1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
// 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 types
import (
"container/heap"
"encoding/binary"
"math/big"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/crypto"
)
// NodeSet is the node set structure as defined in DEXON consensus core.
type NodeSet struct {
IDs map[NodeID]struct{}
}
// SubSetTarget is the sub set target for GetSubSet().
type SubSetTarget struct {
data [][]byte
}
type subSetTargetType byte
const (
targetNotarySet subSetTargetType = iota
targetDKGSet
)
type nodeRank struct {
ID NodeID
rank *big.Int
}
// rankHeap is a MaxHeap structure.
type rankHeap []*nodeRank
func (h rankHeap) Len() int { return len(h) }
func (h rankHeap) Less(i, j int) bool { return h[i].rank.Cmp(h[j].rank) > 0 }
func (h rankHeap) Swap(i, j int) { h[i], h[j] = h[j], h[i] }
func (h *rankHeap) Push(x interface{}) {
*h = append(*h, x.(*nodeRank))
}
func (h *rankHeap) Pop() interface{} {
old := *h
n := len(old)
x := old[n-1]
*h = old[0 : n-1]
return x
}
// NewNodeSet creates a new NodeSet instance.
func NewNodeSet() *NodeSet {
return &NodeSet{
IDs: make(map[NodeID]struct{}),
}
}
// NewNotarySetTarget is the target for getting Notary Set.
func NewNotarySetTarget(crs common.Hash, chainID uint32) *SubSetTarget {
binaryChainID := make([]byte, 4)
binary.LittleEndian.PutUint32(binaryChainID, chainID)
return newTarget(targetNotarySet, crs[:], binaryChainID)
}
// NewDKGSetTarget is the target for getting DKG Set.
func NewDKGSetTarget(crs common.Hash) *SubSetTarget {
return newTarget(targetDKGSet, crs[:])
}
// Add a NodeID to the set.
func (ns *NodeSet) Add(ID NodeID) {
ns.IDs[ID] = struct{}{}
}
// Clone the NodeSet.
func (ns *NodeSet) Clone() *NodeSet {
nsCopy := NewNodeSet()
for ID := range ns.IDs {
nsCopy.Add(ID)
}
return nsCopy
}
// GetSubSet returns the subset of given target.
func (ns *NodeSet) GetSubSet(
size int, target *SubSetTarget) map[NodeID]struct{} {
if size == 0 {
return make(map[NodeID]struct{})
}
h := rankHeap{}
idx := 0
for nID := range ns.IDs {
if idx < size {
h = append(h, newNodeRank(nID, target))
} else if idx == size {
heap.Init(&h)
}
if idx >= size {
rank := newNodeRank(nID, target)
if rank.rank.Cmp(h[0].rank) < 0 {
h[0] = rank
heap.Fix(&h, 0)
}
}
idx++
}
nIDs := make(map[NodeID]struct{}, size)
for _, rank := range h {
nIDs[rank.ID] = struct{}{}
}
return nIDs
}
func newTarget(targetType subSetTargetType, data ...[]byte) *SubSetTarget {
data = append(data, []byte{byte(targetType)})
return &SubSetTarget{
data: data,
}
}
func newNodeRank(ID NodeID, target *SubSetTarget) *nodeRank {
data := make([][]byte, 1, len(target.data)+1)
data[0] = make([]byte, len(ID.Hash))
copy(data[0], ID.Hash[:])
data = append(data, target.data...)
h := crypto.Keccak256Hash(data...)
num := new(big.Int).SetBytes(h[:])
return &nodeRank{
ID: ID,
rank: num,
}
}
|
