web3

README

Go-Web3

fork: https://github.com/umbracle/go-web3 commit: e3fe470083504f038262bcd073fa49e4908320dc

Contract parse tool

Demo: https://abi.yiew.cn

JsonRPC

package main

import (
	"fmt"
	
	web3 "github.com/boolw/go-web3"
	"github.com/boolw/go-web3/jsonrpc"
)

func main() {
	client, err := jsonrpc.NewClient("https://mainnet.infura.io")
	if err != nil {
		panic(err)
	}

	number, err := client.Eth().BlockNumber()
	if err != nil {
		panic(err)
	}

	header, err := client.Eth().GetBlockByNumber(web3.BlockNumber(number), true)
	if err != nil {
		panic(err)
	}

	fmt.Println(header)
}

ABI

The ABI codifier uses randomized tests with e2e integration tests with a real Geth client to ensure that the codification is correct and provides the same results as the AbiEncoder from Solidity.

To use the library import:

"github.com/boolw/go-web3/abi"

Declare basic objects:

typ, err := abi.NewType("uint256")

or

typ = abi.MustNewType("uint256")

and use it to encode/decode the data:

num := big.NewInt(1)

encoded, err := typ.Encode(num)
if err != nil {
    panic(err)
}

decoded, err := typ.Decode(num) // decoded as interface
if err != nil {
    panic(err)
}

num2 := decoded.(*big.Int)
fmt.Println(num.Cmp(num2) == 0) // num == num2

You can also codify structs as Solidity tuples:

import (
	"fmt"
    
	web3 "github.com/boolw/go-web3"
	"github.com/boolw/go-web3/abi"
	"math/big"
)

func main() {
	typ := abi.MustNewType("tuple(address a, uint256 b)")

	type Obj struct {
		A web3.Address
		B *big.Int
	}
	obj := &Obj{
		A: web3.Address{0x1},
		B: big.NewInt(1),
	}

	// Encode
	encoded, err := typ.Encode(obj)
	if err != nil {
		panic(err)
	}

	// Decode output into a map
	res, err := typ.Decode(encoded)
	if err != nil {
		panic(err)
	}

	// Decode into a struct
	var obj2 Obj
	if err := typ.DecodeStruct(encoded, &obj2); err != nil {
		panic(err)
	}

	fmt.Println(res)
	fmt.Println(obj)
}

ENS

Resolve names on the Ethereum Name Service registrar.

import (
    "fmt"

    web3 "github.com/boolw/go-web3"
    "github.com/boolw/go-web3/jsonrpc"
    "github.com/boolw/go-web3/contract/builtin/ens"
)

var mainnetAddress = web3.HexToAddress("0x314159265dD8dbb310642f98f50C066173C1259b")

func main() {
	client, err := jsonrpc.NewClient("https://mainnet.infura.io")
    if err != nil {
        panic(err)
    }

	resolver := ens.NewENSResolver(mainnetAddress, client)
	addr, err := resolver.Resolve("ens_address")
	if err != nil {
		panic(err)
	}

    fmt.Println(addr)
}

Tracker

Complete example of the tracker here

Documentation

Index

• Constants
• func Ether(i uint64) *big.Int
• func Gwei(i uint64) *big.Int
• type Address
  • func HexToAddress(str string) Address
  • func (a Address) MarshalText() ([]byte, error)
  • func (a Address) String() string
  • func (a *Address) UnmarshalText(b []byte) error
• type Block
  • func (t *Block) MarshalJSON() ([]byte, error)
  • func (b *Block) UnmarshalJSON(buf []byte) error
• type BlockNumber
  • func EncodeBlock(block ...BlockNumber) BlockNumber
  • func (b BlockNumber) String() string
• type CallMsg
  • func (c *CallMsg) MarshalJSON() ([]byte, error)
• type Hash
  • func HexToHash(str string) Hash
  • func (h Hash) MarshalText() ([]byte, error)
  • func (h Hash) String() string
  • func (h *Hash) UnmarshalText(b []byte) error
• type Log
  • func (l *Log) MarshalJSON() ([]byte, error)
  • func (r *Log) UnmarshalJSON(buf []byte) error
• type LogFilter
  • func (l *LogFilter) MarshalJSON() ([]byte, error)
  • func (l *LogFilter) SetFromUint64(num uint64)
  • func (l *LogFilter) SetTo(b BlockNumber)
  • func (l *LogFilter) SetToUint64(num uint64)
• type Network
• type Receipt
  • func (r *Receipt) UnmarshalJSON(buf []byte) error
• type Transaction
  • func (t *Transaction) MarshalJSON() ([]byte, error)
  • func (t *Transaction) UnmarshalJSON(buf []byte) error

Constants

const (
	Latest   BlockNumber = -1
	Earliest             = -2
	Pending              = -3
)

Functions

func Ether

func Ether(i uint64) *big.Int

Ether converts a value to the ether unit with 18 decimals

func Gwei

func Gwei(i uint64) *big.Int

Gwei converts a value to the gwei unit with 9 decimals

Types

type Address

type Address [20]byte

Address is an Ethereum address

func HexToAddress

func HexToAddress(str string) Address

HexToAddress converts an hex string value to an address object

func (Address) MarshalText

func (a Address) MarshalText() ([]byte, error)

MarshalText implements the marshal interface

func (Address) String

func (a Address) String() string

func (*Address) UnmarshalText

func (a *Address) UnmarshalText(b []byte) error

UnmarshalText implements the unmarshal interface

type Block

type Block struct {
	Number             uint64
	Hash               Hash
	ParentHash         Hash
	Sha3Uncles         Hash
	TransactionsRoot   Hash
	StateRoot          Hash
	ReceiptsRoot       Hash
	Miner              Address
	Difficulty         *big.Int
	ExtraData          []byte
	GasLimit           uint64
	GasUsed            uint64
	Timestamp          uint64
	Transactions       []*Transaction
	TransactionsHashes []Hash
	Uncles             []Hash
}

func (*Block) MarshalJSON

func (t *Block) MarshalJSON() ([]byte, error)

MarshalJSON implements the marshal interface

func (*Block) UnmarshalJSON

func (b *Block) UnmarshalJSON(buf []byte) error

UnmarshalJSON implements the unmarshal interface

type BlockNumber

type BlockNumber int

func EncodeBlock

func EncodeBlock(block ...BlockNumber) BlockNumber

func (BlockNumber) String

func (b BlockNumber) String() string

type CallMsg

type CallMsg struct {
	From     Address
	To       Address
	Data     []byte
	GasPrice uint64
	Value    *big.Int
}

func (*CallMsg) MarshalJSON

func (c *CallMsg) MarshalJSON() ([]byte, error)

MarshalJSON implements the Marshal interface.

type Hash

type Hash [32]byte

Hash is an Ethereum hash

func HexToHash

func HexToHash(str string) Hash

HexToHash converts an hex string value to a hash object

func (Hash) MarshalText

func (h Hash) MarshalText() ([]byte, error)

MarshalText implements the marshal interface

func (Hash) String

func (h Hash) String() string

func (*Hash) UnmarshalText

func (h *Hash) UnmarshalText(b []byte) error

UnmarshalText implements the unmarshal interface

type Log

type Log struct {
	Removed          bool
	LogIndex         uint64
	TransactionIndex uint64
	TransactionHash  Hash
	BlockHash        Hash
	BlockNumber      uint64
	Address          Address
	Topics           []Hash
	Data             []byte
}

func (*Log) MarshalJSON

func (l *Log) MarshalJSON() ([]byte, error)

MarshalJSON implements the marshal interface

func (*Log) UnmarshalJSON

func (r *Log) UnmarshalJSON(buf []byte) error

UnmarshalJSON implements the unmarshal interface

type LogFilter

type LogFilter struct {
	Address   []Address
	Topics    []*Hash
	BlockHash *Hash
	From      *BlockNumber
	To        *BlockNumber
}

func (*LogFilter) MarshalJSON

func (l *LogFilter) MarshalJSON() ([]byte, error)

MarshalJSON implements the Marshal interface.

func (*LogFilter) SetFromUint64

func (l *LogFilter) SetFromUint64(num uint64)

func (*LogFilter) SetTo

func (l *LogFilter) SetTo(b BlockNumber)

func (*LogFilter) SetToUint64

func (l *LogFilter) SetToUint64(num uint64)

type Network

type Network uint64

Network is a chain id

const (
	// Mainnet is the mainnet network
	Mainnet Network = 1

	// Ropsten is the POW testnet
	Ropsten Network = 3

	// Rinkeby is a POW testnet
	Rinkeby Network = 4

	// Goerli is the Clique testnet
	Goerli = 5
)

type Receipt

type Receipt struct {
	TransactionHash   Hash
	TransactionIndex  uint64
	ContractAddress   Address
	BlockHash         Hash
	From              Address
	BlockNumber       uint64
	Status            uint64
	GasUsed           uint64
	CumulativeGasUsed uint64
	LogsBloom         []byte
	Logs              []*Log
}

func (*Receipt) UnmarshalJSON

func (r *Receipt) UnmarshalJSON(buf []byte) error

UnmarshalJSON implements the unmarshal interface

type Transaction

type Transaction struct {
	Hash     Hash
	From     Address
	To       string
	Input    []byte
	GasPrice uint64
	Gas      uint64
	Value    *big.Int

	/*Exta*/
	BlockHash        Hash
	BlockNumber      uint64
	Nonce            uint64
	TransactionIndex uint64
}

func (*Transaction) MarshalJSON

func (t *Transaction) MarshalJSON() ([]byte, error)

MarshalJSON implements the Marshal interface.

func (*Transaction) UnmarshalJSON

func (t *Transaction) UnmarshalJSON(buf []byte) error

UnmarshalJSON implements the unmarshal interface