// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus 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 dexon-consensus 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 dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.
// TODO(jimmy-dexon): remove comments of WitnessAck before open source.
package types
import (
"bytes"
"fmt"
"io"
"time"
"github.com/dexon-foundation/dexon/rlp"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/crypto"
)
// GenesisHeight refers to the initial height the genesis block should be.
const GenesisHeight uint64 = 1
// BlockVerifyStatus is the return code for core.Application.VerifyBlock
type BlockVerifyStatus int
// Enums for return value of core.Application.VerifyBlock.
const (
// VerifyOK: Block is verified.
VerifyOK BlockVerifyStatus = iota
// VerifyRetryLater: Block is unable to be verified at this moment.
// Try again later.
VerifyRetryLater
// VerifyInvalidBlock: Block is an invalid one.
VerifyInvalidBlock
)
type rlpTimestamp struct {
time.Time
}
func (t *rlpTimestamp) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, uint64(t.UTC().UnixNano()))
}
func (t *rlpTimestamp) DecodeRLP(s *rlp.Stream) error {
var nano uint64
err := s.Decode(&nano)
if err == nil {
sec := int64(nano) / 1000000000
nsec := int64(nano) % 1000000000
t.Time = time.Unix(sec, nsec).UTC()
}
return err
}
// Witness represents the consensus information on the compaction chain.
type Witness struct {
Height uint64 `json:"height"`
Data []byte `json:"data"`
}
// Block represents a single event broadcasted on the network.
type Block struct {
ProposerID NodeID `json:"proposer_id"`
ParentHash common.Hash `json:"parent_hash"`
Hash common.Hash `json:"hash"`
Position Position `json:"position"`
Timestamp time.Time `json:"timestamp"`
Payload []byte `json:"payload"`
PayloadHash common.Hash `json:"payload_hash"`
Witness Witness `json:"witness"`
Randomness []byte `json:"randomness"`
Signature crypto.Signature `json:"signature"`
CRSSignature crypto.Signature `json:"crs_signature"`
}
type rlpBlock struct {
ProposerID NodeID
ParentHash common.Hash
Hash common.Hash
Position Position
Timestamp *rlpTimestamp
Payload []byte
PayloadHash common.Hash
Witness *Witness
Randomness []byte
Signature crypto.Signature
CRSSignature crypto.Signature
}
// EncodeRLP implements rlp.Encoder
func (b *Block) EncodeRLP(w io.Writer) error {
return rlp.Encode(w, rlpBlock{
ProposerID: b.ProposerID,
ParentHash: b.ParentHash,
Hash: b.Hash,
Position: b.Position,
Timestamp: &rlpTimestamp{b.Timestamp},
Payload: b.Payload,
PayloadHash: b.PayloadHash,
Witness: &b.Witness,
Randomness: b.Randomness,
Signature: b.Signature,
CRSSignature: b.CRSSignature,
})
}
// DecodeRLP implements rlp.Decoder
func (b *Block) DecodeRLP(s *rlp.Stream) error {
var dec rlpBlock
err := s.Decode(&dec)
if err == nil {
*b = Block{
ProposerID: dec.ProposerID,
ParentHash: dec.ParentHash,
Hash: dec.Hash,
Position: dec.Position,
Timestamp: dec.Timestamp.Time,
Payload: dec.Payload,
PayloadHash: dec.PayloadHash,
Witness: *dec.Witness,
Randomness: dec.Randomness,
Signature: dec.Signature,
CRSSignature: dec.CRSSignature,
}
}
return err
}
func (b *Block) String() string {
return fmt.Sprintf("Block{Hash:%v %s}", b.Hash.String()[:6], b.Position)
}
// Clone returns a deep copy of a block.
func (b *Block) Clone() (bcopy *Block) {
bcopy = &Block{}
bcopy.ProposerID = b.ProposerID
bcopy.ParentHash = b.ParentHash
bcopy.Hash = b.Hash
bcopy.Position.Round = b.Position.Round
bcopy.Position.Height = b.Position.Height
bcopy.Signature = b.Signature.Clone()
bcopy.CRSSignature = b.CRSSignature.Clone()
bcopy.Witness.Height = b.Witness.Height
bcopy.Witness.Data = common.CopyBytes(b.Witness.Data)
bcopy.Timestamp = b.Timestamp
bcopy.Payload = common.CopyBytes(b.Payload)
bcopy.PayloadHash = b.PayloadHash
bcopy.Randomness = common.CopyBytes(b.Randomness)
return
}
// IsGenesis checks if the block is a genesisBlock
func (b *Block) IsGenesis() bool {
return b.Position.Height == GenesisHeight && b.ParentHash == common.Hash{}
}
// IsFinalized checks if the block is finalized.
func (b *Block) IsFinalized() bool {
return len(b.Randomness) > 0
}
// IsEmpty checks if the block is an 'empty block'.
func (b *Block) IsEmpty() bool {
return b.ProposerID.Hash == common.Hash{}
}
// ByHash is the helper type for sorting slice of blocks by hash.
type ByHash []*Block
func (b ByHash) Len() int {
return len(b)
}
func (b ByHash) Less(i int, j int) bool {
return bytes.Compare([]byte(b[i].Hash[:]), []byte(b[j].Hash[:])) == -1
}
func (b ByHash) Swap(i int, j int) {
b[i], b[j] = b[j], b[i]
}
// BlocksByPosition is the helper type for sorting slice of blocks by position.
type BlocksByPosition []*Block
// Len implements Len method in sort.Sort interface.
func (bs BlocksByPosition) Len() int {
return len(bs)
}
// Less implements Less method in sort.Sort interface.
func (bs BlocksByPosition) Less(i int, j int) bool {
return bs[j].Position.Newer(bs[i].Position)
}
// Swap implements Swap method in sort.Sort interface.
func (bs BlocksByPosition) Swap(i int, j int) {
bs[i], bs[j] = bs[j], bs[i]
}
// Push implements Push method in heap interface.
func (bs *BlocksByPosition) Push(x interface{}) {
*bs = append(*bs, x.(*Block))
}
// Pop implements Pop method in heap interface.
func (bs *BlocksByPosition) Pop() (ret interface{}) {
n := len(*bs)
*bs, ret = (*bs)[0:n-1], (*bs)[n-1]
return
}
