| package main |
| |
| func (this SingleProducerSequencer) Next(slotCount int64) int64 { |
| nextValue := this.pad.Load() |
| nextSequence := nextValue + slotCount |
| wrapPoint := nextSequence - this.ringSize |
| cachedGatingSequence := this.pad[cachedGatingSequencePadIndex] |
| |
| if wrapPoint > cachedGatingSequence || cachedGatingSequence > nextValue { |
| minSequence := int64(0) |
| for wrapPoint > minSequence { |
| minSequence = this.last.Load() |
| } |
| |
| this.pad[cachedGatingSequencePadIndex] = minSequence |
| } |
| |
| this.pad.Store(nextSequence) |
| return nextSequence |
| } |
| |
| func (this SingleProducerSequencer) Publish(sequence int64) { |
| this.cursor.Store(sequence) |
| } |
| |
| func NewSingleProducerSequencer(cursor *Sequence, ringSize int32, last Barrier) SingleProducerSequencer { |
| pad := NewSequence() |
| pad[cachedGatingSequencePadIndex] = InitialSequenceValue |
| |
| return SingleProducerSequencer{ |
| pad: pad, |
| cursor: cursor, |
| ringSize: int64(ringSize), |
| last: last, |
| } |
| } |
| |
| type SingleProducerSequencer struct { |
| pad *Sequence |
| cursor *Sequence |
| ringSize int64 |
| last Barrier |
| } |
| |
| const cachedGatingSequencePadIndex = 1 |
