blob: 53af91ad446f5dfe1b60d381275a2f6de557b168 (
plain)
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
|
package utils
import (
"sync"
)
type ReedSolomonEncoder struct {
gf *GaloisField
polynomes []*GFPoly
m *sync.Mutex
}
func NewReedSolomonEncoder(gf *GaloisField) *ReedSolomonEncoder {
return &ReedSolomonEncoder{
gf, []*GFPoly{NewGFPoly(gf, []int{1})}, new(sync.Mutex),
}
}
func (rs *ReedSolomonEncoder) getPolynomial(degree int) *GFPoly {
rs.m.Lock()
defer rs.m.Unlock()
if degree >= len(rs.polynomes) {
last := rs.polynomes[len(rs.polynomes)-1]
for d := len(rs.polynomes); d <= degree; d++ {
next := last.Multiply(NewGFPoly(rs.gf, []int{1, rs.gf.ALogTbl[d-1+rs.gf.Base]}))
rs.polynomes = append(rs.polynomes, next)
last = next
}
}
return rs.polynomes[degree]
}
func (rs *ReedSolomonEncoder) Encode(data []int, eccCount int) []int {
generator := rs.getPolynomial(eccCount)
info := NewGFPoly(rs.gf, data)
info = info.MultByMonominal(eccCount, 1)
_, remainder := info.Divide(generator)
result := make([]int, eccCount)
numZero := int(eccCount) - len(remainder.Coefficients)
copy(result[numZero:], remainder.Coefficients)
return result
}
|
