micro/registry/random_selector.go
2015-12-09 12:44:38 +00:00

88 lines
1.4 KiB
Go

package registry
import (
"math/rand"
"time"
)
type randomSelector struct {
so SelectorOptions
}
func init() {
rand.Seed(time.Now().Unix())
}
func (r *randomSelector) Select(service string, opts ...SelectOption) (SelectNext, error) {
var sopts SelectOptions
for _, opt := range opts {
opt(&sopts)
}
// get the service
services, err := r.so.Registry.GetService(service)
if err != nil {
return nil, err
}
// apply the filters
for _, filter := range sopts.Filters {
services = filter(services)
}
// if there's nothing left, return
if len(services) == 0 {
return nil, ErrNotFound
}
var nodes []*Node
for _, service := range services {
for _, node := range service.Nodes {
nodes = append(nodes, node)
}
}
if len(nodes) == 0 {
return nil, ErrNotFound
}
return func() (*Node, error) {
i := rand.Int()
j := i % len(services)
if len(services[j].Nodes) == 0 {
return nil, ErrNotFound
}
k := i % len(services[j].Nodes)
return services[j].Nodes[k], nil
}, nil
}
func (r *randomSelector) Mark(service string, node *Node, err error) {
return
}
func (r *randomSelector) Reset(service string) {
return
}
func (r *randomSelector) Close() error {
return nil
}
func NewRandomSelector(opts ...SelectorOption) Selector {
var sopts SelectorOptions
for _, opt := range opts {
opt(&sopts)
}
if sopts.Registry == nil {
sopts.Registry = DefaultRegistry
}
return &randomSelector{sopts}
}