I have queue, witch has to have growing buffer, this excludes usage of buffered channels in go for me.
After some google searching I've come up with this code:
import (
"sync"
)
type Queue struct {
nodes []interface{}
head, tail, count int
lck sync.RWMutex
}
func (q *Queue) Enqueue(v interface{}) {
q.lck.Lock()
defer q.lck.Unlock()
if q.nodes == nil {
q.nodes = make([]interface{}, 2)
}
if q.head == q.tail && q.count > 0 {
nodes := make([]interface{}, len(q.nodes) * 2)
copy(nodes, q.nodes[q.head:])
copy(nodes[len(q.nodes) - q.head:], q.nodes[:q.head])
q.head = 0
q.tail = len(q.nodes)
q.nodes = nodes
}
q.nodes[q.tail] = v
q.tail = (q.tail + 1) % len(q.nodes)
q.count++
}
func (q *Queue) Dequeue() interface{} {
q.lck.Lock()
defer q.lck.Unlock()
if len(q.nodes) == 0 {
return nil
}
node := q.nodes[q.head]
q.head = (q.head + 1) % len(q.nodes)
q.count--
return node
}
func (q *Queue) Len() int {
q.lck.RLock()
defer q.lck.RUnlock()
return q.count
}
Is there any way I could convert this to be non-blocking & lock-free queue?