/*
 * Copyright 2023 CloudWeGo Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package caching

import (
	"fmt"
	"testing"
	"unsafe"

	"github.com/cloudwego/dynamicgo/internal/rt"
)

const (
	_H_basis uint64 = 0xcbf29ce484222325
	_H_prime uint64 = 0x00000100000001b3
)

func fnv1a(s string) uint64 {
	v := _H_basis
	m := (*rt.GoString)(unsafe.Pointer(&s))

	/* hash each byte */
	for i := 0; i < m.Len; i++ {
		v ^= uint64(*(*uint8)(unsafe.Pointer(uintptr(m.Ptr) + uintptr(i))))
		v *= _H_prime
	}

	/* never returns 0 for hash */
	if v == 0 {
		return 1
	} else {
		return v
	}
}

func TestHashing_Fnv1a(t *testing.T) {
	fmt.Printf("%#x\n", fnv1a("hello, world"))
}

func TestHashing_StrHash(t *testing.T) {
	s := "hello, world"
	fmt.Printf("%#x\n", StrHash(s))
}

var fn_fnv1a = fnv1a

func BenchmarkHashing_Fnv1a(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fn_fnv1a("accountid_interval_aweme_second")
	}
}

func BenchmarkHashing_StrHash(b *testing.B) {
	for i := 0; i < b.N; i++ {
		StrHash("accountid_interval_aweme_second")
	}
}

func BenchmarkHashing_DJBHash32(b *testing.B) {
	for i := 0; i < b.N; i++ {
		DJBHash32("accountid_interval_aweme_second")
	}
}
