// Copyright 2018 The dexon-consensus-core Authors
// This file is part of the dexon-consensus-core library.
//
// The dexon-consensus-core 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-core 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-core library. If not, see
// <http://www.gnu.org/licenses/>.
// TODO(jimmy-dexon): remove comments of WitnessAck before open source.
package types
import (
"bytes"
"fmt"
"sort"
"sync"
"time"
"github.com/dexon-foundation/dexon-consensus-core/common"
"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
)
var (
// blockPool is the blocks cache to reuse allocated blocks.
blockPool = sync.Pool{
New: func() interface{} {
return &Block{}
},
}
)
// FinalizationResult represents the result of DEXON consensus algorithm.
type FinalizationResult struct {
Randomness []byte `json:"randomness"`
Timestamp time.Time `json:"timestamp"`
Height uint64 `json:"height"`
}
// Witness represents the consensus information on the compaction chain.
type Witness struct {
Timestamp time.Time `json:"timestamp"`
Height uint64 `json:"height"`
Data []byte `json:"data"`
}
// RecycleBlock put unused block into cache, which might be reused if
// not garbage collected.
func RecycleBlock(b *Block) {
blockPool.Put(b)
}
// NewBlock initiate a block.
func NewBlock() (b *Block) {
b = blockPool.Get().(*Block)
b.Acks = b.Acks[:0]
return
}
// 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"`
Acks common.SortedHashes `json:"acks"`
Payload []byte `json:"payload"`
Witness Witness `json:"witness"`
Finalization FinalizationResult `json:"finalization"`
Signature crypto.Signature `json:"signature"`
CRSSignature crypto.Signature `json:"crs_signature"`
}
func (b *Block) String() string {
return fmt.Sprintf("Block(%v:%d:%d)", b.Hash.String()[:6],
b.Position.ChainID, b.Position.Height)
}
// Clone returns a deep copy of a block.
func (b *Block) Clone() (bcopy *Block) {
bcopy = NewBlock()
bcopy.ProposerID = b.ProposerID
bcopy.ParentHash = b.ParentHash
bcopy.Hash = b.Hash
bcopy.Position.ChainID = b.Position.ChainID
bcopy.Position.Height = b.Position.Height
bcopy.Signature = b.Signature.Clone()
bcopy.CRSSignature = b.CRSSignature.Clone()
bcopy.Finalization.Timestamp = b.Finalization.Timestamp
bcopy.Finalization.Height = b.Finalization.Height
bcopy.Witness.Timestamp = b.Witness.Timestamp
bcopy.Witness.Height = b.Witness.Height
bcopy.Witness.Data = make([]byte, len(b.Witness.Data))
copy(bcopy.Witness.Data, b.Witness.Data)
bcopy.Timestamp = b.Timestamp
bcopy.Acks = make(common.SortedHashes, len(b.Acks))
copy(bcopy.Acks, b.Acks)
bcopy.Payload = make([]byte, len(b.Payload))
copy(bcopy.Payload, b.Payload)
bcopy.Finalization.Randomness = make([]byte, len(b.Finalization.Randomness))
copy(bcopy.Finalization.Randomness, b.Finalization.Randomness)
return
}
// IsGenesis checks if the block is a genesisBlock
func (b *Block) IsGenesis() bool {
return b.Position.Height == 0 && b.ParentHash == common.Hash{}
}
// IsAcking checks if a block acking another by it's hash.
func (b *Block) IsAcking(hash common.Hash) bool {
idx := sort.Search(len(b.Acks), func(i int) bool {
return bytes.Compare(b.Acks[i][:], hash[:]) >= 0
})
return !(idx == len(b.Acks) || b.Acks[idx] != 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]
}
// ByHeight is the helper type for sorting slice of blocks by height.
type ByHeight []*Block
// Len implements Len method in sort.Sort interface.
func (bs ByHeight) Len() int {
return len(bs)
}
// Less implements Less method in sort.Sort interface.
func (bs ByHeight) Less(i int, j int) bool {
return bs[i].Position.Height < bs[j].Position.Height
}
// Swap implements Swap method in sort.Sort interface.
func (bs ByHeight) Swap(i int, j int) {
bs[i], bs[j] = bs[j], bs[i]
}
// Push implements Push method in heap interface.
func (bs *ByHeight) Push(x interface{}) {
*bs = append(*bs, x.(*Block))
}
// Pop implements Pop method in heap interface.
func (bs *ByHeight) Pop() (ret interface{}) {
n := len(*bs)
*bs, ret = (*bs)[0:n-1], (*bs)[n-1]
return
}