consul/vendor/github.com/hashicorp/raft/snapshot.go

41 lines
1.3 KiB
Go

package raft
import (
"io"
)
// SnapshotMeta is for metadata of a snapshot.
type SnapshotMeta struct {
ID string // ID is opaque to the store, and is used for opening
Index uint64
Term uint64
Peers []byte
Size int64
}
// SnapshotStore interface is used to allow for flexible implementations
// of snapshot storage and retrieval. For example, a client could implement
// a shared state store such as S3, allowing new nodes to restore snapshots
// without steaming from the leader.
type SnapshotStore interface {
// Create is used to begin a snapshot at a given index and term,
// with the current peer set already encoded.
Create(index, term uint64, peers []byte) (SnapshotSink, error)
// List is used to list the available snapshots in the store.
// It should return then in descending order, with the highest index first.
List() ([]*SnapshotMeta, error)
// Open takes a snapshot ID and provides a ReadCloser. Once close is
// called it is assumed the snapshot is no longer needed.
Open(id string) (*SnapshotMeta, io.ReadCloser, error)
}
// SnapshotSink is returned by StartSnapshot. The FSM will Write state
// to the sink and call Close on completion. On error, Cancel will be invoked.
type SnapshotSink interface {
io.WriteCloser
ID() string
Cancel() error
}