117 lines
2.3 KiB
Go
117 lines
2.3 KiB
Go
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package srt
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import (
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"math"
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"sort"
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)
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type Datum struct {
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seq_num uint32
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data []byte
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next *Datum
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}
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type DatumLink struct {
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queued int
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root *Datum
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end *Datum
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}
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type chains []*DatumLink
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func (c chains) Len() (int) {
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return len(c)
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}
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func (c chains) Swap(i, j int) {
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c[i], c[j] = c[j], c[i]
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}
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func (c chains) Less(i, j int) (bool) {
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x_1 := c[i].end.seq_num
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x_2 := c[j].root.seq_num
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serial_add_limit := uint32(math.Pow(2, 30))
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if (x_1 < x_2 && x_2 - x_1 < serial_add_limit) || (x_1 > x_2 && x_1 - x_2 > serial_add_limit) {
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return true
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}
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return false
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}
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type DatumStorage struct {
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main *DatumLink
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offshoots chains
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}
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func (buffer *DatumLink) NewDatum(pkt *Packet) {
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datum := new(Datum)
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datum.seq_num = pkt.header_info.(*DataHeader).seq_num
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datum.data = pkt.cif.([]byte)
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buffer.queued += 1
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buffer.end.next = datum
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buffer.end = datum
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}
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func NewDatumLink(pkt *Packet) (*DatumLink) {
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buffer := new(DatumLink)
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root_datum := new(Datum)
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root_datum.seq_num = pkt.header_info.(*DataHeader).seq_num
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root_datum.data = pkt.cif.([]byte)
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buffer.root = root_datum
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buffer.end = root_datum
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buffer.queued = 1
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return buffer
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}
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func NewDatumStorage(packet *Packet) (*DatumStorage) {
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storage := new(DatumStorage)
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storage.main = NewDatumLink(packet)
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return storage
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}
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func (storage *DatumStorage) NewDatum(pkt *Packet) {
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prev_num := (pkt.header_info.(*DataHeader).seq_num - 1) % uint32(math.Pow(2, 31))
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if storage.main.end.seq_num == prev_num {
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storage.main.NewDatum(pkt)
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} else {
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for _, v := range storage.offshoots {
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if v.end.seq_num == prev_num {
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v.NewDatum(pkt)
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break
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}
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}
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}
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}
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func (buffer *DatumLink) Link(buffer_next *DatumLink) {
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buffer.end.next = buffer_next.root
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buffer.end = buffer_next.end
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buffer.queued += buffer_next.queued
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}
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func check_append_serial_next(buffer *DatumLink, buffer_next *DatumLink) (bool) {
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seq_1 := buffer.end.seq_num
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seq_2 := (seq_1 + 1) % uint32(math.Pow(2, 31))
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if seq_1 == seq_2 {
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buffer.Link(buffer_next)
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return true
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}
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return false
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}
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func (storage *DatumStorage) Relink() {
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sort.Sort(storage.offshoots)
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buffer := storage.main
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i := 0
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for i < len(storage.offshoots) {
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if check_append_serial_next(buffer, storage.offshoots[i]) {
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storage.offshoots = append(storage.offshoots[:i], storage.offshoots[i + 1:]...)
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} else {
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buffer = storage.offshoots[i]
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i++
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}
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}
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}
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