Implement block tags (#106)

* Implemented tm/ethermint specific block tags

* Fix edge case for block query

rpc/eth_api.go

@@ -17,7 +17,6 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/ethereum/go-ethereum/rlp"
-	"github.com/ethereum/go-ethereum/rpc"
 
 	"github.com/cosmos/cosmos-sdk/client/context"
 	"github.com/cosmos/cosmos-sdk/client/flags"
@@ -113,7 +112,7 @@ func (e *PublicEthAPI) BlockNumber() (hexutil.Uint64, error) {
 }
 
 // GetBalance returns the provided account's balance up to the provided block number.
-func (e *PublicEthAPI) GetBalance(address common.Address, blockNum rpc.BlockNumber) (*hexutil.Big, error) {
+func (e *PublicEthAPI) GetBalance(address common.Address, blockNum BlockNumber) (*hexutil.Big, error) {
 	ctx := e.cliCtx.WithHeight(blockNum.Int64())
 	res, _, err := ctx.QueryWithData(fmt.Sprintf("custom/%s/balance/%s", types.ModuleName, address), nil)
 	if err != nil {
@@ -127,7 +126,7 @@ func (e *PublicEthAPI) GetBalance(address common.Address, blockNum rpc.BlockNumb
 }
 
 // GetStorageAt returns the contract storage at the given address, block number, and key.
-func (e *PublicEthAPI) GetStorageAt(address common.Address, key string, blockNum rpc.BlockNumber) (hexutil.Bytes, error) {
+func (e *PublicEthAPI) GetStorageAt(address common.Address, key string, blockNum BlockNumber) (hexutil.Bytes, error) {
 	ctx := e.cliCtx.WithHeight(blockNum.Int64())
 	res, _, err := ctx.QueryWithData(fmt.Sprintf("custom/%s/storage/%s/%s", types.ModuleName, address, key), nil)
 	if err != nil {
@@ -140,7 +139,7 @@ func (e *PublicEthAPI) GetStorageAt(address common.Address, key string, blockNum
 }
 
 // GetTransactionCount returns the number of transactions at the given address up to the given block number.
-func (e *PublicEthAPI) GetTransactionCount(address common.Address, blockNum rpc.BlockNumber) (*hexutil.Uint64, error) {
+func (e *PublicEthAPI) GetTransactionCount(address common.Address, blockNum BlockNumber) (*hexutil.Uint64, error) {
 	ctx := e.cliCtx.WithHeight(blockNum.Int64())
 	res, _, err := ctx.QueryWithData(fmt.Sprintf("custom/%s/nonce/%s", types.ModuleName, address), nil)
 	if err != nil {
@@ -158,7 +157,7 @@ func (e *PublicEthAPI) GetBlockTransactionCountByHash(hash common.Hash) hexutil.
 }
 
 // GetBlockTransactionCountByNumber returns the number of transactions in the block identified by number.
-func (e *PublicEthAPI) GetBlockTransactionCountByNumber(blockNum rpc.BlockNumber) (hexutil.Uint, error) {
+func (e *PublicEthAPI) GetBlockTransactionCountByNumber(blockNum BlockNumber) (hexutil.Uint, error) {
 	node, err := e.cliCtx.GetNode()
 	if err != nil {
 		return 0, err
@@ -179,12 +178,12 @@ func (e *PublicEthAPI) GetUncleCountByBlockHash(hash common.Hash) hexutil.Uint {
 }
 
 // GetUncleCountByBlockNumber returns the number of uncles in the block idenfied by number. Always zero.
-func (e *PublicEthAPI) GetUncleCountByBlockNumber(blockNum rpc.BlockNumber) hexutil.Uint {
+func (e *PublicEthAPI) GetUncleCountByBlockNumber(blockNum BlockNumber) hexutil.Uint {
 	return 0
 }
 
 // GetCode returns the contract code at the given address and block number.
-func (e *PublicEthAPI) GetCode(address common.Address, blockNumber rpc.BlockNumber) (hexutil.Bytes, error) {
+func (e *PublicEthAPI) GetCode(address common.Address, blockNumber BlockNumber) (hexutil.Bytes, error) {
 	ctx := e.cliCtx.WithHeight(blockNumber.Int64())
 	res, _, err := ctx.QueryWithData(fmt.Sprintf("custom/%s/code/%s", types.ModuleName, address), nil)
 	if err != nil {
@@ -304,12 +303,12 @@ type CallArgs struct {
 }
 
 // Call performs a raw contract call.
-func (e *PublicEthAPI) Call(args CallArgs, blockNum rpc.BlockNumber) hexutil.Bytes {
+func (e *PublicEthAPI) Call(args CallArgs, blockNum BlockNumber) hexutil.Bytes {
 	return nil
 }
 
 // EstimateGas estimates gas usage for the given smart contract call.
-func (e *PublicEthAPI) EstimateGas(args CallArgs, blockNum rpc.BlockNumber) hexutil.Uint64 {
+func (e *PublicEthAPI) EstimateGas(args CallArgs, blockNum BlockNumber) hexutil.Uint64 {
 	return 0
 }
 
@@ -319,9 +318,16 @@ func (e *PublicEthAPI) GetBlockByHash(hash common.Hash, fullTx bool) map[string]
 }
 
 // GetBlockByNumber returns the block identified by number.
-func (e *PublicEthAPI) GetBlockByNumber(blockNum rpc.BlockNumber, fullTx bool) (map[string]interface{}, error) {
+func (e *PublicEthAPI) GetBlockByNumber(blockNum BlockNumber, fullTx bool) (map[string]interface{}, error) {
 	value := blockNum.Int64()
-	block, err := e.cliCtx.Client.Block(&value)
+
+	// Remove this check when 0 query is fixed ref: (https://github.com/tendermint/tendermint/issues/4014)
+	var blkNumPtr *int64
+	if value != 0 {
+		blkNumPtr = &value
+	}
+
+	block, err := e.cliCtx.Client.Block(blkNumPtr)
 	if err != nil {
 		return nil, err
 	}
@@ -450,7 +456,7 @@ func (e *PublicEthAPI) GetTransactionByBlockHashAndIndex(hash common.Hash, idx h
 }
 
 // GetTransactionByBlockNumberAndIndex returns the transaction identified by number and index.
-func (e *PublicEthAPI) GetTransactionByBlockNumberAndIndex(blockNumber rpc.BlockNumber, idx hexutil.Uint) *Transaction {
+func (e *PublicEthAPI) GetTransactionByBlockNumberAndIndex(blockNumber BlockNumber, idx hexutil.Uint) *Transaction {
 	return nil
 }
 

rpc/types.go

@@ -0,0 +1,62 @@
+package rpc
+
+import (
+	"fmt"
+	"math"
+	"strings"
+
+	"github.com/ethereum/go-ethereum/common/hexutil"
+)
+
+// BlockNumber represents decoding hex string to block values
+type BlockNumber int64
+
+const (
+	// LatestBlockNumber mapping from "latest" to 0 for tm query
+	LatestBlockNumber = BlockNumber(0)
+
+	// EarliestBlockNumber mapping from "earliest" to 1 for tm query (earliest query not supported)
+	EarliestBlockNumber = BlockNumber(1)
+)
+
+// UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports:
+// - "latest", "earliest" or "pending" as string arguments
+// - the block number
+// Returned errors:
+// - 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]
+	}
+
+	switch input {
+	case "earliest":
+		*bn = EarliestBlockNumber
+		return nil
+	case "latest":
+		*bn = LatestBlockNumber
+		return nil
+	case "pending":
+		return fmt.Errorf("pending queries not implemented")
+		// *bn = PendingBlockNumber
+		// return nil
+	}
+
+	blckNum, err := hexutil.DecodeUint64(input)
+	if err != nil {
+		return err
+	}
+	if blckNum > math.MaxInt64 {
+		return fmt.Errorf("Blocknumber too high")
+	}
+
+	*bn = BlockNumber(blckNum)
+	return nil
+}
+
+// Int64 converts block number to primitive type
+func (bn BlockNumber) Int64() int64 {
+	return (int64)(bn)
+}