From 0bcb1fec876da1abc6ad90aa5149530047a30a8c Mon Sep 17 00:00:00 2001
From: truewhile <62226914+truewhile@users.noreply.github.com>
Date: Fri, 21 Aug 2026 22:21:14 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BC=98=E5=8C=96=E7=BD=91=E7=9B=98=E5=9B=BE?=
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优化网盘图片读取逻辑
---
 internal/service/image_proxy.go             |  1 -
 internal/service/image_proxy_cache.go       |  9 ++-------
 internal/service/image_proxy_remote.go      | 22 ++++-----------------
 internal/service/image_proxy_remote_test.go |  7 ++++---
 4 files changed, 10 insertions(+), 29 deletions(-)

diff --git a/internal/service/image_proxy.go b/internal/service/image_proxy.go
index e0f9080..b73772e 100644
--- a/internal/service/image_proxy.go
+++ b/internal/service/image_proxy.go
@@ -44,7 +44,6 @@ type ImageProxy struct {
 const (
 	imageBrowserCacheControl     = "public, max-age=2592000, immutable"
 	imagePlaceholderCacheControl = "no-store"
-	imageNegativeCacheTTL        = 6 * time.Hour
 )
 
 // NewImageProxy is the constructor.
diff --git a/internal/service/image_proxy_cache.go b/internal/service/image_proxy_cache.go
index 691d826..4e5a639 100644
--- a/internal/service/image_proxy_cache.go
+++ b/internal/service/image_proxy_cache.go
@@ -132,14 +132,9 @@ func imageFileETag(key string, stat os.FileInfo) string {
 }
 
 func freshNegativeImageCache(failPath string) bool {
-	stat, err := os.Stat(failPath)
-	if err != nil {
-		return false
+	if _, err := os.Stat(failPath); err == nil {
+		_ = os.Remove(failPath)
 	}
-	if time.Since(stat.ModTime()) < imageNegativeCacheTTL {
-		return true
-	}
-	_ = os.Remove(failPath)
 	return false
 }
 
diff --git a/internal/service/image_proxy_remote.go b/internal/service/image_proxy_remote.go
index 40d59a5..2096337 100644
--- a/internal/service/image_proxy_remote.go
+++ b/internal/service/image_proxy_remote.go
@@ -86,9 +86,8 @@ func (p *ImageProxy) serveRemoteImage(ctx context.Context, w http.ResponseWriter
 	if !forceRefresh && serveCachedImageFile(w, r, key, cachePath) {
 		return nil
 	}
-	if !forceRefresh && p.serveFreshRemoteFailure(w, failPath) {
-		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) {
@@ -128,16 +127,6 @@ func (p *ImageProxy) removeUnusableImageCache(cachePath, failPath string) {
 	_ = os.Remove(failPath)
 }
 
-func (p *ImageProxy) serveFreshRemoteFailure(w http.ResponseWriter, failPath string) bool {
-	if stat, err := os.Stat(failPath); err == nil && time.Since(stat.ModTime()) < imageNegativeCacheTTL {
-		serveCachedPlaceholder(w)
-		return true
-	} else if err == nil {
-		_ = os.Remove(failPath)
-	}
-	return false
-}
-
 func (p *ImageProxy) fetchAndCacheRemoteImage(ctx context.Context, raw, host, cachePath, failPath string) ([]byte, string, string, error) {
 	if err := os.MkdirAll(p.cacheDir, 0o750); err != nil {
 		p.log.Warn("imageproxy: mkdir failed", zap.String("dir", p.cacheDir), zap.Error(err))
@@ -188,11 +177,8 @@ func (p *ImageProxy) Fetch(ctx context.Context, raw string) ([]byte, string, err
 		_ = os.Remove(cachePath)
 		_ = os.Remove(failPath)
 	}
-	if stat, err := os.Stat(failPath); err == nil && time.Since(stat.ModTime()) < imageNegativeCacheTTL {
-		return nil, "", errors.New("recent image fetch failure")
-	} else if err == nil {
-		_ = os.Remove(failPath)
-	}
+	// No negative caching: a previously failed fetch is retried on every
+	// subsequent request, so the image recovers as soon as upstream does.
 	data, ctype, _, err := p.fetchAndCacheRemoteImage(ctx, raw, host, cachePath, failPath)
 	return data, ctype, err
 }
diff --git a/internal/service/image_proxy_remote_test.go b/internal/service/image_proxy_remote_test.go
index 2f56ef0..1d83bd6 100644
--- a/internal/service/image_proxy_remote_test.go
+++ b/internal/service/image_proxy_remote_test.go
@@ -17,7 +17,7 @@ import (
 	"github.com/ShukeBta/MediaStationGo/internal/config"
 )
 
-func TestImageProxyCachesFailedRemoteImageFetch(t *testing.T) {
+func TestImageProxyDoesNotNegativeCacheFailedRemoteImageFetch(t *testing.T) {
 	var calls int32
 	proxy := NewImageProxy(&config.Config{Cache: config.CacheConfig{CacheDir: filepath.Join(t.TempDir(), "cache")}}, zap.NewNop())
 	proxy.client = &http.Client{Transport: imageRoundTripFunc(func(req *http.Request) (*http.Response, error) {
@@ -42,12 +42,13 @@ func TestImageProxyCachesFailedRemoteImageFetch(t *testing.T) {
 		if rec.Body.Len() != len(transparent1x1PNG) {
 			t.Fatalf("body length = %d, want placeholder %d", rec.Body.Len(), len(transparent1x1PNG))
 		}
+		// No negative caching: every request re-attempts upstream.
 		if got := rec.Header().Get("Cache-Control"); got != imagePlaceholderCacheControl {
 			t.Fatalf("Cache-Control = %q, want %q", got, imagePlaceholderCacheControl)
 		}
 	}
-	if got := atomic.LoadInt32(&calls); got != 1 {
-		t.Fatalf("upstream calls = %d, want 1 due to negative cache", got)
+	if got := atomic.LoadInt32(&calls); got != 2 {
+		t.Fatalf("upstream calls = %d, want 2 (one per request, no negative cache)", got)
 	}
 }