Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/web/static_cache.go

@@ -0,0 +1,53 @@
+//go:build embed || unit
+
+package web
+
+import (
+	"net/http"
+	"path"
+	"strings"
+)
+
+// Vite emits content-hashed filenames under assets/, so the backend can apply
+// immutable caching without relying on a reverse proxy to classify paths.
+const staticAssetsCacheControl = "public, max-age=31536000, immutable"
+
+// isFingerprintedEmbeddedAssetPath reports whether a cleaned URL path refers to
+// a Vite asset whose filename contains the default eight-character build hash.
+func isFingerprintedEmbeddedAssetPath(cleanPath string) bool {
+	cleanPath = strings.TrimPrefix(cleanPath, "/")
+	if !strings.HasPrefix(cleanPath, "assets/") {
+		return false
+	}
+
+	filename := path.Base(cleanPath)
+	extension := path.Ext(filename)
+	stem := strings.TrimSuffix(filename, extension)
+	const fingerprintLength = 8
+	delimiterIndex := len(stem) - fingerprintLength - 1
+	if extension == "" || delimiterIndex < 1 || stem[delimiterIndex] != '-' {
+		return false
+	}
+
+	// Vite hashes use URL-safe characters and are stable for immutable caching.
+	fingerprint := stem[delimiterIndex+1:]
+	for _, char := range fingerprint {
+		if (char >= 'a' && char <= 'z') ||
+			(char >= 'A' && char <= 'Z') ||
+			(char >= '0' && char <= '9') ||
+			char == '_' || char == '-' {
+			continue
+		}
+		return false
+	}
+	return true
+}
+
+// applyStaticAssetCacheHeaders sets Cache-Control for long-cacheable static paths.
+// index.html / SPA routes must keep no-cache and are not handled here.
+func applyStaticAssetCacheHeaders(header http.Header, cleanPath string) {
+	if header == nil || !isFingerprintedEmbeddedAssetPath(cleanPath) {
+		return
+	}
+	header.Set("Cache-Control", staticAssetsCacheControl)
+}