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package backoff
import (
"context"
"sync"
)
// NullPolicy does not do any backoff. It allows the caller
// to execute the desired code once, and no more
type NullPolicy struct{}
func NewNull() *NullPolicy {
return &NullPolicy{}
}
func (p *NullPolicy) Start(ctx context.Context) Controller {
return newNullController(ctx)
}
type nullController struct {
mu *sync.RWMutex
ctx context.Context
next chan struct{}
}
func newNullController(ctx context.Context) *nullController {
cctx, cancel := context.WithCancel(ctx)
c := &nullController{
mu: &sync.RWMutex{},
ctx: cctx,
next: make(chan struct{}), // NO BUFFER
}
go func(ch chan struct{}, cancel func()) {
ch <- struct{}{}
close(ch)
cancel()
}(c.next, cancel)
return c
}
func (c *nullController) Done() <-chan struct{} {
c.mu.RLock()
defer c.mu.RUnlock()
return c.ctx.Done()
}
func (c *nullController) Next() <-chan struct{} {
c.mu.RLock()
defer c.mu.RUnlock()
return c.next
}
|
