ethclient

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Published: Nov 28, 2020 License: MIT Imports: 10 Imported by: 0

README

ethclient

An attempt to create an Ethereum Client 100% in Go

Documentation

Overview

Package ethclient provides a client for the ethclient. RPC API.

Package ethclient defines interfaces for interacting with Ethereum.

Index

Constants

This section is empty.

Variables

View Source
var NotFound = errors.New("not found")

NotFound is returned by API methods if the requested item does not exist.

Functions

This section is empty.

Types

type CallMsg

type CallMsg struct {
	From     common.Address  // the sender of the 'transaction'
	To       *common.Address // the destination contract (nil for contract creation)
	Gas      uint64          // if 0, the call executes with near-infinite gas
	GasPrice *big.Int        // wei <-> gas exchange ratio
	Value    *big.Int        // amount of wei sent along with the call
	Data     []byte          // input data, usually an ABI-encoded contract method invocation
}

CallMsg contains parameters for contract calls.

type ChainReader

type ChainReader interface {
	BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)
	BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error)
	HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)
	HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error)
	TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error)
	TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error)

	// This method subscribes to notifications about changes of the head block of
	// the canonical chain.
	SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (Subscription, error)
}

ChainReader provides access to the blockchain. The methods in this interface access raw data from either the canonical chain (when requesting by block number) or any blockchain fork that was previously downloaded and processed by the node. The block number argument can be nil to select the latest canonical block. Reading block headers should be preferred over full blocks whenever possible.

The returned error is NotFound if the requested item does not exist.

type ChainStateReader

type ChainStateReader interface {
	BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error)
	StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error)
	CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)
	NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error)
}

ChainStateReader wraps access to the state trie of the canonical blockchain. Note that implementations of the interface may be unable to return state values for old blocks. In many cases, using CallContract can be preferable to reading raw contract storage.

type ChainSyncReader

type ChainSyncReader interface {
	SyncProgress(ctx context.Context) (*SyncProgress, error)
}

ChainSyncReader wraps access to the node's current sync status. If there's no sync currently running, it returns nil.

type Client

type Client struct {
	// contains filtered or unexported fields
}

Client defines typed wrappers for the ethclient. RPC API.

func Dial

func Dial(rawurl string) (*Client, error)

Dial connects a client to the given URL.

func DialContext

func DialContext(ctx context.Context, rawurl string) (*Client, error)

DialContext connects to a node including session context

func NewClient

func NewClient(c *rpc.Client) *Client

NewClient creates a client that uses the given RPC client.

func (*Client) BalanceAt

func (ec *Client) BalanceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (*big.Int, error)

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 (*Client) BlockByHash

func (ec *Client) BlockByHash(ctx context.Context, hash common.Hash) (*types.Block, error)

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 (*Client) BlockByNumber

func (ec *Client) BlockByNumber(ctx context.Context, number *big.Int) (*types.Block, error)

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 (*Client) BlockNumber

func (ec *Client) BlockNumber(ctx context.Context) (uint64, error)

BlockNumber returns the most recent block number

func (*Client) CallContract

func (ec *Client) CallContract(ctx context.Context, msg CallMsg, blockNumber *big.Int) ([]byte, error)

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 (*Client) ChainID

func (ec *Client) ChainID(ctx context.Context) (*big.Int, error)

ChainID retrieves the current chain ID for transaction replay protection.

func (*Client) Close

func (ec *Client) Close()

Close closes then connection to the node

func (*Client) CodeAt

func (ec *Client) CodeAt(ctx context.Context, account common.Address, blockNumber *big.Int) ([]byte, error)

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 (*Client) EstimateGas

func (ec *Client) EstimateGas(ctx context.Context, msg CallMsg) (uint64, error)

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 (*Client) FilterLogs

func (ec *Client) FilterLogs(ctx context.Context, q FilterQuery) ([]types.Log, error)

FilterLogs executes a filter query.

func (*Client) HeaderByHash

func (ec *Client) HeaderByHash(ctx context.Context, hash common.Hash) (*types.Header, error)

HeaderByHash returns the block header with the given hash.

func (*Client) HeaderByNumber

func (ec *Client) HeaderByNumber(ctx context.Context, number *big.Int) (*types.Header, error)

HeaderByNumber returns a block header from the current canonical chain. If number is nil, the latest known header is returned.

func (*Client) NetworkID

func (ec *Client) NetworkID(ctx context.Context) (*big.Int, error)

NetworkID returns the network ID (also known as the chain ID) for this chain.

func (*Client) NonceAt

func (ec *Client) NonceAt(ctx context.Context, account common.Address, blockNumber *big.Int) (uint64, error)

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 (*Client) PendingBalanceAt

func (ec *Client) PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error)

PendingBalanceAt returns the wei balance of the given account in the pending state.

func (*Client) PendingCallContract

func (ec *Client) PendingCallContract(ctx context.Context, msg CallMsg) ([]byte, error)

PendingCallContract executes a message call transaction using the EVM. The state seen by the contract call is the pending state.

func (*Client) PendingCodeAt

func (ec *Client) PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)

PendingCodeAt returns the contract code of the given account in the pending state.

func (*Client) PendingNonceAt

func (ec *Client) PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)

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 (*Client) PendingStorageAt

func (ec *Client) PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error)

PendingStorageAt returns the value of key in the contract storage of the given account in the pending state.

func (*Client) PendingTransactionCount

func (ec *Client) PendingTransactionCount(ctx context.Context) (uint, error)

PendingTransactionCount returns the total number of transactions in the pending state.

func (*Client) SendTransaction

func (ec *Client) SendTransaction(ctx context.Context, tx *types.Transaction) error

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 (*Client) StorageAt

func (ec *Client) StorageAt(ctx context.Context, account common.Address, key common.Hash, blockNumber *big.Int) ([]byte, error)

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 (*Client) SubscribeFilterLogs

func (ec *Client) SubscribeFilterLogs(ctx context.Context, q FilterQuery, ch chan<- types.Log) (Subscription, error)

SubscribeFilterLogs subscribes to the results of a streaming filter query.

func (*Client) SubscribeNewHead

func (ec *Client) SubscribeNewHead(ctx context.Context, ch chan<- *types.Header) (Subscription, error)

SubscribeNewHead subscribes to notifications about the current blockchain head on the given channel.

func (*Client) SuggestGasPrice

func (ec *Client) SuggestGasPrice(ctx context.Context) (*big.Int, error)

SuggestGasPrice retrieves the currently suggested gas price to allow a timely execution of a transaction.

func (*Client) SyncProgress

func (ec *Client) SyncProgress(ctx context.Context) (*SyncProgress, error)

SyncProgress retrieves the current progress of the sync algorithm. If there's no sync currently running, it returns nil.

func (*Client) TransactionByHash

func (ec *Client) TransactionByHash(ctx context.Context, hash common.Hash) (tx *types.Transaction, isPending bool, err error)

TransactionByHash returns the transaction with the given hash.

func (*Client) TransactionCount

func (ec *Client) TransactionCount(ctx context.Context, blockHash common.Hash) (uint, error)

TransactionCount returns the total number of transactions in the given block.

func (*Client) TransactionInBlock

func (ec *Client) TransactionInBlock(ctx context.Context, blockHash common.Hash, index uint) (*types.Transaction, error)

TransactionInBlock returns a single transaction at index in the given block.

func (*Client) TransactionReceipt

func (ec *Client) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)

TransactionReceipt returns the receipt of a transaction by transaction hash. Note that the receipt is not available for pending transactions.

func (*Client) TransactionSender

func (ec *Client) TransactionSender(ctx context.Context, tx *types.Transaction, block common.Hash, index uint) (common.Address, error)

TransactionSender returns the sender address of the given transaction. The transaction must be known to the remote node and included in the blockchain at the given block and index. The sender is the one derived by the protocol at the time of inclusion.

There is a fast-path for transactions retrieved by TransactionByHash and TransactionInBlock. Getting their sender address can be done without an RPC interaction.

type ContractCaller

type ContractCaller interface {
	CallContract(ctx context.Context, call CallMsg, blockNumber *big.Int) ([]byte, error)
}

A ContractCaller provides contract calls, essentially transactions that are executed by the EVM but not mined into the blockchain. ContractCall is a low-level method to execute such calls. For applications which are structured around specific contracts, the abigen tool provides a nicer, properly typed way to perform calls.

type FilterQuery

type FilterQuery struct {
	BlockHash *common.Hash     // used by eth_getLogs, return logs only from block with this hash
	FromBlock *big.Int         // beginning of the queried range, nil means genesis block
	ToBlock   *big.Int         // end of the range, nil means latest block
	Addresses []common.Address // restricts matches to events created by specific contracts

	// The Topic list restricts matches to particular event topics. Each event has a list
	// of topics. Topics matches a prefix of that list. An empty element slice matches any
	// topic. Non-empty elements represent an alternative that matches any of the
	// contained topics.
	//
	// Examples:
	// {} or nil          matches any topic list
	// {{A}}              matches topic A in first position
	// {{}, {B}}          matches any topic in first position AND B in second position
	// {{A}, {B}}         matches topic A in first position AND B in second position
	// {{A, B}, {C, D}}   matches topic (A OR B) in first position AND (C OR D) in second position
	Topics [][]common.Hash
}

FilterQuery contains options for contract log filtering.

type GasEstimator

type GasEstimator interface {
	EstimateGas(ctx context.Context, call CallMsg) (uint64, error)
}

GasEstimator wraps EstimateGas, which tries to estimate the gas needed to execute a specific transaction based on the pending state. 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.

type GasPricer

type GasPricer interface {
	SuggestGasPrice(ctx context.Context) (*big.Int, error)
}

GasPricer wraps the gas price oracle, which monitors the blockchain to determine the optimal gas price given current fee market conditions.

type LogFilterer

type LogFilterer interface {
	FilterLogs(ctx context.Context, q FilterQuery) ([]types.Log, error)
	SubscribeFilterLogs(ctx context.Context, q FilterQuery, ch chan<- types.Log) (Subscription, error)
}

LogFilterer provides access to contract log events using a one-off query or continuous event subscription.

Logs received through a streaming query subscription may have Removed set to true, indicating that the log was reverted due to a chain reorganisation.

type PendingContractCaller

type PendingContractCaller interface {
	PendingCallContract(ctx context.Context, call CallMsg) ([]byte, error)
}

PendingContractCaller can be used to perform calls against the pending state.

type PendingStateEventer

type PendingStateEventer interface {
	SubscribePendingTransactions(ctx context.Context, ch chan<- *types.Transaction) (Subscription, error)
}

A PendingStateEventer provides access to real time notifications about changes to the pending state.

type PendingStateReader

type PendingStateReader interface {
	PendingBalanceAt(ctx context.Context, account common.Address) (*big.Int, error)
	PendingStorageAt(ctx context.Context, account common.Address, key common.Hash) ([]byte, error)
	PendingCodeAt(ctx context.Context, account common.Address) ([]byte, error)
	PendingNonceAt(ctx context.Context, account common.Address) (uint64, error)
	PendingTransactionCount(ctx context.Context) (uint, error)
}

A PendingStateReader provides access to the pending state, which is the result of all known executable transactions which have not yet been included in the blockchain. It is commonly used to display the result of ’unconfirmed’ actions (e.g. wallet value transfers) initiated by the user. The PendingNonceAt operation is a good way to retrieve the next available transaction nonce for a specific account.

type Subscription

type Subscription interface {
	// Unsubscribe cancels the sending of events to the data channel
	// and closes the error channel.
	Unsubscribe()
	// Err returns the subscription error channel. The error channel receives
	// a value if there is an issue with the subscription (e.g. the network connection
	// delivering the events has been closed). Only one value will ever be sent.
	// The error channel is closed by Unsubscribe.
	Err() <-chan error
}

Subscription represents an event subscription where events are delivered on a data channel.

type SyncProgress

type SyncProgress struct {
	StartingBlock uint64 // Block number where sync began
	CurrentBlock  uint64 // Current block number where sync is at
	HighestBlock  uint64 // Highest alleged block number in the chain
	PulledStates  uint64 // Number of state trie entries already downloaded
	KnownStates   uint64 // Total number of state trie entries known about
}

SyncProgress gives progress indications when the node is synchronising with the Ethereum network.

type TransactionReader

type TransactionReader interface {
	// TransactionByHash checks the pool of pending transactions in addition to the
	// blockchain. The isPending return value indicates whether the transaction has been
	// mined yet. Note that the transaction may not be part of the canonical chain even if
	// it's not pending.
	TransactionByHash(ctx context.Context, txHash common.Hash) (tx *types.Transaction, isPending bool, err error)
	// TransactionReceipt returns the receipt of a mined transaction. Note that the
	// transaction may not be included in the current canonical chain even if a receipt
	// exists.
	TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error)
}

TransactionReader provides access to past transactions and their receipts. Implementations may impose arbitrary restrictions on the transactions and receipts that can be retrieved. Historic transactions may not be available.

Avoid relying on this interface if possible. Contract logs (through the LogFilterer interface) are more reliable and usually safer in the presence of chain reorganisations.

The returned error is NotFound if the requested item does not exist.

type TransactionSender

type TransactionSender interface {
	SendTransaction(ctx context.Context, tx *types.Transaction) error
}

TransactionSender wraps transaction sending. The SendTransaction method injects a signed transaction into the pending transaction pool for execution. If the transaction was a contract creation, the TransactionReceipt method can be used to retrieve the contract address after the transaction has been mined.

The transaction must be signed and have a valid nonce to be included. Consumers of the API can use package accounts to maintain local private keys and need can retrieve the next available nonce using PendingNonceAt.

Directories

Path Synopsis
Package common contains various helper functions.
Package common contains various helper functions.
hexutil
Package hexutil implements hex encoding with 0x prefix.
Package hexutil implements hex encoding with 0x prefix.
math
Package math provides integer math utilities.
Package math provides integer math utilities.
mclock
Package mclock is a wrapper for a monotonic clock source
Package mclock is a wrapper for a monotonic clock source
types
Package types contains data types related to Ethereum consensus.
Package types contains data types related to Ethereum consensus.
Package netutil contains extensions to the net package.
Package netutil contains extensions to the net package.
Package rlp implements the RLP serialization format.
Package rlp implements the RLP serialization format.
Package rpc implements bi-directional JSON-RPC 2.0 on multiple transports.
Package rpc implements bi-directional JSON-RPC 2.0 on multiple transports.

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