v0.34.7

src/cache/model/entry.rs

@@ -61,6 +61,10 @@ impl Settings {
             valid_relative_cache_path(&self.cold_path),
             "cache.cold_path must be a simple relative path inside the data directory"
         );
+        ensure!(
+            self.varnish_grace_seconds <= 604_800,
+            "cache.varnish_grace_seconds must be 0..604800"
+        );
         ensure!(
             (1..=604_800).contains(&self.max_ttl_seconds)
                 && self.default_ttl_seconds <= self.max_ttl_seconds,

src/cache/model/settings.rs

@@ -89,6 +89,8 @@ pub struct Settings {
     pub enabled: bool,
     /// Ignore client freshness directives on cache lookups, like Varnish builtin VCL.
     pub varnish_compatible: bool,
+    /// Implicit grace in seconds for eligible fresh-at-storage cached responses.
+    pub varnish_grace_seconds: u64,
     pub memory_preset: Option<MemoryPreset>,
     pub max_bytes: usize,
     pub max_object_bytes: usize,
@@ -143,6 +145,7 @@ impl Default for Settings {
         Self {
             enabled: true,
             varnish_compatible: true,
+            varnish_grace_seconds: 60,
             memory_preset: None,
             max_bytes: 256 * 1024 * 1024,
             max_object_bytes: 16 * 1024 * 1024,

src/cache/model/views.rs

@@ -132,13 +132,18 @@ fn stale_mode(
         return None;
     }
     let stale_for = age.saturating_sub(ttl);
+    let max_stale = client_max_stale(request_headers);
+    // An explicit client limit must also constrain implicit Varnish grace.
+    // In particular, max-stale=0 must not serve a stale representation.
+    if matches!(max_stale, Some(Some(limit)) if stale_for > limit) {
+        return None;
+    }
     if stale_while_revalidate > 0 && stale_for <= stale_while_revalidate {
         return Some(true);
     }
-    match client_max_stale(request_headers) {
-        Some(None) => Some(false),
-        Some(Some(limit)) if stale_for <= limit => Some(false),
-        _ => None,
+    match max_stale {
+        Some(None) | Some(Some(_)) => Some(false),
+        None => None,
     }
 }