Files
nats-server/server/store.go
Derek Collison c3a5df135f Observable state storage
Signed-off-by: Derek Collison <derek@nats.io>
2020-05-19 14:12:28 -07:00

82 lines
2.3 KiB
Go

// Copyright 2019 The NATS 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 server
import (
"errors"
"time"
)
// StorageType determines how messages are stored for retention.
type StorageType int
const (
// Memory specifies in memory only.
MemoryStorage StorageType = iota
// File specifies on disk, designated by the JetStream config StoreDir.
FileStorage
)
type MsgSetStore interface {
StoreMsg(subj string, msg []byte) (uint64, error)
LoadMsg(seq uint64) (subj string, msg []byte, ts int64, err error)
RemoveMsg(seq uint64) bool
EraseMsg(seq uint64) bool
Purge() uint64
GetSeqFromTime(t time.Time) uint64
StorageBytesUpdate(func(int64))
Stats() MsgSetStats
Stop()
ObservableStore(name string) (ObservableStore, error)
}
// MsgSetStats are stats about this given message set.
type MsgSetStats struct {
Msgs uint64
Bytes uint64
FirstSeq uint64
LastSeq uint64
}
type ObservableStore interface {
State() (*ObservableState, error)
Config() (*ObservableConfig, error)
Update(*ObservableState) error
Stop()
}
// SequencePair has both the observable and the message set sequence. This point to same message.
type SequencePair struct {
ObsSeq uint64
SetSeq uint64
}
// ObservableState represents a stored state for an observable.
type ObservableState struct {
// Delivered keep track of last delivered sequence numbers for both set and observable.
Delivered SequencePair
// AckFloor keeps track of the ack floors for both set and observable.
AckFloor SequencePair
// These are both in set sequence context.
// Pending is for all messages pending and the timestamp for the delivered time.
// This will only be present when the AckPolicy is ExplicitAck.
Pending map[uint64]int64
// This is for messages that have been redelivered, so count > 1.
Redelivery map[uint64]uint64
}
var (
ErrStoreMsgNotFound = errors.New("no message found")
)