98 lines
1.5 KiB
Go
98 lines
1.5 KiB
Go
package main
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import (
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"sync"
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)
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type (
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Request struct {
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Queues []string
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ResponseCh chan Response
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Abort chan bool
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Dead bool
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}
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Response struct {
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Queue string
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Message Message
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}
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)
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var (
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pool struct {
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Requests []*Request
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mutex sync.Mutex
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}
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)
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func RegisterPublication(q string, msg Message) bool {
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for _, r := range pool.Requests {
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if r.Dead {
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continue
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}
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for _, qname := range r.Queues {
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if qname == q {
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rsp := Response{Queue: q, Message: msg}
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ok := r.TryRespond(rsp)
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if ok {
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return true
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}
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}
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}
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}
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ok := GetQueue(q).Push(msg)
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return ok
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}
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func RegisterSubscription(r *Request) {
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for _, qname := range r.Queues {
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q := GetQueue(qname)
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msg, ok := q.TryFetch(r.Abort)
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if ok {
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rsp := Response{Queue: qname, Message: msg}
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ok := r.TryRespond(rsp)
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if !ok {
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q.Push(msg)
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}
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return
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}
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}
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pool.Requests = append(pool.Requests, r)
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}
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func (r *Request) TryRespond(rsp Response) bool {
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okch := make(chan bool)
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go func() {
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defer func() {
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err := recover()
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if err != nil { // Panic!
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r.Dead = true
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okch <- false
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}
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}()
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r.ResponseCh <- rsp // If channel is already closed expect a panic
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okch <- true
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}()
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ok := <-okch
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return ok
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}
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func (r *Request) Purge() {
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pool.mutex.Lock()
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defer pool.mutex.Unlock()
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r.Dead = true
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deleted := 0
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for i, req := range pool.Requests {
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if req.Dead {
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pool.Requests = append(pool.Requests[:i-deleted], pool.Requests[i-deleted+1:]...)
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deleted++
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}
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}
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}
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