github.com/ethereum-optimism/optimism/l2geth@v0.0.0-20230612200230-50b04ade19e3/ethclient/ethclient.go (about)

     1  // Copyright 2016 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  // Package ethclient provides a client for the Ethereum RPC API.
    18  package ethclient
    19  
    20  import (
    21  	"context"
    22  	"encoding/json"
    23  	"errors"
    24  	"fmt"
    25  	"math/big"
    26  
    27  	ethereum "github.com/ethereum-optimism/optimism/l2geth"
    28  	"github.com/ethereum-optimism/optimism/l2geth/common"
    29  	"github.com/ethereum-optimism/optimism/l2geth/common/hexutil"
    30  	"github.com/ethereum-optimism/optimism/l2geth/core/types"
    31  	"github.com/ethereum-optimism/optimism/l2geth/rlp"
    32  	"github.com/ethereum-optimism/optimism/l2geth/rpc"
    33  )
    34  
    35  // Client defines typed wrappers for the Ethereum RPC API.
    36  type Client struct {
    37  	c *rpc.Client
    38  }
    39  
    40  // Dial connects a client to the given URL.
    41  func Dial(rawurl string) (*Client, error) {
    42  	return DialContext(context.Background(), rawurl)
    43  }
    44  
    45  func DialContext(ctx context.Context, rawurl string) (*Client, error) {
    46  	c, err := rpc.DialContext(ctx, rawurl)
    47  	if err != nil {
    48  		return nil, err
    49  	}
    50  	return NewClient(c), nil
    51  }
    52  
    53  // NewClient creates a client that uses the given RPC client.
    54  func NewClient(c *rpc.Client) *Client {
    55  	return &Client{c}
    56  }
    57  
    58  func (ec *Client) Close() {
    59  	ec.c.Close()
    60  }
    61  
    62  // Blockchain Access
    63  
    64  // ChainId retrieves the current chain ID for transaction replay protection.
    65  func (ec *Client) ChainID(ctx context.Context) (*big.Int, error) {
    66  	var result hexutil.Big
    67  	err := ec.c.CallContext(ctx, &result, "eth_chainId")
    68  	if err != nil {
    69  		return nil, err
    70  	}
    71  	return (*big.Int)(&result), err
    72  }
    73  
    74  // BlockByHash returns the given full block.
    75  //
    76  // Note that loading full blocks requires two requests. Use HeaderByHash
    77  // if you don't need all transactions or uncle headers.
    78  func (ec *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) {
    79  	return ec.getBlock(ctx, "eth_getBlockByHash", hash, true)
    80  }
    81  
    82  // BlockByNumber returns a block from the current canonical chain. If number is nil, the
    83  // latest known block is returned.
    84  //
    85  // Note that loading full blocks requires two requests. Use HeaderByNumber
    86  // if you don't need all transactions or uncle headers.
    87  func (ec *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error) {
    88  	return ec.getBlock(ctx, "eth_getBlockByNumber", toBlockNumArg(number), true)
    89  }
    90  
    91  type rpcBlock struct {
    92  	Hash         common.Hash      `json:"hash"`
    93  	Transactions []rpcTransaction `json:"transactions"`
    94  	UncleHashes  []common.Hash    `json:"uncles"`
    95  }
    96  
    97  func (ec *Client) getBlock(ctx context.Context, method string, args ...interface{}) (*types.Block, error) {
    98  	var raw json.RawMessage
    99  	err := ec.c.CallContext(ctx, &raw, method, args...)
   100  	if err != nil {
   101  		return nil, err
   102  	} else if len(raw) == 0 {
   103  		return nil, ethereum.NotFound
   104  	}
   105  	// Decode header and transactions.
   106  	var head *types.Header
   107  	var body rpcBlock
   108  	if err := json.Unmarshal(raw, &head); err != nil {
   109  		return nil, err
   110  	}
   111  	if err := json.Unmarshal(raw, &body); err != nil {
   112  		return nil, err
   113  	}
   114  	// Quick-verify transaction and uncle lists. This mostly helps with debugging the server.
   115  	if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 {
   116  		return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles")
   117  	}
   118  	if head.UncleHash != types.EmptyUncleHash && len(body.UncleHashes) == 0 {
   119  		return nil, fmt.Errorf("server returned empty uncle list but block header indicates uncles")
   120  	}
   121  	if head.TxHash == types.EmptyRootHash && len(body.Transactions) > 0 {
   122  		return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions")
   123  	}
   124  	if head.TxHash != types.EmptyRootHash && len(body.Transactions) == 0 {
   125  		return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions")
   126  	}
   127  	// Load uncles because they are not included in the block response.
   128  	var uncles []*types.Header
   129  	if len(body.UncleHashes) > 0 {
   130  		uncles = make([]*types.Header, len(body.UncleHashes))
   131  		reqs := make([]rpc.BatchElem, len(body.UncleHashes))
   132  		for i := range reqs {
   133  			reqs[i] = rpc.BatchElem{
   134  				Method: "eth_getUncleByBlockHashAndIndex",
   135  				Args:   []interface{}{body.Hash, hexutil.EncodeUint64(uint64(i))},
   136  				Result: &uncles[i],
   137  			}
   138  		}
   139  		if err := ec.c.BatchCallContext(ctx, reqs); err != nil {
   140  			return nil, err
   141  		}
   142  		for i := range reqs {
   143  			if reqs[i].Error != nil {
   144  				return nil, reqs[i].Error
   145  			}
   146  			if uncles[i] == nil {
   147  				return nil, fmt.Errorf("got null header for uncle %d of block %x", i, body.Hash[:])
   148  			}
   149  		}
   150  	}
   151  	// Fill the sender cache of transactions in the block.
   152  	txs := make([]*types.Transaction, len(body.Transactions))
   153  	for i, tx := range body.Transactions {
   154  		if tx.From != nil {
   155  			setSenderFromServer(tx.tx, *tx.From, body.Hash)
   156  		}
   157  		meta := types.NewTransactionMeta(
   158  			tx.meta.L1BlockNumber, tx.meta.L1Timestamp,
   159  			tx.meta.L1MessageSender, tx.meta.QueueOrigin,
   160  			tx.meta.Index, tx.meta.QueueIndex,
   161  			tx.meta.RawTransaction,
   162  		)
   163  		tx.tx.SetTransactionMeta(meta)
   164  		txs[i] = tx.tx
   165  	}
   166  	return types.NewBlockWithHeader(head).WithBody(txs, uncles), nil
   167  }
   168  
   169  // HeaderByHash returns the block header with the given hash.
   170  func (ec *Client) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) {
   171  	var head *types.Header
   172  	err := ec.c.CallContext(ctx, &head, "eth_getBlockByHash", hash, false)
   173  	if err == nil && head == nil {
   174  		err = ethereum.NotFound
   175  	}
   176  	return head, err
   177  }
   178  
   179  // HeaderByNumber returns a block header from the current canonical chain. If number is
   180  // nil, the latest known header is returned.
   181  func (ec *Client) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) {
   182  	var head *types.Header
   183  	err := ec.c.CallContext(ctx, &head, "eth_getBlockByNumber", toBlockNumArg(number), false)
   184  	if err == nil && head == nil {
   185  		err = ethereum.NotFound
   186  	}
   187  	return head, err
   188  }
   189  
   190  type rpcTransaction struct {
   191  	tx   *types.Transaction
   192  	meta *rpcTransactionMeta
   193  	txExtraInfo
   194  }
   195  
   196  //go:generate gencodec -type rpcTransactionMeta -field-override rpcTransactionMetaMarshaling -out gen_rpc_tx_meta_json.go
   197  
   198  type rpcTransactionMeta struct {
   199  	L1BlockNumber   *big.Int          `json:"l1BlockNumber"`
   200  	L1Timestamp     uint64            `json:"l1Timestamp"`
   201  	L1MessageSender *common.Address   `json:"l1MessageSender"`
   202  	QueueOrigin     types.QueueOrigin `json:"queueOrigin"`
   203  	Index           *uint64           `json:"index"`
   204  	QueueIndex      *uint64           `json:"queueIndex"`
   205  	RawTransaction  []byte            `json:"rawTransaction"`
   206  }
   207  
   208  type rpcTransactionMetaMarshaling struct {
   209  	L1BlockNumber  *hexutil.Big
   210  	L1Timestamp    hexutil.Uint64
   211  	Index          *hexutil.Uint64
   212  	QueueIndex     *hexutil.Uint64
   213  	RawTransaction hexutil.Bytes
   214  }
   215  
   216  type txExtraInfo struct {
   217  	BlockNumber *string         `json:"blockNumber,omitempty"`
   218  	BlockHash   *common.Hash    `json:"blockHash,omitempty"`
   219  	From        *common.Address `json:"from,omitempty"`
   220  }
   221  
   222  func (tx *rpcTransaction) UnmarshalJSON(msg []byte) error {
   223  	if err := json.Unmarshal(msg, &tx.tx); err != nil {
   224  		return err
   225  	}
   226  	if err := json.Unmarshal(msg, &tx.meta); err != nil {
   227  		return err
   228  	}
   229  	return json.Unmarshal(msg, &tx.txExtraInfo)
   230  }
   231  
   232  // TransactionByHash returns the transaction with the given hash.
   233  func (ec *Client) TransactionByHash(ctx context.Context, hash common.Hash) (tx *types.Transaction, isPending bool, err error) {
   234  	var json *rpcTransaction
   235  	err = ec.c.CallContext(ctx, &json, "eth_getTransactionByHash", hash)
   236  	if err != nil {
   237  		return nil, false, err
   238  	} else if json == nil {
   239  		return nil, false, ethereum.NotFound
   240  	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
   241  		return nil, false, fmt.Errorf("server returned transaction without signature")
   242  	}
   243  	if json.From != nil && json.BlockHash != nil {
   244  		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
   245  	}
   246  	return json.tx, json.BlockNumber == nil, nil
   247  }
   248  
   249  // TransactionSender returns the sender address of the given transaction. The transaction
   250  // must be known to the remote node and included in the blockchain at the given block and
   251  // index. The sender is the one derived by the protocol at the time of inclusion.
   252  //
   253  // There is a fast-path for transactions retrieved by TransactionByHash and
   254  // TransactionInBlock. Getting their sender address can be done without an RPC interaction.
   255  func (ec *Client) TransactionSender(ctx context.Context, tx *types.Transaction, block common.Hash, index uint) (common.Address, error) {
   256  	// Try to load the address from the cache.
   257  	sender, err := types.Sender(&senderFromServer{blockhash: block}, tx)
   258  	if err == nil {
   259  		return sender, nil
   260  	}
   261  	var meta struct {
   262  		Hash common.Hash
   263  		From common.Address
   264  	}
   265  	if err = ec.c.CallContext(ctx, &meta, "eth_getTransactionByBlockHashAndIndex", block, hexutil.Uint64(index)); err != nil {
   266  		return common.Address{}, err
   267  	}
   268  	if meta.Hash == (common.Hash{}) || meta.Hash != tx.Hash() {
   269  		return common.Address{}, errors.New("wrong inclusion block/index")
   270  	}
   271  	return meta.From, nil
   272  }
   273  
   274  // TransactionCount returns the total number of transactions in the given block.
   275  func (ec *Client) TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error) {
   276  	var num hexutil.Uint
   277  	err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByHash", blockHash)
   278  	return uint(num), err
   279  }
   280  
   281  // TransactionInBlock returns a single transaction at index in the given block.
   282  func (ec *Client) TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error) {
   283  	var json *rpcTransaction
   284  	err := ec.c.CallContext(ctx, &json, "eth_getTransactionByBlockHashAndIndex", blockHash, hexutil.Uint64(index))
   285  	if err != nil {
   286  		return nil, err
   287  	}
   288  	if json == nil {
   289  		return nil, ethereum.NotFound
   290  	} else if _, r, _ := json.tx.RawSignatureValues(); r == nil {
   291  		return nil, fmt.Errorf("server returned transaction without signature")
   292  	}
   293  	if json.From != nil && json.BlockHash != nil {
   294  		setSenderFromServer(json.tx, *json.From, *json.BlockHash)
   295  	}
   296  	return json.tx, err
   297  }
   298  
   299  // TransactionReceipt returns the receipt of a transaction by transaction hash.
   300  // Note that the receipt is not available for pending transactions.
   301  func (ec *Client) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {
   302  	var r *types.Receipt
   303  	err := ec.c.CallContext(ctx, &r, "eth_getTransactionReceipt", txHash)
   304  	if err == nil {
   305  		if r == nil {
   306  			return nil, ethereum.NotFound
   307  		}
   308  	}
   309  	return r, err
   310  }
   311  
   312  func toBlockNumArg(number *big.Int) string {
   313  	if number == nil {
   314  		return "latest"
   315  	}
   316  	return hexutil.EncodeBig(number)
   317  }
   318  
   319  type rpcProgress struct {
   320  	StartingBlock hexutil.Uint64
   321  	CurrentBlock  hexutil.Uint64
   322  	HighestBlock  hexutil.Uint64
   323  	PulledStates  hexutil.Uint64
   324  	KnownStates   hexutil.Uint64
   325  }
   326  
   327  // SyncProgress retrieves the current progress of the sync algorithm. If there's
   328  // no sync currently running, it returns nil.
   329  func (ec *Client) SyncProgress(ctx context.Context) (*ethereum.SyncProgress, error) {
   330  	var raw json.RawMessage
   331  	if err := ec.c.CallContext(ctx, &raw, "eth_syncing"); err != nil {
   332  		return nil, err
   333  	}
   334  	// Handle the possible response types
   335  	var syncing bool
   336  	if err := json.Unmarshal(raw, &syncing); err == nil {
   337  		return nil, nil // Not syncing (always false)
   338  	}
   339  	var progress *rpcProgress
   340  	if err := json.Unmarshal(raw, &progress); err != nil {
   341  		return nil, err
   342  	}
   343  	return &ethereum.SyncProgress{
   344  		StartingBlock: uint64(progress.StartingBlock),
   345  		CurrentBlock:  uint64(progress.CurrentBlock),
   346  		HighestBlock:  uint64(progress.HighestBlock),
   347  		PulledStates:  uint64(progress.PulledStates),
   348  		KnownStates:   uint64(progress.KnownStates),
   349  	}, nil
   350  }
   351  
   352  // SubscribeNewHead subscribes to notifications about the current blockchain head
   353  // on the given channel.
   354  func (ec *Client) SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (ethereum.Subscription, error) {
   355  	return ec.c.EthSubscribe(ctx, ch, "newHeads")
   356  }
   357  
   358  // State Access
   359  
   360  // NetworkID returns the network ID (also known as the chain ID) for this chain.
   361  func (ec *Client) NetworkID(ctx context.Context) (*big.Int, error) {
   362  	version := new(big.Int)
   363  	var ver string
   364  	if err := ec.c.CallContext(ctx, &ver, "net_version"); err != nil {
   365  		return nil, err
   366  	}
   367  	if _, ok := version.SetString(ver, 10); !ok {
   368  		return nil, fmt.Errorf("invalid net_version result %q", ver)
   369  	}
   370  	return version, nil
   371  }
   372  
   373  // BalanceAt returns the wei balance of the given account.
   374  // The block number can be nil, in which case the balance is taken from the latest known block.
   375  func (ec *Client) BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error) {
   376  	var result hexutil.Big
   377  	err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, toBlockNumArg(blockNumber))
   378  	return (*big.Int)(&result), err
   379  }
   380  
   381  // StorageAt returns the value of key in the contract storage of the given account.
   382  // The block number can be nil, in which case the value is taken from the latest known block.
   383  func (ec *Client) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) {
   384  	var result hexutil.Bytes
   385  	err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, toBlockNumArg(blockNumber))
   386  	return result, err
   387  }
   388  
   389  // CodeAt returns the contract code of the given account.
   390  // The block number can be nil, in which case the code is taken from the latest known block.
   391  func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error) {
   392  	var result hexutil.Bytes
   393  	err := ec.c.CallContext(ctx, &result, "eth_getCode", account, toBlockNumArg(blockNumber))
   394  	return result, err
   395  }
   396  
   397  // NonceAt returns the account nonce of the given account.
   398  // The block number can be nil, in which case the nonce is taken from the latest known block.
   399  func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error) {
   400  	var result hexutil.Uint64
   401  	err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, toBlockNumArg(blockNumber))
   402  	return uint64(result), err
   403  }
   404  
   405  // Filters
   406  
   407  // FilterLogs executes a filter query.
   408  func (ec *Client) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]types.Log, error) {
   409  	var result []types.Log
   410  	arg, err := toFilterArg(q)
   411  	if err != nil {
   412  		return nil, err
   413  	}
   414  	err = ec.c.CallContext(ctx, &result, "eth_getLogs", arg)
   415  	return result, err
   416  }
   417  
   418  // SubscribeFilterLogs subscribes to the results of a streaming filter query.
   419  func (ec *Client) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- types.Log) (ethereum.Subscription, error) {
   420  	arg, err := toFilterArg(q)
   421  	if err != nil {
   422  		return nil, err
   423  	}
   424  	return ec.c.EthSubscribe(ctx, ch, "logs", arg)
   425  }
   426  
   427  func toFilterArg(q ethereum.FilterQuery) (interface{}, error) {
   428  	arg := map[string]interface{}{
   429  		"address": q.Addresses,
   430  		"topics":  q.Topics,
   431  	}
   432  	if q.BlockHash != nil {
   433  		arg["blockHash"] = *q.BlockHash
   434  		if q.FromBlock != nil || q.ToBlock != nil {
   435  			return nil, fmt.Errorf("cannot specify both BlockHash and FromBlock/ToBlock")
   436  		}
   437  	} else {
   438  		if q.FromBlock == nil {
   439  			arg["fromBlock"] = "0x0"
   440  		} else {
   441  			arg["fromBlock"] = toBlockNumArg(q.FromBlock)
   442  		}
   443  		arg["toBlock"] = toBlockNumArg(q.ToBlock)
   444  	}
   445  	return arg, nil
   446  }
   447  
   448  // Pending State
   449  
   450  // PendingBalanceAt returns the wei balance of the given account in the pending state.
   451  func (ec *Client) PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error) {
   452  	var result hexutil.Big
   453  	err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, "pending")
   454  	return (*big.Int)(&result), err
   455  }
   456  
   457  // PendingStorageAt returns the value of key in the contract storage of the given account in the pending state.
   458  func (ec *Client) PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error) {
   459  	var result hexutil.Bytes
   460  	err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, "pending")
   461  	return result, err
   462  }
   463  
   464  // PendingCodeAt returns the contract code of the given account in the pending state.
   465  func (ec *Client) PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error) {
   466  	var result hexutil.Bytes
   467  	err := ec.c.CallContext(ctx, &result, "eth_getCode", account, "pending")
   468  	return result, err
   469  }
   470  
   471  // PendingNonceAt returns the account nonce of the given account in the pending state.
   472  // This is the nonce that should be used for the next transaction.
   473  func (ec *Client) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) {
   474  	var result hexutil.Uint64
   475  	err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, "pending")
   476  	return uint64(result), err
   477  }
   478  
   479  // PendingTransactionCount returns the total number of transactions in the pending state.
   480  func (ec *Client) PendingTransactionCount(ctx context.Context) (uint, error) {
   481  	var num hexutil.Uint
   482  	err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByNumber", "pending")
   483  	return uint(num), err
   484  }
   485  
   486  // TODO: SubscribePendingTransactions (needs server side)
   487  
   488  // Contract Calling
   489  
   490  // CallContract executes a message call transaction, which is directly executed in the VM
   491  // of the node, but never mined into the blockchain.
   492  //
   493  // blockNumber selects the block height at which the call runs. It can be nil, in which
   494  // case the code is taken from the latest known block. Note that state from very old
   495  // blocks might not be available.
   496  func (ec *Client) CallContract(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) {
   497  	var hex hexutil.Bytes
   498  	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), toBlockNumArg(blockNumber))
   499  	if err != nil {
   500  		return nil, err
   501  	}
   502  	return hex, nil
   503  }
   504  
   505  // PendingCallContract executes a message call transaction using the EVM.
   506  // The state seen by the contract call is the pending state.
   507  func (ec *Client) PendingCallContract(ctx context.Context, msg ethereum.CallMsg) ([]byte, error) {
   508  	var hex hexutil.Bytes
   509  	err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), "pending")
   510  	if err != nil {
   511  		return nil, err
   512  	}
   513  	return hex, nil
   514  }
   515  
   516  // SuggestGasPrice retrieves the currently suggested gas price to allow a timely
   517  // execution of a transaction.
   518  func (ec *Client) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
   519  	var hex hexutil.Big
   520  	if err := ec.c.CallContext(ctx, &hex, "eth_gasPrice"); err != nil {
   521  		return nil, err
   522  	}
   523  	return (*big.Int)(&hex), nil
   524  }
   525  
   526  // EstimateGas tries to estimate the gas needed to execute a specific transaction based on
   527  // the current pending state of the backend blockchain. There is no guarantee that this is
   528  // the true gas limit requirement as other transactions may be added or removed by miners,
   529  // but it should provide a basis for setting a reasonable default.
   530  func (ec *Client) EstimateGas(ctx context.Context, msg ethereum.CallMsg) (uint64, error) {
   531  	var hex hexutil.Uint64
   532  	err := ec.c.CallContext(ctx, &hex, "eth_estimateGas", toCallArg(msg))
   533  	if err != nil {
   534  		return 0, err
   535  	}
   536  	return uint64(hex), nil
   537  }
   538  
   539  // SendTransaction injects a signed transaction into the pending pool for execution.
   540  //
   541  // If the transaction was a contract creation use the TransactionReceipt method to get the
   542  // contract address after the transaction has been mined.
   543  func (ec *Client) SendTransaction(ctx context.Context, tx *types.Transaction) error {
   544  	data, err := rlp.EncodeToBytes(tx)
   545  	if err != nil {
   546  		return err
   547  	}
   548  	return ec.c.CallContext(ctx, nil, "eth_sendRawTransaction", hexutil.Encode(data))
   549  }
   550  
   551  func toCallArg(msg ethereum.CallMsg) interface{} {
   552  	arg := map[string]interface{}{
   553  		"from": msg.From,
   554  		"to":   msg.To,
   555  	}
   556  	if len(msg.Data) > 0 {
   557  		arg["data"] = hexutil.Bytes(msg.Data)
   558  	}
   559  	if msg.Value != nil {
   560  		arg["value"] = (*hexutil.Big)(msg.Value)
   561  	}
   562  	if msg.Gas != 0 {
   563  		arg["gas"] = hexutil.Uint64(msg.Gas)
   564  	}
   565  	if msg.GasPrice != nil {
   566  		arg["gasPrice"] = (*hexutil.Big)(msg.GasPrice)
   567  	}
   568  	return arg
   569  }