github.com/ConsenSys/Quorum@v20.10.0+incompatible/consensus/istanbul/types.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package istanbul
    18  
    19  import (
    20  	"fmt"
    21  	"io"
    22  	"math/big"
    23  
    24  	"github.com/ethereum/go-ethereum/common"
    25  	"github.com/ethereum/go-ethereum/core/types"
    26  	"github.com/ethereum/go-ethereum/rlp"
    27  )
    28  
    29  // Proposal supports retrieving height and serialized block to be used during Istanbul consensus.
    30  type Proposal interface {
    31  	// Number retrieves the sequence number of this proposal.
    32  	Number() *big.Int
    33  
    34  	// Hash retrieves the hash of this proposal.
    35  	Hash() common.Hash
    36  
    37  	EncodeRLP(w io.Writer) error
    38  
    39  	DecodeRLP(s *rlp.Stream) error
    40  
    41  	String() string
    42  }
    43  
    44  type Request struct {
    45  	Proposal Proposal
    46  }
    47  
    48  // View includes a round number and a sequence number.
    49  // Sequence is the block number we'd like to commit.
    50  // Each round has a number and is composed by 3 steps: preprepare, prepare and commit.
    51  //
    52  // If the given block is not accepted by validators, a round change will occur
    53  // and the validators start a new round with round+1.
    54  type View struct {
    55  	Round    *big.Int
    56  	Sequence *big.Int
    57  }
    58  
    59  // EncodeRLP serializes b into the Ethereum RLP format.
    60  func (v *View) EncodeRLP(w io.Writer) error {
    61  	return rlp.Encode(w, []interface{}{v.Round, v.Sequence})
    62  }
    63  
    64  // DecodeRLP implements rlp.Decoder, and load the consensus fields from a RLP stream.
    65  func (v *View) DecodeRLP(s *rlp.Stream) error {
    66  	var view struct {
    67  		Round    *big.Int
    68  		Sequence *big.Int
    69  	}
    70  
    71  	if err := s.Decode(&view); err != nil {
    72  		return err
    73  	}
    74  	v.Round, v.Sequence = view.Round, view.Sequence
    75  	return nil
    76  }
    77  
    78  func (v *View) String() string {
    79  	return fmt.Sprintf("{Round: %d, Sequence: %d}", v.Round.Uint64(), v.Sequence.Uint64())
    80  }
    81  
    82  // Cmp compares v and y and returns:
    83  //   -1 if v <  y
    84  //    0 if v == y
    85  //   +1 if v >  y
    86  func (v *View) Cmp(y *View) int {
    87  	if v.Sequence.Cmp(y.Sequence) != 0 {
    88  		return v.Sequence.Cmp(y.Sequence)
    89  	}
    90  	if v.Round.Cmp(y.Round) != 0 {
    91  		return v.Round.Cmp(y.Round)
    92  	}
    93  	return 0
    94  }
    95  
    96  type Preprepare struct {
    97  	View     *View
    98  	Proposal Proposal
    99  }
   100  
   101  // EncodeRLP serializes b into the Ethereum RLP format.
   102  func (b *Preprepare) EncodeRLP(w io.Writer) error {
   103  	return rlp.Encode(w, []interface{}{b.View, b.Proposal})
   104  }
   105  
   106  // DecodeRLP implements rlp.Decoder, and load the consensus fields from a RLP stream.
   107  func (b *Preprepare) DecodeRLP(s *rlp.Stream) error {
   108  	var preprepare struct {
   109  		View     *View
   110  		Proposal *types.Block
   111  	}
   112  
   113  	if err := s.Decode(&preprepare); err != nil {
   114  		return err
   115  	}
   116  	b.View, b.Proposal = preprepare.View, preprepare.Proposal
   117  
   118  	return nil
   119  }
   120  
   121  type Subject struct {
   122  	View   *View
   123  	Digest common.Hash
   124  }
   125  
   126  // EncodeRLP serializes b into the Ethereum RLP format.
   127  func (b *Subject) EncodeRLP(w io.Writer) error {
   128  	return rlp.Encode(w, []interface{}{b.View, b.Digest})
   129  }
   130  
   131  // DecodeRLP implements rlp.Decoder, and load the consensus fields from a RLP stream.
   132  func (b *Subject) DecodeRLP(s *rlp.Stream) error {
   133  	var subject struct {
   134  		View   *View
   135  		Digest common.Hash
   136  	}
   137  
   138  	if err := s.Decode(&subject); err != nil {
   139  		return err
   140  	}
   141  	b.View, b.Digest = subject.View, subject.Digest
   142  	return nil
   143  }
   144  
   145  func (b *Subject) String() string {
   146  	return fmt.Sprintf("{View: %v, Digest: %v}", b.View, b.Digest.String())
   147  }