84 lines
1.8 KiB
Go
84 lines
1.8 KiB
Go
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package hub
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import (
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"sync"
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)
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type (
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alertFunc func(missed int)
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nonBlockingSubscriber struct {
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ch chan Message
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alert alertFunc
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onceClose sync.Once
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}
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// blockingSubscriber uses an channel to receive events.
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blockingSubscriber struct {
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ch chan Message
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onceClose sync.Once
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}
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)
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// newNonBlockingSubscriber returns a new nonBlockingSubscriber
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// this subscriber will never block when sending an message, if the capacity is full
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// we will ignore the message and call the Alert function from the Alerter.
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func newNonBlockingSubscriber(cap int, alerter alertFunc) *nonBlockingSubscriber {
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if cap <= 0 {
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cap = 10
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}
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return &nonBlockingSubscriber{
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ch: make(chan Message, cap),
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alert: alerter,
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}
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}
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// Set inserts the given Event into the diode.
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func (s *nonBlockingSubscriber) Set(msg Message) {
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select {
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case s.ch <- msg:
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default:
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s.alert(1)
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}
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}
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// Ch return the channel used by subscriptions to consume messages.
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func (s *nonBlockingSubscriber) Ch() <-chan Message {
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return s.ch
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}
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// Close will close the internal channel and stop receiving messages.
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func (s *nonBlockingSubscriber) Close() {
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s.onceClose.Do(func() {
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close(s.ch)
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})
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}
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// newBlockingSubscriber returns a blocking subscriber using chanels imternally.
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func newBlockingSubscriber(cap int) *blockingSubscriber {
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if cap < 0 {
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cap = 0
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}
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return &blockingSubscriber{
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ch: make(chan Message, cap),
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}
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}
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// Set will send the message using the channel.
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func (s *blockingSubscriber) Set(msg Message) {
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s.ch <- msg
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}
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// Ch return the channel used by subscriptions to consume messages.
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func (s *blockingSubscriber) Ch() <-chan Message {
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return s.ch
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}
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// Close will close the internal channel and stop receiving messages.
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func (s *blockingSubscriber) Close() {
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s.onceClose.Do(func() {
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close(s.ch)
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})
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}
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