Event Broken Concept

pkg/eventbroker/worker_pool.go

@@ -0,0 +1,141 @@
+package eventbroker
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+
+	"github.com/bitechdev/ResolveSpec/pkg/logger"
+)
+
+// workerPool manages a pool of workers for async event processing
+type workerPool struct {
+	workerCount int
+	bufferSize  int
+	eventQueue  chan *Event
+	processor   func(context.Context, *Event) error
+
+	activeWorkers atomic.Int32
+	isRunning     atomic.Bool
+	stopCh        chan struct{}
+	wg            sync.WaitGroup
+}
+
+// newWorkerPool creates a new worker pool
+func newWorkerPool(workerCount, bufferSize int, processor func(context.Context, *Event) error) *workerPool {
+	return &workerPool{
+		workerCount: workerCount,
+		bufferSize:  bufferSize,
+		eventQueue:  make(chan *Event, bufferSize),
+		processor:   processor,
+		stopCh:      make(chan struct{}),
+	}
+}
+
+// Start starts the worker pool
+func (wp *workerPool) Start() {
+	if wp.isRunning.Load() {
+		return
+	}
+
+	wp.isRunning.Store(true)
+
+	// Start workers
+	for i := 0; i < wp.workerCount; i++ {
+		wp.wg.Add(1)
+		go wp.worker(i)
+	}
+
+	logger.Info("Worker pool started with %d workers", wp.workerCount)
+}
+
+// Stop stops the worker pool gracefully
+func (wp *workerPool) Stop(ctx context.Context) error {
+	if !wp.isRunning.Load() {
+		return nil
+	}
+
+	wp.isRunning.Store(false)
+
+	// Close event queue to signal workers
+	close(wp.eventQueue)
+
+	// Wait for workers to finish with context timeout
+	done := make(chan struct{})
+	go func() {
+		wp.wg.Wait()
+		close(done)
+	}()
+
+	select {
+	case <-done:
+		logger.Info("Worker pool stopped gracefully")
+		return nil
+	case <-ctx.Done():
+		logger.Warn("Worker pool stop timed out, some events may be lost")
+		return ctx.Err()
+	}
+}
+
+// Submit submits an event to the queue
+func (wp *workerPool) Submit(ctx context.Context, event *Event) error {
+	if !wp.isRunning.Load() {
+		return ErrWorkerPoolStopped
+	}
+
+	select {
+	case wp.eventQueue <- event:
+		return nil
+	case <-ctx.Done():
+		return ctx.Err()
+	default:
+		return ErrQueueFull
+	}
+}
+
+// worker is a worker goroutine that processes events from the queue
+func (wp *workerPool) worker(id int) {
+	defer wp.wg.Done()
+
+	logger.Debug("Worker %d started", id)
+
+	for event := range wp.eventQueue {
+		wp.activeWorkers.Add(1)
+
+		// Process event with background context (detached from original request)
+		ctx := context.Background()
+		if err := wp.processor(ctx, event); err != nil {
+			logger.Error("Worker %d failed to process event %s: %v", id, event.ID, err)
+		}
+
+		wp.activeWorkers.Add(-1)
+	}
+
+	logger.Debug("Worker %d stopped", id)
+}
+
+// QueueSize returns the current queue size
+func (wp *workerPool) QueueSize() int {
+	return len(wp.eventQueue)
+}
+
+// ActiveWorkers returns the number of currently active workers
+func (wp *workerPool) ActiveWorkers() int {
+	return int(wp.activeWorkers.Load())
+}
+
+// Error definitions
+var (
+	ErrWorkerPoolStopped = &BrokerError{Code: "worker_pool_stopped", Message: "worker pool is stopped"}
+	ErrQueueFull         = &BrokerError{Code: "queue_full", Message: "event queue is full"}
+)
+
+// BrokerError represents an error from the event broker
+type BrokerError struct {
+	Code    string
+	Message string
+}
+
+func (e *BrokerError) Error() string {
+	return e.Message
+}