path: root/core/types/receipt.go

// Copyright 2014 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 types

import (
    "bytes"
    "fmt"
    "io"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/hexutil"
    "github.com/ethereum/go-ethereum/rlp"
)

//go:generate gencodec -type Receipt -field-override receiptMarshaling -out gen_receipt_json.go

var (
    receiptStatusFailed     = []byte{}
    receiptStatusSuccessful = []byte{0x01}
)

// Receipt represents the results of a transaction.
type Receipt struct {
    // Consensus fields
    PostState         []byte   `json:"root"`
    Failed            bool     `json:"failed"`
    CumulativeGasUsed *big.Int `json:"cumulativeGasUsed" gencodec:"required"`
    Bloom             Bloom    `json:"logsBloom"         gencodec:"required"`
    Logs              []*Log   `json:"logs"              gencodec:"required"`

    // Implementation fields (don't reorder!)
    TxHash          common.Hash    `json:"transactionHash" gencodec:"required"`
    ContractAddress common.Address `json:"contractAddress"`
    GasUsed         *big.Int       `json:"gasUsed" gencodec:"required"`
}

type receiptMarshaling struct {
    PostState         hexutil.Bytes
    CumulativeGasUsed *hexutil.Big
    GasUsed           *hexutil.Big
}

// receiptRLP is the consensus encoding of a receipt.
type receiptRLP struct {
    PostStateOrStatus []byte
    CumulativeGasUsed *big.Int
    Bloom             Bloom
    Logs              []*Log
}

type receiptStorageRLP struct {
    PostStateOrStatus []byte
    CumulativeGasUsed *big.Int
    Bloom             Bloom
    TxHash            common.Hash
    ContractAddress   common.Address
    Logs              []*LogForStorage
    GasUsed           *big.Int
}

// NewReceipt creates a barebone transaction receipt, copying the init fields.
func NewReceipt(root []byte, failed bool, cumulativeGasUsed *big.Int) *Receipt {
    return &Receipt{PostState: common.CopyBytes(root), Failed: failed, CumulativeGasUsed: new(big.Int).Set(cumulativeGasUsed)}
}

// EncodeRLP implements rlp.Encoder, and flattens the consensus fields of a receipt
// into an RLP stream. If no post state is present, metropolis fork is assumed.
func (r *Receipt) EncodeRLP(w io.Writer) error {
    return rlp.Encode(w, &receiptRLP{r.statusEncoding(), r.CumulativeGasUsed, r.Bloom, r.Logs})
}

// DecodeRLP implements rlp.Decoder, and loads the consensus fields of a receipt
// from an RLP stream.
func (r *Receipt) DecodeRLP(s *rlp.Stream) error {
    var dec receiptRLP
    if err := s.Decode(&dec); err != nil {
        return err
    }
    if err := r.setStatus(dec.PostStateOrStatus); err != nil {
        return err
    }
    r.CumulativeGasUsed, r.Bloom, r.Logs = dec.CumulativeGasUsed, dec.Bloom, dec.Logs
    return nil
}

func (r *Receipt) setStatus(postStateOrStatus []byte) error {
    switch {
    case bytes.Equal(postStateOrStatus, receiptStatusSuccessful):
        r.Failed = false
    case bytes.Equal(postStateOrStatus, receiptStatusFailed):
        r.Failed = true
    case len(postStateOrStatus) == len(common.Hash{}):
        r.PostState = postStateOrStatus
    default:
        return fmt.Errorf("invalid receipt status %x", postStateOrStatus)
    }
    return nil
}

func (r *Receipt) statusEncoding() []byte {
    if len(r.PostState) == 0 {
        if r.Failed {
            return receiptStatusFailed
        } else {
            return receiptStatusSuccessful
        }
    }
    return r.PostState
}

// String implements the Stringer interface.
func (r *Receipt) String() string {
    if r.PostState == nil {
        return fmt.Sprintf("receipt{failed=%t cgas=%v bloom=%x logs=%v}", r.Failed, r.CumulativeGasUsed, r.Bloom, r.Logs)
    }
    return fmt.Sprintf("receipt{med=%x cgas=%v bloom=%x logs=%v}", r.PostState, r.CumulativeGasUsed, r.Bloom, r.Logs)
}

// ReceiptForStorage is a wrapper around a Receipt that flattens and parses the
// entire content of a receipt, as opposed to only the consensus fields originally.
type ReceiptForStorage Receipt

// EncodeRLP implements rlp.Encoder, and flattens all content fields of a receipt
// into an RLP stream.
func (r *ReceiptForStorage) EncodeRLP(w io.Writer) error {
    enc := &receiptStorageRLP{
        PostStateOrStatus: (*Receipt)(r).statusEncoding(),
        CumulativeGasUsed: r.CumulativeGasUsed,
        Bloom:             r.Bloom,
        TxHash:            r.TxHash,
        ContractAddress:   r.ContractAddress,
        Logs:              make([]*LogForStorage, len(r.Logs)),
        GasUsed:           r.GasUsed,
    }
    for i, log := range r.Logs {
        enc.Logs[i] = (*LogForStorage)(log)
    }
    return rlp.Encode(w, enc)
}

// DecodeRLP implements rlp.Decoder, and loads both consensus and implementation
// fields of a receipt from an RLP stream.
func (r *ReceiptForStorage) DecodeRLP(s *rlp.Stream) error {
    var dec receiptStorageRLP
    if err := s.Decode(&dec); err != nil {
        return err
    }
    if err := (*Receipt)(r).setStatus(dec.PostStateOrStatus); err != nil {
        return err
    }
    // Assign the consensus fields
    r.CumulativeGasUsed, r.Bloom = dec.CumulativeGasUsed, dec.Bloom
    r.Logs = make([]*Log, len(dec.Logs))
    for i, log := range dec.Logs {
        r.Logs[i] = (*Log)(log)
    }
    // Assign the implementation fields
    r.TxHash, r.ContractAddress, r.GasUsed = dec.TxHash, dec.ContractAddress, dec.GasUsed
    return nil
}

// Receipts is a wrapper around a Receipt array to implement DerivableList.
type Receipts []*Receipt

// Len returns the number of receipts in this list.
func (r Receipts) Len() int { return len(r) }

// GetRlp returns the RLP encoding of one receipt from the list.
func (r Receipts) GetRlp(i int) []byte {
    bytes, err := rlp.EncodeToBytes(r[i])
    if err != nil {
        panic(err)
    }
    return bytes
}