ethrpc

README

ethrpc

Simple go lib to make RPC calls to Ethereum-like nodes easy

Example use

    target := ethrpc.New("https://cloudflare-eth.com")
    currentBlockNo, err := ethrpc.ReadUint64(target.Do("eth_blockNumber"))

TODO

• Support websocket

Documentation

Index

• Variables
• func ReadBigInt(v json.RawMessage, e error) (*big.Int, error)
• func ReadString(v json.RawMessage, e error) (string, error)
• func ReadTo(target any) func(v json.RawMessage, e error) error
• func ReadUint64(v json.RawMessage, e error) (uint64, error)
• type Api
  • func (a *Api) BlockNumber(ctx context.Context) (uint64, error)
  • func (a *Api) ChainId(ctx context.Context) (uint64, error)
  • func (a *Api) Do(method string, args ...any) (json.RawMessage, error)
  • func (a *Api) To(target any, method string, args ...any) error
  • func (a *Api) ToCtx(ctx context.Context, target any, method string, args ...any) error
• type Handler
  • func Evaluate(ctx context.Context, servers ...string) (Handler, error)
• type RPC
  • func New(h string) *RPC
  • func (r *RPC) Do(method string, args ...any) (json.RawMessage, error)
  • func (r *RPC) DoCtx(ctx context.Context, method string, args ...any) (json.RawMessage, error)
  • func (r *RPC) To(target any, method string, args ...any) error
• type RPCList
  • func (r RPCList) DoCtx(ctx context.Context, method string, args ...any) (json.RawMessage, error)

Variables

var (
	ErrNoAvailableServer = errors.New("no available server")
)

Functions

func ReadBigInt

func ReadBigInt(v json.RawMessage, e error) (*big.Int, error)

ReadBigInt can decode a json-encoded bigint in various ways, including if it is a number literal or a string.

func ReadString

func ReadString(v json.RawMessage, e error) (string, error)

ReadString decodes the return value as a string and returns it

func ReadTo

func ReadTo(target any) func(v json.RawMessage, e error) error

ReadTo returns a setter function that will return an error if an error happens. This is a bit convoluted because of limitation in Go's syntax, but this could be used as:

err = ReadTo(&block)(target.Do("eth_getBlockByNumber", "0x1b4", true))

func ReadUint64

func ReadUint64(v json.RawMessage, e error) (uint64, error)

ReadUint64 decodes the return value and passes it as a uint64.

This can be used as: res, err := ReadUint64(target.Do("eth_blockNumber"))

Types

type Api

type Api struct {
	Handler
}

func (*Api) BlockNumber

func (a *Api) BlockNumber(ctx context.Context) (uint64, error)

func (*Api) ChainId

func (a *Api) ChainId(ctx context.Context) (uint64, error)

func (*Api) Do

func (a *Api) Do(method string, args ...any) (json.RawMessage, error)

func (*Api) To

func (a *Api) To(target any, method string, args ...any) error

func (*Api) ToCtx

func (a *Api) ToCtx(ctx context.Context, target any, method string, args ...any) error

type Handler

type Handler interface {
	DoCtx(ctx context.Context, method string, args ...any) (json.RawMessage, error)
}

func Evaluate

func Evaluate(ctx context.Context, servers ...string) (Handler, error)

Evaluate will call the various servers in the list and return a list of servers that work (if any)

This will send a eth_blockNumber request to all the servers and measure the response time

type RPC

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

TODO support ws protocol

func New

func New(h string) *RPC

New returns a new instance of RPC to perform requests to the given RPC endpoint

func (*RPC) Do

func (r *RPC) Do(method string, args ...any) (json.RawMessage, error)

Do performs a RPC request

func (*RPC) DoCtx

func (r *RPC) DoCtx(ctx context.Context, method string, args ...any) (json.RawMessage, error)

DoCtx performs a RPC request, taking an optional context that can be cancelled to stop the request

func (*RPC) To

func (r *RPC) To(target any, method string, args ...any) error

type RPCList

type RPCList []*RPC

func (RPCList) DoCtx

func (r RPCList) DoCtx(ctx context.Context, method string, args ...any) (json.RawMessage, error)