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36 lines
610 B
Go
36 lines
610 B
Go
package wakeup
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import (
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"context"
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"errors"
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)
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type contextKey int
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const contextKeyWakeup contextKey = iota
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func Wait(ctx context.Context) <-chan struct{} {
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wc, ok := ctx.Value(contextKeyWakeup).(chan struct{})
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if !ok {
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wc = make(chan struct{})
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}
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return wc
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}
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type Func func() error
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var AlreadyWokenUp = errors.New("already woken up")
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func Context(ctx context.Context) (context.Context, Func) {
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wc := make(chan struct{})
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wuf := func() error {
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select {
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case wc <- struct{}{}:
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return nil
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default:
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return AlreadyWokenUp
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}
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}
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return context.WithValue(ctx, contextKeyWakeup, wc), wuf
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}
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