1 files changed, 0 insertions, 211 deletions
diff --git a/core/negative-ack.go b/core/negative-ack.go
deleted file mode 100644
index 4178629..0000000
--- a/core/negative-ack.go
+++ /dev/null
@@ -1,211 +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 (
-	"time"
-
-	"github.com/dexon-foundation/dexon-consensus/core/types"
-)
-
-type negativeAck struct {
-	// owner is the ID of proposer itself, this is used when deciding
-	// a node to be restricted or not.
-	owner types.NodeID
-
-	numOfNodes int
-
-	// timeDelay and timeExpire are for nack timeout.
-	timeDelay  time.Duration
-	timeExpire time.Duration
-
-	// restricteds stores nodes which has been restricted and the time it's
-	// restricted.
-	restricteds map[types.NodeID]time.Time
-
-	// lastVotes and lockedVotes store the votes for nack. lastVotes[nid1][nid2]
-	// and lockedVotes[nid1][nid2] both mean that nid2 votes nid1. The difference
-	// is lockedVotes works only when nid1 is restricted, so that the votes are
-	// needed to be locked.
-	lastVotes   map[types.NodeID]map[types.NodeID]struct{}
-	lockedVotes map[types.NodeID]map[types.NodeID]struct{}
-
-	// timeDiffs is the cache for last time stamps. timeDiffs[nid1][nid2] means
-	// the last updated timestamps nid1 sees nid2.
-	timeDiffs map[types.NodeID]map[types.NodeID]map[types.NodeID]time.Time
-}
-
-// newNegativeAck creates a new negaticeAck instance.
-func newNegativeAck(nid types.NodeID) *negativeAck {
-	n := &negativeAck{
-		owner:       nid,
-		numOfNodes:  0,
-		restricteds: make(map[types.NodeID]time.Time),
-		lastVotes:   make(map[types.NodeID]map[types.NodeID]struct{}),
-		lockedVotes: make(map[types.NodeID]map[types.NodeID]struct{}),
-		timeDiffs:   make(map[types.NodeID]map[types.NodeID]map[types.NodeID]time.Time),
-	}
-	n.addNode(nid)
-	return n
-}
-
-// processNewVote is called when a new "vote" occurs, that is, a node
-// sees that other 2f + 1 nodes think a node is slow. "nid" is the
-// node which propesed the block which the timestamps votes and "h" is
-// the node been voted to be nacked.
-func (n *negativeAck) processNewVote(
-	nid types.NodeID,
-	h types.NodeID,
-) []types.NodeID {
-
-	nackeds := []types.NodeID{}
-	if _, exist := n.restricteds[h]; exist {
-		n.lockedVotes[h][nid] = struct{}{}
-		if len(n.lockedVotes[h]) > 2*(n.numOfNodes-1)/3 {
-			nackeds = append(nackeds, h)
-			delete(n.restricteds, h)
-		}
-	} else {
-		if n.owner == nid {
-			n.restrict(h)
-		} else {
-			n.lastVotes[h][nid] = struct{}{}
-			if len(n.lastVotes[h]) > (n.numOfNodes-1)/3 {
-				n.restrict(h)
-			}
-		}
-	}
-	return nackeds
-}
-
-// processTimestamps process new timestamps of a block which is proposed by
-// node nid, and returns the nodes being nacked.
-func (n *negativeAck) processTimestamps(
-	nid types.NodeID,
-	ts map[types.NodeID]time.Time,
-) []types.NodeID {
-
-	n.checkRestrictExpire()
-
-	nackeds := []types.NodeID{}
-	for h := range n.timeDiffs {
-		if n.timeDiffs[nid][h][h].Equal(ts[h]) {
-			votes := 0
-			for hh := range n.timeDiffs {
-				if ts[hh].Sub(n.timeDiffs[nid][h][hh]) >= n.timeDelay {
-					votes++
-				}
-			}
-			if votes > 2*((n.numOfNodes-1)/3) {
-				n.lastVotes[h][nid] = struct{}{}
-				nack := n.processNewVote(nid, h)
-				for _, i := range nack {
-					nackeds = append(nackeds, i)
-				}
-			} else {
-				delete(n.lastVotes[h], nid)
-			}
-		} else {
-			for hh := range n.timeDiffs {
-				n.timeDiffs[nid][h][hh] = ts[hh]
-			}
-			delete(n.lastVotes[h], nid)
-		}
-	}
-	return nackeds
-}
-
-func (n *negativeAck) checkRestrictExpire() {
-	expired := []types.NodeID{}
-	now := time.Now()
-	for h, t := range n.restricteds {
-		if now.Sub(t) >= n.timeExpire {
-			expired = append(expired, h)
-		}
-	}
-	for _, h := range expired {
-		delete(n.restricteds, h)
-	}
-}
-
-func (n *negativeAck) restrict(nid types.NodeID) {
-	if _, exist := n.restricteds[nid]; !exist {
-		n.restricteds[nid] = time.Now().UTC()
-		n.lockedVotes[nid] = map[types.NodeID]struct{}{}
-		for h := range n.lastVotes[nid] {
-			n.lockedVotes[nid][h] = struct{}{}
-		}
-	}
-}
-
-func (n *negativeAck) getRestrictedNodes() map[types.NodeID]struct{} {
-	n.checkRestrictExpire()
-	ret := map[types.NodeID]struct{}{}
-	for h := range n.restricteds {
-		ret[h] = struct{}{}
-	}
-	return ret
-}
-
-func (n *negativeAck) setTimeDelay(t time.Duration) {
-	n.timeDelay = t
-}
-
-func (n *negativeAck) setTimeExpire(t time.Duration) {
-	n.timeExpire = t
-}
-
-func (n *negativeAck) addNode(nid types.NodeID) {
-	n.numOfNodes++
-	n.lastVotes[nid] = make(map[types.NodeID]struct{})
-	n.lockedVotes[nid] = make(map[types.NodeID]struct{})
-
-	newTimeDiff := make(map[types.NodeID]map[types.NodeID]time.Time)
-	for h := range n.timeDiffs {
-		newTimeDiff2 := make(map[types.NodeID]time.Time)
-		for hh := range n.timeDiffs {
-			newTimeDiff2[hh] = time.Time{}
-		}
-		newTimeDiff[h] = newTimeDiff2
-	}
-	n.timeDiffs[nid] = newTimeDiff
-	for h := range n.timeDiffs {
-		n.timeDiffs[h][nid] = make(map[types.NodeID]time.Time)
-	}
-}
-
-func (n *negativeAck) deleteNode(nid types.NodeID) {
-	n.numOfNodes--
-
-	delete(n.timeDiffs, nid)
-
-	for h := range n.lastVotes {
-		delete(n.lastVotes[h], nid)
-	}
-	delete(n.lastVotes, nid)
-	delete(n.lockedVotes, nid)
-
-	for h := range n.timeDiffs {
-		delete(n.timeDiffs[h], nid)
-		for hh := range n.timeDiffs[h] {
-			delete(n.timeDiffs[h][hh], nid)
-		}
-	}
-
-	delete(n.restricteds, nid)
-}