Girish Kumar | 46d7c3a | 2020-05-18 12:06:33 +0000 | [diff] [blame] | 1 | // Copyright (c) 2017 Uber Technologies, Inc. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package baggage |
| 16 | |
| 17 | const ( |
| 18 | defaultMaxValueLength = 2048 |
| 19 | ) |
| 20 | |
| 21 | // Restriction determines whether a baggage key is allowed and contains any restrictions on the baggage value. |
| 22 | type Restriction struct { |
| 23 | keyAllowed bool |
| 24 | maxValueLength int |
| 25 | } |
| 26 | |
| 27 | // NewRestriction returns a new Restriction. |
| 28 | func NewRestriction(keyAllowed bool, maxValueLength int) *Restriction { |
| 29 | return &Restriction{ |
| 30 | keyAllowed: keyAllowed, |
| 31 | maxValueLength: maxValueLength, |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | // KeyAllowed returns whether the baggage key for this restriction is allowed. |
| 36 | func (r *Restriction) KeyAllowed() bool { |
| 37 | return r.keyAllowed |
| 38 | } |
| 39 | |
| 40 | // MaxValueLength returns the max length for the baggage value. |
| 41 | func (r *Restriction) MaxValueLength() int { |
| 42 | return r.maxValueLength |
| 43 | } |
| 44 | |
| 45 | // RestrictionManager keeps track of valid baggage keys and their restrictions. The manager |
| 46 | // will return a Restriction for a specific baggage key which will determine whether the baggage |
| 47 | // key is allowed for the current service and any other applicable restrictions on the baggage |
| 48 | // value. |
| 49 | type RestrictionManager interface { |
| 50 | GetRestriction(service, key string) *Restriction |
| 51 | } |
| 52 | |
| 53 | // DefaultRestrictionManager allows any baggage key. |
| 54 | type DefaultRestrictionManager struct { |
| 55 | defaultRestriction *Restriction |
| 56 | } |
| 57 | |
| 58 | // NewDefaultRestrictionManager returns a DefaultRestrictionManager. |
| 59 | func NewDefaultRestrictionManager(maxValueLength int) *DefaultRestrictionManager { |
| 60 | if maxValueLength == 0 { |
| 61 | maxValueLength = defaultMaxValueLength |
| 62 | } |
| 63 | return &DefaultRestrictionManager{ |
| 64 | defaultRestriction: &Restriction{keyAllowed: true, maxValueLength: maxValueLength}, |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // GetRestriction implements RestrictionManager#GetRestriction. |
| 69 | func (m *DefaultRestrictionManager) GetRestriction(service, key string) *Restriction { |
| 70 | return m.defaultRestriction |
| 71 | } |