mirror of
https://github.com/etcd-io/etcd.git
synced 2024-09-27 06:25:44 +00:00
130 lines
3.3 KiB
Go
130 lines
3.3 KiB
Go
// Copyright 2016 CoreOS, Inc.
|
|
//
|
|
// Licensed 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 recipe
|
|
|
|
import (
|
|
"sync"
|
|
"time"
|
|
|
|
"github.com/coreos/etcd/Godeps/_workspace/src/golang.org/x/net/context"
|
|
"github.com/coreos/etcd/clientv3"
|
|
pb "github.com/coreos/etcd/etcdserver/etcdserverpb"
|
|
"github.com/coreos/etcd/lease"
|
|
)
|
|
|
|
// only keep one ephemeral lease per client
|
|
var clientLeases clientLeaseMgr = clientLeaseMgr{leases: make(map[*clientv3.Client]*leaseKeepAlive)}
|
|
|
|
type clientLeaseMgr struct {
|
|
leases map[*clientv3.Client]*leaseKeepAlive
|
|
mu sync.Mutex
|
|
}
|
|
|
|
type leaseKeepAlive struct {
|
|
id lease.LeaseID
|
|
donec chan struct{}
|
|
}
|
|
|
|
func SessionLease(client *clientv3.Client) (lease.LeaseID, error) {
|
|
return clientLeases.sessionLease(client, 120)
|
|
}
|
|
|
|
func SessionLeaseTTL(client *clientv3.Client, ttl int64) (lease.LeaseID, error) {
|
|
return clientLeases.sessionLease(client, ttl)
|
|
}
|
|
|
|
// StopSessionLease ends the refresh for the session lease. This is useful
|
|
// in case the state of the client connection is indeterminate (revoke
|
|
// would fail) or if transferring lease ownership.
|
|
func StopSessionLease(client *clientv3.Client) {
|
|
clientLeases.mu.Lock()
|
|
lka, ok := clientLeases.leases[client]
|
|
if ok {
|
|
delete(clientLeases.leases, client)
|
|
}
|
|
clientLeases.mu.Unlock()
|
|
if lka != nil {
|
|
lka.donec <- struct{}{}
|
|
<-lka.donec
|
|
}
|
|
}
|
|
|
|
// RevokeSessionLease revokes the session lease.
|
|
func RevokeSessionLease(client *clientv3.Client) (err error) {
|
|
clientLeases.mu.Lock()
|
|
lka := clientLeases.leases[client]
|
|
clientLeases.mu.Unlock()
|
|
StopSessionLease(client)
|
|
if lka != nil {
|
|
req := &pb.LeaseRevokeRequest{ID: int64(lka.id)}
|
|
_, err = client.Lease.LeaseRevoke(context.TODO(), req)
|
|
}
|
|
return err
|
|
}
|
|
|
|
func (clm *clientLeaseMgr) sessionLease(client *clientv3.Client, ttl int64) (lease.LeaseID, error) {
|
|
clm.mu.Lock()
|
|
defer clm.mu.Unlock()
|
|
if lka, ok := clm.leases[client]; ok {
|
|
return lka.id, nil
|
|
}
|
|
|
|
resp, err := client.Lease.LeaseCreate(context.TODO(), &pb.LeaseCreateRequest{TTL: ttl})
|
|
if err != nil {
|
|
return lease.NoLease, err
|
|
}
|
|
id := lease.LeaseID(resp.ID)
|
|
|
|
ctx, cancel := context.WithCancel(context.Background())
|
|
keepAlive, err := client.Lease.LeaseKeepAlive(ctx)
|
|
if err != nil || keepAlive == nil {
|
|
return lease.NoLease, err
|
|
}
|
|
|
|
lka := &leaseKeepAlive{id: id, donec: make(chan struct{})}
|
|
clm.leases[client] = lka
|
|
|
|
// keep the lease alive until client error
|
|
go func() {
|
|
defer func() {
|
|
keepAlive.CloseSend()
|
|
clm.mu.Lock()
|
|
delete(clm.leases, client)
|
|
clm.mu.Unlock()
|
|
cancel()
|
|
close(lka.donec)
|
|
}()
|
|
|
|
ttl := resp.TTL
|
|
for {
|
|
lreq := &pb.LeaseKeepAliveRequest{ID: int64(id)}
|
|
select {
|
|
case <-lka.donec:
|
|
return
|
|
case <-time.After(time.Duration(ttl/2) * time.Second):
|
|
}
|
|
if err := keepAlive.Send(lreq); err != nil {
|
|
break
|
|
}
|
|
resp, err := keepAlive.Recv()
|
|
if err != nil {
|
|
break
|
|
}
|
|
ttl = resp.TTL
|
|
}
|
|
}()
|
|
|
|
return id, nil
|
|
}
|