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43 lines
922 B
43 lines
922 B
package random
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import (
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"context"
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"fmt"
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"math/rand"
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"sync"
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"github.com/go-kratos/kratos/v2/registry"
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"github.com/go-kratos/kratos/v2/transport/http/balancer"
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)
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var _ balancer.Balancer = &Balancer{}
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type Balancer struct {
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lock sync.RWMutex
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nodes []*registry.ServiceInstance
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}
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func New() *Balancer {
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return &Balancer{}
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}
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func (b *Balancer) Pick(ctx context.Context) (node *registry.ServiceInstance, done func(context.Context, balancer.DoneInfo), err error) {
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b.lock.RLock()
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nodes := b.nodes
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b.lock.RUnlock()
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if len(nodes) == 0 {
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return nil, nil, fmt.Errorf("no instances available")
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}
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if len(nodes) == 1 {
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return nodes[0], func(context.Context, balancer.DoneInfo) {}, nil
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}
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idx := rand.Intn(len(nodes))
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return nodes[idx], func(context.Context, balancer.DoneInfo) {}, nil
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}
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func (b *Balancer) Update(nodes []*registry.ServiceInstance) {
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b.lock.Lock()
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defer b.lock.Unlock()
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b.nodes = nodes
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}
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