// 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 utils
import (
"context"
"fmt"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/types"
typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
)
type configAccessor interface {
Configuration(round uint64) *types.Config
}
// GetConfigWithPanic is a helper to access configs, and panic when config for
// that round is not ready yet.
func GetConfigWithPanic(accessor configAccessor, round uint64,
logger common.Logger) *types.Config {
if logger != nil {
logger.Debug("Calling Governance.Configuration", "round", round)
}
c := accessor.Configuration(round)
if c == nil {
panic(fmt.Errorf("configuration is not ready %v", round))
}
return c
}
type crsAccessor interface {
CRS(round uint64) common.Hash
}
// GetCRSWithPanic is a helper to access CRS, and panic when CRS for that
// round is not ready yet.
func GetCRSWithPanic(accessor crsAccessor, round uint64,
logger common.Logger) common.Hash {
if logger != nil {
logger.Debug("Calling Governance.CRS", "round", round)
}
crs := accessor.CRS(round)
if (crs == common.Hash{}) {
panic(fmt.Errorf("CRS is not ready %v", round))
}
return crs
}
// VerifyDKGComplaint verifies if its a valid DKGCompliant.
func VerifyDKGComplaint(
complaint *typesDKG.Complaint, mpk *typesDKG.MasterPublicKey) (bool, error) {
ok, err := VerifyDKGComplaintSignature(complaint)
if err != nil {
return false, err
}
if !ok {
return false, nil
}
if complaint.IsNack() {
return true, nil
}
if complaint.Round != mpk.Round {
return false, nil
}
ok, err = VerifyDKGMasterPublicKeySignature(mpk)
if err != nil {
return false, err
}
if !ok {
return false, nil
}
ok, err = mpk.PublicKeyShares.VerifyPrvShare(
typesDKG.NewID(complaint.PrivateShare.ReceiverID),
&complaint.PrivateShare.PrivateShare)
if err != nil {
return false, err
}
return ok, nil
}
// LaunchDummyReceiver launches a go routine to receive from the receive
// channel of a network module. An context is required to stop the go routine
// automatically. An optinal message handler could be provided.
func LaunchDummyReceiver(
ctx context.Context, recv <-chan interface{}, handler func(interface{})) (
context.CancelFunc, <-chan struct{}) {
var (
dummyCtx, dummyCancel = context.WithCancel(ctx)
finishedChan = make(chan struct{}, 1)
)
go func() {
defer func() {
finishedChan <- struct{}{}
}()
loop:
for {
select {
case <-dummyCtx.Done():
break loop
case v, ok := <-recv:
if !ok {
panic(fmt.Errorf(
"receive channel is closed before dummy receiver"))
}
if handler != nil {
handler(v)
}
}
}
}()
return dummyCancel, finishedChan
}