User workerpool for scanning and hashing

workerpool/workerpool.go

@@ -0,0 +1,67 @@
+package workerpool
+
+import (
+	"context"
+	"sync"
+)
+
+type WorkerPool struct {
+	workers int
+	ctx     context.Context
+	cancel  context.CancelFunc
+	wg      sync.WaitGroup
+	queue   chan func(context.Context)
+	qg      sync.WaitGroup
+}
+
+func NewWorkerPool(workers int, queueSize int) *WorkerPool {
+	ctx, cancel := context.WithCancel(context.Background())
+	queue := make(chan func(context.Context), queueSize)
+
+	workerPool := WorkerPool{
+		workers: workers,
+		ctx:     ctx,
+		cancel:  cancel,
+		queue:   queue,
+	}
+
+	for i := 0; i < workerPool.workers; i++ {
+		workerPool.wg.Add(1)
+		go workerPool.work(workerPool.ctx)
+	}
+
+	return &workerPool
+}
+
+func (wp *WorkerPool) Stop() {
+	wp.cancel()
+	wp.wg.Wait()
+}
+
+func (wp *WorkerPool) QueueJob(job func(context.Context)) {
+	wp.qg.Add(1)
+	wp.queue <- job
+}
+
+func (wp *WorkerPool) WaitForEmptyQueue() {
+	wp.qg.Wait()
+}
+
+func (wp *WorkerPool) QueueLength() int {
+	return len(wp.queue)
+}
+
+func (wp *WorkerPool) work(ctx context.Context) {
+	for {
+		select {
+		case <-ctx.Done():
+			wp.wg.Done()
+			return
+		case job := <-wp.queue:
+			func() {
+				defer wp.qg.Done()
+				job(ctx)
+			}()
+		}
+	}
+}