pool certificate issuance requests

internal/pkg/utils/pool/pool.go

@@ -0,0 +1,46 @@
+package pool
+
+import (
+	"context"
+)
+
+type Task[I, O any] func(I) O
+
+type Pool[I, O any] struct {
+	ch   chan struct{}
+	size int
+}
+
+func NewPool[I, O any](size int) *Pool[I, O] {
+	return &Pool[I, O]{
+		ch:   make(chan struct{}, size),
+		size: size,
+	}
+}
+
+func (p *Pool[I, O]) Submit(ctx context.Context, task Task[I, O], input I) <-chan O {
+	resultChan := make(chan O, 1)
+
+	go func() {
+		select {
+		case p.ch <- struct{}{}:
+			defer func() {
+				<-p.ch
+				close(resultChan)
+			}()
+
+			result := task(input)
+			select {
+			case <-ctx.Done():
+				return
+			case resultChan <- result:
+			}
+
+		case <-ctx.Done():
+			close(resultChan)
+			return
+		}
+	}()
+
+	return resultChan
+}