diff options
Diffstat (limited to 'vendor/github.com/dexon-foundation/dexon-consensus-core/core/leader-selector.go')
-rw-r--r-- | vendor/github.com/dexon-foundation/dexon-consensus-core/core/leader-selector.go | 136 |
1 files changed, 0 insertions, 136 deletions
diff --git a/vendor/github.com/dexon-foundation/dexon-consensus-core/core/leader-selector.go b/vendor/github.com/dexon-foundation/dexon-consensus-core/core/leader-selector.go deleted file mode 100644 index 2be596abc..000000000 --- a/vendor/github.com/dexon-foundation/dexon-consensus-core/core/leader-selector.go +++ /dev/null @@ -1,136 +0,0 @@ -// 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 ( - "fmt" - "math/big" - "sync" - - "github.com/dexon-foundation/dexon-consensus/common" - "github.com/dexon-foundation/dexon-consensus/core/crypto" - "github.com/dexon-foundation/dexon-consensus/core/types" -) - -// Errors for leader module. -var ( - ErrIncorrectCRSSignature = fmt.Errorf("incorrect CRS signature") -) - -type validLeaderFn func(*types.Block) bool - -// Some constant value. -var ( - maxHash *big.Int - one *big.Rat -) - -func init() { - hash := make([]byte, common.HashLength) - for i := range hash { - hash[i] = 0xff - } - maxHash = big.NewInt(0).SetBytes(hash) - one = big.NewRat(1, 1) -} - -type leaderSelector struct { - hashCRS common.Hash - numCRS *big.Int - minCRSBlock *big.Int - minBlockHash common.Hash - pendingBlocks []*types.Block - validLeader validLeaderFn - lock sync.Mutex -} - -func newLeaderSelector( - crs common.Hash, validLeader validLeaderFn) *leaderSelector { - numCRS := big.NewInt(0) - numCRS.SetBytes(crs[:]) - return &leaderSelector{ - numCRS: numCRS, - hashCRS: crs, - minCRSBlock: maxHash, - validLeader: validLeader, - } -} - -func (l *leaderSelector) distance(sig crypto.Signature) *big.Int { - hash := crypto.Keccak256Hash(sig.Signature[:]) - num := big.NewInt(0) - num.SetBytes(hash[:]) - num.Abs(num.Sub(l.numCRS, num)) - return num -} - -func (l *leaderSelector) probability(sig crypto.Signature) float64 { - dis := l.distance(sig) - prob := big.NewRat(1, 1).SetFrac(dis, maxHash) - p, _ := prob.Sub(one, prob).Float64() - return p -} - -func (l *leaderSelector) restart() { - l.lock.Lock() - defer l.lock.Unlock() - l.minCRSBlock = maxHash - l.minBlockHash = common.Hash{} - l.pendingBlocks = []*types.Block{} -} - -func (l *leaderSelector) leaderBlockHash() common.Hash { - l.lock.Lock() - defer l.lock.Unlock() - newPendingBlocks := []*types.Block{} - for _, b := range l.pendingBlocks { - if l.validLeader(b) { - l.updateLeader(b) - } else { - newPendingBlocks = append(newPendingBlocks, b) - } - } - l.pendingBlocks = newPendingBlocks - return l.minBlockHash -} - -func (l *leaderSelector) processBlock(block *types.Block) error { - ok, err := verifyCRSSignature(block, l.hashCRS) - if err != nil { - return err - } - if !ok { - return ErrIncorrectCRSSignature - } - l.lock.Lock() - defer l.lock.Unlock() - if !l.validLeader(block) { - l.pendingBlocks = append(l.pendingBlocks, block) - return nil - } - l.updateLeader(block) - return nil -} -func (l *leaderSelector) updateLeader(block *types.Block) { - dist := l.distance(block.CRSSignature) - cmp := l.minCRSBlock.Cmp(dist) - if cmp > 0 || (cmp == 0 && block.Hash.Less(l.minBlockHash)) { - l.minCRSBlock = dist - l.minBlockHash = block.Hash - } -} |