package bcap

import (
	"strings"
	"sync"
)

func fnvHash(key string) uint32 {
	hash := uint32(2166136261)
	for i := 0; i < len(key); i++ {
		hash ^= uint32(key[i])
		hash *= 16777619
	}
	return hash
}

var stringBuilderPool = sync.Pool{
	New: func() interface{} {
		return &strings.Builder{}
	},
}

func getStringBuilder() *strings.Builder {
	return stringBuilderPool.Get().(*strings.Builder)
}

func putStringBuilder(sb *strings.Builder) {
	sb.Reset()
	stringBuilderPool.Put(sb)
}

func buildKey(protocol, srcIP, srcPort, dstIP, dstPort string) string {
	sb := getStringBuilder()
	defer putStringBuilder(sb)

	sb.WriteString(protocol)
	sb.WriteString("://")
	sb.WriteString(srcIP)
	if srcPort != "" {
		sb.WriteString(":")
		sb.WriteString(srcPort)
	}
	sb.WriteString("=")
	sb.WriteString(dstIP)
	if dstPort != "" {
		sb.WriteString(":")
		sb.WriteString(dstPort)
	}
	return sb.String()
}