35 lines
885 B
Go
35 lines
885 B
Go
package slowmessage
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import (
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"time"
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)
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// SlowFunc is the function that could be slow. Usually, you'll have to
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// wrap an existing function in a lambda to make it match this type signature.
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type SlowFunc func() error
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// CallbackFunc is the function that is triggered when the threshold is reached.
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type CallbackFunc func()
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// Do calls sf. If threshold time has passed, cb is called. Note that this
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// call will be made concurrently to sf still running.
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func Do(threshold time.Duration, sf SlowFunc, cb CallbackFunc) error {
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// Call the slow function
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errCh := make(chan error, 1)
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go func() {
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errCh <- sf()
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}()
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// Wait for it to complete or the threshold to pass
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select {
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case err := <-errCh:
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return err
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case <-time.After(threshold):
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// Threshold reached, call the callback
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cb()
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}
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// Wait an indefinite amount of time for it to finally complete
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return <-errCh
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}
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