80 lines
1.9 KiB
Go
80 lines
1.9 KiB
Go
package eventbus
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import (
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"fmt"
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"runtime"
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"strings"
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"sync/atomic"
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)
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type subSettings struct {
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buffer int
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name string
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}
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var subCnt int64
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var subSettingsDefault = subSettings{
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buffer: 16,
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}
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// newSubSettings returns the settings for a new subscriber
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// The default naming strategy is sub-<fileName>-L<lineNum>
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func newSubSettings() subSettings {
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settings := subSettingsDefault
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_, file, line, ok := runtime.Caller(2) // skip=1 is eventbus.Subscriber
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if ok {
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file = strings.TrimPrefix(file, "github.com/")
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// remove the version number from the path, for example
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// go-libp2p-package@v0.x.y-some-hash-123/file.go will be shortened go go-libp2p-package/file.go
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if idx1 := strings.Index(file, "@"); idx1 != -1 {
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if idx2 := strings.Index(file[idx1:], "/"); idx2 != -1 {
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file = file[:idx1] + file[idx1+idx2:]
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}
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}
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settings.name = fmt.Sprintf("%s-L%d", file, line)
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} else {
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settings.name = fmt.Sprintf("subscriber-%d", atomic.AddInt64(&subCnt, 1))
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}
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return settings
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}
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func BufSize(n int) func(interface{}) error {
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return func(s interface{}) error {
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s.(*subSettings).buffer = n
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return nil
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}
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}
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func Name(name string) func(interface{}) error {
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return func(s interface{}) error {
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s.(*subSettings).name = name
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return nil
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}
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}
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type emitterSettings struct {
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makeStateful bool
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}
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// Stateful is an Emitter option which makes the eventbus channel
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// 'remember' last event sent, and when a new subscriber joins the
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// bus, the remembered event is immediately sent to the subscription
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// channel.
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//
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// This allows to provide state tracking for dynamic systems, and/or
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// allows new subscribers to verify that there are Emitters on the channel
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func Stateful(s interface{}) error {
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s.(*emitterSettings).makeStateful = true
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return nil
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}
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type Option func(*basicBus)
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func WithMetricsTracer(metricsTracer MetricsTracer) Option {
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return func(bus *basicBus) {
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bus.metricsTracer = metricsTracer
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bus.wildcard.metricsTracer = metricsTracer
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}
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}
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