diff options
Diffstat (limited to 'ethclient')
| -rw-r--r-- | ethclient/ethclient.go | 382 | ||||
| -rw-r--r-- | ethclient/ethclient_test.go | 17 |
2 files changed, 399 insertions, 0 deletions
diff --git a/ethclient/ethclient.go b/ethclient/ethclient.go new file mode 100644 index 000000000..575a7cb44 --- /dev/null +++ b/ethclient/ethclient.go @@ -0,0 +1,382 @@ +// Copyright 2016 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 ethclient provides a client for the Ethereum RPC API. +package ethclient + +import ( + "encoding/json" + "fmt" + "math/big" + + "github.com/ethereum/go-ethereum" + "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/core/types" + "github.com/ethereum/go-ethereum/core/vm" + "github.com/ethereum/go-ethereum/rlp" + "github.com/ethereum/go-ethereum/rpc" + "golang.org/x/net/context" +) + +// Client defines typed wrappers for the Ethereum RPC API. +type Client struct { + c *rpc.Client +} + +// Dial connects a client to the given URL. +func Dial(rawurl string) (*Client, error) { + c, err := rpc.Dial(rawurl) + if err != nil { + return nil, err + } + return NewClient(c), nil +} + +// NewClient creates a client that uses the given RPC client. +func NewClient(c *rpc.Client) *Client { + return &Client{c} +} + +// Blockchain Access + +// BlockByHash returns the given full block. +// +// Note that loading full blocks requires two requests. Use HeaderByHash +// if you don't need all transactions or uncle headers. +func (ec *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error) { + return ec.getBlock(ctx, "eth_getBlockByHash", hash, true) +} + +// BlockByNumber returns a block from the current canonical chain. If number is nil, the +// latest known block is returned. +// +// Note that loading full blocks requires two requests. Use HeaderByNumber +// if you don't need all transactions or uncle headers. +func (ec *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error) { + return ec.getBlock(ctx, "eth_getBlockByNumber", toBlockNumArg(number), true) +} + +type rpcBlock struct { + Hash common.Hash `json:"hash"` + Transactions []*types.Transaction `json:"transactions"` + UncleHashes []common.Hash `json:"uncles"` +} + +func (ec *Client) getBlock(ctx context.Context, method string, args ...interface{}) (*types.Block, error) { + var raw json.RawMessage + err := ec.c.CallContext(ctx, &raw, method, args...) + if err != nil { + return nil, err + } + // Decode header and transactions. + var head *types.Header + var body rpcBlock + if err := json.Unmarshal(raw, &head); err != nil { + return nil, err + } + if err := json.Unmarshal(raw, &body); err != nil { + return nil, err + } + // Quick-verify transaction and uncle lists. This mostly helps with debugging the server. + if head.UncleHash == types.EmptyUncleHash && len(body.UncleHashes) > 0 { + return nil, fmt.Errorf("server returned non-empty uncle list but block header indicates no uncles") + } + if head.UncleHash != types.EmptyUncleHash && len(body.UncleHashes) == 0 { + return nil, fmt.Errorf("server returned empty uncle list but block header indicates uncles") + } + if head.TxHash == types.EmptyRootHash && len(body.Transactions) > 0 { + return nil, fmt.Errorf("server returned non-empty transaction list but block header indicates no transactions") + } + if head.TxHash != types.EmptyRootHash && len(body.Transactions) == 0 { + return nil, fmt.Errorf("server returned empty transaction list but block header indicates transactions") + } + // Load uncles because they are not included in the block response. + var uncles []*types.Header + if len(body.UncleHashes) > 0 { + uncles = make([]*types.Header, len(body.UncleHashes)) + reqs := make([]rpc.BatchElem, len(body.UncleHashes)) + for i := range reqs { + reqs[i] = rpc.BatchElem{ + Method: "eth_getUncleByBlockHashAndIndex", + Args: []interface{}{body.Hash, fmt.Sprintf("%#x", i)}, + Result: &uncles[i], + } + } + if err := ec.c.BatchCallContext(ctx, reqs); err != nil { + return nil, err + } + for i := range reqs { + if reqs[i].Error != nil { + return nil, reqs[i].Error + } + } + } + return types.NewBlockWithHeader(head).WithBody(body.Transactions, uncles), nil +} + +// HeaderByHash returns the block header with the given hash. +func (ec *Client) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error) { + var head *types.Header + err := ec.c.CallContext(ctx, &head, "eth_getBlockByHash", hash, false) + return head, err +} + +// HeaderByNumber returns a block header from the current canonical chain. If number is +// nil, the latest known header is returned. +func (ec *Client) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error) { + var head *types.Header + err := ec.c.CallContext(ctx, &head, "eth_getBlockByNumber", toBlockNumArg(number), false) + return head, err +} + +// TransactionByHash returns the transaction with the given hash. +func (ec *Client) TransactionByHash(ctx context.Context, hash common.Hash) (*types.Transaction, error) { + var tx *types.Transaction + err := ec.c.CallContext(ctx, &tx, "eth_getTransactionByHash", hash, false) + if err == nil { + if _, r, _ := tx.SignatureValues(); r == nil { + return nil, fmt.Errorf("server returned transaction without signature") + } + } + return tx, err +} + +// TransactionCount returns the total number of transactions in the given block. +func (ec *Client) TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error) { + var num rpc.HexNumber + err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByHash", blockHash) + return num.Uint(), err +} + +// TransactionInBlock returns a single transaction at index in the given block. +func (ec *Client) TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error) { + var tx *types.Transaction + err := ec.c.CallContext(ctx, &tx, "eth_getTransactionByBlockHashAndIndex", blockHash, index) + if err == nil { + if _, r, _ := tx.SignatureValues(); r == nil { + return nil, fmt.Errorf("server returned transaction without signature") + } + } + return tx, err +} + +// TransactionReceipt returns the receipt of a transaction by transaction hash. +// Note that the receipt is not available for pending transactions. +func (ec *Client) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) { + var r *types.Receipt + err := ec.c.CallContext(ctx, &r, "eth_getTransactionReceipt", txHash) + if err == nil && r != nil && len(r.PostState) == 0 { + return nil, fmt.Errorf("server returned receipt without post state") + } + return r, err +} + +func toBlockNumArg(number *big.Int) string { + if number == nil { + return "latest" + } + return fmt.Sprintf("%#x", number) +} + +// SubscribeNewHead subscribes to notifications about the current blockchain head +// on the given channel. +func (ec *Client) SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (ethereum.Subscription, error) { + return ec.c.EthSubscribe(ctx, ch, "newBlocks", map[string]struct{}{}) +} + +// State Access + +// BalanceAt returns the wei balance of the given account. +// The block number can be nil, in which case the balance is taken from the latest known block. +func (ec *Client) BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error) { + var result rpc.HexNumber + err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, toBlockNumArg(blockNumber)) + return (*big.Int)(&result), err +} + +// StorageAt returns the value of key in the contract storage of the given account. +// The block number can be nil, in which case the value is taken from the latest known block. +func (ec *Client) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error) { + var result rpc.HexBytes + err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, toBlockNumArg(blockNumber)) + return result, err +} + +// CodeAt returns the contract code of the given account. +// The block number can be nil, in which case the code is taken from the latest known block. +func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error) { + var result rpc.HexBytes + err := ec.c.CallContext(ctx, &result, "eth_getCode", account, toBlockNumArg(blockNumber)) + return result, err +} + +// NonceAt returns the account nonce of the given account. +// The block number can be nil, in which case the nonce is taken from the latest known block. +func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error) { + var result rpc.HexNumber + err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, toBlockNumArg(blockNumber)) + return result.Uint64(), err +} + +// Filters + +// FilterLogs executes a filter query. +func (ec *Client) FilterLogs(ctx context.Context, q ethereum.FilterQuery) ([]vm.Log, error) { + var result []vm.Log + err := ec.c.CallContext(ctx, &result, "eth_getFilterLogs", toFilterArg(q)) + return result, err +} + +// SubscribeFilterLogs subscribes to the results of a streaming filter query. +func (ec *Client) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- vm.Log) (ethereum.Subscription, error) { + return ec.c.EthSubscribe(ctx, ch, "logs", toFilterArg(q)) +} + +func toFilterArg(q ethereum.FilterQuery) interface{} { + arg := map[string]interface{}{ + "fromBlock": toBlockNumArg(q.FromBlock), + "endBlock": toBlockNumArg(q.ToBlock), + "addresses": q.Addresses, + "topics": q.Topics, + } + if q.FromBlock == nil { + arg["fromBlock"] = "0x0" + } + return arg +} + +// Pending State + +// PendingBalanceAt returns the wei balance of the given account in the pending state. +func (ec *Client) PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error) { + var result rpc.HexNumber + err := ec.c.CallContext(ctx, &result, "eth_getBalance", account, "pending") + return (*big.Int)(&result), err +} + +// PendingStorageAt returns the value of key in the contract storage of the given account in the pending state. +func (ec *Client) PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error) { + var result rpc.HexBytes + err := ec.c.CallContext(ctx, &result, "eth_getStorageAt", account, key, "pending") + return result, err +} + +// PendingCodeAt returns the contract code of the given account in the pending state. +func (ec *Client) PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error) { + var result rpc.HexBytes + err := ec.c.CallContext(ctx, &result, "eth_getCode", account, "pending") + return result, err +} + +// PendingNonceAt returns the account nonce of the given account in the pending state. +// This is the nonce that should be used for the next transaction. +func (ec *Client) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error) { + var result rpc.HexNumber + err := ec.c.CallContext(ctx, &result, "eth_getTransactionCount", account, "pending") + return result.Uint64(), err +} + +// PendingTransactionCount returns the total number of transactions in the pending state. +func (ec *Client) PendingTransactionCount(ctx context.Context) (uint, error) { + var num rpc.HexNumber + err := ec.c.CallContext(ctx, &num, "eth_getBlockTransactionCountByNumber", "pending") + return num.Uint(), err +} + +// TODO: SubscribePendingTransactions (needs server side) + +// Contract Calling + +// CallContract executes a message call transaction, which is directly executed in the VM +// of the node, but never mined into the blockchain. +// +// blockNumber selects the block height at which the call runs. It can be nil, in which +// case the code is taken from the latest known block. Note that state from very old +// blocks might not be available. +func (ec *Client) CallContract(ctx context.Context, msg ethereum.CallMsg, blockNumber *big.Int) ([]byte, error) { + var hex string + err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), toBlockNumArg(blockNumber)) + if err != nil { + return nil, err + } + return common.FromHex(hex), nil +} + +// PendingCallContract executes a message call transaction using the EVM. +// The state seen by the contract call is the pending state. +func (ec *Client) PendingCallContract(ctx context.Context, msg ethereum.CallMsg) ([]byte, error) { + var hex string + err := ec.c.CallContext(ctx, &hex, "eth_call", toCallArg(msg), "pending") + if err != nil { + return nil, err + } + return common.FromHex(hex), nil +} + +// SuggestGasPrice retrieves the currently suggested gas price to allow a timely +// execution of a transaction. +func (ec *Client) SuggestGasPrice(ctx context.Context) (*big.Int, error) { + var hex rpc.HexNumber + if err := ec.c.CallContext(ctx, &hex, "eth_gasPrice"); err != nil { + return nil, err + } + return (*big.Int)(&hex), nil +} + +// EstimateGas tries to estimate the gas needed to execute a specific transaction based on +// the current pending state of the backend blockchain. There is no guarantee that this is +// the true gas limit requirement as other transactions may be added or removed by miners, +// but it should provide a basis for setting a reasonable default. +func (ec *Client) EstimateGas(ctx context.Context, msg ethereum.CallMsg) (*big.Int, error) { + var hex rpc.HexNumber + err := ec.c.CallContext(ctx, &hex, "eth_estimateGas", toCallArg(msg)) + if err != nil { + return nil, err + } + return (*big.Int)(&hex), nil +} + +// SendTransaction injects a signed transaction into the pending pool for execution. +// +// If the transaction was a contract creation use the TransactionReceipt method to get the +// contract address after the transaction has been mined. +func (ec *Client) SendTransaction(ctx context.Context, tx *types.Transaction) error { + data, err := rlp.EncodeToBytes(tx) + if err != nil { + return err + } + return ec.c.CallContext(ctx, nil, "eth_sendRawTransaction", common.ToHex(data)) +} + +func toCallArg(msg ethereum.CallMsg) interface{} { + arg := map[string]interface{}{ + "from": msg.From, + "to": msg.To, + } + if len(msg.Data) > 0 { + arg["data"] = fmt.Sprintf("%#x", msg.Data) + } + if msg.Value != nil { + arg["value"] = fmt.Sprintf("%#x", msg.Value) + } + if msg.Gas != nil { + arg["gas"] = fmt.Sprintf("%#x", msg.Gas) + } + if msg.GasPrice != nil { + arg["gasPrice"] = fmt.Sprintf("%#x", msg.GasPrice) + } + return arg +} diff --git a/ethclient/ethclient_test.go b/ethclient/ethclient_test.go new file mode 100644 index 000000000..47e37c0ce --- /dev/null +++ b/ethclient/ethclient_test.go @@ -0,0 +1,17 @@ +package ethclient + +import "github.com/ethereum/go-ethereum" + +// Verify that Client implements the ethereum interfaces. +var ( + _ = ethereum.ChainReader(&Client{}) + _ = ethereum.ChainStateReader(&Client{}) + _ = ethereum.ChainHeadEventer(&Client{}) + _ = ethereum.ContractCaller(&Client{}) + _ = ethereum.GasEstimator(&Client{}) + _ = ethereum.GasPricer(&Client{}) + _ = ethereum.LogFilterer(&Client{}) + _ = ethereum.PendingStateReader(&Client{}) + // _ = ethereum.PendingStateEventer(&Client{}) + _ = ethereum.PendingContractCaller(&Client{}) +) |