mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
103 lines
3.0 KiB
Go
103 lines
3.0 KiB
Go
// Copyright 2016 CoreOS, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package concurrency
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import (
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"fmt"
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"math"
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"time"
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"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
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v3 "github.com/coreos/etcd/clientv3"
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"github.com/coreos/etcd/storage/storagepb"
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)
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// NewUniqueKey creates a new key from a given prefix.
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func NewUniqueKey(ctx context.Context, kv v3.KV, pfx string, opts ...v3.OpOption) (string, int64, error) {
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return NewUniqueKV(ctx, kv, pfx, "", opts...)
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}
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func NewUniqueKV(ctx context.Context, kv v3.KV, pfx, val string, opts ...v3.OpOption) (string, int64, error) {
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for {
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newKey := fmt.Sprintf("%s/%v", pfx, time.Now().UnixNano())
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put := v3.OpPut(newKey, val, opts...)
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cmp := v3.Compare(v3.ModifiedRevision(newKey), "=", 0)
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resp, err := kv.Txn(ctx).If(cmp).Then(put).Commit()
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if err != nil {
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return "", 0, err
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}
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if !resp.Succeeded {
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continue
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}
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return newKey, resp.Header.Revision, nil
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}
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}
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func waitUpdate(ctx context.Context, client *v3.Client, key string, opts ...v3.OpOption) error {
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cctx, cancel := context.WithCancel(ctx)
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defer cancel()
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wresp, ok := <-client.Watch(cctx, key, opts...)
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if !ok {
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return ctx.Err()
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}
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return wresp.Err()
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}
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func waitDelete(ctx context.Context, client *v3.Client, key string, rev int64) error {
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cctx, cancel := context.WithCancel(ctx)
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defer cancel()
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wch := client.Watch(cctx, key, v3.WithRev(rev))
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for wr := range wch {
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for _, ev := range wr.Events {
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if ev.Type == storagepb.DELETE {
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return nil
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}
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}
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}
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if err := ctx.Err(); err != nil {
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return err
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}
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return fmt.Errorf("lost watcher waiting for delete")
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}
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// waitDeletes efficiently waits until all keys matched by Get(key, opts...) are deleted
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func waitDeletes(ctx context.Context, client *v3.Client, key string, opts ...v3.OpOption) error {
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getOpts := []v3.OpOption{v3.WithSort(v3.SortByCreatedRev, v3.SortAscend)}
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getOpts = append(getOpts, opts...)
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resp, err := client.Get(ctx, key, getOpts...)
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maxRev := int64(math.MaxInt64)
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getOpts = append(getOpts, v3.WithRev(0))
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for err == nil {
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for len(resp.Kvs) > 0 {
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i := len(resp.Kvs) - 1
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if resp.Kvs[i].CreateRevision <= maxRev {
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break
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}
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resp.Kvs = resp.Kvs[:i]
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}
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if len(resp.Kvs) == 0 {
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break
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}
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lastKV := resp.Kvs[len(resp.Kvs)-1]
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maxRev = lastKV.CreateRevision
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err = waitDelete(ctx, client, string(lastKV.Key), maxRev)
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if err != nil || len(resp.Kvs) == 1 {
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break
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}
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getOpts = append(getOpts, v3.WithLimit(int64(len(resp.Kvs)-1)))
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resp, err = client.Get(ctx, key, getOpts...)
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}
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return err
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}
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