various: extract magic numbers into named constants

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I854b2f9b5f39e4629c32e5681e6322826a6a6964

internal/aggregate/metrics.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"notashelf.dev/watchdog/internal/config"
+	"notashelf.dev/watchdog/internal/limits"
 )
 
 var prometheusLabelPattern = regexp.MustCompile(`^[a-zA-Z0-9_/:.-]*$`)
@@ -121,11 +122,11 @@ func NewMetricsAggregator(
 	return m
 }
 
-// Background goroutine to update the unique visitors gauge every 10 seconds
+// Background goroutine to update the unique visitors gauge periodically
 // instead of on every request. This should help with performance.
 func (m *MetricsAggregator) updateUniquesGauge() {
 	defer m.wg.Done()
-	ticker := time.NewTicker(10 * time.Second)
+	ticker := time.NewTicker(limits.UniquesUpdatePeriod)
 	defer ticker.Stop()
 
 	for {

internal/limits/constants.go

@@ -1,5 +1,7 @@
 package limits
 
+import "time"
+
 // Size limits for request processing
 const (
 	MaxEventSize = 4 * 1024 // 4KB max event payload
@@ -7,3 +9,12 @@ const (
 	MaxRefLen    = 2048     // max referrer length
 	MaxWidth     = 10000    // max reasonable screen width
 )
+
+// Timeout constants
+const (
+	HTTPReadTimeout     = 10 * time.Second // HTTP server read timeout
+	HTTPWriteTimeout    = 10 * time.Second // HTTP server write timeout
+	HTTPIdleTimeout     = 60 * time.Second // HTTP server idle timeout
+	ShutdownTimeout     = 30 * time.Second // graceful shutdown timeout
+	UniquesUpdatePeriod = 10 * time.Second // HLL gauge update interval
+)

internal/normalize/path.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 
 	"notashelf.dev/watchdog/internal/config"
+	"notashelf.dev/watchdog/internal/limits"
 )
 
 type PathNormalizer struct {
@@ -14,7 +15,7 @@ type PathNormalizer struct {
 func NewPathNormalizer(cfg config.PathConfig) *PathNormalizer {
 	return &PathNormalizer{
 		cfg:       cfg,
-		maxLength: 2048,
+		maxLength: limits.MaxPathLen,
 	}
 }