Implement api eth.getCandidateStatus

internal/ethapi/api.go

@@ -44,10 +44,17 @@ import (
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/syndtr/goleveldb/leveldb"
 	"github.com/syndtr/goleveldb/leveldb/util"
+	contractValidator "github.com/ethereum/go-ethereum/contracts/validator/contract"
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 )
 
 const (
 	defaultGasPrice 		= 50 * params.Shannon
+	// statuses of candidates
+	statusMasternode 		= "MASTERNODE"
+	statusSlashed			= "SLASHED"
+	statusProposed			= "PROPOSED"
+
 )
 
 // PublicEthereumAPI provides an API to access Ethereum related information.
@@ -613,7 +620,7 @@ func (s *PublicBlockChainAPI) GetBlockSignersByHash(ctx context.Context, blockHa
 	if err != nil || block == nil {
 		return []common.Address{}, err
 	}
-	masternodes, err := s.GetMasternodes(block, ctx)
+	masternodes, err := s.GetMasternodes(ctx, block)
 	if err != nil || len(masternodes) == 0 {
 		log.Error("Failed to get masternodes", "err", err, "len(masternodes)", len(masternodes))
 		return []common.Address{}, err
@@ -626,7 +633,7 @@ func (s *PublicBlockChainAPI) GetBlockSignersByNumber(ctx context.Context, block
 	if err != nil || block == nil {
 		return []common.Address{}, err
 	}
-	masternodes, err := s.GetMasternodes(block, ctx)
+	masternodes, err := s.GetMasternodes(ctx, block)
 	if err != nil || len(masternodes) == 0 {
 		log.Error("Failed to get masternodes", "err", err, "len(masternodes)", len(masternodes))
 		return []common.Address{}, err
@@ -639,7 +646,7 @@ func (s *PublicBlockChainAPI) GetBlockFinalityByHash(ctx context.Context, blockH
 	if err != nil || block == nil {
 		return int32(0), err
 	}
-	masternodes, err := s.GetMasternodes(block, ctx)
+	masternodes, err := s.GetMasternodes(ctx, block)
 	if err != nil || len(masternodes) == 0 {
 		log.Error("Failed to get masternodes", "err", err, "len(masternodes)", len(masternodes))
 		return int32(0), err
@@ -656,7 +663,7 @@ func (s *PublicBlockChainAPI) GetBlockFinalityByNumber(ctx context.Context, bloc
 	if err != nil || block == nil {
 		return int32(0), err
 	}
-	masternodes, err := s.GetMasternodes(block, ctx)
+	masternodes, err := s.GetMasternodes(ctx, block)
 	if err != nil || len(masternodes) == 0 {
 		log.Error("Failed to get masternodes", "err", err, "len(masternodes)", len(masternodes))
 		return int32(0), err
@@ -667,9 +674,11 @@ func (s *PublicBlockChainAPI) GetBlockFinalityByNumber(ctx context.Context, bloc
 	}
 	return int32(100 * len(blockSigners) / len(masternodes)), err
 }
-func (s *PublicBlockChainAPI) GetMasternodes(b *types.Block, ctx context.Context) ([]common.Address, error) {
+
+// GetMasternodes returns masternodes set at the starting block of epoch of the given block
+func (s *PublicBlockChainAPI) GetMasternodes(ctx context.Context, b *types.Block) ([]common.Address, error) {
 	var masternodes []common.Address
-	if b.Number().Int64() > 0 {
+	if b.Number().Int64() >= 0 {
 		curBlockNumber := b.Number().Uint64()
 		prevBlockNumber := curBlockNumber + (common.MergeSignRange - (curBlockNumber % common.MergeSignRange))
 		latestBlockNumber := s.b.CurrentBlock().Number().Uint64()
@@ -690,6 +699,91 @@ func (s *PublicBlockChainAPI) GetMasternodes(b *types.Block, ctx context.Context
 	return masternodes, nil
 }
 
+
+// GetCandidateStatus returns status of the given candidate at a specified epochNumber
+func (s *PublicBlockChainAPI) GetCandidateStatus(ctx context.Context, coinbaseAddress common.Address, epochNumber rpc.EpochNumber) (string, error) {
+	var (
+		block *types.Block
+		masternodes, penaltyList, candidates, proposedList []common.Address
+		penalties []byte
+		err error
+	)
+	block = s.b.CurrentBlock()
+	epoch := s.b.ChainConfig().Posv.Epoch
+	// TODO: we currently support the latest epoch only
+	//if epochNumber == rpc.LatestEpochNumber {
+	//	block = s.b.CurrentBlock()
+	//} else {
+	//	checkpointNumber := rpc.BlockNumber((uint64(epochNumber) - 1) * epoch)
+	//	if checkpointNumber < 0 {
+	//		checkpointNumber = 0
+	//	}
+	//	block, err = s.b.BlockByNumber(ctx, checkpointNumber)
+	//	if err != nil || block == nil {
+	//		return "", err
+	//	}
+	//}
+	blockNum := block.Number().Uint64()
+	masternodes, err = s.GetMasternodes(ctx, block)
+	if err != nil || len(masternodes) == 0 {
+		log.Error("Failed to get masternodes", "err", err, "len(masternodes)", len(masternodes))
+		return "", err
+	}
+	for _, masternode := range masternodes {
+		if coinbaseAddress == masternode {
+			return statusMasternode, nil
+		}
+	}
+
+	// look up recent checkpoint headers to get penalty list
+	for i := 0; i <= common.LimitPenaltyEpoch; i++ {
+		if blockNum > uint64(i) * epoch {
+			blockCheckpointNumber := rpc.BlockNumber(blockNum - (blockNum % epoch) - (uint64(i) * epoch))
+			blockCheckpoint, err := s.b.BlockByNumber(ctx, blockCheckpointNumber)
+			if err != nil {
+				log.Error("Failed to get block  by number", "num", blockCheckpointNumber, "err", err)
+				continue
+			}
+			penalties = append(penalties, blockCheckpoint.Penalties()...)
+		}
+	}
+	if len(penalties) > 0 {
+		penaltyList = common.ExtractAddressFromBytes(penalties)
+		for _, pen := range penaltyList {
+			if coinbaseAddress == pen {
+				return statusSlashed, nil
+			}
+		}
+	}
+
+	// read smart contract to get candidate list
+	client, err := s.b.GetIPCClient()
+	if err != nil {
+		return "", err
+	}
+	addr := common.HexToAddress(common.MasternodeVotingSMC)
+	validator, err := contractValidator.NewTomoValidator(addr, client)
+	if err != nil {
+		return "", err
+	}
+	opts := new(bind.CallOpts)
+	candidates, err = validator.GetCandidates(opts)
+	if err != nil {
+		return "", err
+	}
+	// exclude masternodes
+	proposedList = common.RemoveItemFromArray(candidates, masternodes)
+	// exclude penalties
+	proposedList = common.RemoveItemFromArray(proposedList, penaltyList)
+
+	for _, proposed := range proposedList {
+		if coinbaseAddress == proposed {
+			return statusProposed, nil
+		}
+	}
+	return "", nil
+}
+
 // CallArgs represents the arguments for a call.
 type CallArgs struct {
 	From     common.Address  `json:"from"`

internal/jsre/deps/web3.js

@@ -3715,6 +3715,13 @@ var inputBlockNumberFormatter = function (blockNumber) {
     return utils.toHex(blockNumber);
 };
 
+var inputEpochNumberFormatter = function (epochNumber) {
+  if (epochNumber === undefined || epochNumber === "latest") {
+    return "latest";
+  }
+  return utils.toHex(epochNumber);
+};
+
 /**
  * Formats the input of a transaction and converts all values to HEX
  *
@@ -3966,6 +3973,7 @@ var outputSyncingFormatter = function(result) {
 module.exports = {
     inputDefaultBlockNumberFormatter: inputDefaultBlockNumberFormatter,
     inputBlockNumberFormatter: inputBlockNumberFormatter,
+    inputEpochNumberFormatter: inputEpochNumberFormatter,
     inputCallFormatter: inputCallFormatter,
     inputTransactionFormatter: inputTransactionFormatter,
     inputAddressFormatter: inputAddressFormatter,
@@ -5472,6 +5480,12 @@ var methods = function () {
         params: 0
     });
 
+    var getCandidateStatus = new Method({
+      name: 'getCandidateStatus',
+      call: 'eth_getCandidateStatus',
+      params: 2,
+      inputFormatter: [formatters.inputAddressFormatter, formatters.inputEpochNumberFormatter]
+    });
     return [
         getBalance,
         getStorageAt,
@@ -5479,6 +5493,7 @@ var methods = function () {
         getBlock,
         getBlockSigners,
         getBlockFinality,
+        getCandidateStatus,
         getUncle,
         getCompilers,
         getBlockTransactionCount,

rpc/types.go

@@ -117,11 +117,13 @@ type ServerCodec interface {
 }
 
 type BlockNumber int64
+type EpochNumber int64
 
 const (
 	PendingBlockNumber  = BlockNumber(-2)
 	LatestBlockNumber   = BlockNumber(-1)
 	EarliestBlockNumber = BlockNumber(0)
+	LatestEpochNumber	= EpochNumber(-1)
 )
 
 // UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports:
@@ -131,11 +133,7 @@ const (
 // - an invalid block number error when the given argument isn't a known strings
 // - an out of range error when the given block number is either too little or too large
 func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
-	input := strings.TrimSpace(string(data))
-	if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
-		input = input[1 : len(input)-1]
-	}
-
+	input := trimData(data)
 	switch input {
 	case "earliest":
 		*bn = EarliestBlockNumber
@@ -163,3 +161,34 @@ func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
 func (bn BlockNumber) Int64() int64 {
 	return (int64)(bn)
 }
+
+func (e *EpochNumber) UnmarshalJSON(data []byte) error {
+	input := trimData(data)
+	if input == "latest" {
+		*e = LatestEpochNumber
+		return nil
+	}
+
+	eNum, err := hexutil.DecodeUint64(input)
+	if err != nil {
+		return err
+	}
+	if eNum > math.MaxInt64 {
+		return fmt.Errorf("EpochNumber too high")
+	}
+
+	*e = EpochNumber(eNum)
+	return nil
+}
+
+func (e EpochNumber) Int64() int64 {
+	return (int64)(e)
+}
+
+func trimData(data []byte) string {
+	input := strings.TrimSpace(string(data))
+	if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
+		input = input[1 : len(input)-1]
+	}
+	return input
+}