status-go/vendor/github.com/pion/sctp/pending_queue.go

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2022-03-10 09:44:48 +00:00
package sctp
import (
"errors"
)
// pendingBaseQueue
type pendingBaseQueue struct {
queue []*chunkPayloadData
}
func newPendingBaseQueue() *pendingBaseQueue {
return &pendingBaseQueue{queue: []*chunkPayloadData{}}
}
func (q *pendingBaseQueue) push(c *chunkPayloadData) {
q.queue = append(q.queue, c)
}
func (q *pendingBaseQueue) pop() *chunkPayloadData {
if len(q.queue) == 0 {
return nil
}
c := q.queue[0]
q.queue = q.queue[1:]
return c
}
func (q *pendingBaseQueue) get(i int) *chunkPayloadData {
if len(q.queue) == 0 || i < 0 || i >= len(q.queue) {
return nil
}
return q.queue[i]
}
func (q *pendingBaseQueue) size() int {
return len(q.queue)
}
// pendingQueue
type pendingQueue struct {
unorderedQueue *pendingBaseQueue
orderedQueue *pendingBaseQueue
nBytes int
selected bool
unorderedIsSelected bool
}
var (
errUnexpectedChuckPoppedUnordered = errors.New("unexpected chunk popped (unordered)")
errUnexpectedChuckPoppedOrdered = errors.New("unexpected chunk popped (ordered)")
errUnexpectedQState = errors.New("unexpected q state (should've been selected)")
)
func newPendingQueue() *pendingQueue {
return &pendingQueue{
unorderedQueue: newPendingBaseQueue(),
orderedQueue: newPendingBaseQueue(),
}
}
func (q *pendingQueue) push(c *chunkPayloadData) {
if c.unordered {
q.unorderedQueue.push(c)
} else {
q.orderedQueue.push(c)
}
q.nBytes += len(c.userData)
}
func (q *pendingQueue) peek() *chunkPayloadData {
if q.selected {
if q.unorderedIsSelected {
return q.unorderedQueue.get(0)
}
return q.orderedQueue.get(0)
}
if c := q.unorderedQueue.get(0); c != nil {
return c
}
return q.orderedQueue.get(0)
}
func (q *pendingQueue) pop(c *chunkPayloadData) error {
if q.selected {
var popped *chunkPayloadData
if q.unorderedIsSelected {
popped = q.unorderedQueue.pop()
if popped != c {
return errUnexpectedChuckPoppedUnordered
}
} else {
popped = q.orderedQueue.pop()
if popped != c {
return errUnexpectedChuckPoppedOrdered
}
}
if popped.endingFragment {
q.selected = false
}
} else {
if !c.beginningFragment {
return errUnexpectedQState
}
if c.unordered {
popped := q.unorderedQueue.pop()
if popped != c {
return errUnexpectedChuckPoppedUnordered
}
if !popped.endingFragment {
q.selected = true
q.unorderedIsSelected = true
}
} else {
popped := q.orderedQueue.pop()
if popped != c {
return errUnexpectedChuckPoppedOrdered
}
if !popped.endingFragment {
q.selected = true
q.unorderedIsSelected = false
}
}
}
q.nBytes -= len(c.userData)
return nil
}
func (q *pendingQueue) getNumBytes() int {
return q.nBytes
}
func (q *pendingQueue) size() int {
return q.unorderedQueue.size() + q.orderedQueue.size()
}