etcd/store/event_history.go
Xiang Li 53084ebead etcd: fix refresh feature
When using refresh, etcd store v2 watch is broken. Although with refresh
store should not trigger current watchers, it should still add events into
the watchhub to make a complete history. Current store fails to add the event
into the watchhub, which causes issues.
2016-05-25 13:33:31 -07:00

130 lines
2.9 KiB
Go

// Copyright 2015 The etcd Authors
//
// 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 store
import (
"fmt"
"path"
"strings"
"sync"
etcdErr "github.com/coreos/etcd/error"
)
type EventHistory struct {
Queue eventQueue
StartIndex uint64
LastIndex uint64
rwl sync.RWMutex
}
func newEventHistory(capacity int) *EventHistory {
return &EventHistory{
Queue: eventQueue{
Capacity: capacity,
Events: make([]*Event, capacity),
},
}
}
// addEvent function adds event into the eventHistory
func (eh *EventHistory) addEvent(e *Event) *Event {
eh.rwl.Lock()
defer eh.rwl.Unlock()
eh.Queue.insert(e)
eh.LastIndex = e.Index()
eh.StartIndex = eh.Queue.Events[eh.Queue.Front].Index()
return e
}
// scan enumerates events from the index history and stops at the first point
// where the key matches.
func (eh *EventHistory) scan(key string, recursive bool, index uint64) (*Event, *etcdErr.Error) {
eh.rwl.RLock()
defer eh.rwl.RUnlock()
// index should be after the event history's StartIndex
if index < eh.StartIndex {
return nil,
etcdErr.NewError(etcdErr.EcodeEventIndexCleared,
fmt.Sprintf("the requested history has been cleared [%v/%v]",
eh.StartIndex, index), 0)
}
// the index should come before the size of the queue minus the duplicate count
if index > eh.LastIndex { // future index
return nil, nil
}
offset := index - eh.StartIndex
i := (eh.Queue.Front + int(offset)) % eh.Queue.Capacity
for {
e := eh.Queue.Events[i]
if !e.Refresh {
ok := (e.Node.Key == key)
if recursive {
// add tailing slash
key = path.Clean(key)
if key[len(key)-1] != '/' {
key = key + "/"
}
ok = ok || strings.HasPrefix(e.Node.Key, key)
}
if (e.Action == Delete || e.Action == Expire) && e.PrevNode != nil && e.PrevNode.Dir {
ok = ok || strings.HasPrefix(key, e.PrevNode.Key)
}
if ok {
return e, nil
}
}
i = (i + 1) % eh.Queue.Capacity
if i == eh.Queue.Back {
return nil, nil
}
}
}
// clone will be protected by a stop-world lock
// do not need to obtain internal lock
func (eh *EventHistory) clone() *EventHistory {
clonedQueue := eventQueue{
Capacity: eh.Queue.Capacity,
Events: make([]*Event, eh.Queue.Capacity),
Size: eh.Queue.Size,
Front: eh.Queue.Front,
Back: eh.Queue.Back,
}
copy(clonedQueue.Events, eh.Queue.Events)
return &EventHistory{
StartIndex: eh.StartIndex,
Queue: clonedQueue,
LastIndex: eh.LastIndex,
}
}