util.go (1334B)
1 /* 2 * 3 * Copyright 2020 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 19 package credentials 20 21 import ( 22 "crypto/tls" 23 ) 24 25 const alpnProtoStrH2 = "h2" 26 27 // AppendH2ToNextProtos appends h2 to next protos. 28 func AppendH2ToNextProtos(ps []string) []string { 29 for _, p := range ps { 30 if p == alpnProtoStrH2 { 31 return ps 32 } 33 } 34 ret := make([]string, 0, len(ps)+1) 35 ret = append(ret, ps...) 36 return append(ret, alpnProtoStrH2) 37 } 38 39 // CloneTLSConfig returns a shallow clone of the exported 40 // fields of cfg, ignoring the unexported sync.Once, which 41 // contains a mutex and must not be copied. 42 // 43 // If cfg is nil, a new zero tls.Config is returned. 44 // 45 // TODO: inline this function if possible. 46 func CloneTLSConfig(cfg *tls.Config) *tls.Config { 47 if cfg == nil { 48 return &tls.Config{} 49 } 50 51 return cfg.Clone() 52 }