// 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.
func (s *EtcdServer) createMergedSnapshotMessage(m raftpb.Message, snapi uint64, confState raftpb.ConfState) snap.Message {
snapt, err := s.r.raftStorage.Term(snapi)
if err != nil {
log.Panicf("get term should never fail: %v", err)
}
// get a snapshot of v2 store as []byte
clone := s.store.Clone()
d, err := clone.SaveNoCopy()
if err != nil {
plog.Panicf("store save should never fail: %v", err)
}
dbsnap := s.be.Snapshot()
// get a snapshot of v3 KV as readCloser
rc := newSnapshotReaderCloser(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 TestSnapshotSend(t *testing.T) {
tests := []struct {
m raftpb.Message
rc io.ReadCloser
size int64
wsent bool
wfiles int
}{
// sent and receive with no errors
{
m: raftpb.Message{Type: raftpb.MsgSnap, To: 1},
rc: strReaderCloser{strings.NewReader("hello")},
size: 5,
wsent: true,
wfiles: 1,
},
// error when reading snapshot for send
{
m: raftpb.Message{Type: raftpb.MsgSnap, To: 1},
rc: &errReadCloser{fmt.Errorf("snapshot error")},
size: 1,
wsent: false,
wfiles: 0,
},
// sends less than the given snapshot length
{
m: raftpb.Message{Type: raftpb.MsgSnap, To: 1},
rc: strReaderCloser{strings.NewReader("hello")},
size: 10000,
wsent: false,
wfiles: 0,
},
// sends less than actual snapshot length
{
m: raftpb.Message{Type: raftpb.MsgSnap, To: 1},
rc: strReaderCloser{strings.NewReader("hello")},
size: 1,
wsent: false,
wfiles: 0,
},
}
for i, tt := range tests {
sent, files := testSnapshotSend(t, snap.NewMessage(tt.m, tt.rc, tt.size))
if tt.wsent != sent {
t.Errorf("#%d: snapshot expected %v, got %v", i, tt.wsent, sent)
}
if tt.wfiles != len(files) {
t.Fatalf("#%d: expected %d files, got %d files", i, tt.wfiles, len(files))
}
}
}