main_test.go

package main

import (
	"strings"
	"testing"
)

var m = map[string]bool{"hello.goodbye": true}

func old(req string, filter map[string]bool) string {

	// Try to match path from full string to less levels
	var pathSplitted []string = strings.Split(req, "/")

	for curDepth := len(pathSplitted); curDepth > 0; curDepth-- {
		path := strings.Join(pathSplitted[0:curDepth], ".")

		if filter[path] {
			return path
		}

	}

	return ""
}

func faster(req string, filter map[string]bool) string {

	// Try to match path from full string to less levels
	var metric = strings.Replace(req, "/", ".", -1)

	for metric != "" {
		if filter[metric] {
			return metric
		}

		idx := strings.LastIndexByte(metric, '.')

		if idx == -1 {
			break
		}

		metric = metric[:idx]
	}

	return ""
}

func TestFaster(t *testing.T) {
	if old("hello/goodbye/foo/bar/baz/zot", m) != faster("hello/goodbye/foo/bar/baz/zot", m) {
		t.Error("fail")
	}
}

var sink int

func BenchmarkOld(b *testing.B) {
	for i := 0; i < b.N; i++ {
		sink += len(old("foo/bar/baz/zot", m))
	}
}

func BenchmarkFaster(b *testing.B) {
	for i := 0; i < b.N; i++ {
		sink += len(faster("foo/bar/baz/zot", m))
	}
}