Function FromOutgoingContext

metadata/metadata.go:260–290

FromOutgoingContext returns the outgoing metadata in ctx if it exists. All keys in the returned MD are lowercase.

(ctx context.Context)

//
// All keys in the returned MD are lowercase.
func FromOutgoingContext(ctx context.Context) (MD, bool) {
	raw, ok := ctx.Value(mdOutgoingKey{}).(rawMD)
	if !ok {
		return nil, false
	}

	mdSize := len(raw.md)
	for i := range raw.added {
		mdSize += len(raw.added[i]) / 2
	}

	out := make(MD, mdSize)
	for k, v := range raw.md {
		// We need to manually convert all keys to lower case, because MD is a
		// map, and there's no guarantee that the MD attached to the context is
		// created using our helper functions.
		key := strings.ToLower(k)
		out[key] = copyOf(v)
	}
	for _, added := range raw.added {
		if len(added)%2 == 1 {
			panic(fmt.Sprintf("metadata: FromOutgoingContext got an odd number of input pairs for metadata: %d", len(added)))
		}

		for i := 0; i < len(added); i += 2 {
			key := strings.ToLower(added[i])
			out[key] = append(out[key], added[i+1])
		}
	}
	return out, ok
}

type rawMD struct {
	md    MD