// 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 dex
import (
"bytes"
"fmt"
"math/big"
"sync"
"time"
coreCommon "github.com/dexon-foundation/dexon-consensus-core/common"
coreTypes "github.com/dexon-foundation/dexon-consensus-core/core/types"
"github.com/dexon-foundation/dexon/common"
"github.com/dexon-foundation/dexon/core"
"github.com/dexon-foundation/dexon/core/state"
"github.com/dexon-foundation/dexon/core/types"
"github.com/dexon-foundation/dexon/core/vm"
"github.com/dexon-foundation/dexon/ethdb"
"github.com/dexon-foundation/dexon/log"
"github.com/dexon-foundation/dexon/rlp"
)
// DexconApp implementes the DEXON consensus core application interface.
type DexconApp struct {
txPool *core.TxPool
blockchain *core.BlockChain
gov *DexconGovernance
chainDB ethdb.Database
config *Config
vmConfig vm.Config
notifyChan map[uint64]*notify
mutex *sync.Mutex
lastHeight uint64
insertMu sync.Mutex
}
type notify struct {
results []chan uint64
}
type witnessData struct {
Root common.Hash
TxHash common.Hash
ReceiptHash common.Hash
}
func NewDexconApp(txPool *core.TxPool, blockchain *core.BlockChain, gov *DexconGovernance, chainDB ethdb.Database, config *Config, vmConfig vm.Config) *DexconApp {
return &DexconApp{
txPool: txPool,
blockchain: blockchain,
gov: gov,
chainDB: chainDB,
config: config,
vmConfig: vmConfig,
notifyChan: make(map[uint64]*notify),
mutex: &sync.Mutex{},
}
}
func (d *DexconApp) addNotify(height uint64) <-chan uint64 {
d.mutex.Lock()
defer d.mutex.Unlock()
result := make(chan uint64)
if n, exist := d.notifyChan[height]; exist {
n.results = append(n.results, result)
} else {
d.notifyChan[height] = ¬ify{}
d.notifyChan[height].results = append(d.notifyChan[height].results, result)
}
return result
}
func (d *DexconApp) notify(height uint64) {
d.mutex.Lock()
defer d.mutex.Unlock()
for h, n := range d.notifyChan {
if height >= h {
for _, ch := range n.results {
ch <- height
}
delete(d.notifyChan, h)
}
}
d.lastHeight = height
}
func (d *DexconApp) checkChain(address common.Address, chainSize, chainID *big.Int) bool {
addrModChainSize := new(big.Int)
return addrModChainSize.Mod(address.Big(), chainSize).Cmp(chainID) == 0
}
// PreparePayload is called when consensus core is preparing payload for block.
func (d *DexconApp) PreparePayload(position coreTypes.Position) (payload []byte, err error) {
d.insertMu.Lock()
defer d.insertMu.Unlock()
txsMap, err := d.txPool.Pending()
if err != nil {
return
}
chainID := new(big.Int).SetUint64(uint64(position.ChainID))
chainSize := new(big.Int).SetUint64(uint64(d.gov.GetNumChains(position.Round)))
var allTxs types.Transactions
for addr, txs := range txsMap {
// every address's transactions will appear in fixed chain
if !d.checkChain(addr, chainSize, chainID) {
continue
}
var stateDB *state.StateDB
if d.lastHeight > 0 {
stateDB, err = d.blockchain.StateAt(d.blockchain.GetPendingBlockByHeight(d.lastHeight).Root())
if err != nil {
return nil, fmt.Errorf("PreparePayload d.blockchain.StateAt err %v", err)
}
} else {
stateDB, err = d.blockchain.State()
if err != nil {
return nil, fmt.Errorf("PreparePayload d.blockchain.State err %v", err)
}
}
for _, tx := range txs {
if tx.Nonce() != stateDB.GetNonce(addr) {
log.Debug("Break transaction", "tx.hash", tx.Hash(), "nonce", tx.Nonce(), "expect", stateDB.GetNonce(addr))
break
}
log.Debug("Receive transaction", "tx.hash", tx.Hash(), "nonce", tx.Nonce(), "amount", tx.Value())
allTxs = append(allTxs, tx)
}
}
payload, err = rlp.EncodeToBytes(&allTxs)
if err != nil {
return
}
return
}
// PrepareWitness will return the witness data no lower than consensusHeight.
func (d *DexconApp) PrepareWitness(consensusHeight uint64) (witness coreTypes.Witness, err error) {
// TODO(bojie): the witness logic need to correct
var witnessBlock *types.Block
if d.lastHeight == 0 && consensusHeight == 0 {
witnessBlock = d.blockchain.CurrentBlock()
} else if d.lastHeight >= consensusHeight {
witnessBlock = d.blockchain.GetPendingBlockByHeight(d.lastHeight)
} else if h := <-d.addNotify(consensusHeight); h >= consensusHeight {
witnessBlock = d.blockchain.GetPendingBlockByHeight(h)
} else {
log.Error("need pending block")
return witness, fmt.Errorf("need pending block")
}
witnessData, err := rlp.EncodeToBytes(&witnessData{
Root: witnessBlock.Root(),
TxHash: witnessBlock.TxHash(),
ReceiptHash: witnessBlock.ReceiptHash(),
})
if err != nil {
return
}
return coreTypes.Witness{
Timestamp: time.Unix(witnessBlock.Time().Int64(), 0),
Height: witnessBlock.NumberU64(),
Data: witnessData,
}, nil
}
// VerifyBlock verifies if the payloads are valid.
func (d *DexconApp) VerifyBlock(block *coreTypes.Block) bool {
// TODO(bojie): implement this
return true
}
// BlockDelivered is called when a block is add to the compaction chain.
func (d *DexconApp) BlockDelivered(blockHash coreCommon.Hash, result coreTypes.FinalizationResult) {
d.insertMu.Lock()
defer d.insertMu.Unlock()
block := d.blockchain.GetConfirmedBlockByHash(blockHash)
if block == nil {
log.Error("Can not get confirmed block")
return
}
var transactions types.Transactions
err := rlp.Decode(bytes.NewReader(block.Payload), &transactions)
if err != nil {
log.Error("Payload rlp decode failed", "error", err)
return
}
var witnessData witnessData
err = rlp.Decode(bytes.NewReader(block.Witness.Data), &witnessData)
if err != nil {
log.Error("Witness rlp decode failed", "error", err)
return
}
log.Debug("Block proposer id", "hash", block.ProposerID)
newBlock := types.NewBlock(&types.Header{
Number: new(big.Int).SetUint64(result.Height),
Time: big.NewInt(result.Timestamp.Unix()),
Coinbase: common.BytesToAddress(block.ProposerID.Bytes()),
Position: block.Position,
WitnessHeight: block.Witness.Height,
WitnessRoot: witnessData.Root,
WitnessReceiptHash: witnessData.ReceiptHash,
// TODO(bojie): fix it
GasLimit: 8000000,
Difficulty: big.NewInt(1),
}, transactions, nil, nil)
_, err = d.blockchain.InsertPendingBlock([]*types.Block{newBlock})
if err != nil {
log.Error("Insert chain", "error", err)
return
}
log.Debug("Insert pending block success", "height", result.Height)
d.blockchain.RemoveConfirmedBlock(blockHash)
d.notify(result.Height)
}
// BlockConfirmed is called when a block is confirmed and added to lattice.
func (d *DexconApp) BlockConfirmed(block coreTypes.Block) {
d.blockchain.AddConfirmedBlock(&block)
}