// NewFSM is used to construct a new FSM with a blank state
func NewFSM(gc *state.TombstoneGC, logOutput io.Writer) (*consulFSM, error) {
stateNew, err := state.NewStateStore(gc)
if err != nil {
return nil, err
}
fsm := &consulFSM{
logOutput: logOutput,
logger: log.New(logOutput, "", log.LstdFlags),
state: stateNew,
gc: gc,
}
return fsm, nil
}
func (c *consulFSM) Restore(old io.ReadCloser) error {
defer old.Close()
// Create a new state store
stateNew, err := state.NewStateStore(c.gc)
if err != nil {
return err
}
c.state = stateNew
// Set up a new restore transaction
restore := c.state.Restore()
defer restore.Abort()
// Create a decoder
dec := codec.NewDecoder(old, msgpackHandle)
// Read in the header
var header snapshotHeader
if err := dec.Decode(&header); err != nil {
return err
}
// Populate the new state
msgType := make([]byte, 1)
for {
// Read the message type
_, err := old.Read(msgType)
if err == io.EOF {
break
} else if err != nil {
return err
}
// Decode
switch structs.MessageType(msgType[0]) {
case structs.RegisterRequestType:
var req structs.RegisterRequest
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.Registration(header.LastIndex, &req); err != nil {
return err
}
case structs.KVSRequestType:
var req structs.DirEntry
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.KVS(&req); err != nil {
return err
}
case structs.TombstoneRequestType:
var req structs.DirEntry
if err := dec.Decode(&req); err != nil {
return err
}
// For historical reasons, these are serialized in the
// snapshots as KV entries. We want to keep the snapshot
// format compatible with pre-0.6 versions for now.
stone := &state.Tombstone{
Key: req.Key,
Index: req.ModifyIndex,
}
if err := restore.Tombstone(stone); err != nil {
return err
}
case structs.SessionRequestType:
var req structs.Session
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.Session(&req); err != nil {
return err
}
case structs.ACLRequestType:
var req structs.ACL
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.ACL(&req); err != nil {
return err
}
case structs.CoordinateBatchUpdateType:
var req structs.Coordinates
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.Coordinates(header.LastIndex, req); err != nil {
return err
}
case structs.PreparedQueryRequestType:
var req structs.PreparedQuery
if err := dec.Decode(&req); err != nil {
return err
}
if err := restore.PreparedQuery(&req); err != nil {
return err
}
default:
return fmt.Errorf("Unrecognized msg type: %v", msgType)
}
}
restore.Commit()
return nil
}