-
Notifications
You must be signed in to change notification settings - Fork 0
/
ballot.go
144 lines (120 loc) · 3.29 KB
/
ballot.go
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
package types
import (
"sort"
sdk "github.com/cosmos/cosmos-sdk/types"
)
// NOTE: we don't need to implement proto interface on this file
// these are not used in store or rpc response
// VoteForTally is a convenience wrapper to reduce redundant lookup cost
type VoteForTally struct {
Denom string
ExchangeRate sdk.Dec
Voter sdk.ValAddress
Power int64
}
// NewVoteForTally returns a new VoteForTally instance
func NewVoteForTally(rate sdk.Dec, denom string, voter sdk.ValAddress, power int64) VoteForTally {
return VoteForTally{
ExchangeRate: rate,
Denom: denom,
Voter: voter,
Power: power,
}
}
// ExchangeRateBallot is a convenience wrapper around a ExchangeRateVote slice
type ExchangeRateBallot []VoteForTally
// ToMap return organized exchange rate map by validator
func (pb ExchangeRateBallot) ToMap() map[string]sdk.Dec {
exchangeRateMap := make(map[string]sdk.Dec)
for _, vote := range pb {
if vote.ExchangeRate.IsPositive() {
exchangeRateMap[string(vote.Voter)] = vote.ExchangeRate
}
}
return exchangeRateMap
}
// Power returns the total amount of voting power in the ballot
func (pb ExchangeRateBallot) Power() int64 {
totalPower := int64(0)
for _, vote := range pb {
totalPower += vote.Power
}
return totalPower
}
// WeightedMedian returns the median weighted by the power of the ExchangeRateVote.
// CONTRACT: ballot must be sorted
func (pb ExchangeRateBallot) WeightedMedian() (sdk.Dec, error) {
if !sort.IsSorted(pb) {
return sdk.ZeroDec(), ErrBallotNotSorted
}
totalPower := pb.Power()
if pb.Len() > 0 {
pivot := int64(0)
for _, v := range pb {
votePower := v.Power
pivot += votePower
if pivot >= (totalPower / 2) {
return v.ExchangeRate, nil
}
}
}
return sdk.ZeroDec(), nil
}
// StandardDeviation returns the standard deviation by the power of the ExchangeRateVote.
func (pb ExchangeRateBallot) StandardDeviation() (sdk.Dec, error) {
if len(pb) == 0 {
return sdk.ZeroDec(), nil
}
median, err := pb.WeightedMedian()
if err != nil {
return sdk.ZeroDec(), err
}
sum := sdk.ZeroDec()
ballotLength := int64(len(pb))
for _, v := range pb {
func() {
defer func() {
if e := recover(); e != nil {
ballotLength--
}
}()
deviation := v.ExchangeRate.Sub(median)
sum = sum.Add(deviation.Mul(deviation))
}()
}
variance := sum.QuoInt64(ballotLength)
standardDeviation, err := variance.ApproxSqrt()
if err != nil {
return sdk.ZeroDec(), err
}
return standardDeviation, nil
}
// Len implements sort.Interface
func (pb ExchangeRateBallot) Len() int {
return len(pb)
}
// Less reports whether the element with
// index i should sort before the element with index j.
func (pb ExchangeRateBallot) Less(i, j int) bool {
return pb[i].ExchangeRate.LT(pb[j].ExchangeRate)
}
// Swap implements sort.Interface.
func (pb ExchangeRateBallot) Swap(i, j int) {
pb[i], pb[j] = pb[j], pb[i]
}
// Claim is an interface that directs its rewards to an attached bank account.
type Claim struct {
Power int64
Weight int64
WinCount int64
Recipient sdk.ValAddress
}
// NewClaim generates a Claim instance.
func NewClaim(power, weight, winCount int64, recipient sdk.ValAddress) Claim {
return Claim{
Power: power,
Weight: weight,
WinCount: winCount,
Recipient: recipient,
}
}