milvus/internal/kv/etcd/embed_etcd_kv.go
shaoyue 34fadc9ab6
[skip ci] Add comment for EmbedEtcdKV (#12964)
Signed-off-by: shaoyue.chen <shaoyue.chen@zilliz.com>
2021-12-08 15:11:33 +08:00

383 lines
12 KiB
Go

// Licensed to the LF AI & Data foundation under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package etcdkv
import (
"context"
"errors"
"fmt"
"path"
"sync"
"time"
clientv3 "go.etcd.io/etcd/client/v3"
"go.etcd.io/etcd/server/v3/embed"
"go.etcd.io/etcd/server/v3/etcdserver/api/v3client"
"go.uber.org/zap"
"github.com/milvus-io/milvus/internal/log"
)
type EmbedEtcdKV struct {
client *clientv3.Client
rootPath string
etcd *embed.Etcd
closeOnce sync.Once
}
// NewEmbededEtcdKV creates a new etcd kv.
func NewEmbededEtcdKV(cfg *embed.Config, rootPath string) (*EmbedEtcdKV, error) {
e, err := embed.StartEtcd(cfg)
if err != nil {
return nil, err
}
client := v3client.New(e.Server)
kv := &EmbedEtcdKV{
client: client,
rootPath: rootPath,
etcd: e,
}
//wait until embed etcd is ready
select {
case <-e.Server.ReadyNotify():
log.Info("Embedded etcd is ready!")
case <-time.After(60 * time.Second):
e.Server.Stop() // trigger a shutdown
return nil, errors.New("Embedded etcd took too long to start")
}
return kv, nil
}
// Close closes the embedded etcd
func (kv *EmbedEtcdKV) Close() {
kv.closeOnce.Do(func() {
kv.client.Close()
kv.etcd.Close()
})
}
// GetPath returns the full path by given key
func (kv *EmbedEtcdKV) GetPath(key string) string {
return path.Join(kv.rootPath, key)
}
// LoadWithPrefix returns all the keys and values with the given key prefix
func (kv *EmbedEtcdKV) LoadWithPrefix(key string) ([]string, []string, error) {
key = path.Join(kv.rootPath, key)
log.Debug("LoadWithPrefix ", zap.String("prefix", key))
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Get(ctx, key, clientv3.WithPrefix(),
clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend))
if err != nil {
return nil, nil, err
}
keys := make([]string, 0, resp.Count)
values := make([]string, 0, resp.Count)
for _, kv := range resp.Kvs {
keys = append(keys, string(kv.Key))
values = append(values, string(kv.Value))
}
return keys, values, nil
}
// LoadWithPrefix2 returns all the keys and values with versions by the given key prefix
func (kv *EmbedEtcdKV) LoadWithPrefix2(key string) ([]string, []string, []int64, error) {
key = path.Join(kv.rootPath, key)
log.Debug("LoadWithPrefix ", zap.String("prefix", key))
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Get(ctx, key, clientv3.WithPrefix(),
clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend))
if err != nil {
return nil, nil, nil, err
}
keys := make([]string, 0, resp.Count)
values := make([]string, 0, resp.Count)
versions := make([]int64, 0, resp.Count)
for _, kv := range resp.Kvs {
keys = append(keys, string(kv.Key))
values = append(values, string(kv.Value))
versions = append(versions, kv.Version)
}
return keys, values, versions, nil
}
func (kv *EmbedEtcdKV) Load(key string) (string, error) {
key = path.Join(kv.rootPath, key)
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Get(ctx, key)
if err != nil {
return "", err
}
if resp.Count <= 0 {
return "", fmt.Errorf("there is no value on key = %s", key)
}
return string(resp.Kvs[0].Value), nil
}
func (kv *EmbedEtcdKV) MultiLoad(keys []string) ([]string, error) {
ops := make([]clientv3.Op, 0, len(keys))
for _, keyLoad := range keys {
ops = append(ops, clientv3.OpGet(path.Join(kv.rootPath, keyLoad)))
}
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
if err != nil {
return []string{}, err
}
result := make([]string, 0, len(keys))
invalid := make([]string, 0, len(keys))
for index, rp := range resp.Responses {
if rp.GetResponseRange().Kvs == nil || len(rp.GetResponseRange().Kvs) == 0 {
invalid = append(invalid, keys[index])
result = append(result, "")
}
for _, ev := range rp.GetResponseRange().Kvs {
log.Debug("MultiLoad", zap.ByteString("key", ev.Key),
zap.ByteString("value", ev.Value))
result = append(result, string(ev.Value))
}
}
if len(invalid) != 0 {
log.Debug("MultiLoad: there are invalid keys",
zap.Strings("keys", invalid))
err = fmt.Errorf("there are invalid keys: %s", invalid)
return result, err
}
return result, nil
}
func (kv *EmbedEtcdKV) LoadWithRevision(key string) ([]string, []string, int64, error) {
key = path.Join(kv.rootPath, key)
log.Debug("LoadWithPrefix ", zap.String("prefix", key))
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Get(ctx, key, clientv3.WithPrefix(),
clientv3.WithSort(clientv3.SortByKey, clientv3.SortAscend))
if err != nil {
return nil, nil, 0, err
}
keys := make([]string, 0, resp.Count)
values := make([]string, 0, resp.Count)
for _, kv := range resp.Kvs {
keys = append(keys, string(kv.Key))
values = append(values, string(kv.Value))
}
return keys, values, resp.Header.Revision, nil
}
func (kv *EmbedEtcdKV) Save(key, value string) error {
key = path.Join(kv.rootPath, key)
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Put(ctx, key, value)
return err
}
// SaveWithLease is a function to put value in etcd with etcd lease options.
func (kv *EmbedEtcdKV) SaveWithLease(key, value string, id clientv3.LeaseID) error {
key = path.Join(kv.rootPath, key)
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Put(ctx, key, value, clientv3.WithLease(id))
return err
}
func (kv *EmbedEtcdKV) MultiSave(kvs map[string]string) error {
ops := make([]clientv3.Op, 0, len(kvs))
for key, value := range kvs {
ops = append(ops, clientv3.OpPut(path.Join(kv.rootPath, key), value))
}
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
return err
}
func (kv *EmbedEtcdKV) RemoveWithPrefix(prefix string) error {
key := path.Join(kv.rootPath, prefix)
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Delete(ctx, key, clientv3.WithPrefix())
return err
}
func (kv *EmbedEtcdKV) Remove(key string) error {
key = path.Join(kv.rootPath, key)
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Delete(ctx, key)
return err
}
func (kv *EmbedEtcdKV) MultiRemove(keys []string) error {
ops := make([]clientv3.Op, 0, len(keys))
for _, key := range keys {
ops = append(ops, clientv3.OpDelete(path.Join(kv.rootPath, key)))
}
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
return err
}
func (kv *EmbedEtcdKV) MultiSaveAndRemove(saves map[string]string, removals []string) error {
ops := make([]clientv3.Op, 0, len(saves)+len(removals))
for key, value := range saves {
ops = append(ops, clientv3.OpPut(path.Join(kv.rootPath, key), value))
}
for _, keyDelete := range removals {
ops = append(ops, clientv3.OpDelete(path.Join(kv.rootPath, keyDelete)))
}
log.Debug("MultiSaveAndRemove")
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
return err
}
func (kv *EmbedEtcdKV) Watch(key string) clientv3.WatchChan {
key = path.Join(kv.rootPath, key)
rch := kv.client.Watch(context.Background(), key, clientv3.WithCreatedNotify())
return rch
}
func (kv *EmbedEtcdKV) WatchWithPrefix(key string) clientv3.WatchChan {
key = path.Join(kv.rootPath, key)
rch := kv.client.Watch(context.Background(), key, clientv3.WithPrefix(), clientv3.WithCreatedNotify())
return rch
}
func (kv *EmbedEtcdKV) WatchWithRevision(key string, revision int64) clientv3.WatchChan {
key = path.Join(kv.rootPath, key)
rch := kv.client.Watch(context.Background(), key, clientv3.WithPrefix(), clientv3.WithPrevKV(), clientv3.WithRev(revision))
return rch
}
func (kv *EmbedEtcdKV) MultiRemoveWithPrefix(keys []string) error {
ops := make([]clientv3.Op, 0, len(keys))
for _, k := range keys {
op := clientv3.OpDelete(path.Join(kv.rootPath, k), clientv3.WithPrefix())
ops = append(ops, op)
}
log.Debug("MultiRemoveWithPrefix")
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
return err
}
func (kv *EmbedEtcdKV) MultiSaveAndRemoveWithPrefix(saves map[string]string, removals []string) error {
ops := make([]clientv3.Op, 0, len(saves))
for key, value := range saves {
ops = append(ops, clientv3.OpPut(path.Join(kv.rootPath, key), value))
}
for _, keyDelete := range removals {
ops = append(ops, clientv3.OpDelete(path.Join(kv.rootPath, keyDelete), clientv3.WithPrefix()))
}
log.Debug("MultiSaveAndRemove")
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
_, err := kv.client.Txn(ctx).If().Then(ops...).Commit()
return err
}
// Grant creates a new lease implemented in etcd grant interface.
func (kv *EmbedEtcdKV) Grant(ttl int64) (id clientv3.LeaseID, err error) {
resp, err := kv.client.Grant(context.Background(), ttl)
return resp.ID, err
}
// KeepAlive keeps the lease alive forever with leaseID.
// Implemented in etcd interface.
func (kv *EmbedEtcdKV) KeepAlive(id clientv3.LeaseID) (<-chan *clientv3.LeaseKeepAliveResponse, error) {
ch, err := kv.client.KeepAlive(context.Background(), id)
if err != nil {
return nil, err
}
return ch, nil
}
// CompareValueAndSwap compares the existing value with compare, and if they are
// equal, the target is stored in etcd.
func (kv *EmbedEtcdKV) CompareValueAndSwap(key, value, target string, opts ...clientv3.OpOption) error {
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Txn(ctx).If(
clientv3.Compare(
clientv3.Value(path.Join(kv.rootPath, key)),
"=",
value)).
Then(clientv3.OpPut(path.Join(kv.rootPath, key), target, opts...)).Commit()
if err != nil {
return err
}
if !resp.Succeeded {
return fmt.Errorf("function CompareAndSwap error for compare is false for key: %s", key)
}
return nil
}
// CompareVersionAndSwap compares the existing key-value's version with version, and if
// they are equal, the target is stored in etcd.
func (kv *EmbedEtcdKV) CompareVersionAndSwap(key string, version int64, target string, opts ...clientv3.OpOption) error {
ctx, cancel := context.WithTimeout(context.TODO(), RequestTimeout)
defer cancel()
resp, err := kv.client.Txn(ctx).If(
clientv3.Compare(
clientv3.Version(path.Join(kv.rootPath, key)),
"=",
version)).
Then(clientv3.OpPut(path.Join(kv.rootPath, key), target, opts...)).Commit()
if err != nil {
return err
}
if !resp.Succeeded {
return fmt.Errorf("function CompareAndSwap error for compare is false for key: %s", key)
}
return nil
}
func (kv *EmbedEtcdKV) GetConfig() embed.Config {
return kv.etcd.Config()
}