util.go 1.3 KB

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