Scott Baker | 2c1c482 | 2019-10-16 11:02:41 -0700 | [diff] [blame] | 1 | // Copyright 2016 The etcd Authors |
| 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 concurrency |
| 16 | |
| 17 | import ( |
| 18 | "context" |
| 19 | "fmt" |
| 20 | |
| 21 | v3 "go.etcd.io/etcd/clientv3" |
| 22 | pb "go.etcd.io/etcd/etcdserver/etcdserverpb" |
| 23 | "go.etcd.io/etcd/mvcc/mvccpb" |
| 24 | ) |
| 25 | |
| 26 | func waitDelete(ctx context.Context, client *v3.Client, key string, rev int64) error { |
| 27 | cctx, cancel := context.WithCancel(ctx) |
| 28 | defer cancel() |
| 29 | |
| 30 | var wr v3.WatchResponse |
| 31 | wch := client.Watch(cctx, key, v3.WithRev(rev)) |
| 32 | for wr = range wch { |
| 33 | for _, ev := range wr.Events { |
| 34 | if ev.Type == mvccpb.DELETE { |
| 35 | return nil |
| 36 | } |
| 37 | } |
| 38 | } |
| 39 | if err := wr.Err(); err != nil { |
| 40 | return err |
| 41 | } |
| 42 | if err := ctx.Err(); err != nil { |
| 43 | return err |
| 44 | } |
| 45 | return fmt.Errorf("lost watcher waiting for delete") |
| 46 | } |
| 47 | |
| 48 | // waitDeletes efficiently waits until all keys matching the prefix and no greater |
| 49 | // than the create revision. |
| 50 | func waitDeletes(ctx context.Context, client *v3.Client, pfx string, maxCreateRev int64) (*pb.ResponseHeader, error) { |
| 51 | getOpts := append(v3.WithLastCreate(), v3.WithMaxCreateRev(maxCreateRev)) |
| 52 | for { |
| 53 | resp, err := client.Get(ctx, pfx, getOpts...) |
| 54 | if err != nil { |
| 55 | return nil, err |
| 56 | } |
| 57 | if len(resp.Kvs) == 0 { |
| 58 | return resp.Header, nil |
| 59 | } |
| 60 | lastKey := string(resp.Kvs[0].Key) |
| 61 | if err = waitDelete(ctx, client, lastKey, resp.Header.Revision); err != nil { |
| 62 | return nil, err |
| 63 | } |
| 64 | } |
| 65 | } |