path: root/eth/api.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package eth

import (
    "bytes"
    "encoding/hex"
    "encoding/json"
    "errors"
    "fmt"
    "io"
    "io/ioutil"
    "math/big"
    "os"
    "runtime"
    "strings"
    "sync"
    "time"

    "github.com/ethereum/ethash"
    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/compiler"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/state"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/core/vm"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/miner"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/rlp"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/syndtr/goleveldb/leveldb"
    "golang.org/x/net/context"
)

// errNoCode is returned by call and transact operations for which the requested
// recipient contract to operate on does not exist in the state db or does not
// have any code associated with it (i.e. suicided).
//
// Please note, this error string is part of the RPC API and is expected by the
// native contract bindings to signal this particular error. Do not change this
// as it will break all dependent code!
var errNoCode = errors.New("no contract code at given address")

const defaultGas = uint64(90000)

// blockByNumber is a commonly used helper function which retrieves and returns
// the block for the given block number, capable of handling two special blocks:
// rpc.LatestBlockNumber and rpc.PendingBlockNumber. It returns nil when no block
// could be found.
func blockByNumber(m *miner.Miner, bc *core.BlockChain, blockNr rpc.BlockNumber) *types.Block {
    // Pending block is only known by the miner
    if blockNr == rpc.PendingBlockNumber {
        block, _ := m.Pending()
        return block
    }
    // Otherwise resolve and return the block
    if blockNr == rpc.LatestBlockNumber {
        return bc.CurrentBlock()
    }
    return bc.GetBlockByNumber(uint64(blockNr))
}

// stateAndBlockByNumber is a commonly used helper function which retrieves and
// returns the state and containing block for the given block number, capable of
// handling two special states: rpc.LatestBlockNumber and rpc.PendingBlockNumber.
// It returns nil when no block or state could be found.
func stateAndBlockByNumber(m *miner.Miner, bc *core.BlockChain, blockNr rpc.BlockNumber, chainDb ethdb.Database) (*state.StateDB, *types.Block, error) {
    // Pending state is only known by the miner
    if blockNr == rpc.PendingBlockNumber {
        block, state := m.Pending()
        return state, block, nil
    }
    // Otherwise resolve the block number and return its state
    block := blockByNumber(m, bc, blockNr)
    if block == nil {
        return nil, nil, nil
    }
    stateDb, err := state.New(block.Root(), chainDb)
    return stateDb, block, err
}

// PublicEthereumAPI provides an API to access Ethereum related information.
// It offers only methods that operate on public data that is freely available to anyone.
type PublicEthereumAPI struct {
    e   *Ethereum
    gpo *GasPriceOracle
}

// NewPublicEthereumAPI creates a new Ethereum protocol API.
func NewPublicEthereumAPI(e *Ethereum) *PublicEthereumAPI {
    return &PublicEthereumAPI{
        e:   e,
        gpo: e.gpo,
    }
}

// GasPrice returns a suggestion for a gas price.
func (s *PublicEthereumAPI) GasPrice() *big.Int {
    return s.gpo.SuggestPrice()
}

// GetCompilers returns the collection of available smart contract compilers
func (s *PublicEthereumAPI) GetCompilers() ([]string, error) {
    solc, err := s.e.Solc()
    if err != nil && solc != nil {
        return []string{"Solidity"}, nil
    }

    return []string{}, nil
}

// CompileSolidity compiles the given solidity source
func (s *PublicEthereumAPI) CompileSolidity(source string) (map[string]*compiler.Contract, error) {
    solc, err := s.e.Solc()
    if err != nil {
        return nil, err
    }

    if solc == nil {
        return nil, errors.New("solc (solidity compiler) not found")
    }

    return solc.Compile(source)
}

// Etherbase is the address that mining rewards will be send to
func (s *PublicEthereumAPI) Etherbase() (common.Address, error) {
    return s.e.Etherbase()
}

// see Etherbase
func (s *PublicEthereumAPI) Coinbase() (common.Address, error) {
    return s.Etherbase()
}

// ProtocolVersion returns the current Ethereum protocol version this node supports
func (s *PublicEthereumAPI) ProtocolVersion() *rpc.HexNumber {
    return rpc.NewHexNumber(s.e.EthVersion())
}

// Hashrate returns the POW hashrate
func (s *PublicEthereumAPI) Hashrate() *rpc.HexNumber {
    return rpc.NewHexNumber(s.e.Miner().HashRate())
}

// Syncing returns false in case the node is currently not syncing with the network. It can be up to date or has not
// yet received the latest block headers from its pears. In case it is synchronizing:
// - startingBlock: block number this node started to synchronise from
// - currentBlock:  block number this node is currently importing
// - highestBlock:  block number of the highest block header this node has received from peers
// - pulledStates:  number of state entries processed until now
// - knownStates:   number of known state entries that still need to be pulled
func (s *PublicEthereumAPI) Syncing() (interface{}, error) {
    origin, current, height, pulled, known := s.e.Downloader().Progress()

    // Return not syncing if the synchronisation already completed
    if current >= height {
        return false, nil
    }
    // Otherwise gather the block sync stats
    return map[string]interface{}{
        "startingBlock": rpc.NewHexNumber(origin),
        "currentBlock":  rpc.NewHexNumber(current),
        "highestBlock":  rpc.NewHexNumber(height),
        "pulledStates":  rpc.NewHexNumber(pulled),
        "knownStates":   rpc.NewHexNumber(known),
    }, nil
}

// PublicMinerAPI provides an API to control the miner.
// It offers only methods that operate on data that pose no security risk when it is publicly accessible.
type PublicMinerAPI struct {
    e     *Ethereum
    agent *miner.RemoteAgent
}

// NewPublicMinerAPI create a new PublicMinerAPI instance.
func NewPublicMinerAPI(e *Ethereum) *PublicMinerAPI {
    agent := miner.NewRemoteAgent()
    e.Miner().Register(agent)

    return &PublicMinerAPI{e, agent}
}

// Mining returns an indication if this node is currently mining.
func (s *PublicMinerAPI) Mining() bool {
    return s.e.IsMining()
}

// SubmitWork can be used by external miner to submit their POW solution. It returns an indication if the work was
// accepted. Note, this is not an indication if the provided work was valid!
func (s *PublicMinerAPI) SubmitWork(nonce rpc.HexNumber, solution, digest common.Hash) bool {
    return s.agent.SubmitWork(nonce.Uint64(), digest, solution)
}

// GetWork returns a work package for external miner. The work package consists of 3 strings
// result[0], 32 bytes hex encoded current block header pow-hash
// result[1], 32 bytes hex encoded seed hash used for DAG
// result[2], 32 bytes hex encoded boundary condition ("target"), 2^256/difficulty
func (s *PublicMinerAPI) GetWork() ([]string, error) {
    if !s.e.IsMining() {
        if err := s.e.StartMining(0, ""); err != nil {
            return nil, err
        }
    }
    if work, err := s.agent.GetWork(); err == nil {
        return work[:], nil
    } else {
        glog.Infof("%v\n", err)
    }
    return nil, fmt.Errorf("mining not ready")
}

// SubmitHashrate can be used for remote miners to submit their hash rate. This enables the node to report the combined
// hash rate of all miners which submit work through this node. It accepts the miner hash rate and an identifier which
// must be unique between nodes.
func (s *PublicMinerAPI) SubmitHashrate(hashrate rpc.HexNumber, id common.Hash) bool {
    s.agent.SubmitHashrate(id, hashrate.Uint64())
    return true
}

// PrivateMinerAPI provides private RPC methods to control the miner.
// These methods can be abused by external users and must be considered insecure for use by untrusted users.
type PrivateMinerAPI struct {
    e *Ethereum
}

// NewPrivateMinerAPI create a new RPC service which controls the miner of this node.
func NewPrivateMinerAPI(e *Ethereum) *PrivateMinerAPI {
    return &PrivateMinerAPI{e: e}
}

// Start the miner with the given number of threads. If threads is nil the number of
// workers started is equal to the number of logical CPU's that are usable by this process.
func (s *PrivateMinerAPI) Start(threads *rpc.HexNumber) (bool, error) {
    s.e.StartAutoDAG()

    if threads == nil {
        threads = rpc.NewHexNumber(runtime.NumCPU())
    }

    err := s.e.StartMining(threads.Int(), "")
    if err == nil {
        return true, nil
    }
    return false, err
}

// Stop the miner
func (s *PrivateMinerAPI) Stop() bool {
    s.e.StopMining()
    return true
}

// SetExtra sets the extra data string that is included when this miner mines a block.
func (s *PrivateMinerAPI) SetExtra(extra string) (bool, error) {
    if err := s.e.Miner().SetExtra([]byte(extra)); err != nil {
        return false, err
    }
    return true, nil
}

// SetGasPrice sets the minimum accepted gas price for the miner.
func (s *PrivateMinerAPI) SetGasPrice(gasPrice rpc.HexNumber) bool {
    s.e.Miner().SetGasPrice(gasPrice.BigInt())
    return true
}

// SetEtherbase sets the etherbase of the miner
func (s *PrivateMinerAPI) SetEtherbase(etherbase common.Address) bool {
    s.e.SetEtherbase(etherbase)
    return true
}

// StartAutoDAG starts auto DAG generation. This will prevent the DAG generating on epoch change
// which will cause the node to stop mining during the generation process.
func (s *PrivateMinerAPI) StartAutoDAG() bool {
    s.e.StartAutoDAG()
    return true
}

// StopAutoDAG stops auto DAG generation
func (s *PrivateMinerAPI) StopAutoDAG() bool {
    s.e.StopAutoDAG()
    return true
}

// MakeDAG creates the new DAG for the given block number
func (s *PrivateMinerAPI) MakeDAG(blockNr rpc.BlockNumber) (bool, error) {
    if err := ethash.MakeDAG(uint64(blockNr.Int64()), ""); err != nil {
        return false, err
    }
    return true, nil
}

// PublicTxPoolAPI offers and API for the transaction pool. It only operates on data that is non confidential.
type PublicTxPoolAPI struct {
    e *Ethereum
}

// NewPublicTxPoolAPI creates a new tx pool service that gives information about the transaction pool.
func NewPublicTxPoolAPI(e *Ethereum) *PublicTxPoolAPI {
    return &PublicTxPoolAPI{e}
}

// Content returns the transactions contained within the transaction pool.
func (s *PublicTxPoolAPI) Content() map[string]map[string]map[string][]*RPCTransaction {
    content := map[string]map[string]map[string][]*RPCTransaction{
        "pending": make(map[string]map[string][]*RPCTransaction),
        "queued":  make(map[string]map[string][]*RPCTransaction),
    }
    pending, queue := s.e.TxPool().Content()

    // Flatten the pending transactions
    for account, batches := range pending {
        dump := make(map[string][]*RPCTransaction)
        for nonce, txs := range batches {
            nonce := fmt.Sprintf("%d", nonce)
            for _, tx := range txs {
                dump[nonce] = append(dump[nonce], newRPCPendingTransaction(tx))
            }
        }
        content["pending"][account.Hex()] = dump
    }
    // Flatten the queued transactions
    for account, batches := range queue {
        dump := make(map[string][]*RPCTransaction)
        for nonce, txs := range batches {
            nonce := fmt.Sprintf("%d", nonce)
            for _, tx := range txs {
                dump[nonce] = append(dump[nonce], newRPCPendingTransaction(tx))
            }
        }
        content["queued"][account.Hex()] = dump
    }
    return content
}

// Status returns the number of pending and queued transaction in the pool.
func (s *PublicTxPoolAPI) Status() map[string]*rpc.HexNumber {
    pending, queue := s.e.TxPool().Stats()
    return map[string]*rpc.HexNumber{
        "pending": rpc.NewHexNumber(pending),
        "queued":  rpc.NewHexNumber(queue),
    }
}

// Inspect retrieves the content of the transaction pool and flattens it into an
// easily inspectable list.
func (s *PublicTxPoolAPI) Inspect() map[string]map[string]map[string][]string {
    content := map[string]map[string]map[string][]string{
        "pending": make(map[string]map[string][]string),
        "queued":  make(map[string]map[string][]string),
    }
    pending, queue := s.e.TxPool().Content()

    // Define a formatter to flatten a transaction into a string
    var format = func(tx *types.Transaction) string {
        if to := tx.To(); to != nil {
            return fmt.Sprintf("%s: %v wei + %v × %v gas", tx.To().Hex(), tx.Value(), tx.Gas(), tx.GasPrice())
        }
        return fmt.Sprintf("contract creation: %v wei + %v × %v gas", tx.Value(), tx.Gas(), tx.GasPrice())
    }
    // Flatten the pending transactions
    for account, batches := range pending {
        dump := make(map[string][]string)
        for nonce, txs := range batches {
            nonce := fmt.Sprintf("%d", nonce)
            for _, tx := range txs {
                dump[nonce] = append(dump[nonce], format(tx))
            }
        }
        content["pending"][account.Hex()] = dump
    }
    // Flatten the queued transactions
    for account, batches := range queue {
        dump := make(map[string][]string)
        for nonce, txs := range batches {
            nonce := fmt.Sprintf("%d", nonce)
            for _, tx := range txs {
                dump[nonce] = append(dump[nonce], format(tx))
            }
        }
        content["queued"][account.Hex()] = dump
    }
    return content
}

// PublicAccountAPI provides an API to access accounts managed by this node.
// It offers only methods that can retrieve accounts.
type PublicAccountAPI struct {
    am *accounts.Manager
}

// NewPublicAccountAPI creates a new PublicAccountAPI.
func NewPublicAccountAPI(am *accounts.Manager) *PublicAccountAPI {
    return &PublicAccountAPI{am: am}
}

// Accounts returns the collection of accounts this node manages
func (s *PublicAccountAPI) Accounts() []accounts.Account {
    return s.am.Accounts()
}

// PrivateAccountAPI provides an API to access accounts managed by this node.
// It offers methods to create, (un)lock en list accounts.
type PrivateAccountAPI struct {
    am *accounts.Manager
}

// NewPrivateAccountAPI create a new PrivateAccountAPI.
func NewPrivateAccountAPI(am *accounts.Manager) *PrivateAccountAPI {
    return &PrivateAccountAPI{am}
}

// ListAccounts will return a list of addresses for accounts this node manages.
func (s *PrivateAccountAPI) ListAccounts() []common.Address {
    accounts := s.am.Accounts()
    addresses := make([]common.Address, len(accounts))
    for i, acc := range accounts {
        addresses[i] = acc.Address
    }
    return addresses
}

// NewAccount will create a new account and returns the address for the new account.
func (s *PrivateAccountAPI) NewAccount(password string) (common.Address, error) {
    acc, err := s.am.NewAccount(password)
    if err == nil {
        return acc.Address, nil
    }
    return common.Address{}, err
}

func (s *PrivateAccountAPI) ImportRawKey(privkey string, password string) (common.Address, error) {
    hexkey, err := hex.DecodeString(privkey)
    if err != nil {
        return common.Address{}, err
    }

    acc, err := s.am.ImportECDSA(crypto.ToECDSA(hexkey), password)
    return acc.Address, err
}

// UnlockAccount will unlock the account associated with the given address with
// the given password for duration seconds. If duration is nil it will use a
// default of 300 seconds. It returns an indication if the account was unlocked.
func (s *PrivateAccountAPI) UnlockAccount(addr common.Address, password string, duration *rpc.HexNumber) (bool, error) {
    if duration == nil {
        duration = rpc.NewHexNumber(300)
    }
    a := accounts.Account{Address: addr}
    d := time.Duration(duration.Int64()) * time.Second
    if err := s.am.TimedUnlock(a, password, d); err != nil {
        return false, err
    }
    return true, nil
}

// LockAccount will lock the account associated with the given address when it's unlocked.
func (s *PrivateAccountAPI) LockAccount(addr common.Address) bool {
    return s.am.Lock(addr) == nil
}

// PublicBlockChainAPI provides an API to access the Ethereum blockchain.
// It offers only methods that operate on public data that is freely available to anyone.
type PublicBlockChainAPI struct {
    config                  *core.ChainConfig
    bc                      *core.BlockChain
    chainDb                 ethdb.Database
    eventMux                *event.TypeMux
    muNewBlockSubscriptions sync.Mutex                             // protects newBlocksSubscriptions
    newBlockSubscriptions   map[string]func(core.ChainEvent) error // callbacks for new block subscriptions
    am                      *accounts.Manager
    miner                   *miner.Miner
    gpo                     *GasPriceOracle
}

// NewPublicBlockChainAPI creates a new Etheruem blockchain API.
func NewPublicBlockChainAPI(config *core.ChainConfig, bc *core.BlockChain, m *miner.Miner, chainDb ethdb.Database, gpo *GasPriceOracle, eventMux *event.TypeMux, am *accounts.Manager) *PublicBlockChainAPI {
    api := &PublicBlockChainAPI{
        config:   config,
        bc:       bc,
        miner:    m,
        chainDb:  chainDb,
        eventMux: eventMux,
        am:       am,
        newBlockSubscriptions: make(map[string]func(core.ChainEvent) error),
        gpo: gpo,
    }

    go api.subscriptionLoop()

    return api
}

// subscriptionLoop reads events from the global event mux and creates notifications for the matched subscriptions.
func (s *PublicBlockChainAPI) subscriptionLoop() {
    sub := s.eventMux.Subscribe(core.ChainEvent{})
    for event := range sub.Chan() {
        if chainEvent, ok := event.Data.(core.ChainEvent); ok {
            s.muNewBlockSubscriptions.Lock()
            for id, notifyOf := range s.newBlockSubscriptions {
                if notifyOf(chainEvent) == rpc.ErrNotificationNotFound {
                    delete(s.newBlockSubscriptions, id)
                }
            }
            s.muNewBlockSubscriptions.Unlock()
        }
    }
}

// BlockNumber returns the block number of the chain head.
func (s *PublicBlockChainAPI) BlockNumber() *big.Int {
    return s.bc.CurrentHeader().Number
}

// GetBalance returns the amount of wei for the given address in the state of the
// given block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta
// block numbers are also allowed.
func (s *PublicBlockChainAPI) GetBalance(address common.Address, blockNr rpc.BlockNumber) (*big.Int, error) {
    state, _, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if state == nil || err != nil {
        return nil, err
    }
    return state.GetBalance(address), nil
}

// GetBlockByNumber returns the requested block. When blockNr is -1 the chain head is returned. When fullTx is true all
// transactions in the block are returned in full detail, otherwise only the transaction hash is returned.
func (s *PublicBlockChainAPI) GetBlockByNumber(blockNr rpc.BlockNumber, fullTx bool) (map[string]interface{}, error) {
    if block := blockByNumber(s.miner, s.bc, blockNr); block != nil {
        response, err := s.rpcOutputBlock(block, true, fullTx)
        if err == nil && blockNr == rpc.PendingBlockNumber {
            // Pending blocks need to nil out a few fields
            for _, field := range []string{"hash", "nonce", "logsBloom", "miner"} {
                response[field] = nil
            }
        }
        return response, err
    }
    return nil, nil
}

// GetBlockByHash returns the requested block. When fullTx is true all transactions in the block are returned in full
// detail, otherwise only the transaction hash is returned.
func (s *PublicBlockChainAPI) GetBlockByHash(blockHash common.Hash, fullTx bool) (map[string]interface{}, error) {
    if block := s.bc.GetBlock(blockHash); block != nil {
        return s.rpcOutputBlock(block, true, fullTx)
    }
    return nil, nil
}

// GetUncleByBlockNumberAndIndex returns the uncle block for the given block hash and index. When fullTx is true
// all transactions in the block are returned in full detail, otherwise only the transaction hash is returned.
func (s *PublicBlockChainAPI) GetUncleByBlockNumberAndIndex(blockNr rpc.BlockNumber, index rpc.HexNumber) (map[string]interface{}, error) {
    if block := blockByNumber(s.miner, s.bc, blockNr); block != nil {
        uncles := block.Uncles()
        if index.Int() < 0 || index.Int() >= len(uncles) {
            glog.V(logger.Debug).Infof("uncle block on index %d not found for block #%d", index.Int(), blockNr)
            return nil, nil
        }
        block = types.NewBlockWithHeader(uncles[index.Int()])
        return s.rpcOutputBlock(block, false, false)
    }
    return nil, nil
}

// GetUncleByBlockHashAndIndex returns the uncle block for the given block hash and index. When fullTx is true
// all transactions in the block are returned in full detail, otherwise only the transaction hash is returned.
func (s *PublicBlockChainAPI) GetUncleByBlockHashAndIndex(blockHash common.Hash, index rpc.HexNumber) (map[string]interface{}, error) {
    if block := s.bc.GetBlock(blockHash); block != nil {
        uncles := block.Uncles()
        if index.Int() < 0 || index.Int() >= len(uncles) {
            glog.V(logger.Debug).Infof("uncle block on index %d not found for block %s", index.Int(), blockHash.Hex())
            return nil, nil
        }
        block = types.NewBlockWithHeader(uncles[index.Int()])
        return s.rpcOutputBlock(block, false, false)
    }
    return nil, nil
}

// GetUncleCountByBlockNumber returns number of uncles in the block for the given block number
func (s *PublicBlockChainAPI) GetUncleCountByBlockNumber(blockNr rpc.BlockNumber) *rpc.HexNumber {
    if block := blockByNumber(s.miner, s.bc, blockNr); block != nil {
        return rpc.NewHexNumber(len(block.Uncles()))
    }
    return nil
}

// GetUncleCountByBlockHash returns number of uncles in the block for the given block hash
func (s *PublicBlockChainAPI) GetUncleCountByBlockHash(blockHash common.Hash) *rpc.HexNumber {
    if block := s.bc.GetBlock(blockHash); block != nil {
        return rpc.NewHexNumber(len(block.Uncles()))
    }
    return nil
}

// NewBlocksArgs allows the user to specify if the returned block should include transactions and in which format.
type NewBlocksArgs struct {
    IncludeTransactions bool `json:"includeTransactions"`
    TransactionDetails  bool `json:"transactionDetails"`
}

// NewBlocks triggers a new block event each time a block is appended to the chain. It accepts an argument which allows
// the caller to specify whether the output should contain transactions and in what format.
func (s *PublicBlockChainAPI) NewBlocks(ctx context.Context, args NewBlocksArgs) (rpc.Subscription, error) {
    notifier, supported := rpc.NotifierFromContext(ctx)
    if !supported {
        return nil, rpc.ErrNotificationsUnsupported
    }

    // create a subscription that will remove itself when unsubscribed/cancelled
    subscription, err := notifier.NewSubscription(func(subId string) {
        s.muNewBlockSubscriptions.Lock()
        delete(s.newBlockSubscriptions, subId)
        s.muNewBlockSubscriptions.Unlock()
    })

    if err != nil {
        return nil, err
    }

    // add a callback that is called on chain events which will format the block and notify the client
    s.muNewBlockSubscriptions.Lock()
    s.newBlockSubscriptions[subscription.ID()] = func(e core.ChainEvent) error {
        if notification, err := s.rpcOutputBlock(e.Block, args.IncludeTransactions, args.TransactionDetails); err == nil {
            return subscription.Notify(notification)
        } else {
            glog.V(logger.Warn).Info("unable to format block %v\n", err)
        }
        return nil
    }
    s.muNewBlockSubscriptions.Unlock()

    return subscription, nil
}

// GetCode returns the code stored at the given address in the state for the given block number.
func (s *PublicBlockChainAPI) GetCode(address common.Address, blockNr rpc.BlockNumber) (string, error) {
    state, _, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if state == nil || err != nil {
        return "", err
    }
    res := state.GetCode(address)
    if len(res) == 0 { // backwards compatibility
        return "0x", nil
    }
    return common.ToHex(res), nil
}

// GetStorageAt returns the storage from the state at the given address, key and
// block number. The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta block
// numbers are also allowed.
func (s *PublicBlockChainAPI) GetStorageAt(address common.Address, key string, blockNr rpc.BlockNumber) (string, error) {
    state, _, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if state == nil || err != nil {
        return "0x", err
    }
    return state.GetState(address, common.HexToHash(key)).Hex(), nil
}

// callmsg is the message type used for call transactions.
type callmsg struct {
    from          *state.StateObject
    to            *common.Address
    gas, gasPrice *big.Int
    value         *big.Int
    data          []byte
}

// accessor boilerplate to implement core.Message
func (m callmsg) From() (common.Address, error)         { return m.from.Address(), nil }
func (m callmsg) FromFrontier() (common.Address, error) { return m.from.Address(), nil }
func (m callmsg) Nonce() uint64                         { return m.from.Nonce() }
func (m callmsg) To() *common.Address                   { return m.to }
func (m callmsg) GasPrice() *big.Int                    { return m.gasPrice }
func (m callmsg) Gas() *big.Int                         { return m.gas }
func (m callmsg) Value() *big.Int                       { return m.value }
func (m callmsg) Data() []byte                          { return m.data }

type CallArgs struct {
    From     common.Address  `json:"from"`
    To       *common.Address `json:"to"`
    Gas      *rpc.HexNumber  `json:"gas"`
    GasPrice *rpc.HexNumber  `json:"gasPrice"`
    Value    rpc.HexNumber   `json:"value"`
    Data     string          `json:"data"`
}

func (s *PublicBlockChainAPI) doCall(args CallArgs, blockNr rpc.BlockNumber) (string, *big.Int, error) {
    // Fetch the state associated with the block number
    stateDb, block, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if stateDb == nil || err != nil {
        return "0x", nil, err
    }
    stateDb = stateDb.Copy()

    // If there's no code to interact with, respond with an appropriate error
    if args.To != nil {
        if code := stateDb.GetCode(*args.To); len(code) == 0 {
            return "0x", nil, errNoCode
        }
    }
    // Retrieve the account state object to interact with
    var from *state.StateObject
    if args.From == (common.Address{}) {
        accounts := s.am.Accounts()
        if len(accounts) == 0 {
            from = stateDb.GetOrNewStateObject(common.Address{})
        } else {
            from = stateDb.GetOrNewStateObject(accounts[0].Address)
        }
    } else {
        from = stateDb.GetOrNewStateObject(args.From)
    }
    from.SetBalance(common.MaxBig)

    // Assemble the CALL invocation
    msg := callmsg{
        from:     from,
        to:       args.To,
        gas:      args.Gas.BigInt(),
        gasPrice: args.GasPrice.BigInt(),
        value:    args.Value.BigInt(),
        data:     common.FromHex(args.Data),
    }
    if msg.gas == nil {
        msg.gas = big.NewInt(50000000)
    }
    if msg.gasPrice == nil {
        msg.gasPrice = s.gpo.SuggestPrice()
    }

    // Execute the call and return
    vmenv := core.NewEnv(stateDb, s.config, s.bc, msg, block.Header(), s.config.VmConfig)
    gp := new(core.GasPool).AddGas(common.MaxBig)

    res, requiredGas, _, err := core.NewStateTransition(vmenv, msg, gp).TransitionDb()
    if len(res) == 0 { // backwards compatibility
        return "0x", requiredGas, err
    }
    return common.ToHex(res), requiredGas, err
}

// Call executes the given transaction on the state for the given block number.
// It doesn't make and changes in the state/blockchain and is useful to execute and retrieve values.
func (s *PublicBlockChainAPI) Call(args CallArgs, blockNr rpc.BlockNumber) (string, error) {
    result, _, err := s.doCall(args, blockNr)
    return result, err
}

// EstimateGas returns an estimate of the amount of gas needed to execute the given transaction.
func (s *PublicBlockChainAPI) EstimateGas(args CallArgs) (*rpc.HexNumber, error) {
    _, gas, err := s.doCall(args, rpc.PendingBlockNumber)
    return rpc.NewHexNumber(gas), err
}

// rpcOutputBlock converts the given block to the RPC output which depends on fullTx. If inclTx is true transactions are
// returned. When fullTx is true the returned block contains full transaction details, otherwise it will only contain
// transaction hashes.
func (s *PublicBlockChainAPI) rpcOutputBlock(b *types.Block, inclTx bool, fullTx bool) (map[string]interface{}, error) {
    fields := map[string]interface{}{
        "number":           rpc.NewHexNumber(b.Number()),
        "hash":             b.Hash(),
        "parentHash":       b.ParentHash(),
        "nonce":            b.Header().Nonce,
        "sha3Uncles":       b.UncleHash(),
        "logsBloom":        b.Bloom(),
        "stateRoot":        b.Root(),
        "miner":            b.Coinbase(),
        "difficulty":       rpc.NewHexNumber(b.Difficulty()),
        "totalDifficulty":  rpc.NewHexNumber(s.bc.GetTd(b.Hash())),
        "extraData":        fmt.Sprintf("0x%x", b.Extra()),
        "size":             rpc.NewHexNumber(b.Size().Int64()),
        "gasLimit":         rpc.NewHexNumber(b.GasLimit()),
        "gasUsed":          rpc.NewHexNumber(b.GasUsed()),
        "timestamp":        rpc.NewHexNumber(b.Time()),
        "transactionsRoot": b.TxHash(),
        "receiptRoot":      b.ReceiptHash(),
    }

    if inclTx {
        formatTx := func(tx *types.Transaction) (interface{}, error) {
            return tx.Hash(), nil
        }

        if fullTx {
            formatTx = func(tx *types.Transaction) (interface{}, error) {
                return newRPCTransaction(b, tx.Hash())
            }
        }

        txs := b.Transactions()
        transactions := make([]interface{}, len(txs))
        var err error
        for i, tx := range b.Transactions() {
            if transactions[i], err = formatTx(tx); err != nil {
                return nil, err
            }
        }
        fields["transactions"] = transactions
    }

    uncles := b.Uncles()
    uncleHashes := make([]common.Hash, len(uncles))
    for i, uncle := range uncles {
        uncleHashes[i] = uncle.Hash()
    }
    fields["uncles"] = uncleHashes

    return fields, nil
}

// RPCTransaction represents a transaction that will serialize to the RPC representation of a transaction
type RPCTransaction struct {
    BlockHash        common.Hash     `json:"blockHash"`
    BlockNumber      *rpc.HexNumber  `json:"blockNumber"`
    From             common.Address  `json:"from"`
    Gas              *rpc.HexNumber  `json:"gas"`
    GasPrice         *rpc.HexNumber  `json:"gasPrice"`
    Hash             common.Hash     `json:"hash"`
    Input            string          `json:"input"`
    Nonce            *rpc.HexNumber  `json:"nonce"`
    To               *common.Address `json:"to"`
    TransactionIndex *rpc.HexNumber  `json:"transactionIndex"`
    Value            *rpc.HexNumber  `json:"value"`
}

// newRPCPendingTransaction returns a pending transaction that will serialize to the RPC representation
func newRPCPendingTransaction(tx *types.Transaction) *RPCTransaction {
    from, _ := tx.FromFrontier()

    return &RPCTransaction{
        From:     from,
        Gas:      rpc.NewHexNumber(tx.Gas()),
        GasPrice: rpc.NewHexNumber(tx.GasPrice()),
        Hash:     tx.Hash(),
        Input:    fmt.Sprintf("0x%x", tx.Data()),
        Nonce:    rpc.NewHexNumber(tx.Nonce()),
        To:       tx.To(),
        Value:    rpc.NewHexNumber(tx.Value()),
    }
}

// newRPCTransaction returns a transaction that will serialize to the RPC representation.
func newRPCTransactionFromBlockIndex(b *types.Block, txIndex int) (*RPCTransaction, error) {
    if txIndex >= 0 && txIndex < len(b.Transactions()) {
        tx := b.Transactions()[txIndex]
        from, err := tx.FromFrontier()
        if err != nil {
            return nil, err
        }

        return &RPCTransaction{
            BlockHash:        b.Hash(),
            BlockNumber:      rpc.NewHexNumber(b.Number()),
            From:             from,
            Gas:              rpc.NewHexNumber(tx.Gas()),
            GasPrice:         rpc.NewHexNumber(tx.GasPrice()),
            Hash:             tx.Hash(),
            Input:            fmt.Sprintf("0x%x", tx.Data()),
            Nonce:            rpc.NewHexNumber(tx.Nonce()),
            To:               tx.To(),
            TransactionIndex: rpc.NewHexNumber(txIndex),
            Value:            rpc.NewHexNumber(tx.Value()),
        }, nil
    }

    return nil, nil
}

// newRPCTransaction returns a transaction that will serialize to the RPC representation.
func newRPCTransaction(b *types.Block, txHash common.Hash) (*RPCTransaction, error) {
    for idx, tx := range b.Transactions() {
        if tx.Hash() == txHash {
            return newRPCTransactionFromBlockIndex(b, idx)
        }
    }

    return nil, nil
}

// PublicTransactionPoolAPI exposes methods for the RPC interface
type PublicTransactionPoolAPI struct {
    eventMux        *event.TypeMux
    chainDb         ethdb.Database
    gpo             *GasPriceOracle
    bc              *core.BlockChain
    miner           *miner.Miner
    am              *accounts.Manager
    txPool          *core.TxPool
    txMu            sync.Mutex
    muPendingTxSubs sync.Mutex
    pendingTxSubs   map[string]rpc.Subscription
}

// NewPublicTransactionPoolAPI creates a new RPC service with methods specific for the transaction pool.
func NewPublicTransactionPoolAPI(e *Ethereum) *PublicTransactionPoolAPI {
    api := &PublicTransactionPoolAPI{
        eventMux:      e.eventMux,
        gpo:           e.gpo,
        chainDb:       e.chainDb,
        bc:            e.blockchain,
        am:            e.accountManager,
        txPool:        e.txPool,
        miner:         e.miner,
        pendingTxSubs: make(map[string]rpc.Subscription),
    }
    go api.subscriptionLoop()

    return api
}

// subscriptionLoop listens for events on the global event mux and creates notifications for subscriptions.
func (s *PublicTransactionPoolAPI) subscriptionLoop() {
    sub := s.eventMux.Subscribe(core.TxPreEvent{})
    for event := range sub.Chan() {
        tx := event.Data.(core.TxPreEvent)
        if from, err := tx.Tx.FromFrontier(); err == nil {
            if s.am.HasAddress(from) {
                s.muPendingTxSubs.Lock()
                for id, sub := range s.pendingTxSubs {
                    if sub.Notify(tx.Tx.Hash()) == rpc.ErrNotificationNotFound {
                        delete(s.pendingTxSubs, id)
                    }
                }
                s.muPendingTxSubs.Unlock()
            }
        }
    }
}

func getTransaction(chainDb ethdb.Database, txPool *core.TxPool, txHash common.Hash) (*types.Transaction, bool, error) {
    txData, err := chainDb.Get(txHash.Bytes())
    isPending := false
    tx := new(types.Transaction)

    if err == nil && len(txData) > 0 {
        if err := rlp.DecodeBytes(txData, tx); err != nil {
            return nil, isPending, err
        }
    } else {
        // pending transaction?
        tx = txPool.GetTransaction(txHash)
        isPending = true
    }

    return tx, isPending, nil
}

// GetBlockTransactionCountByNumber returns the number of transactions in the block with the given block number.
func (s *PublicTransactionPoolAPI) GetBlockTransactionCountByNumber(blockNr rpc.BlockNumber) *rpc.HexNumber {
    if block := blockByNumber(s.miner, s.bc, blockNr); block != nil {
        return rpc.NewHexNumber(len(block.Transactions()))
    }
    return nil
}

// GetBlockTransactionCountByHash returns the number of transactions in the block with the given hash.
func (s *PublicTransactionPoolAPI) GetBlockTransactionCountByHash(blockHash common.Hash) *rpc.HexNumber {
    if block := s.bc.GetBlock(blockHash); block != nil {
        return rpc.NewHexNumber(len(block.Transactions()))
    }
    return nil
}

// GetTransactionByBlockNumberAndIndex returns the transaction for the given block number and index.
func (s *PublicTransactionPoolAPI) GetTransactionByBlockNumberAndIndex(blockNr rpc.BlockNumber, index rpc.HexNumber) (*RPCTransaction, error) {
    if block := blockByNumber(s.miner, s.bc, blockNr); block != nil {
        return newRPCTransactionFromBlockIndex(block, index.Int())
    }
    return nil, nil
}

// GetTransactionByBlockHashAndIndex returns the transaction for the given block hash and index.
func (s *PublicTransactionPoolAPI) GetTransactionByBlockHashAndIndex(blockHash common.Hash, index rpc.HexNumber) (*RPCTransaction, error) {
    if block := s.bc.GetBlock(blockHash); block != nil {
        return newRPCTransactionFromBlockIndex(block, index.Int())
    }
    return nil, nil
}

// GetTransactionCount returns the number of transactions the given address has sent for the given block number
func (s *PublicTransactionPoolAPI) GetTransactionCount(address common.Address, blockNr rpc.BlockNumber) (*rpc.HexNumber, error) {
    state, _, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if state == nil || err != nil {
        return nil, err
    }
    return rpc.NewHexNumber(state.GetNonce(address)), nil
}

// getTransactionBlockData fetches the meta data for the given transaction from the chain database. This is useful to
// retrieve block information for a hash. It returns the block hash, block index and transaction index.
func getTransactionBlockData(chainDb ethdb.Database, txHash common.Hash) (common.Hash, uint64, uint64, error) {
    var txBlock struct {
        BlockHash  common.Hash
        BlockIndex uint64
        Index      uint64
    }

    blockData, err := chainDb.Get(append(txHash.Bytes(), 0x0001))
    if err != nil {
        return common.Hash{}, uint64(0), uint64(0), err
    }

    reader := bytes.NewReader(blockData)
    if err = rlp.Decode(reader, &txBlock); err != nil {
        return common.Hash{}, uint64(0), uint64(0), err
    }

    return txBlock.BlockHash, txBlock.BlockIndex, txBlock.Index, nil
}

// GetTransactionByHash returns the transaction for the given hash
func (s *PublicTransactionPoolAPI) GetTransactionByHash(txHash common.Hash) (*RPCTransaction, error) {
    var tx *types.Transaction
    var isPending bool
    var err error

    if tx, isPending, err = getTransaction(s.chainDb, s.txPool, txHash); err != nil {
        glog.V(logger.Debug).Infof("%v\n", err)
        return nil, nil
    } else if tx == nil {
        return nil, nil
    }

    if isPending {
        return newRPCPendingTransaction(tx), nil
    }

    blockHash, _, _, err := getTransactionBlockData(s.chainDb, txHash)
    if err != nil {
        glog.V(logger.Debug).Infof("%v\n", err)
        return nil, nil
    }

    if block := s.bc.GetBlock(blockHash); block != nil {
        return newRPCTransaction(block, txHash)
    }

    return nil, nil
}

// GetTransactionReceipt returns the transaction receipt for the given transaction hash.
func (s *PublicTransactionPoolAPI) GetTransactionReceipt(txHash common.Hash) (map[string]interface{}, error) {
    receipt := core.GetReceipt(s.chainDb, txHash)
    if receipt == nil {
        glog.V(logger.Debug).Infof("receipt not found for transaction %s", txHash.Hex())
        return nil, nil
    }

    tx, _, err := getTransaction(s.chainDb, s.txPool, txHash)
    if err != nil {
        glog.V(logger.Debug).Infof("%v\n", err)
        return nil, nil
    }

    txBlock, blockIndex, index, err := getTransactionBlockData(s.chainDb, txHash)
    if err != nil {
        glog.V(logger.Debug).Infof("%v\n", err)
        return nil, nil
    }

    from, err := tx.FromFrontier()
    if err != nil {
        glog.V(logger.Debug).Infof("%v\n", err)
        return nil, nil
    }

    fields := map[string]interface{}{
        "root":              common.Bytes2Hex(receipt.PostState),
        "blockHash":         txBlock,
        "blockNumber":       rpc.NewHexNumber(blockIndex),
        "transactionHash":   txHash,
        "transactionIndex":  rpc.NewHexNumber(index),
        "from":              from,
        "to":                tx.To(),
        "gasUsed":           rpc.NewHexNumber(receipt.GasUsed),
        "cumulativeGasUsed": rpc.NewHexNumber(receipt.CumulativeGasUsed),
        "contractAddress":   nil,
        "logs":              receipt.Logs,
    }

    if receipt.Logs == nil {
        fields["logs"] = []vm.Logs{}
    }

    // If the ContractAddress is 20 0x0 bytes, assume it is not a contract creation
    if bytes.Compare(receipt.ContractAddress.Bytes(), bytes.Repeat([]byte{0}, 20)) != 0 {
        fields["contractAddress"] = receipt.ContractAddress
    }

    return fields, nil
}

// sign is a helper function that signs a transaction with the private key of the given address.
func (s *PublicTransactionPoolAPI) sign(addr common.Address, tx *types.Transaction) (*types.Transaction, error) {
    signature, err := s.am.Sign(addr, tx.SigHash().Bytes())
    if err != nil {
        return nil, err
    }
    return tx.WithSignature(signature)
}

type SendTxArgs struct {
    From     common.Address  `json:"from"`
    To       *common.Address `json:"to"`
    Gas      *rpc.HexNumber  `json:"gas"`
    GasPrice *rpc.HexNumber  `json:"gasPrice"`
    Value    *rpc.HexNumber  `json:"value"`
    Data     string          `json:"data"`
    Nonce    *rpc.HexNumber  `json:"nonce"`
}

// SendTransaction will create a transaction for the given transaction argument, sign it and submit it to the
// transaction pool.
func (s *PublicTransactionPoolAPI) SendTransaction(args SendTxArgs) (common.Hash, error) {
    if args.Gas == nil {
        args.Gas = rpc.NewHexNumber(defaultGas)
    }
    if args.GasPrice == nil {
        args.GasPrice = rpc.NewHexNumber(s.gpo.SuggestPrice())
    }
    if args.Value == nil {
        args.Value = rpc.NewHexNumber(0)
    }

    s.txMu.Lock()
    defer s.txMu.Unlock()

    if args.Nonce == nil {
        args.Nonce = rpc.NewHexNumber(s.txPool.State().GetNonce(args.From))
    }

    var tx *types.Transaction
    contractCreation := (args.To == nil)

    if contractCreation {
        tx = types.NewContractCreation(args.Nonce.Uint64(), args.Value.BigInt(), args.Gas.BigInt(), args.GasPrice.BigInt(), common.FromHex(args.Data))
    } else {
        tx = types.NewTransaction(args.Nonce.Uint64(), *args.To, args.Value.BigInt(), args.Gas.BigInt(), args.GasPrice.BigInt(), common.FromHex(args.Data))
    }

    signedTx, err := s.sign(args.From, tx)
    if err != nil {
        return common.Hash{}, err
    }

    s.txPool.SetLocal(signedTx)
    if err := s.txPool.Add(signedTx); err != nil {
        return common.Hash{}, err
    }

    if contractCreation {
        addr := crypto.CreateAddress(args.From, args.Nonce.Uint64())
        glog.V(logger.Info).Infof("Tx(%s) created: %s\n", signedTx.Hash().Hex(), addr.Hex())
    } else {
        glog.V(logger.Info).Infof("Tx(%s) to: %s\n", signedTx.Hash().Hex(), tx.To().Hex())
    }

    return signedTx.Hash(), nil
}

// SendRawTransaction will add the signed transaction to the transaction pool.
// The sender is responsible for signing the transaction and using the correct nonce.
func (s *PublicTransactionPoolAPI) SendRawTransaction(encodedTx string) (string, error) {
    tx := new(types.Transaction)
    if err := rlp.DecodeBytes(common.FromHex(encodedTx), tx); err != nil {
        return "", err
    }

    s.txPool.SetLocal(tx)
    if err := s.txPool.Add(tx); err != nil {
        return "", err
    }

    if tx.To() == nil {
        from, err := tx.FromFrontier()
        if err != nil {
            return "", err
        }
        addr := crypto.CreateAddress(from, tx.Nonce())
        glog.V(logger.Info).Infof("Tx(%x) created: %x\n", tx.Hash(), addr)
    } else {
        glog.V(logger.Info).Infof("Tx(%x) to: %x\n", tx.Hash(), tx.To())
    }

    return tx.Hash().Hex(), nil
}

// Sign signs the given hash using the key that matches the address. The key must be
// unlocked in order to sign the hash.
func (s *PublicTransactionPoolAPI) Sign(addr common.Address, hash common.Hash) (string, error) {
    signature, error := s.am.Sign(addr, hash[:])
    return common.ToHex(signature), error
}

type SignTransactionArgs struct {
    From     common.Address
    To       *common.Address
    Nonce    *rpc.HexNumber
    Value    *rpc.HexNumber
    Gas      *rpc.HexNumber
    GasPrice *rpc.HexNumber
    Data     string

    BlockNumber int64
}

// Tx is a helper object for argument and return values
type Tx struct {
    tx *types.Transaction

    To       *common.Address `json:"to"`
    From     common.Address  `json:"from"`
    Nonce    *rpc.HexNumber  `json:"nonce"`
    Value    *rpc.HexNumber  `json:"value"`
    Data     string          `json:"data"`
    GasLimit *rpc.HexNumber  `json:"gas"`
    GasPrice *rpc.HexNumber  `json:"gasPrice"`
    Hash     common.Hash     `json:"hash"`
}

func (tx *Tx) UnmarshalJSON(b []byte) (err error) {
    req := struct {
        To       *common.Address `json:"to"`
        From     common.Address  `json:"from"`
        Nonce    *rpc.HexNumber  `json:"nonce"`
        Value    *rpc.HexNumber  `json:"value"`
        Data     string          `json:"data"`
        GasLimit *rpc.HexNumber  `json:"gas"`
        GasPrice *rpc.HexNumber  `json:"gasPrice"`
        Hash     common.Hash     `json:"hash"`
    }{}

    if err := json.Unmarshal(b, &req); err != nil {
        return err
    }

    tx.To = req.To
    tx.From = req.From
    tx.Nonce = req.Nonce
    tx.Value = req.Value
    tx.Data = req.Data
    tx.GasLimit = req.GasLimit
    tx.GasPrice = req.GasPrice
    tx.Hash = req.Hash

    data := common.Hex2Bytes(tx.Data)

    if tx.Nonce == nil {
        return fmt.Errorf("need nonce")
    }
    if tx.Value == nil {
        tx.Value = rpc.NewHexNumber(0)
    }
    if tx.GasLimit == nil {
        tx.GasLimit = rpc.NewHexNumber(0)
    }
    if tx.GasPrice == nil {
        tx.GasPrice = rpc.NewHexNumber(int64(50000000000))
    }

    contractCreation := (req.To == nil)
    if contractCreation {
        tx.tx = types.NewContractCreation(tx.Nonce.Uint64(), tx.Value.BigInt(), tx.GasLimit.BigInt(), tx.GasPrice.BigInt(), data)
    } else {
        tx.tx = types.NewTransaction(tx.Nonce.Uint64(), *tx.To, tx.Value.BigInt(), tx.GasLimit.BigInt(), tx.GasPrice.BigInt(), data)
    }

    return nil
}

type SignTransactionResult struct {
    Raw string `json:"raw"`
    Tx  *Tx    `json:"tx"`
}

func newTx(t *types.Transaction) *Tx {
    from, _ := t.FromFrontier()
    return &Tx{
        tx:       t,
        To:       t.To(),
        From:     from,
        Value:    rpc.NewHexNumber(t.Value()),
        Nonce:    rpc.NewHexNumber(t.Nonce()),
        Data:     "0x" + common.Bytes2Hex(t.Data()),
        GasLimit: rpc.NewHexNumber(t.Gas()),
        GasPrice: rpc.NewHexNumber(t.GasPrice()),
        Hash:     t.Hash(),
    }
}

// SignTransaction will sign the given transaction with the from account.
// The node needs to have the private key of the account corresponding with
// the given from address and it needs to be unlocked.
func (s *PublicTransactionPoolAPI) SignTransaction(args SignTransactionArgs) (*SignTransactionResult, error) {
    if args.Gas == nil {
        args.Gas = rpc.NewHexNumber(defaultGas)
    }
    if args.GasPrice == nil {
        args.GasPrice = rpc.NewHexNumber(s.gpo.SuggestPrice())
    }
    if args.Value == nil {
        args.Value = rpc.NewHexNumber(0)
    }

    s.txMu.Lock()
    defer s.txMu.Unlock()

    if args.Nonce == nil {
        args.Nonce = rpc.NewHexNumber(s.txPool.State().GetNonce(args.From))
    }

    var tx *types.Transaction
    contractCreation := (args.To == nil)

    if contractCreation {
        tx = types.NewContractCreation(args.Nonce.Uint64(), args.Value.BigInt(), args.Gas.BigInt(), args.GasPrice.BigInt(), common.FromHex(args.Data))
    } else {
        tx = types.NewTransaction(args.Nonce.Uint64(), *args.To, args.Value.BigInt(), args.Gas.BigInt(), args.GasPrice.BigInt(), common.FromHex(args.Data))
    }

    signedTx, err := s.sign(args.From, tx)
    if err != nil {
        return nil, err
    }

    data, err := rlp.EncodeToBytes(signedTx)
    if err != nil {
        return nil, err
    }

    return &SignTransactionResult{"0x" + common.Bytes2Hex(data), newTx(tx)}, nil
}

// PendingTransactions returns the transactions that are in the transaction pool and have a from address that is one of
// the accounts this node manages.
func (s *PublicTransactionPoolAPI) PendingTransactions() []*RPCTransaction {
    pending := s.txPool.GetTransactions()
    transactions := make([]*RPCTransaction, 0)
    for _, tx := range pending {
        from, _ := tx.FromFrontier()
        if s.am.HasAddress(from) {
            transactions = append(transactions, newRPCPendingTransaction(tx))
        }
    }
    return transactions
}

// NewPendingTransaction creates a subscription that is triggered each time a transaction enters the transaction pool
// and is send from one of the transactions this nodes manages.
func (s *PublicTransactionPoolAPI) NewPendingTransactions(ctx context.Context) (rpc.Subscription, error) {
    notifier, supported := rpc.NotifierFromContext(ctx)
    if !supported {
        return nil, rpc.ErrNotificationsUnsupported
    }

    subscription, err := notifier.NewSubscription(func(id string) {
        s.muPendingTxSubs.Lock()
        delete(s.pendingTxSubs, id)
        s.muPendingTxSubs.Unlock()
    })

    if err != nil {
        return nil, err
    }

    s.muPendingTxSubs.Lock()
    s.pendingTxSubs[subscription.ID()] = subscription
    s.muPendingTxSubs.Unlock()

    return subscription, nil
}

// Resend accepts an existing transaction and a new gas price and limit. It will remove the given transaction from the
// pool and reinsert it with the new gas price and limit.
func (s *PublicTransactionPoolAPI) Resend(tx Tx, gasPrice, gasLimit *rpc.HexNumber) (common.Hash, error) {

    pending := s.txPool.GetTransactions()
    for _, p := range pending {
        if pFrom, err := p.FromFrontier(); err == nil && pFrom == tx.From && p.SigHash() == tx.tx.SigHash() {
            if gasPrice == nil {
                gasPrice = rpc.NewHexNumber(tx.tx.GasPrice())
            }
            if gasLimit == nil {
                gasLimit = rpc.NewHexNumber(tx.tx.Gas())
            }

            var newTx *types.Transaction
            contractCreation := (tx.tx.To() == nil)
            if contractCreation {
                newTx = types.NewContractCreation(tx.tx.Nonce(), tx.tx.Value(), gasPrice.BigInt(), gasLimit.BigInt(), tx.tx.Data())
            } else {
                newTx = types.NewTransaction(tx.tx.Nonce(), *tx.tx.To(), tx.tx.Value(), gasPrice.BigInt(), gasLimit.BigInt(), tx.tx.Data())
            }

            signedTx, err := s.sign(tx.From, newTx)
            if err != nil {
                return common.Hash{}, err
            }

            s.txPool.RemoveTx(tx.Hash)
            if err = s.txPool.Add(signedTx); err != nil {
                return common.Hash{}, err
            }

            return signedTx.Hash(), nil
        }
    }

    return common.Hash{}, fmt.Errorf("Transaction %#x not found", tx.Hash)
}

// PrivateAdminAPI is the collection of Etheruem APIs exposed over the private
// admin endpoint.
type PrivateAdminAPI struct {
    eth *Ethereum
}

// NewPrivateAdminAPI creates a new API definition for the private admin methods
// of the Ethereum service.
func NewPrivateAdminAPI(eth *Ethereum) *PrivateAdminAPI {
    return &PrivateAdminAPI{eth: eth}
}

// SetSolc sets the Solidity compiler path to be used by the node.
func (api *PrivateAdminAPI) SetSolc(path string) (string, error) {
    solc, err := api.eth.SetSolc(path)
    if err != nil {
        return "", err
    }
    return solc.Info(), nil
}

// ExportChain exports the current blockchain into a local file.
func (api *PrivateAdminAPI) ExportChain(file string) (bool, error) {
    // Make sure we can create the file to export into
    out, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.ModePerm)
    if err != nil {
        return false, err
    }
    defer out.Close()

    // Export the blockchain
    if err := api.eth.BlockChain().Export(out); err != nil {
        return false, err
    }
    return true, nil
}

func hasAllBlocks(chain *core.BlockChain, bs []*types.Block) bool {
    for _, b := range bs {
        if !chain.HasBlock(b.Hash()) {
            return false
        }
    }

    return true
}

// ImportChain imports a blockchain from a local file.
func (api *PrivateAdminAPI) ImportChain(file string) (bool, error) {
    // Make sure the can access the file to import
    in, err := os.Open(file)
    if err != nil {
        return false, err
    }
    defer in.Close()

    // Run actual the import in pre-configured batches
    stream := rlp.NewStream(in, 0)

    blocks, index := make([]*types.Block, 0, 2500), 0
    for batch := 0; ; batch++ {
        // Load a batch of blocks from the input file
        for len(blocks) < cap(blocks) {
            block := new(types.Block)
            if err := stream.Decode(block); err == io.EOF {
                break
            } else if err != nil {
                return false, fmt.Errorf("block %d: failed to parse: %v", index, err)
            }
            blocks = append(blocks, block)
            index++
        }
        if len(blocks) == 0 {
            break
        }

        if hasAllBlocks(api.eth.BlockChain(), blocks) {
            blocks = blocks[:0]
            continue
        }
        // Import the batch and reset the buffer
        if _, err := api.eth.BlockChain().InsertChain(blocks); err != nil {
            return false, fmt.Errorf("batch %d: failed to insert: %v", batch, err)
        }
        blocks = blocks[:0]
    }
    return true, nil
}

// PublicDebugAPI is the collection of Etheruem APIs exposed over the public
// debugging endpoint.
type PublicDebugAPI struct {
    eth *Ethereum
}

// NewPublicDebugAPI creates a new API definition for the public debug methods
// of the Ethereum service.
func NewPublicDebugAPI(eth *Ethereum) *PublicDebugAPI {
    return &PublicDebugAPI{eth: eth}
}

// DumpBlock retrieves the entire state of the database at a given block.
func (api *PublicDebugAPI) DumpBlock(number uint64) (state.World, error) {
    block := api.eth.BlockChain().GetBlockByNumber(number)
    if block == nil {
        return state.World{}, fmt.Errorf("block #%d not found", number)
    }
    stateDb, err := state.New(block.Root(), api.eth.ChainDb())
    if err != nil {
        return state.World{}, err
    }
    return stateDb.RawDump(), nil
}

// GetBlockRlp retrieves the RLP encoded for of a single block.
func (api *PublicDebugAPI) GetBlockRlp(number uint64) (string, error) {
    block := api.eth.BlockChain().GetBlockByNumber(number)
    if block == nil {
        return "", fmt.Errorf("block #%d not found", number)
    }
    encoded, err := rlp.EncodeToBytes(block)
    if err != nil {
        return "", err
    }
    return fmt.Sprintf("%x", encoded), nil
}

// PrintBlock retrieves a block and returns its pretty printed form.
func (api *PublicDebugAPI) PrintBlock(number uint64) (string, error) {
    block := api.eth.BlockChain().GetBlockByNumber(number)
    if block == nil {
        return "", fmt.Errorf("block #%d not found", number)
    }
    return fmt.Sprintf("%s", block), nil
}

// SeedHash retrieves the seed hash of a block.
func (api *PublicDebugAPI) SeedHash(number uint64) (string, error) {
    block := api.eth.BlockChain().GetBlockByNumber(number)
    if block == nil {
        return "", fmt.Errorf("block #%d not found", number)
    }
    hash, err := ethash.GetSeedHash(number)
    if err != nil {
        return "", err
    }
    return fmt.Sprintf("0x%x", hash), nil
}

// PrivateDebugAPI is the collection of Etheruem APIs exposed over the private
// debugging endpoint.
type PrivateDebugAPI struct {
    config *core.ChainConfig
    eth    *Ethereum
}

// NewPrivateDebugAPI creates a new API definition for the private debug methods
// of the Ethereum service.
func NewPrivateDebugAPI(config *core.ChainConfig, eth *Ethereum) *PrivateDebugAPI {
    return &PrivateDebugAPI{config: config, eth: eth}
}

// ChaindbProperty returns leveldb properties of the chain database.
func (api *PrivateDebugAPI) ChaindbProperty(property string) (string, error) {
    ldb, ok := api.eth.chainDb.(interface {
        LDB() *leveldb.DB
    })
    if !ok {
        return "", fmt.Errorf("chaindbProperty does not work for memory databases")
    }
    if property == "" {
        property = "leveldb.stats"
    } else if !strings.HasPrefix(property, "leveldb.") {
        property = "leveldb." + property
    }
    return ldb.LDB().GetProperty(property)
}

// BlockTraceResults is the returned value when replaying a block to check for
// consensus results and full VM trace logs for all included transactions.
type BlockTraceResult struct {
    Validated  bool           `json:"validated"`
    StructLogs []structLogRes `json:"structLogs"`
    Error      string         `json:"error"`
}

// TraceBlock processes the given block's RLP but does not import the block in to
// the chain.
func (api *PrivateDebugAPI) TraceBlock(blockRlp []byte, config *vm.Config) BlockTraceResult {
    var block types.Block
    err := rlp.Decode(bytes.NewReader(blockRlp), &block)
    if err != nil {
        return BlockTraceResult{Error: fmt.Sprintf("could not decode block: %v", err)}
    }

    validated, logs, err := api.traceBlock(&block, config)
    return BlockTraceResult{
        Validated:  validated,
        StructLogs: formatLogs(logs),
        Error:      formatError(err),
    }
}

// TraceBlockFromFile loads the block's RLP from the given file name and attempts to
// process it but does not import the block in to the chain.
func (api *PrivateDebugAPI) TraceBlockFromFile(file string, config *vm.Config) BlockTraceResult {
    blockRlp, err := ioutil.ReadFile(file)
    if err != nil {
        return BlockTraceResult{Error: fmt.Sprintf("could not read file: %v", err)}
    }
    return api.TraceBlock(blockRlp, config)
}

// TraceProcessBlock processes the block by canonical block number.
func (api *PrivateDebugAPI) TraceBlockByNumber(number uint64, config *vm.Config) BlockTraceResult {
    // Fetch the block that we aim to reprocess
    block := api.eth.BlockChain().GetBlockByNumber(number)
    if block == nil {
        return BlockTraceResult{Error: fmt.Sprintf("block #%d not found", number)}
    }

    validated, logs, err := api.traceBlock(block, config)
    return BlockTraceResult{
        Validated:  validated,
        StructLogs: formatLogs(logs),
        Error:      formatError(err),
    }
}

// TraceBlockByHash processes the block by hash.
func (api *PrivateDebugAPI) TraceBlockByHash(hash common.Hash, config *vm.Config) BlockTraceResult {
    // Fetch the block that we aim to reprocess
    block := api.eth.BlockChain().GetBlock(hash)
    if block == nil {
        return BlockTraceResult{Error: fmt.Sprintf("block #%x not found", hash)}
    }

    validated, logs, err := api.traceBlock(block, config)
    return BlockTraceResult{
        Validated:  validated,
        StructLogs: formatLogs(logs),
        Error:      formatError(err),
    }
}

// TraceCollector collects EVM structered logs.
//
// TraceCollector implements vm.Collector
type TraceCollector struct {
    traces []vm.StructLog
}

// AddStructLog adds a structered log.
func (t *TraceCollector) AddStructLog(slog vm.StructLog) {
    t.traces = append(t.traces, slog)
}

// traceBlock processes the given block but does not save the state.
func (api *PrivateDebugAPI) traceBlock(block *types.Block, config *vm.Config) (bool, []vm.StructLog, error) {
    // Validate and reprocess the block
    var (
        blockchain = api.eth.BlockChain()
        validator  = blockchain.Validator()
        processor  = blockchain.Processor()
        collector  = &TraceCollector{}
    )
    if config == nil {
        config = new(vm.Config)
    }
    config.Debug = true // make sure debug is set.
    config.Logger.Collector = collector

    if err := core.ValidateHeader(api.config, blockchain.AuxValidator(), block.Header(), blockchain.GetHeader(block.ParentHash()), true, false); err != nil {
        return false, collector.traces, err
    }
    statedb, err := state.New(blockchain.GetBlock(block.ParentHash()).Root(), api.eth.ChainDb())
    if err != nil {
        return false, collector.traces, err
    }

    receipts, _, usedGas, err := processor.Process(block, statedb, *config)
    if err != nil {
        return false, collector.traces, err
    }
    if err := validator.ValidateState(block, blockchain.GetBlock(block.ParentHash()), statedb, receipts, usedGas); err != nil {
        return false, collector.traces, err
    }
    return true, collector.traces, nil
}

// SetHead rewinds the head of the blockchain to a previous block.
func (api *PrivateDebugAPI) SetHead(number uint64) {
    api.eth.BlockChain().SetHead(number)
}

// ExecutionResult groups all structured logs emitted by the EVM
// while replaying a transaction in debug mode as well as the amount of
// gas used and the return value
type ExecutionResult struct {
    Gas         *big.Int       `json:"gas"`
    ReturnValue string         `json:"returnValue"`
    StructLogs  []structLogRes `json:"structLogs"`
}

// structLogRes stores a structured log emitted by the EVM while replaying a
// transaction in debug mode
type structLogRes struct {
    Pc      uint64            `json:"pc"`
    Op      string            `json:"op"`
    Gas     *big.Int          `json:"gas"`
    GasCost *big.Int          `json:"gasCost"`
    Depth   int               `json:"depth"`
    Error   string            `json:"error"`
    Stack   []string          `json:"stack"`
    Memory  []string          `json:"memory"`
    Storage map[string]string `json:"storage"`
}

// VmLoggerOptions are the options used for debugging transactions and capturing
// specific data.
type VmLoggerOptions struct {
    DisableMemory  bool // disable memory capture
    DisableStack   bool // disable stack capture
    DisableStorage bool // disable storage capture
    FullStorage    bool // show full storage (slow)
}

// formatLogs formats EVM returned structured logs for json output
func formatLogs(structLogs []vm.StructLog) []structLogRes {
    formattedStructLogs := make([]structLogRes, len(structLogs))
    for index, trace := range structLogs {
        formattedStructLogs[index] = structLogRes{
            Pc:      trace.Pc,
            Op:      trace.Op.String(),
            Gas:     trace.Gas,
            GasCost: trace.GasCost,
            Depth:   trace.Depth,
            Error:   formatError(trace.Err),
            Stack:   make([]string, len(trace.Stack)),
            Storage: make(map[string]string),
        }

        for i, stackValue := range trace.Stack {
            formattedStructLogs[index].Stack[i] = fmt.Sprintf("%x", common.LeftPadBytes(stackValue.Bytes(), 32))
        }

        for i := 0; i+32 <= len(trace.Memory); i += 32 {
            formattedStructLogs[index].Memory = append(formattedStructLogs[index].Memory, fmt.Sprintf("%x", trace.Memory[i:i+32]))
        }

        for i, storageValue := range trace.Storage {
            formattedStructLogs[index].Storage[fmt.Sprintf("%x", i)] = fmt.Sprintf("%x", storageValue)
        }
    }
    return formattedStructLogs
}

// formatError formats a Go error into either an empty string or the data content
// of the error itself.
func formatError(err error) string {
    if err == nil {
        return ""
    }
    return err.Error()
}

// TraceTransaction returns the structured logs created during the execution of EVM
// and returns them as a JSON object.
func (s *PrivateDebugAPI) TraceTransaction(txHash common.Hash, logger *vm.LogConfig) (*ExecutionResult, error) {
    if logger == nil {
        logger = new(vm.LogConfig)
    }
    // Retrieve the tx from the chain and the containing block
    tx, blockHash, _, txIndex := core.GetTransaction(s.eth.ChainDb(), txHash)
    if tx == nil {
        return nil, fmt.Errorf("transaction %x not found", txHash)
    }
    block := s.eth.BlockChain().GetBlock(blockHash)
    if block == nil {
        return nil, fmt.Errorf("block %x not found", blockHash)
    }
    // Create the state database to mutate and eventually trace
    parent := s.eth.BlockChain().GetBlock(block.ParentHash())
    if parent == nil {
        return nil, fmt.Errorf("block parent %x not found", block.ParentHash())
    }
    stateDb, err := state.New(parent.Root(), s.eth.ChainDb())
    if err != nil {
        return nil, err
    }
    // Mutate the state and trace the selected transaction
    for idx, tx := range block.Transactions() {
        // Assemble the transaction call message
        from, err := tx.FromFrontier()
        if err != nil {
            return nil, fmt.Errorf("sender retrieval failed: %v", err)
        }
        msg := callmsg{
            from:     stateDb.GetOrNewStateObject(from),
            to:       tx.To(),
            gas:      tx.Gas(),
            gasPrice: tx.GasPrice(),
            value:    tx.Value(),
            data:     tx.Data(),
        }
        // Mutate the state if we haven't reached the tracing transaction yet
        if uint64(idx) < txIndex {
            vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, block.Header(), vm.Config{})
            _, _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
            if err != nil {
                return nil, fmt.Errorf("mutation failed: %v", err)
            }
            continue
        }
        // Otherwise trace the transaction and return
        vmenv := core.NewEnv(stateDb, s.config, s.eth.BlockChain(), msg, block.Header(), vm.Config{Debug: true, Logger: *logger})
        ret, gas, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas()))
        if err != nil {
            return nil, fmt.Errorf("tracing failed: %v", err)
        }
        return &ExecutionResult{
            Gas:         gas,
            ReturnValue: fmt.Sprintf("%x", ret),
            StructLogs:  formatLogs(vmenv.StructLogs()),
        }, nil
    }
    return nil, errors.New("database inconsistency")
}

func (s *PublicBlockChainAPI) TraceCall(args CallArgs, blockNr rpc.BlockNumber) (*ExecutionResult, error) {
    // Fetch the state associated with the block number
    stateDb, block, err := stateAndBlockByNumber(s.miner, s.bc, blockNr, s.chainDb)
    if stateDb == nil || err != nil {
        return nil, err
    }
    stateDb = stateDb.Copy()

    // Retrieve the account state object to interact with
    var from *state.StateObject
    if args.From == (common.Address{}) {
        accounts := s.am.Accounts()
        if len(accounts) == 0 {
            from = stateDb.GetOrNewStateObject(common.Address{})
        } else {
            from = stateDb.GetOrNewStateObject(accounts[0].Address)
        }
    } else {
        from = stateDb.GetOrNewStateObject(args.From)
    }
    from.SetBalance(common.MaxBig)

    // Assemble the CALL invocation
    msg := callmsg{
        from:     from,
        to:       args.To,
        gas:      args.Gas.BigInt(),
        gasPrice: args.GasPrice.BigInt(),
        value:    args.Value.BigInt(),
        data:     common.FromHex(args.Data),
    }
    if msg.gas.Cmp(common.Big0) == 0 {
        msg.gas = big.NewInt(50000000)
    }
    if msg.gasPrice.Cmp(common.Big0) == 0 {
        msg.gasPrice = new(big.Int).Mul(big.NewInt(50), common.Shannon)
    }

    // Execute the call and return
    vmenv := core.NewEnv(stateDb, s.config, s.bc, msg, block.Header(), vm.Config{
        Debug: true,
    })
    gp := new(core.GasPool).AddGas(common.MaxBig)

    ret, gas, err := core.ApplyMessage(vmenv, msg, gp)
    return &ExecutionResult{
        Gas:         gas,
        ReturnValue: fmt.Sprintf("%x", ret),
        StructLogs:  formatLogs(vmenv.StructLogs()),
    }, nil
}

// PublicNetAPI offers network related RPC methods
type PublicNetAPI struct {
    net            *p2p.Server
    networkVersion int
}

// NewPublicNetAPI creates a new net API instance.
func NewPublicNetAPI(net *p2p.Server, networkVersion int) *PublicNetAPI {
    return &PublicNetAPI{net, networkVersion}
}

// Listening returns an indication if the node is listening for network connections.
func (s *PublicNetAPI) Listening() bool {
    return true // always listening
}

// Peercount returns the number of connected peers
func (s *PublicNetAPI) PeerCount() *rpc.HexNumber {
    return rpc.NewHexNumber(s.net.PeerCount())
}

// ProtocolVersion returns the current ethereum protocol version.
func (s *PublicNetAPI) Version() string {
    return fmt.Sprintf("%d", s.networkVersion)
}