AUTH-2105: Adds support for local forwarding. Refactor auditlogger creation.

AUTH-2088: Adds dynamic destination routing

vendor/google.golang.org/grpc/rpc_util.go

@@ -694,14 +694,34 @@ func recv(p *parser, c baseCodec, s *transport.Stream, dc Decompressor, m interf
 	return nil
 }
 
+// Information about RPC
 type rpcInfo struct {
-	failfast bool
+	failfast      bool
+	preloaderInfo *compressorInfo
+}
+
+// Information about Preloader
+// Responsible for storing codec, and compressors
+// If stream (s) has  context s.Context which stores rpcInfo that has non nil
+// pointers to codec, and compressors, then we can use preparedMsg for Async message prep
+// and reuse marshalled bytes
+type compressorInfo struct {
+	codec baseCodec
+	cp    Compressor
+	comp  encoding.Compressor
 }
 
 type rpcInfoContextKey struct{}
 
-func newContextWithRPCInfo(ctx context.Context, failfast bool) context.Context {
-	return context.WithValue(ctx, rpcInfoContextKey{}, &rpcInfo{failfast: failfast})
+func newContextWithRPCInfo(ctx context.Context, failfast bool, codec baseCodec, cp Compressor, comp encoding.Compressor) context.Context {
+	return context.WithValue(ctx, rpcInfoContextKey{}, &rpcInfo{
+		failfast: failfast,
+		preloaderInfo: &compressorInfo{
+			codec: codec,
+			cp:    cp,
+			comp:  comp,
+		},
+	})
 }
 
 func rpcInfoFromContext(ctx context.Context) (s *rpcInfo, ok bool) {