func (this *BWT) Forward(src, dst []byte) (uint, uint, error) {
count := int(this.size)
if this.size == 0 {
count = len(src)
}
if count < 2 {
if count == 1 {
dst[0] = src[0]
}
return uint(count), uint(count), nil
}
if this.saAlgo == nil {
var err error
if this.saAlgo, err = util.NewDivSufSort(); err != nil {
return 0, 0, err
}
} else {
this.saAlgo.Reset()
}
// Compute suffix array
sa := this.saAlgo.ComputeSuffixArray(src[0:count])
i := 0
for i < count {
// Found primary index
if sa[i] == 0 {
break
}
dst[i] = src[sa[i]-1]
i++
}
dst[i] = src[count-1]
this.SetPrimaryIndex(uint(i))
i++
for i < count {
dst[i] = src[sa[i]-1]
i++
}
return uint(count), uint(count), nil
}
func (this *BWTS) Forward(src, dst []byte) (uint, uint, error) {
count := int(this.size)
if this.size == 0 {
count = len(src)
}
if count < 2 {
if count == 1 {
dst[0] = src[0]
}
return uint(count), uint(count), nil
}
// Lazy dynamic memory allocations
if len(this.buffer) < count {
this.buffer = make([]int, count)
}
if this.saAlgo == nil {
var err error
if this.saAlgo, err = util.NewDivSufSort(); err != nil {
return 0, 0, err
}
} else {
this.saAlgo.Reset()
}
// Compute suffix array
sa := this.saAlgo.ComputeSuffixArray(src[0:count])
// Aliasing
isa := this.buffer
for i := 0; i < count; i++ {
isa[sa[i]] = i
}
min := isa[0]
idxMin := 0
for i := 1; i < count && min > 0; i++ {
if isa[i] >= min {
continue
}
headRank := this.moveLyndonWordHead(sa, src, count, idxMin, i-idxMin, min)
refRank := headRank
for j := i - 1; j > idxMin; j-- {
// iterate through the new lyndon word from end to start
testRank := isa[j]
startRank := testRank
for testRank < count-1 {
nextRankStart := sa[testRank+1]
if j > nextRankStart || src[j] != src[nextRankStart] || refRank < isa[nextRankStart+1] {
break
}
sa[testRank] = nextRankStart
isa[nextRankStart] = testRank
testRank++
}
sa[testRank] = j
isa[j] = testRank
refRank = testRank
if startRank == testRank {
break
}
}
min = isa[i]
idxMin = i
}
min = count
for i := 0; i < count; i++ {
if isa[i] >= min {
dst[isa[i]] = src[i-1]
continue
}
if min < count {
dst[min] = src[i-1]
}
min = isa[i]
}
dst[0] = src[count-1]
return uint(count), uint(count), nil
}