forked from github-mirrors/zerolog
81 lines
1.6 KiB
Go
81 lines
1.6 KiB
Go
package diodes
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import (
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"context"
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"time"
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)
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// Diode is any implementation of a diode.
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type Diode interface {
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Set(GenericDataType)
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TryNext() (GenericDataType, bool)
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}
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// Poller will poll a diode until a value is available.
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type Poller struct {
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Diode
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interval time.Duration
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ctx context.Context
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}
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// PollerConfigOption can be used to setup the poller.
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type PollerConfigOption func(*Poller)
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// WithPollingInterval sets the interval at which the diode is queried
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// for new data. The default is 10ms.
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func WithPollingInterval(interval time.Duration) PollerConfigOption {
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return func(c *Poller) {
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c.interval = interval
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}
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}
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// WithPollingContext sets the context to cancel any retrieval (Next()). It
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// will not change any results for adding data (Set()). Default is
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// context.Background().
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func WithPollingContext(ctx context.Context) PollerConfigOption {
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return func(c *Poller) {
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c.ctx = ctx
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}
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}
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// NewPoller returns a new Poller that wraps the given diode.
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func NewPoller(d Diode, opts ...PollerConfigOption) *Poller {
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p := &Poller{
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Diode: d,
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interval: 10 * time.Millisecond,
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ctx: context.Background(),
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}
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for _, o := range opts {
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o(p)
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}
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return p
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}
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// Next polls the diode until data is available or until the context is done.
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// If the context is done, then nil will be returned.
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func (p *Poller) Next() GenericDataType {
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for {
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data, ok := p.Diode.TryNext()
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if !ok {
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if p.isDone() {
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return nil
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}
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time.Sleep(p.interval)
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continue
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}
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return data
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}
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}
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func (p *Poller) isDone() bool {
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select {
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case <-p.ctx.Done():
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return true
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default:
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return false
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}
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}
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