// 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 simulation
import (
"encoding/json"
"fmt"
"sync"
"time"
"github.com/dexon-foundation/dexon-consensus-core/common"
"github.com/dexon-foundation/dexon-consensus-core/core/types"
)
// simApp is an DEXON app for simulation.
type simApp struct {
NodeID types.NodeID
Outputs []*types.Block
Early bool
netModule *network
DeliverID int
// blockSeen stores the time when block is delivered by Total Ordering.
blockSeen map[common.Hash]time.Time
// uncofirmBlocks stores the blocks whose timestamps are not ready.
unconfirmedBlocks map[types.NodeID]common.Hashes
blockByHash map[common.Hash]*types.Block
blockByHashMutex sync.RWMutex
latestWitness types.Witness
latestWitnessReady *sync.Cond
}
// newSimApp returns point to a new instance of simApp.
func newSimApp(id types.NodeID, netModule *network) *simApp {
return &simApp{
NodeID: id,
netModule: netModule,
DeliverID: 0,
blockSeen: make(map[common.Hash]time.Time),
unconfirmedBlocks: make(map[types.NodeID]common.Hashes),
blockByHash: make(map[common.Hash]*types.Block),
latestWitnessReady: sync.NewCond(&sync.Mutex{}),
}
}
// BlockConfirmed implements core.Application.
func (a *simApp) BlockConfirmed(block types.Block) {
a.blockByHashMutex.Lock()
defer a.blockByHashMutex.Unlock()
// TODO(jimmy-dexon) : Remove block in this hash if it's no longer needed.
a.blockByHash[block.Hash] = &block
a.blockSeen[block.Hash] = time.Now().UTC()
}
// VerifyBlock implements core.Application.
func (a *simApp) VerifyBlock(block *types.Block) bool {
return true
}
// getAckedBlocks will return all unconfirmed blocks' hash with lower Height
// than the block with ackHash.
func (a *simApp) getAckedBlocks(ackHash common.Hash) (output common.Hashes) {
// TODO(jimmy-dexon): Why there are some acks never seen?
ackBlock, exist := a.blockByHash[ackHash]
if !exist {
return
}
hashes, exist := a.unconfirmedBlocks[ackBlock.ProposerID]
if !exist {
return
}
for i, blockHash := range hashes {
if a.blockByHash[blockHash].Position.Height > ackBlock.Position.Height {
output, a.unconfirmedBlocks[ackBlock.ProposerID] = hashes[:i], hashes[i:]
break
}
}
// All of the Height of unconfirmed blocks are lower than the acked block.
if len(output) == 0 {
output, a.unconfirmedBlocks[ackBlock.ProposerID] = hashes, common.Hashes{}
}
return
}
// PreparePayload implements core.Application.
func (a *simApp) PreparePayload(position types.Position) ([]byte, error) {
return []byte{}, nil
}
// PrepareWitness implements core.Application.
func (a *simApp) PrepareWitness(height uint64) (types.Witness, error) {
a.latestWitnessReady.L.Lock()
defer a.latestWitnessReady.L.Unlock()
for a.latestWitness.Height < height {
a.latestWitnessReady.Wait()
}
return a.latestWitness, nil
}
// StronglyAcked is called when a block is strongly acked by DEXON
// Reliabe Broadcast algorithm.
func (a *simApp) StronglyAcked(blockHash common.Hash) {
}
// TotalOrderingDelivered is called when blocks are delivered by the total
// ordering algorithm.
func (a *simApp) TotalOrderingDelivered(
blockHashes common.Hashes, mode uint32) {
fmt.Println("OUTPUT", a.NodeID, mode, blockHashes)
blockList := &BlockList{
ID: a.DeliverID,
BlockHash: blockHashes,
}
a.netModule.report(blockList)
a.DeliverID++
}
// BlockDelivered is called when a block in compaction chain is delivered.
func (a *simApp) BlockDelivered(
blockHash common.Hash, result types.FinalizationResult) {
if len(result.Randomness) == 0 && func() bool {
if block, exist := a.blockByHash[blockHash]; exist {
if block.Position.Round == 0 {
return false
}
}
return true
}() {
panic(fmt.Errorf("Block %s randomness is empty", blockHash))
}
func() {
a.latestWitnessReady.L.Lock()
defer a.latestWitnessReady.L.Unlock()
a.latestWitness = types.Witness{
Timestamp: result.Timestamp,
Height: result.Height,
}
a.latestWitnessReady.Broadcast()
}()
seenTime, exist := a.blockSeen[blockHash]
if !exist {
return
}
now := time.Now()
payload := []timestampMessage{
{
BlockHash: blockHash,
Event: blockSeen,
Timestamp: seenTime,
},
{
BlockHash: blockHash,
Event: timestampConfirm,
Timestamp: now,
},
}
jsonPayload, err := json.Marshal(payload)
if err != nil {
fmt.Println(err)
return
}
msg := &message{
Type: blockTimestamp,
Payload: jsonPayload,
}
a.netModule.report(msg)
}