// 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 test
import (
"fmt"
"sync"
"time"
"github.com/dexon-foundation/dexon-consensus-core/common"
"github.com/dexon-foundation/dexon-consensus-core/core/types"
)
var (
// ErrEmptyDeliverSequence means there is no delivery event in this App
// instance.
ErrEmptyDeliverSequence = fmt.Errorf("emptry deliver sequence")
// ErrMismatchBlockHashSequence means the delivering sequence between two App
// instances are different.
ErrMismatchBlockHashSequence = fmt.Errorf("mismatch block hash sequence")
// ErrMismatchConsensusTime means the consensus timestamp between two blocks
// with the same hash from two App instances are different.
ErrMismatchConsensusTime = fmt.Errorf("mismatch consensus time")
// ErrApplicationIntegrityFailed means the internal datum in a App instance
// is not integrated.
ErrApplicationIntegrityFailed = fmt.Errorf("application integrity failed")
// ErrConsensusTimestampOutOfOrder means the later delivered block has
// consensus timestamp older than previous block.
ErrConsensusTimestampOutOfOrder = fmt.Errorf(
"consensus timestamp out of order")
// ErrDeliveredBlockNotAcked means some block delivered (confirmed) but
// not strongly acked.
ErrDeliveredBlockNotAcked = fmt.Errorf("delivered block not acked")
// ErrMismatchTotalOrderingAndDelivered mean the sequence of total ordering
// and delivered are different.
ErrMismatchTotalOrderingAndDelivered = fmt.Errorf(
"mismatch total ordering and delivered sequence")
)
// AppAckedRecord caches information when this application received
// a strongly-acked notification.
type AppAckedRecord struct {
When time.Time
}
// AppTotalOrderRecord caches information when this application received
// a total-ordering deliver notification.
type AppTotalOrderRecord struct {
BlockHashes common.Hashes
Mode uint32
When time.Time
}
// AppDeliveredRecord caches information when this application received
// a block delivered notification.
type AppDeliveredRecord struct {
ConsensusTime time.Time
When time.Time
}
// App implements Application interface for testing purpose.
type App struct {
Acked map[common.Hash]*AppAckedRecord
ackedLock sync.RWMutex
TotalOrdered []*AppTotalOrderRecord
TotalOrderedByHash map[common.Hash]*AppTotalOrderRecord
totalOrderedLock sync.RWMutex
Delivered map[common.Hash]*AppDeliveredRecord
DeliverSequence common.Hashes
deliveredLock sync.RWMutex
}
// NewApp constructs a TestApp instance.
func NewApp() *App {
return &App{
Acked: make(map[common.Hash]*AppAckedRecord),
TotalOrdered: []*AppTotalOrderRecord{},
TotalOrderedByHash: make(map[common.Hash]*AppTotalOrderRecord),
Delivered: make(map[common.Hash]*AppDeliveredRecord),
DeliverSequence: common.Hashes{},
}
}
// PreparePayload implements Application interface.
func (app *App) PreparePayload(position types.Position) ([]byte, error) {
return []byte{}, nil
}
// PrepareWitness implements Application interface.
func (app *App) PrepareWitness(height uint64) (types.Witness, error) {
return types.Witness{
Height: height,
}, nil
}
// VerifyBlock implements Application.
func (app *App) VerifyBlock(block *types.Block) bool {
return true
}
// BlockConfirmed implements Application interface.
func (app *App) BlockConfirmed(_ types.Block) {
}
// StronglyAcked implements Application interface.
func (app *App) StronglyAcked(blockHash common.Hash) {
app.ackedLock.Lock()
defer app.ackedLock.Unlock()
app.Acked[blockHash] = &AppAckedRecord{When: time.Now().UTC()}
}
// TotalOrderingDelivered implements Application interface.
func (app *App) TotalOrderingDelivered(blockHashes common.Hashes, mode uint32) {
app.totalOrderedLock.Lock()
defer app.totalOrderedLock.Unlock()
rec := &AppTotalOrderRecord{
BlockHashes: blockHashes,
Mode: mode,
When: time.Now().UTC(),
}
app.TotalOrdered = append(app.TotalOrdered, rec)
for _, h := range blockHashes {
if _, exists := app.TotalOrderedByHash[h]; exists {
panic(fmt.Errorf("deliver duplicated blocks from total ordering"))
}
app.TotalOrderedByHash[h] = rec
}
}
// BlockDelivered implements Application interface.
func (app *App) BlockDelivered(
blockHash common.Hash, result types.FinalizationResult) {
app.deliveredLock.Lock()
defer app.deliveredLock.Unlock()
app.Delivered[blockHash] = &AppDeliveredRecord{
ConsensusTime: result.Timestamp,
When: time.Now().UTC(),
}
app.DeliverSequence = append(app.DeliverSequence, blockHash)
}
// Compare performs these checks against another App instance
// and return erros if not passed:
// - deliver sequence by comparing block hashes.
// - consensus timestamp of each block are equal.
func (app *App) Compare(other *App) error {
app.deliveredLock.RLock()
defer app.deliveredLock.RUnlock()
other.deliveredLock.RLock()
defer other.deliveredLock.RUnlock()
minLength := len(app.DeliverSequence)
if minLength > len(other.DeliverSequence) {
minLength = len(other.DeliverSequence)
}
if minLength == 0 {
return ErrEmptyDeliverSequence
}
for idx, h := range app.DeliverSequence[:minLength] {
hOther := other.DeliverSequence[idx]
if hOther != h {
return ErrMismatchBlockHashSequence
}
if app.Delivered[h].ConsensusTime != other.Delivered[h].ConsensusTime {
return ErrMismatchConsensusTime
}
}
return nil
}
// Verify checks the integrity of date received by this App instance.
func (app *App) Verify() error {
app.deliveredLock.RLock()
defer app.deliveredLock.RUnlock()
if len(app.DeliverSequence) == 0 {
return ErrEmptyDeliverSequence
}
if len(app.DeliverSequence) != len(app.Delivered) {
return ErrApplicationIntegrityFailed
}
app.ackedLock.RLock()
defer app.ackedLock.RUnlock()
prevTime := time.Time{}
for _, h := range app.DeliverSequence {
// Make sure delivered block is strongly acked.
if _, acked := app.Acked[h]; !acked {
return ErrDeliveredBlockNotAcked
}
rec, exists := app.Delivered[h]
if !exists {
return ErrApplicationIntegrityFailed
}
// Make sure the consensus time is incremental.
ok := prevTime.Before(rec.ConsensusTime) ||
prevTime.Equal(rec.ConsensusTime)
if !ok {
return ErrConsensusTimestampOutOfOrder
}
prevTime = rec.ConsensusTime
}
// Make sure the order of delivered and total ordering are the same by
// comparing the concated string.
app.totalOrderedLock.RLock()
defer app.totalOrderedLock.RUnlock()
hashSequenceIdx := 0
Loop:
for _, rec := range app.TotalOrdered {
for _, h := range rec.BlockHashes {
if hashSequenceIdx >= len(app.DeliverSequence) {
break Loop
}
if h != app.DeliverSequence[hashSequenceIdx] {
return ErrMismatchTotalOrderingAndDelivered
}
hashSequenceIdx++
}
}
if hashSequenceIdx != len(app.DeliverSequence) {
// The count of delivered blocks should be larger than those delivered
// by total ordering.
return ErrMismatchTotalOrderingAndDelivered
}
return nil
}
// Check provides a backdoor to check status of App with reader lock.
func (app *App) Check(checker func(*App)) {
app.ackedLock.RLock()
defer app.ackedLock.RUnlock()
app.totalOrderedLock.RLock()
defer app.totalOrderedLock.RUnlock()
app.deliveredLock.RLock()
defer app.deliveredLock.RUnlock()
checker(app)
}
