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go-micro/selector/default.go
2019-02-13 17:47:31 +08:00

107 lines
1.8 KiB
Go

package selector
import (
"time"
"github.com/micro/go-micro/registry"
"github.com/micro/go-rcache"
)
type registrySelector struct {
so Options
rc rcache.Cache
}
func (c *registrySelector) newRCache() rcache.Cache {
ropts := []rcache.Option{}
if c.so.Context != nil {
if t, ok := c.so.Context.Value("selector_ttl").(time.Duration); ok {
ropts = append(ropts, rcache.WithTTL(t))
}
}
return rcache.New(c.so.Registry, ropts...)
}
func (c *registrySelector) Init(opts ...Option) error {
for _, o := range opts {
o(&c.so)
}
c.rc.Stop()
c.rc = c.newRCache()
return nil
}
func (c *registrySelector) Options() Options {
return c.so
}
func (c *registrySelector) Select(service string, opts ...SelectOption) (Next, error) {
sopts := SelectOptions{
Strategy: c.so.Strategy,
}
for _, opt := range opts {
opt(&sopts)
}
// get the service
// try the cache first
// if that fails go directly to the registry
services, err := c.rc.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, ErrNoneAvailable
}
return sopts.Strategy(services), nil
}
func (c *registrySelector) Mark(service string, node *registry.Node, err error) {
}
func (c *registrySelector) Reset(service string) {
}
// Close stops the watcher and destroys the cache
func (c *registrySelector) Close() error {
c.rc.Stop()
return nil
}
func (c *registrySelector) String() string {
return "registry"
}
func NewSelector(opts ...Option) Selector {
sopts := Options{
Strategy: Random,
}
for _, opt := range opts {
opt(&sopts)
}
if sopts.Registry == nil {
sopts.Registry = registry.DefaultRegistry
}
s := &registrySelector{
so: sopts,
}
s.rc = s.newRCache()
return s
}