完善应用功能与界面交互

internal/service/image_proxy_remote.go

@@ -55,26 +55,32 @@ func (p *ImageProxy) RemoveFailed(raw string) error {
 // Serve writes the requested image to w. Caller is expected to validate
 // the JWT before invoking it.
 func (p *ImageProxy) Serve(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string) error {
+	// Emby 客户端用 maxWidth / maxHeight / quality 请求缩略图。不解析这些
+	// 参数就会把多兆字节的原图发给客户端，移动端往往在下载中途超时。
+	opts := parseImageResizeOptions(r)
 	if isLocalImagePath(raw) {
-		return p.serveLocalImage(w, r, raw)
+		return p.serveLocalImage(w, r, raw, opts)
 	}
-	return p.serveRemoteImage(ctx, w, r, raw)
+	return p.serveRemoteImage(ctx, w, r, raw, opts)
 }
 
-func (p *ImageProxy) serveLocalImage(w http.ResponseWriter, r *http.Request, raw string) error {
+func (p *ImageProxy) serveLocalImage(w http.ResponseWriter, r *http.Request, raw string, opts imageResizeOptions) error {
 	path := filepath.Clean(raw)
 	abs, err := filepath.Abs(path)
 	if err != nil || !p.isAllowedLocalPath(abs) {
 		servePlaceholder(w)
 		return nil
 	}
+	if opts.active() && p.serveResizedFromFile(w, r, abs, opts) {
+		return nil
+	}
 	if !serveImageFile(w, r, filepath.Base(abs), abs, imageBrowserCacheControl) {
 		servePlaceholder(w)
 	}
 	return nil
 }
 
-func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string) error {
+func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter, r *http.Request, raw string, opts imageResizeOptions) error {
 	u, err := p.validateURL(raw)
 	if err != nil {
 		return err
@@ -83,14 +89,14 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 	key, cachePath, failPath := p.remoteImageCachePathsForValidated(raw)
 	forceRefresh := r.URL.Query().Get("refresh") != ""
 	p.removeUnusableImageCache(cachePath, failPath)
-	if !forceRefresh && serveCachedImageFile(w, r, key, cachePath) {
+	if !forceRefresh && p.serveCachedImage(w, r, key, cachePath, opts) {
 		return nil
 	}
 	// No negative caching: a previously failed fetch is retried on every
 	// subsequent request, so the image recovers as soon as upstream does.
 	data, ctype, contentLength, err := p.fetchAndCacheRemoteImage(ctx, raw, host, cachePath, failPath)
 	if err != nil {
-		if forceRefresh && serveCachedImageFile(w, r, key, cachePath) {
+		if forceRefresh && p.serveCachedImage(w, r, key, cachePath, opts) {
 			return nil
 		}
 		if errors.Is(err, errImageProxyRequestSetup) {
@@ -100,6 +106,10 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 		}
 		return nil
 	}
+	// 上游原图已落盘，缩放结果复用同一条缓存流水线。
+	if opts.active() && p.serveResizedFromFile(w, r, cachePath, opts) {
+		return nil
+	}
 	w.Header().Set("Content-Type", ctype)
 	if contentLength != "" {
 		w.Header().Set("Content-Length", contentLength)
@@ -114,6 +124,15 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 	return nil
 }
 
+// serveCachedImage 在远程原图已缓存时提供服务。请求带缩放参数时优先命中
+// 缩放缓存，未命中则从已缓存的原图生成一份；缩放不可用时退回原图直出。
+func (p *ImageProxy) serveCachedImage(w http.ResponseWriter, r *http.Request, key, cachePath string, opts imageResizeOptions) bool {
+	if opts.active() && p.serveResizedFromFile(w, r, cachePath, opts) {
+		return true
+	}
+	return serveCachedImageFile(w, r, key, cachePath)
+}
+
 func (p *ImageProxy) removeUnusableImageCache(cachePath, failPath string) {
 	data, err := os.ReadFile(cachePath) // #nosec G304 -- cachePath is SHA-derived under cacheDir.
 	if err != nil {