feat: break main into feature files

tools.go

@@ -0,0 +1,74 @@
+package main
+
+import (
+	"log"
+	"os"
+	"strconv"
+	"sync"
+)
+
+// Counter mutex for counter
+type counter struct {
+	mu sync.Mutex
+	n  int
+}
+
+// Global counter
+var C counter
+
+// Add value to counter
+func (c *counter) Add() {
+	c.mu.Lock()
+	c.n++
+	c.mu.Unlock()
+}
+
+// Get value from counter
+func (c *counter) Get() int {
+	c.mu.Lock()
+	n := c.n
+	c.mu.Unlock()
+	return n
+}
+
+// Reset counter
+func (c *counter) Reset() {
+	c.mu.Lock()
+	c.n = 0
+	c.mu.Unlock()
+}
+
+// serve evaluates if the limit of requests is reached
+func serve(l int) bool {
+	return C.Get() < l
+}
+
+// reverse returns a reversed byte array of c
+func reverse[C ~[]E, E any](c C) C {
+	for i, j := 0, len(c)-1; i < j; i, j = i+1, j-1 {
+		c[i], c[j] = c[j], c[i]
+	}
+	return c
+}
+
+// getenv reads an environment  variable named k and returns it as type D
+func getenv[D ~string | int](k string, d D) D {
+	v := os.Getenv(k)
+	if len(v) == 0 {
+		return d
+	}
+	var r any
+	switch any(d).(type) {
+	case string:
+		r = v
+	case int:
+		i, err := strconv.Atoi(v)
+		if err != nil {
+			log.Fatalf("Invalid Value, %s not a valid integer", k)
+		}
+		r = i
+	default:
+		log.Fatalf("Invalid Value, %T not valid", k)
+	}
+	return r.(D)
+}