path: root/core/types/block.go

// 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/>.

package types

import (
    "bytes"
    "fmt"
    "time"

    "github.com/dexon-foundation/dexon-consensus-core/common"
    "github.com/dexon-foundation/dexon-consensus-core/crypto"
)

// Status represents the block process state.
type Status int

// Block Status.
const (
    BlockStatusInit Status = iota
    BlockStatusAcked
    BlockStatusOrdering
    BlockStatusFinal
)

// CompactionChainAck represents the acking to the compaction chain.
type CompactionChainAck struct {
    AckingBlockHash common.Hash `json:"acking_block_hash"`
    // Signature is the signature of the hash value of
    // Block.ConsensusInfoParentHash and Block.ConsensusInfo.
    ConsensusSignature crypto.Signature `json:"consensus_signature"`
}

// ConsensusInfo represents the consensus information on the compaction chain.
type ConsensusInfo struct {
    Timestamp time.Time `json:"timestamp"`
    Height    uint64    `json:"height"`
}

// Block represents a single event broadcasted on the network.
type Block struct {
    ProposerID         ValidatorID               `json:"proposer_id"`
    ParentHash         common.Hash               `json:"parent_hash"`
    Hash               common.Hash               `json:"hash"`
    Height             uint64                    `json:"height"`
    Timestamps         map[ValidatorID]time.Time `json:"timestamps"`
    Acks               map[common.Hash]struct{}  `json:"acks"`
    CompactionChainAck CompactionChainAck        `json:"compaction_chain_ack"`

    ConsensusInfo ConsensusInfo `json:"consensus_info"`
    // ConsensusInfoParentHash is the hash value of Block.ConsensusInfoParentHash
    // and Block.ConsensusInfo, where Block is the previous block on
    // the compaction chain.
    ConsensusInfoParentHash common.Hash `json:"consensus_info_parent_hash"`

    Ackeds          map[common.Hash]struct{} `json:"-"`
    AckedValidators map[ValidatorID]struct{} `json:"-"`
    Status          Status                   `json:"-"`
}

// BlockConverter interface define the interface for extracting block
// information from an existing object.
type BlockConverter interface {
    Block() *Block
}

func (b *Block) String() string {
    return fmt.Sprintf("Block(%v)", b.Hash.String()[:6])
}

// Clone returns a deep copy of a block.
func (b *Block) Clone() *Block {
    bcopy := &Block{
        ProposerID: b.ProposerID,
        ParentHash: b.ParentHash,
        Hash:       b.Hash,
        Height:     b.Height,
        Timestamps: make(map[ValidatorID]time.Time),
        Acks:       make(map[common.Hash]struct{}),
        CompactionChainAck: CompactionChainAck{
            AckingBlockHash: b.CompactionChainAck.AckingBlockHash,
        },
        ConsensusInfo: ConsensusInfo{
            Timestamp: b.ConsensusInfo.Timestamp,
            Height:    b.ConsensusInfo.Height,
        },
        ConsensusInfoParentHash: b.ConsensusInfoParentHash,
    }
    bcopy.CompactionChainAck.ConsensusSignature = append(
        crypto.Signature(nil), b.CompactionChainAck.ConsensusSignature...)
    for k, v := range b.Timestamps {
        bcopy.Timestamps[k] = v
    }
    for k, v := range b.Acks {
        bcopy.Acks[k] = v
    }
    return bcopy
}

// 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

func (b ByHeight) Len() int {
    return len(b)
}

func (b ByHeight) Less(i int, j int) bool {
    return b[i].Height < b[j].Height
}

func (b ByHeight) Swap(i int, j int) {
    b[i], b[j] = b[j], b[i]
}