Store coin in internal state and verify that rpc coin matches db coin

blockbook.go

@@ -156,7 +156,7 @@ func main() {
 	}
 	defer index.Close()
 
-	common.IS, err = index.LoadInternalState()
+	common.IS, err = index.LoadInternalState(*coin)
 	if err != nil {
 		glog.Fatal("internalState: ", err)
 	}

common/internalstate.go

@@ -26,6 +26,8 @@ type InternalStateColumn struct {
 type InternalState struct {
 	mux sync.Mutex
 
+	Coin string `json:"coin"`
+
 	DbState uint32 `json:"dbState"`
 
 	LastStore time.Time `json:"lastStore"`

db/rocksdb.go

@@ -875,7 +875,7 @@ func (d *RocksDB) DeleteTx(txid string) error {
 const internalStateKey = "internalState"
 
 // LoadInternalState loads from db internal state or initializes a new one if not yet stored
-func (d *RocksDB) LoadInternalState() (*common.InternalState, error) {
+func (d *RocksDB) LoadInternalState(rpcCoin string) (*common.InternalState, error) {
 	val, err := d.db.GetCF(d.ro, d.cfh[cfDefault], []byte(internalStateKey))
 	if err != nil {
 		return nil, err
@@ -884,12 +884,19 @@ func (d *RocksDB) LoadInternalState() (*common.InternalState, error) {
 	data := val.Data()
 	var is *common.InternalState
 	if len(data) == 0 {
-		is = &common.InternalState{}
+		is = &common.InternalState{Coin: rpcCoin}
 	} else {
 		is, err = common.UnpackInternalState(data)
 		if err != nil {
 			return nil, err
 		}
+		// verify that the rpc coin matches DB coin
+		// running it mismatched would corrupt the database
+		if is.Coin == "" {
+			is.Coin = rpcCoin
+		} else if is.Coin != rpcCoin {
+			return nil, errors.Errorf("Coins do not match. DB coin %v, RPC coin %v", is.Coin, rpcCoin)
+		}
 	}
 	// make sure that column stats match the columns
 	sc := is.DbColumns