mirror of https://github.com/nealey/vail.git
93 lines
1.4 KiB
Go
93 lines
1.4 KiB
Go
package main
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import (
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"io"
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"log"
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)
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type Book struct {
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entries map[string]*Repeater
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events chan bookEvent
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}
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func NewBook() Book {
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return Book{
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entries: make(map[string]*Repeater),
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events: make(chan bookEvent, 5),
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}
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}
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type bookEventType int
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const (
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joinEvent = bookEventType(iota)
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partEvent
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sendEvent
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)
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type bookEvent struct {
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eventType bookEventType
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name string
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w io.Writer
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p []byte
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}
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func (b Book) Join(name string, w io.Writer) {
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b.events <- bookEvent{
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eventType: joinEvent,
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name: name,
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w: w,
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}
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}
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func (b Book) Part(name string, w io.Writer) {
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b.events <- bookEvent{
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eventType: partEvent,
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name: name,
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w: w,
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}
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}
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func (b Book) Send(name string, p []byte) {
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b.events <- bookEvent{
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eventType: sendEvent,
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name: name,
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p: p,
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}
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}
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func (b Book) Run() {
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for {
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b.loop()
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}
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}
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func (b Book) loop() {
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event := <-b.events
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repeater, ok := b.entries[event.name]
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switch event.eventType {
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case joinEvent:
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if ! ok {
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repeater = NewRepeater()
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b.entries[event.name] = repeater
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}
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repeater.Join(event.w)
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case partEvent:
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if ! ok {
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log.Println("WARN: Parting an empty channel:", event.name)
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break
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}
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repeater.Part(event.w)
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if len(repeater.subscribers) == 0 {
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delete(b.entries, event.name)
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}
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case sendEvent:
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if ! ok {
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log.Println("WARN: Sending to an empty channel:", event.name)
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break
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}
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repeater.Send(event.p)
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}
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}
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