restriction_manager.go 2.6 KB

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  1. // Copyright (c) 2017 Uber Technologies, Inc.
  2. //
  3. // Permission is hereby granted, free of charge, to any person obtaining a copy
  4. // of this software and associated documentation files (the "Software"), to deal
  5. // in the Software without restriction, including without limitation the rights
  6. // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  7. // copies of the Software, and to permit persons to whom the Software is
  8. // furnished to do so, subject to the following conditions:
  9. //
  10. // The above copyright notice and this permission notice shall be included in
  11. // all copies or substantial portions of the Software.
  12. //
  13. // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  14. // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  15. // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  16. // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  17. // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  18. // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  19. // THE SOFTWARE.
  20. package baggage
  21. const (
  22. defaultMaxValueLength = 2048
  23. )
  24. // Restriction determines whether a baggage key is allowed and contains any restrictions on the baggage value.
  25. type Restriction struct {
  26. keyAllowed bool
  27. maxValueLength int
  28. }
  29. // NewRestriction returns a new Restriction.
  30. func NewRestriction(keyAllowed bool, maxValueLength int) *Restriction {
  31. return &Restriction{
  32. keyAllowed: keyAllowed,
  33. maxValueLength: maxValueLength,
  34. }
  35. }
  36. // KeyAllowed returns whether the baggage key for this restriction is allowed.
  37. func (r *Restriction) KeyAllowed() bool {
  38. return r.keyAllowed
  39. }
  40. // MaxValueLength returns the max length for the baggage value.
  41. func (r *Restriction) MaxValueLength() int {
  42. return r.maxValueLength
  43. }
  44. // RestrictionManager keeps track of valid baggage keys and their restrictions.
  45. type RestrictionManager interface {
  46. GetRestriction(key string) *Restriction
  47. }
  48. // DefaultRestrictionManager allows any baggage key.
  49. type DefaultRestrictionManager struct {
  50. defaultRestriction *Restriction
  51. }
  52. // NewDefaultRestrictionManager returns a DefaultRestrictionManager.
  53. func NewDefaultRestrictionManager(maxValueLength int) *DefaultRestrictionManager {
  54. if maxValueLength == 0 {
  55. maxValueLength = defaultMaxValueLength
  56. }
  57. return &DefaultRestrictionManager{
  58. defaultRestriction: &Restriction{keyAllowed: true, maxValueLength: maxValueLength},
  59. }
  60. }
  61. // GetRestriction implements RestrictionManager#GetRestriction.
  62. func (m *DefaultRestrictionManager) GetRestriction(key string) *Restriction {
  63. return m.defaultRestriction
  64. }