr := c.Param("id")
+	uploadID, err := strconv.ParseUint(idStr, 10, 64)
+	if err != nil {
+		return nil, err
+	}
+
+	upload, err := cache.GetUploadByID(c.Request.Context(), uploadID)
+	if err != nil {
+		return nil, err
+	}
+
+	return &upload, nil
+}
+
+func getFileTypeCategory(upload *models.Upload) fileTypeCategory {
+	mime := strings.ToLower(upload.MimeType)
+	ext := strings.ToLower(upload.Extension)
+
+	if strings.HasPrefix(mime, "image/") || util.IsImageExtension(ext) {
+		return fileTypeImage
+	}
+	if strings.HasPrefix(mime, "video/") {
+		return fileTypeVideo
+	}
+	if strings.HasPrefix(mime, "audio/") {
+		return fileTypeAudio
+	}
+	return fileTypeOther
+}
+
+// ServeUpload 将已存在的文件内容读取并流式响应给客户端。
+func ServeUpload(c *gin.Context, upload *models.Upload) {
+	setCacheHeaders(c, upload)
+
+	category := getFileTypeCategory(upload)
+	quality := util.NormalizeImageQuality(c.Query("quality"))
+
+	switch category {
+	case fileTypeImage:
+		if quality != shared.ImageQualityOrigin {
+			serveCompressedImage(c, upload, quality)
+			return
+		}
+		fallthrough
+	default:
+		serveOriginalWithConditionalCheck(c, upload)
+	}
+}
+
+func setCacheHeaders(c *gin.Context, upload *models.Upload) {
+	if cache.IsFilePublic(c.Request.Context(), upload.Type) {
+		c.Header("Cache-Control", "public, max-age=31536000")
+	} else {
+		c.Header("Cache-Control", "private, no-cache")
+	}
+}
+
+func serveOriginalWithConditionalCheck(c *gin.Context, upload *models.Upload) {
+	etag := fmt.Sprintf(`W/"%s"`, upload.Hash)
+	c.Header("ETag", etag)
+
+	if c.GetHeader("If-None-Match") == etag {
+		c.AbortWithStatus(http.StatusNotModified)
+		return
+	}
+
+	serveOriginal(c, upload)
+}
+
+func serveCompressedImage(c *gin.Context, upload *models.Upload, quality string) {
+	etag := fmt.Sprintf(`W/"%s-%s"`, upload.Hash, quality)
+	c.Header("ETag", etag)
+
+	if c.GetHeader("If-None-Match") == etag {
+		c.AbortWithStatus(http.StatusNotModified)
+		return
+	}
+
+	webpBytes, hit, err := EnsureCompressedImageCache(c.Request.Context(), upload, quality)
+	if hit {
+		c.Header("X-Cache", "HIT")
+	} else {
+		c.Header("X-Cache", "MISS")
+	}
+	if err != nil {
+		if len(webpBytes) > 0 {
+			logger.WarnF(c.Request.Context(), "failed to cache compressed image: %v", err)
+			c.Data(http.StatusOK, "image/webp", webpBytes)
+			return
+		}
+		logger.ErrorF(c.Request.Context(), "failed to prepare compressed image cache: %v", err)
+		serveOriginal(c, upload)
+		return
+	}
+
+	c.Data(http.StatusOK, "image/webp", webpBytes)
+}
+
+// EnsureCompressedImageCache returns cached or freshly generated WebP bytes for an upload.
+func EnsureCompressedImageCache(
+	ctx context.Context,
+	upload *models.Upload,
+	quality string,
+) ([]byte, bool, error) {
+	cacheStore := diskcache.GetGlobalCache()
+	cacheKey := ImageCompressionCacheKey(upload, quality)
+	webpBytes, err := cacheStore.Get(cacheKey)
+	if err == nil {
+		return webpBytes, true, nil
+	}
+	if !errors.Is(err, diskcache.ErrCacheMiss) {
+		return nil, false, fmt.Errorf("read compressed image cache: %w", err)
+	}
+
+	result, err, _ := compressedImageFlight.Do(cacheKey, func() (any, error) {
+		return generateCompressedImageCache(ctx, upload, quality, cacheKey)
+	})
+	if err != nil {
+		return nil, false, err
+	}
+
+	res := result.(compressedImageCacheResult)
+	return res.bytes, res.cached, res.err
+}
+
+func generateCompressedImageCache(
+	ctx context.Context,
+	upload *models.Upload,
+	quality string,
+	cacheKey string,
+) (compressedImageCacheResult, error) {
+	cacheStore := diskcache.GetGlobalCache()
+
+	webpBytes, err := cacheStore.Get(cacheKey)
+	if err == nil {
+		return compressedImageCacheResult{bytes: webpBytes, cached: true}, nil
+	}
+	if !errors.Is(err, diskcache.ErrCacheMiss) {
+		return compressedImageCacheResult{}, fmt.Errorf("read compressed image cache: %w", err)
+	}
+
+	origBytes, err := getOriginalFileBytes(ctx, upload)
+	if err != nil {
+		return compressedImageCacheResult{}, fmt.Errorf("read original image: %w", err)
+	}
+
+	webpBytes, err = util.CompressImageToWebP(bytes.NewReader(origBytes), quality)
+	if err != nil {
+		return compressedImageCacheResult{}, fmt.Errorf("compress image to WebP: %w", err)
+	}
+
+	if err := cacheStore.Set(cacheKey, webpBytes, diskcache.NoExpiration); err != nil {
+		return compressedImageCacheResult{
+			bytes: webpBytes,
+			err:   fmt.Errorf("write compressed image cache: %w", err),
+		}, nil
+	}
+
+	return compressedImageCacheResult{bytes: webpBytes}, nil
+}
+
+// ImageCompressionCacheKey returns the disk cache key for a compressed upload image.
+func ImageCompressionCacheKey(upload *models.Upload, quality string) string {
+	return fmt.Sprintf(
+		"upload_webp_v1_%d_%d_%d_%s_%s",
+		upload.ID,
+		upload.UpdatedAt.UnixNano(),
+		upload.FileSize,
+		upload.Hash,
+		quality,
+	)
+}
+
+func serveOriginal(c *gin.Context, upload *models.Upload) {
+	obj, err := uploadstorage.OpenStoredObject(c.Request.Context(), upload)
+	if err != nil {
+		response.AbortNotFound(c, "文件未找到")
+		return
+	}
+	defer func() { _ = obj.Body.Close() }()
+	c.DataFromReader(http.StatusOK, obj.ContentLength, obj.ContentType, obj.Body, nil)
+}
+
+func getOriginalFileBytes(ctx context.Context, upload *models.Upload) ([]byte, error) {
+	obj, err := uploadstorage.OpenStoredObject(ctx, upload)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = obj.Body.Close() }()
+	return io.ReadAll(obj.Body)
+}
+
+func checkPrivateFileOwner(c *gin.Context, ownerID uint64) error {
+	var currUserID uint64
+	var isAdmin bool
+	if u, ok := pkgutil.GetFromContext[*contracts.UserDTO](c, contracts.AuthUserObjKey); ok && u != nil {
+		currUserID = u.ID
+		isAdmin = u.IsAdmin
+	} else {
+		u, err := auth.GetUserFromRequest(c)
+		if err != nil {
+			return err
+		}
+		currUserID = u.ID
+		isAdmin = u.IsAdmin
+	}
+	if isAdmin {
+		return nil
+	}
+	if currUserID != ownerID {
+		return errors.New("forbidden: cross-user access denied")
+	}
+	return nil
+}
+
+// CheckFileAccessPermission 校验文件是否可以被当前请求访问
+func CheckFileAccessPermission(c *gin.Context, upload *models.Upload) error {
+	if upload.AccessMode == 0 {
+		return checkPrivateFileOwner(c, upload.UserID)
+	}
+
+	if !cache.IsFilePublic(c.Request.Context(), upload.Type) {
+		if _, ok := pkgutil.GetFromContext[*contracts.UserDTO](c, contracts.AuthUserObjKey); !ok {
+			if _, err := auth.GetUserFromRequest(c); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}