etcdserver/snapshot_merge.go
func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapt, snapi uint64, confState raftpb.ConfState) snap.Message {
	// get a snapshot of v2 store as []byte
	clone := s.v2store.Clone()
	d, err := clone.SaveNoCopy()
	if err != nil {
		if lg := s.getLogger(); lg != nil {
			lg.Panic("failed to save v2 store data", zap.Error(err))
		} else {
			plog.Panicf("store save should never fail: %v", err)
		}
	}

	// commit kv to write metadata(for example: consistent index).
	s.KV().Commit()
	dbsnap := s.be.Snapshot()
	// get a snapshot of v3 KV as readCloser
	rc := newSnapshotReaderCloser(s.getLogger(), dbsnap)

	// put the []byte snapshot of store into raft snapshot and return the merged snapshot with
	// KV readCloser snapshot.
	snapshot := raftpb.Snapshot{
		Metadata: raftpb.SnapshotMetadata{
			Index:     snapi,
			Term:      snapt,
			ConfState: confState,
		},
		Data: d,
	}
	m.Snapshot = snapshot

	return *snap.NewMessage(m, rc, dbsnap.Size())
}
func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapt, snapi uint64, confState raftpb.ConfState) snap.Message {
	// get a snapshot of v2 store as []byte
	clone := s.v2store.Clone()
	d, err := clone.SaveNoCopy()
	if err != nil {
		if lg := s.getLogger(); lg != nil {
			lg.Panic("failed to save v2 store data", zap.Error(err))
		} else {
			plog.Panicf("store save should never fail: %v", err)
		}
	}

	// commit kv to write metadata(for example: consistent index).
	s.KV().Commit()
	dbsnap := s.be.Snapshot()
	// get a snapshot of v3 KV as readCloser
	rc := newSnapshotReaderCloser(s.getLogger(), dbsnap)

	// put the []byte snapshot of store into raft snapshot and return the merged snapshot with
	// KV readCloser snapshot.
	snapshot := raftpb.Snapshot{
		Metadata: raftpb.SnapshotMetadata{
			Index:     snapi,
			Term:      snapt,
			ConfState: confState,
		},
		Data: d,
	}
	m.Snapshot = snapshot

	return *snap.NewMessage(m, rc, dbsnap.Size())
}
func ( s * EtcdServer ) createMergedSnapshotMessage ( m raftpb . Message , snapt , snapi uint64 , confState raftpb . ConfState ) snap . Message { // get a snapshot of v2 store as []byte clone := s . v2store . Clone ( ) d , err := clone . SaveNoCopy ( ) if err != nil { if lg := s . getLogger ( ) ; lg != nil { lg . Panic ( " " , zap . Error ( err ) ) } else { plog . Panicf ( " " , err ) } } // commit kv to write metadata(for example: consistent index). s . KV ( ) . Commit ( ) dbsnap := s . be . Snapshot ( ) // get a snapshot of v3 KV as readCloser rc := newSnapshotReaderCloser ( s . getLogger ( ) , dbsnap ) // put the []byte snapshot of store into raft snapshot and return the merged snapshot with // KV readCloser snapshot. snapshot := raftpb . Snapshot { Metadata : raftpb . SnapshotMetadata { Index : snapi , Term : snapt , ConfState : confState , } , Data : d , } m . Snapshot = snapshot return * snap . NewMessage ( m , rc , dbsnap . Size ( ) ) }
// createMergedSnapshotMessage creates a snapshot message that contains: raft status (term, conf),
// a snapshot of v2 store inside raft.Snapshot as []byte, a snapshot of v3 KV in the top level message
// as ReadCloser.
createMergedSnapshotMessage creates a snapshot message that contains : raft status ( term conf ) a snapshot of v2 store inside raft . Snapshot as [] byte a snapshot of v3 KV in the top level message as ReadCloser .