blob: 5f44bc6c82e08a8608da33a52082454f701b1fc5 [file] [log] [blame]
package disruptor
type Writer struct {
written *Cursor
upstream Barrier
capacity int64
previous int64
gate int64
}
func NewWriter(written *Cursor, upstream Barrier, capacity int64) *Writer {
assertPowerOfTwo(capacity)
return &Writer{
upstream: upstream,
written: written,
capacity: capacity,
previous: InitialSequenceValue,
gate: InitialSequenceValue,
}
}
func assertPowerOfTwo(value int64) {
if value > 0 && (value&(value-1)) != 0 {
// Wikipedia entry: http://bit.ly/1krhaSB
panic("The ring capacity must be a power of two, e.g. 2, 4, 8, 16, 32, 64, etc.")
}
}
func (this *Writer) Reserve(count int64) int64 {
this.previous += count
for this.previous-this.capacity > this.gate {
this.gate = this.upstream.Read(0)
}
return this.previous
}
func (this *Writer) Await(next int64) {
for next-this.capacity > this.gate {
this.gate = this.upstream.Read(0)
}
}