k8s.io/apiserver@v0.31.1/pkg/storage/etcd3/event.go (about) 1 /* 2 Copyright 2016 The Kubernetes Authors. 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package etcd3 18 19 import ( 20 "fmt" 21 "go.etcd.io/etcd/api/v3/mvccpb" 22 clientv3 "go.etcd.io/etcd/client/v3" 23 ) 24 25 type event struct { 26 key string 27 value []byte 28 prevValue []byte 29 rev int64 30 isDeleted bool 31 isCreated bool 32 isProgressNotify bool 33 // isInitialEventsEndBookmark helps us keep track 34 // of whether we have sent an annotated bookmark event. 35 // 36 // when this variable is set to true, 37 // a special annotation will be added 38 // to the bookmark event. 39 // 40 // note that we decided to extend the event 41 // struct field to eliminate contention 42 // between startWatching and processEvent 43 isInitialEventsEndBookmark bool 44 } 45 46 // parseKV converts a KeyValue retrieved from an initial sync() listing to a synthetic isCreated event. 47 func parseKV(kv *mvccpb.KeyValue) *event { 48 return &event{ 49 key: string(kv.Key), 50 value: kv.Value, 51 prevValue: nil, 52 rev: kv.ModRevision, 53 isDeleted: false, 54 isCreated: true, 55 } 56 } 57 58 func parseEvent(e *clientv3.Event) (*event, error) { 59 if !e.IsCreate() && e.PrevKv == nil { 60 // If the previous value is nil, error. One example of how this is possible is if the previous value has been compacted already. 61 return nil, fmt.Errorf("etcd event received with PrevKv=nil (key=%q, modRevision=%d, type=%s)", string(e.Kv.Key), e.Kv.ModRevision, e.Type.String()) 62 63 } 64 ret := &event{ 65 key: string(e.Kv.Key), 66 value: e.Kv.Value, 67 rev: e.Kv.ModRevision, 68 isDeleted: e.Type == clientv3.EventTypeDelete, 69 isCreated: e.IsCreate(), 70 } 71 if e.PrevKv != nil { 72 ret.prevValue = e.PrevKv.Value 73 } 74 return ret, nil 75 } 76 77 func progressNotifyEvent(rev int64) *event { 78 return &event{ 79 rev: rev, 80 isProgressNotify: true, 81 } 82 }