consensus: get Validators from Genesis instead of statedb in v1 conso…

…rtium because in snap sync, we will disable accessing to triedb when enabling path scheme for protecting the persistent storing, the validators only used for some beginning block which we can return hardcores from genesis data too

consensus/consortium/v1/consortium.go

@@ -338,9 +338,20 @@ func (c *Consortium) snapshot(chain consensus.ChainHeaderReader, number uint64,
 			if cpHeader != nil {
 				hash := cpHeader.Hash()
 
-				validators, err := c.getValidatorsFromContract(chain, number)
-				if err != nil {
-					return nil, err
+				// Snap Sync mode.
+				var validators []common.Address
+				var err error
+				// Snap Sync mode.
+				if c.skipCheckpointHeaderCheck {
+					validators, err = c.getValidatorsFromGenesis()
+					if err != nil {
+						return nil, err
+					}
+				} else {
+					validators, err = c.getValidatorsFromContract(chain, number-1)
+					if err != nil {
+						return nil, err
+					}
 				}
 
 				snap = newSnapshot(c.config, c.signatures, number, hash, validators)
@@ -485,9 +496,17 @@ func (c *Consortium) Prepare(chain consensus.ChainHeaderReader, header *types.He
 	header.Extra = header.Extra[:extraVanity]
 
 	if number%c.config.Epoch == 0 {
-		validators, err := c.getValidatorsFromContract(chain, number)
-		if err != nil {
-			return err
+		var validators []common.Address
+		if c.skipCheckpointHeaderCheck {
+			validators, err = c.getValidatorsFromGenesis()
+			if err != nil {
+				return err
+			}
+		} else {
+			validators, err = c.getValidatorsFromContract(chain, number-1)
+			if err != nil {
+				return err
+			}
 		}
 
 		for _, signer := range validators {
@@ -756,6 +775,35 @@ func (c *Consortium) doCalcDifficulty(signer common.Address, number uint64, vali
 	return new(big.Int).Set(diffNoTurn)
 }
 
+// getValidatorsFromGenesis gets the list of validators from the genesis block support backward compatibility in V1, only used in Snap Sync.
+func (c *Consortium) getValidatorsFromGenesis() ([]common.Address, error) {
+	if c.chainConfig.ConsortiumV2Block == nil {
+		return nil, errors.New("No genesis block supplied")
+	}
+	var validatorSet []string
+	switch {
+	case c.chainConfig.ChainID.Cmp(big.NewInt(2020)) == 0:
+		validatorSet = []string{
+			"0x000000000000000000000000f224beff587362a88d859e899d0d80c080e1e812",
+			"0x00000000000000000000000011360eacdedd59bc433afad4fc8f0417d1fbebab",
+			"0x00000000000000000000000070bb1fb41c8c42f6ddd53a708e2b82209495e455",
+		}
+	case c.chainConfig.ChainID.Cmp(big.NewInt(2021)) == 0:
+		validatorSet = []string{
+			"0x0000000000000000000000004a4bc674a97737376cfe990ae2fe0d2b6e738393",
+			"0x000000000000000000000000b6bc5bc0410773a3f86b1537ce7495c52e38f88b",
+		}
+	default:
+		log.Info("chainID", c.chainConfig.ChainID)
+		return nil, errors.New("No validator set for this chain only support Mainnet & Testnet")
+	}
+	var addresses []common.Address
+	for _, str := range validatorSet {
+		addresses = append(addresses, common.HexToAddress(str))
+	}
+	return addresses, nil
+}
+
 // Read the validator list from contract
 func (c *Consortium) getValidatorsFromContract(chain consensus.ChainHeaderReader, number uint64) ([]common.Address, error) {
 	if chain.Config().IsFenix(big.NewInt(int64(number))) {
@@ -779,7 +827,7 @@ func (c *Consortium) getValidatorsFromLastCheckpoint(chain consensus.ChainHeader
 
 	if lastCheckpoint == 0 {
 		// TODO(andy): Review if we should put validators in genesis block's extra data
-		return c.getValidatorsFromContract(chain, number)
+		return c.getValidatorsFromGenesis()
 	}
 
 	var header *types.Header