package task
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import (
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"sync"
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"time"
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)
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// Periodic is a task that runs periodically.
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type Periodic struct {
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// Interval of the task being run
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Interval time.Duration
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// Execute is the task function
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Execute func() error
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access sync.Mutex
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timer *time.Timer
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running bool
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}
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func (t *Periodic) hasClosed() bool {
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t.access.Lock()
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defer t.access.Unlock()
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return !t.running
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}
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func (t *Periodic) checkedExecute() error {
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if t.hasClosed() {
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return nil
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}
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if err := t.Execute(); err != nil {
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t.access.Lock()
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t.running = false
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t.access.Unlock()
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return err
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}
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t.access.Lock()
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defer t.access.Unlock()
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if !t.running {
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return nil
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}
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t.timer = time.AfterFunc(t.Interval, func() {
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t.checkedExecute()
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})
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return nil
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}
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// Start implements common.Runnable.
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func (t *Periodic) Start() error {
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t.access.Lock()
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if t.running {
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t.access.Unlock()
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return nil
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}
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t.running = true
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t.access.Unlock()
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if err := t.checkedExecute(); err != nil {
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t.access.Lock()
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t.running = false
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t.access.Unlock()
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return err
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}
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return nil
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}
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// Close implements common.Closable.
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func (t *Periodic) Close() error {
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t.access.Lock()
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defer t.access.Unlock()
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t.running = false
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if t.timer != nil {
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t.timer.Stop()
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t.timer = nil
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}
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return nil
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}
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