/
round_robin.go
64 lines (53 loc) · 1.04 KB
/
round_robin.go
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package balancer
import "sync"
// 轮询负载均衡器
type RoundRobin struct {
sync.RWMutex
idx uint64
hosts []string
}
func init() {
factories["round-robin"] = NewRoundRobin
}
func NewRoundRobin(hosts []string) Balancer {
return &RoundRobin{
idx: 0,
hosts: hosts,
}
}
func (r *RoundRobin) Add(host string) {
r.Lock()
defer r.Unlock()
for _, h := range r.hosts {
if h == host {
return
}
}
r.hosts = append(r.hosts, host)
}
func (r *RoundRobin) Remove(host string) {
r.Lock()
defer r.Unlock()
for i, h := range r.hosts {
if h == host {
r.hosts = append(r.hosts[:i], r.hosts[i+1:]...)
return
}
}
}
func (r *RoundRobin) Balance(_ string) (string, error) {
r.RLock()
defer r.RUnlock()
if len(r.hosts) == 0 {
return "", NoHostError
}
host := r.hosts[r.idx%uint64(len(r.hosts))]
r.idx++
return host, nil
}
// Inc .
func (r *RoundRobin) Inc(_ string) {}
// Done .
func (r *RoundRobin) Done(_ string) {}
func (r *RoundRobin) Len() int { return len(r.hosts) }
func (r *RoundRobin) Mode() string { return "round-robin" }