initiall commit

apps/backend/internal/observability/metrics.go

@@ -0,0 +1,58 @@
+package observability
+
+import (
+	"sync"
+	"time"
+)
+
+// Metrics provides basic in-memory metrics collection
+type Metrics struct {
+	mu                sync.RWMutex
+	requestCount      int64
+	errorCount        int64
+	totalResponseTime time.Duration
+	activeRequests    int64
+}
+
+func NewMetrics() *Metrics {
+	return &Metrics{}
+}
+
+func (m *Metrics) RecordRequest(duration time.Duration, isError bool) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.requestCount++
+	m.totalResponseTime += duration
+	if isError {
+		m.errorCount++
+	}
+}
+
+func (m *Metrics) IncrementActive() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.activeRequests++
+}
+
+func (m *Metrics) DecrementActive() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.activeRequests--
+}
+
+func (m *Metrics) GetStats() map[string]any {
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	
+	avgResponseTime := int64(0)
+	if m.requestCount > 0 {
+		avgResponseTime = m.totalResponseTime.Milliseconds() / m.requestCount
+	}
+	
+	return map[string]any{
+		"total_requests":       m.requestCount,
+		"total_errors":         m.errorCount,
+		"active_requests":      m.activeRequests,
+		"avg_response_time_ms": avgResponseTime,
+	}
+}