// 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/>.
package core
import (
"sort"
"sync"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/types"
)
type totalOrderingSyncer struct {
lock sync.RWMutex
numChains uint32
syncHeight map[uint32]uint64
syncDeliverySetIdx int
pendingBlocks []*types.Block
inPendingBlocks map[common.Hash]struct{}
bootstrapChain map[uint32]struct{}
// Data to restore delivery set.
pendingDeliveryBlocks []*types.Block
deliverySet map[int][]*types.Block
mapToDeliverySet map[common.Hash]int
}
func newTotalOrderingSyncer(numChains uint32) *totalOrderingSyncer {
return &totalOrderingSyncer{
numChains: numChains,
syncHeight: make(map[uint32]uint64),
syncDeliverySetIdx: -1,
inPendingBlocks: make(map[common.Hash]struct{}),
bootstrapChain: make(map[uint32]struct{}),
deliverySet: make(map[int][]*types.Block),
mapToDeliverySet: make(map[common.Hash]int),
}
}
func (tos *totalOrderingSyncer) synced() bool {
tos.lock.RLock()
defer tos.lock.RUnlock()
return tos.syncDeliverySetIdx != -1
}
func (tos *totalOrderingSyncer) processBlock(
block *types.Block) (delivered []*types.Block) {
if tos.synced() {
if tos.syncHeight[block.Position.ChainID] >= block.Position.Height {
return
}
delivered = append(delivered, block)
return
}
tos.lock.Lock()
defer tos.lock.Unlock()
tos.inPendingBlocks[block.Hash] = struct{}{}
tos.pendingBlocks = append(tos.pendingBlocks, block)
if block.Position.Height == 0 {
tos.bootstrapChain[block.Position.ChainID] = struct{}{}
}
if uint32(len(tos.bootstrapChain)) == tos.numChains {
// Bootstrap mode.
delivered = tos.pendingBlocks
tos.syncDeliverySetIdx = 0
for i := uint32(0); i < tos.numChains; i++ {
tos.syncHeight[i] = uint64(0)
}
} else {
maxDeliverySetIdx := -1
// TODO(jimmy-dexon): below for loop can be optimized.
PendingBlockLoop:
for i, block := range tos.pendingBlocks {
idx, exist := tos.mapToDeliverySet[block.Hash]
if !exist {
continue
}
deliverySet := tos.deliverySet[idx]
// Check if all the blocks in deliverySet are in the pendingBlocks.
for _, dBlock := range deliverySet {
if _, exist := tos.inPendingBlocks[dBlock.Hash]; !exist {
continue PendingBlockLoop
}
}
if idx > maxDeliverySetIdx {
maxDeliverySetIdx = idx
}
// Check if all of the chains have delivered.
for _, dBlock := range deliverySet {
if h, exist := tos.syncHeight[dBlock.Position.ChainID]; exist {
if dBlock.Position.Height < h {
continue
}
}
tos.syncHeight[dBlock.Position.ChainID] = dBlock.Position.Height
}
if uint32(len(tos.syncHeight)) != tos.numChains {
continue
}
// Core is fully synced, it can start delivering blocks from idx.
tos.syncDeliverySetIdx = maxDeliverySetIdx
delivered = make([]*types.Block, 0, i)
break
}
if tos.syncDeliverySetIdx == -1 {
return
}
// Generating delivering blocks.
for i := maxDeliverySetIdx; i < len(tos.deliverySet); i++ {
deliverySet := tos.deliverySet[i]
sort.Sort(types.ByHash(deliverySet))
for _, block := range deliverySet {
if block.Position.Height > tos.syncHeight[block.Position.ChainID] {
tos.syncHeight[block.Position.ChainID] = block.Position.Height
}
delivered = append(delivered, block)
}
}
// Flush remaining blocks.
for _, block := range tos.pendingBlocks {
if _, exist := tos.mapToDeliverySet[block.Hash]; exist {
continue
}
if block.Position.Height > tos.syncHeight[block.Position.ChainID] {
tos.syncHeight[block.Position.ChainID] = block.Position.Height
}
delivered = append(delivered, block)
}
}
// Clean internal data model to save memory.
tos.pendingBlocks = nil
tos.inPendingBlocks = nil
tos.bootstrapChain = nil
tos.pendingDeliveryBlocks = nil
tos.deliverySet = nil
tos.mapToDeliverySet = nil
return
}
// The finalized block should be passed by the order of consensus height.
func (tos *totalOrderingSyncer) processFinalizedBlock(block *types.Block) {
if tos.synced() {
return
}
tos.lock.Lock()
defer tos.lock.Unlock()
if len(tos.pendingDeliveryBlocks) > 0 {
if block.Hash.Less(
tos.pendingDeliveryBlocks[len(tos.pendingDeliveryBlocks)-1].Hash) {
// pendingDeliveryBlocks forms a deliverySet.
idx := len(tos.deliverySet)
tos.deliverySet[idx] = tos.pendingDeliveryBlocks
for _, block := range tos.pendingDeliveryBlocks {
tos.mapToDeliverySet[block.Hash] = idx
}
tos.pendingDeliveryBlocks = []*types.Block{}
}
}
tos.pendingDeliveryBlocks = append(tos.pendingDeliveryBlocks, block)
}
