From d1e08ec402f680d8f82df378fb91b4e2c7ea4391 Mon Sep 17 00:00:00 2001 From: xfy Date: Thu, 18 Jun 2026 13:40:48 +0800 Subject: [PATCH] fix(image): write disk cache atomically via temp-file + rename MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit .dat/.ct 改为先写 .tmp 再 rename，避免并发请求读到内容与 content-type 错配的半成品文件（L5）。写失败或 rename 失败时清理临时文件与目标。 --- src/api/image.rs | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/src/api/image.rs b/src/api/image.rs index 07738b1..2e89802 100644 --- a/src/api/image.rs +++ b/src/api/image.rs @@ -435,11 +435,31 @@ async fn write_disk_cache(cache_key: &str, cached: &CachedImage) { .content_type .to_str() .unwrap_or("application/octet-stream"); - if let Err(e) = tokio::fs::write(format!("{}.dat", base), &cached.data).await { - tracing::warn!("Failed to write disk cache data: {:?}", e); + + // 原子写：先写 .tmp 再 rename，避免并发请求读到 .dat 与 .ct 错配的半成品（L5）。 + let dat_path = format!("{}.dat", base); + let ct_path = format!("{}.ct", base); + let dat_tmp = format!("{}.dat.tmp", base); + let ct_tmp = format!("{}.ct.tmp", base); + + // 两个临时文件都写成功后才 rename；任一失败则清理半成品。 + let writes_ok = tokio::fs::write(&dat_tmp, &cached.data).await.is_ok() + && tokio::fs::write(&ct_tmp, ct_str).await.is_ok(); + + if !writes_ok { + let _ = tokio::fs::remove_file(&dat_tmp).await; + let _ = tokio::fs::remove_file(&ct_tmp).await; + tracing::warn!("Failed to write disk cache temp files at {}", base); + return; } - if let Err(e) = tokio::fs::write(format!("{}.ct", base), ct_str).await { - tracing::warn!("Failed to write disk cache content type: {:?}", e); + + let rename_dat = tokio::fs::rename(&dat_tmp, &dat_path).await; + let rename_ct = tokio::fs::rename(&ct_tmp, &ct_path).await; + if rename_dat.is_err() || rename_ct.is_err() { + // rename 失败：清理可能残留的临时文件与目标，避免读到错配内容。 + let _ = tokio::fs::remove_file(&dat_tmp).await; + let _ = tokio::fs::remove_file(&ct_tmp).await; + tracing::warn!("Failed to atomically rename disk cache at {}", base); } }