micro/selector/strategy.go

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2016-05-03 22:06:19 +01:00
package selector
import (
"math/rand"
"sync"
"time"
"github.com/micro/go-micro/registry"
)
func init() {
rand.Seed(time.Now().UnixNano())
}
// Random is a random strategy algorithm for node selection
func Random(services []*registry.Service) Next {
var nodes []*registry.Node
for _, service := range services {
nodes = append(nodes, service.Nodes...)
}
return func() (*registry.Node, error) {
if len(nodes) == 0 {
return nil, ErrNoneAvailable
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}
i := rand.Int() % len(nodes)
return nodes[i], nil
}
}
// RoundRobin is a roundrobin strategy algorithm for node selection
func RoundRobin(services []*registry.Service) Next {
var nodes []*registry.Node
for _, service := range services {
nodes = append(nodes, service.Nodes...)
}
var i int
var mtx sync.Mutex
return func() (*registry.Node, error) {
if len(nodes) == 0 {
return nil, ErrNoneAvailable
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}
mtx.Lock()
node := nodes[i%len(nodes)]
i++
mtx.Unlock()
return node, nil
}
}