🐛 bug: apply limits to msgp serialization

middleware/cache/manager.go

@@ -12,16 +12,18 @@ import (
 )
 
 // msgp -file="manager.go" -o="manager_msgp.go" -tests=true -unexported
+// Default slice limits are sized for cache payloads, with tighter field caps below.
 //
 //go:generate msgp -o=manager_msgp.go -tests=true -unexported
+//nolint:revive // msgp requires tags on unexported fields for limit enforcement.
 type item struct {
-	headers         []cachedHeader
-	body            []byte
-	ctype           []byte
-	cencoding       []byte
-	cacheControl    []byte
-	expires         []byte
-	etag            []byte
+	headers         []cachedHeader `msg:",limit=1024"` // Typical HTTP header count stays well below this.
+	body            []byte         // Cache bodies are bounded by storage policy, not msgp limits.
+	ctype           []byte         `msg:",limit=256"`  // Content-Type values are short per RFCs.
+	cencoding       []byte         `msg:",limit=128"`  // Content-Encoding is typically a short token.
+	cacheControl    []byte         `msg:",limit=2048"` // Cache-Control directives are bounded.
+	expires         []byte         `msg:",limit=128"`  // Expires is a short HTTP-date string.
+	etag            []byte         `msg:",limit=256"`  // ETags are small tokens/quoted strings.
 	date            uint64
 	status          int
 	age             uint64
@@ -35,9 +37,10 @@ type item struct {
 	heapidx int
 }
 
+//nolint:revive // msgp requires tags on unexported fields for limit enforcement.
 type cachedHeader struct {
-	key   []byte
-	value []byte
+	key   []byte `msg:",limit=512"`   // Header names are small.
+	value []byte `msg:",limit=16384"` // Header values are bounded to reasonable sizes.
 }
 
 //msgp:ignore manager