// 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 rpc
import (
"context"
"encoding/json"
"fmt"
"math"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
)
// API describes the set of methods offered over the RPC interface
type API struct {
Namespace string // namespace under which the rpc methods of Service are exposed
Version string // api version for DApp's
Service interface{} // receiver instance which holds the methods
Public bool // indication if the methods must be considered safe for public use
}
// Error wraps RPC errors, which contain an error code in addition to the message.
type Error interface {
Error() string // returns the message
ErrorCode() int // returns the code
}
// A DataError contains some data in addition to the error message.
type DataError interface {
Error() string // returns the message
ErrorData() interface{} // returns the error data
}
// ServerCodec implements reading, parsing and writing RPC messages for the server side of
// a RPC session. Implementations must be go-routine safe since the codec can be called in
// multiple go-routines concurrently.
type ServerCodec interface {
readBatch() (msgs []*jsonrpcMessage, isBatch bool, err error)
close()
jsonWriter
}
// jsonWriter can write JSON messages to its underlying connection.
// Implementations must be safe for concurrent use.
type jsonWriter interface {
writeJSON(context.Context, interface{}) error
// Closed returns a channel which is closed when the connection is closed.
closed() <-chan interface{}
// RemoteAddr returns the peer address of the connection.
remoteAddr() string
}
type BlockNumber int64
const (
AcceptedBlockNumber = BlockNumber(-3)
PendingBlockNumber = BlockNumber(-2)
LatestBlockNumber = BlockNumber(-1)
EarliestBlockNumber = BlockNumber(0)
)
// UnmarshalJSON parses the given JSON fragment into a BlockNumber. It supports:
// - "latest", "earliest" or "pending" as string arguments
// - the block number
// Returned errors:
// - an invalid block number error when the given argument isn't a known strings
// - an out of range error when the given block number is either too little or too large
func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
input := strings.TrimSpace(string(data))
if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
input = input[1 : len(input)-1]
}
switch input {
case "earliest":
*bn = EarliestBlockNumber
return nil
case "latest":
*bn = LatestBlockNumber
return nil
case "pending":
*bn = PendingBlockNumber
return nil
case "accepted":
*bn = AcceptedBlockNumber
return nil
}
blckNum, err := hexutil.DecodeUint64(input)
if err != nil {
return err
}
if blckNum > math.MaxInt64 {
return fmt.Errorf("block number larger than int64")
}
*bn = BlockNumber(blckNum)
return nil
}
func (bn BlockNumber) Int64() int64 {
return (int64)(bn)
}
// IsAccepted returns true if this blockNumber should be treated as a request for the last accepted block
func (bn BlockNumber) IsAccepted() bool {
return bn < EarliestBlockNumber && bn >= AcceptedBlockNumber
}
type BlockNumberOrHash struct {
BlockNumber *BlockNumber `json:"blockNumber,omitempty"`
BlockHash *common.Hash `json:"blockHash,omitempty"`
RequireCanonical bool `json:"requireCanonical,omitempty"`
}
func (bnh *BlockNumberOrHash) UnmarshalJSON(data []byte) error {
type erased BlockNumberOrHash
e := erased{}
err := json.Unmarshal(data, &e)
if err == nil {
if e.BlockNumber != nil && e.BlockHash != nil {
return fmt.Errorf("cannot specify both BlockHash and BlockNumber, choose one or the other")
}
bnh.BlockNumber = e.BlockNumber
bnh.BlockHash = e.BlockHash
bnh.RequireCanonical = e.RequireCanonical
return nil
}
var input string
err = json.Unmarshal(data, &input)
if err != nil {
return err
}
switch input {
case "earliest":
bn := EarliestBlockNumber
bnh.BlockNumber = &bn
return nil
case "latest":
bn := LatestBlockNumber
bnh.BlockNumber = &bn
return nil
case "pending":
bn := PendingBlockNumber
bnh.BlockNumber = &bn
return nil
case "accepted":
bn := AcceptedBlockNumber
bnh.BlockNumber = &bn
return nil
default:
if len(input) == 66 {
hash := common.Hash{}
err := hash.UnmarshalText([]byte(input))
if err != nil {
return err
}
bnh.BlockHash = &hash
return nil
} else {
blckNum, err := hexutil.DecodeUint64(input)
if err != nil {
return err
}
if blckNum > math.MaxInt64 {
return fmt.Errorf("blocknumber too high")
}
bn := BlockNumber(blckNum)
bnh.BlockNumber = &bn
return nil
}
}
}
func (bnh *BlockNumberOrHash) Number() (BlockNumber, bool) {
if bnh.BlockNumber != nil {
return *bnh.BlockNumber, true
}
return BlockNumber(0), false
}
func (bnh *BlockNumberOrHash) Hash() (common.Hash, bool) {
if bnh.BlockHash != nil {
return *bnh.BlockHash, true
}
return common.Hash{}, false
}
func BlockNumberOrHashWithNumber(blockNr BlockNumber) BlockNumberOrHash {
return BlockNumberOrHash{
BlockNumber: &blockNr,
BlockHash: nil,
RequireCanonical: false,
}
}
func BlockNumberOrHashWithHash(hash common.Hash, canonical bool) BlockNumberOrHash {
return BlockNumberOrHash{
BlockNumber: nil,
BlockHash: &hash,
RequireCanonical: canonical,
}
}