// 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 core
import (
"fmt"
"sync"
"github.com/dexon-foundation/dexon-consensus-core/common"
"github.com/dexon-foundation/dexon-consensus-core/core/crypto"
"github.com/dexon-foundation/dexon-consensus-core/core/types"
)
// Errors for compaction chain module.
var (
ErrBlockNotRegistered = fmt.Errorf(
"block not registered")
)
type compactionChain struct {
gov Governance
blocks map[common.Hash]*types.Block
pendingBlocks []*types.Block
pendingFinalizedBlocks []*types.Block
blocksLock sync.RWMutex
prevBlockLock sync.RWMutex
prevBlock *types.Block
}
func newCompactionChain(gov Governance) *compactionChain {
return &compactionChain{
gov: gov,
blocks: make(map[common.Hash]*types.Block),
}
}
func (cc *compactionChain) registerBlock(block *types.Block) {
if cc.blockRegistered(block.Hash) {
return
}
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
cc.blocks[block.Hash] = block
}
func (cc *compactionChain) blockRegistered(hash common.Hash) (exist bool) {
cc.blocksLock.RLock()
defer cc.blocksLock.RUnlock()
_, exist = cc.blocks[hash]
return
}
func (cc *compactionChain) processBlock(block *types.Block) error {
prevBlock := cc.lastBlock()
if prevBlock != nil {
block.Finalization.Height = prevBlock.Finalization.Height + 1
} else {
block.Finalization.Height = 1
}
cc.prevBlockLock.Lock()
defer cc.prevBlockLock.Unlock()
cc.prevBlock = block
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
cc.pendingBlocks = append(cc.pendingBlocks, block)
return nil
}
func (cc *compactionChain) processFinalizedBlock(block *types.Block) (
[]*types.Block, error) {
blocks := func() []*types.Block {
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
blocks := cc.pendingFinalizedBlocks
cc.pendingFinalizedBlocks = []*types.Block{}
return blocks
}()
threshold := make(map[uint64]int)
gpks := make(map[uint64]*DKGGroupPublicKey)
toPending := []*types.Block{}
confirmed := []*types.Block{}
blocks = append(blocks, block)
for _, b := range blocks {
if !cc.gov.IsDKGFinal(b.Position.Round) {
toPending = append(toPending, b)
continue
}
round := b.Position.Round
if _, exist := gpks[round]; !exist {
threshold[round] = int(cc.gov.Configuration(round).DKGSetSize)/3 + 1
var err error
gpks[round], err = NewDKGGroupPublicKey(
round,
cc.gov.DKGMasterPublicKeys(round), cc.gov.DKGComplaints(round),
threshold[round])
if err != nil {
continue
}
}
gpk := gpks[round]
if ok := gpk.VerifySignature(b.Hash, crypto.Signature{
Type: "bls",
Signature: b.Finalization.Randomness}); !ok {
continue
}
confirmed = append(confirmed, b)
}
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
cc.pendingFinalizedBlocks = append(cc.pendingFinalizedBlocks, toPending...)
return confirmed, nil
}
func (cc *compactionChain) extractBlocks() []*types.Block {
deliveringBlocks := make([]*types.Block, 0)
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
for len(cc.pendingBlocks) != 0 &&
(len(cc.pendingBlocks[0].Finalization.Randomness) != 0 ||
cc.pendingBlocks[0].Position.Round == 0) {
var block *types.Block
block, cc.pendingBlocks = cc.pendingBlocks[0], cc.pendingBlocks[1:]
delete(cc.blocks, block.Hash)
deliveringBlocks = append(deliveringBlocks, block)
}
return deliveringBlocks
}
func (cc *compactionChain) processBlockRandomnessResult(
rand *types.BlockRandomnessResult) error {
if !cc.blockRegistered(rand.BlockHash) {
return ErrBlockNotRegistered
}
cc.blocksLock.Lock()
defer cc.blocksLock.Unlock()
cc.blocks[rand.BlockHash].Finalization.Randomness = rand.Randomness
return nil
}
func (cc *compactionChain) lastBlock() *types.Block {
cc.prevBlockLock.RLock()
defer cc.prevBlockLock.RUnlock()
return cc.prevBlock
}
