1/* 2 * 3 * Copyright 2019 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19package grpc 20 21import ( 22 "google.golang.org/grpc/codes" 23 "google.golang.org/grpc/status" 24) 25 26// PreparedMsg is responsible for creating a Marshalled and Compressed object. 27// 28// This API is EXPERIMENTAL. 29type PreparedMsg struct { 30 // Struct for preparing msg before sending them 31 encodedData []byte 32 hdr []byte 33 payload []byte 34} 35 36// Encode marshalls and compresses the message using the codec and compressor for the stream. 37func (p *PreparedMsg) Encode(s Stream, msg interface{}) error { 38 ctx := s.Context() 39 rpcInfo, ok := rpcInfoFromContext(ctx) 40 if !ok { 41 return status.Errorf(codes.Internal, "grpc: unable to get rpcInfo") 42 } 43 44 // check if the context has the relevant information to prepareMsg 45 if rpcInfo.preloaderInfo == nil { 46 return status.Errorf(codes.Internal, "grpc: rpcInfo.preloaderInfo is nil") 47 } 48 if rpcInfo.preloaderInfo.codec == nil { 49 return status.Errorf(codes.Internal, "grpc: rpcInfo.preloaderInfo.codec is nil") 50 } 51 52 // prepare the msg 53 data, err := encode(rpcInfo.preloaderInfo.codec, msg) 54 if err != nil { 55 return err 56 } 57 p.encodedData = data 58 compData, err := compress(data, rpcInfo.preloaderInfo.cp, rpcInfo.preloaderInfo.comp) 59 if err != nil { 60 return err 61 } 62 p.hdr, p.payload = msgHeader(data, compData) 63 return nil 64} 65