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 (
    "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

const (
    receiptStatusSuccessful = byte(0x01)
    receiptStatusFailed     = byte(0x00)
)

// 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
}

// homesteadReceiptRLP contains the receipt's Homestead consensus fields, used
// during RLP serialization.
type homesteadReceiptRLP struct {
    PostState         []byte
    CumulativeGasUsed *big.Int
    Bloom             Bloom
    Logs              []*Log
}

// metropolisReceiptRLP contains the receipt's Metropolis consensus fields, used
// during RLP serialization.
type metropolisReceiptRLP struct {
    Status            byte
    CumulativeGasUsed *big.Int
    Bloom             Bloom
    Logs              []*Log
}

// 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 {
    if r.PostState == nil {
        status := receiptStatusSuccessful
        if r.Failed {
            status = receiptStatusFailed
        }
        return rlp.Encode(w, &metropolisReceiptRLP{status, r.CumulativeGasUsed, r.Bloom, r.Logs})
    }
    return rlp.Encode(w, &homesteadReceiptRLP{r.PostState, 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 {
    // Load the raw bytes since we have multiple possible formats
    raw, err := s.Raw()
    if err != nil {
        return err
    }
    content, _, err := rlp.SplitList(raw)
    if err != nil {
        return err
    }
    kind, cnt, _, err := rlp.Split(content)
    if err != nil {
        return err
    }
    // Deserialize based on the first component type.
    switch {
    case kind == rlp.Byte || kind == rlp.String && len(cnt) == 0:
        // The first component of metropolis receipts is Byte
        // or empty String(byte with 0x00 value).
        var metro metropolisReceiptRLP
        if err := rlp.DecodeBytes(raw, &metro); err != nil {
            return err
        }
        r.Failed = metro.Status == receiptStatusFailed
        r.CumulativeGasUsed = metro.CumulativeGasUsed
        r.Bloom = metro.Bloom
        r.Logs = metro.Logs
        return nil

    case kind == rlp.String:
        // The first component of homestead receipts is non-empty String.
        var home homesteadReceiptRLP
        if err := rlp.DecodeBytes(raw, &home); err != nil {
            return err
        }
        r.PostState = home.PostState[:]
        r.CumulativeGasUsed = home.CumulativeGasUsed
        r.Bloom = home.Bloom
        r.Logs = home.Logs
        return nil

    default:
        return fmt.Errorf("invalid first receipt component: %v", kind)
    }
}

// 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 {
    logs := make([]*LogForStorage, len(r.Logs))
    for i, log := range r.Logs {
        logs[i] = (*LogForStorage)(log)
    }
    return rlp.Encode(w, []interface{}{r.PostState, r.Failed, r.CumulativeGasUsed, r.Bloom, r.TxHash, r.ContractAddress, logs, r.GasUsed})
}

// 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 receipt struct {
        PostState         []byte
        Failed            bool
        CumulativeGasUsed *big.Int
        Bloom             Bloom
        TxHash            common.Hash
        ContractAddress   common.Address
        Logs              []*LogForStorage
        GasUsed           *big.Int
    }
    if err := s.Decode(&receipt); err != nil {
        return err
    }
    // Assign the consensus fields
    r.PostState, r.Failed, r.CumulativeGasUsed, r.Bloom = receipt.PostState, receipt.Failed, receipt.CumulativeGasUsed, receipt.Bloom
    r.Logs = make([]*Log, len(receipt.Logs))
    for i, log := range receipt.Logs {
        r.Logs[i] = (*Log)(log)
    }
    // Assign the implementation fields
    r.TxHash, r.ContractAddress, r.GasUsed = receipt.TxHash, receipt.ContractAddress, receipt.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
}