From ff6f4803d9b10ec0a1bfed5420eb354e8a71c59f Mon Sep 17 00:00:00 2001 From: "Dr. Stefan Schimanski" Date: Fri, 1 Jun 2018 22:31:25 +0000 Subject: [PATCH] apimachinery: adapt ObjectConvertor invariant We avoid deepcopies in the codec/conversion stack by re-using data structures. This means that the out object of a conversion must be deepcopied before mutation in order to not mutate the in object as well. This guarantees that e.g. runtime.Encode (which uses conversion from internal -> versioned) does not mutate the input. This would be highly unexpected (and we do not mention possible mutation of the input for runtime.Encode). --- .../k8s.io/apimachinery/pkg/runtime/interfaces.go | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/staging/src/k8s.io/apimachinery/pkg/runtime/interfaces.go b/staging/src/k8s.io/apimachinery/pkg/runtime/interfaces.go index cfe819e0a28..ba48e6146ed 100644 --- a/staging/src/k8s.io/apimachinery/pkg/runtime/interfaces.go +++ b/staging/src/k8s.io/apimachinery/pkg/runtime/interfaces.go @@ -174,13 +174,16 @@ type ObjectVersioner interface { // ObjectConvertor converts an object to a different version. type ObjectConvertor interface { - // Convert attempts to convert one object into another, or returns an error. This method does - // not guarantee the in object is not mutated. The context argument will be passed to - // all nested conversions. + // Convert attempts to convert one object into another, or returns an error. This + // method does not mutate the in object, but the in and out object might share data structures, + // i.e. the out object cannot be mutated without mutating the in object as well. + // The context argument will be passed to all nested conversions. Convert(in, out, context interface{}) error // ConvertToVersion takes the provided object and converts it the provided version. This - // method does not guarantee that the in object is not mutated. This method is similar to - // Convert() but handles specific details of choosing the correct output version. + // method does not mutate the in object, but the in and out object might share data structures, + // i.e. the out object cannot be mutated without mutating the in object as well. + // This method is similar to Convert() but handles specific details of choosing the correct + // output version. ConvertToVersion(in Object, gv GroupVersioner) (out Object, err error) ConvertFieldLabel(version, kind, label, value string) (string, string, error) }