import "github.com/gogf/gf/v2/encoding/ghash"

goos: darwin
goarch: amd64
pkg: github.com/gogf/gf/v2/encoding/ghash
cpu: Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz
Benchmark_BKDR
Benchmark_BKDR-12      	39315165	        26.88 ns/op
Benchmark_BKDR64
Benchmark_BKDR64-12    	62891215	        22.61 ns/op
Benchmark_SDBM
Benchmark_SDBM-12      	49689925	        25.40 ns/op
Benchmark_SDBM64
Benchmark_SDBM64-12    	48860472	        24.38 ns/op
Benchmark_RS
Benchmark_RS-12        	39463418	        25.52 ns/op
Benchmark_RS64
Benchmark_RS64-12     	53318370	        19.45 ns/op
Benchmark_JS
Benchmark_JS-12        	53751033	        23.20 ns/op
Benchmark_JS64
Benchmark_JS64-12      	62440287	        19.25 ns/op
Benchmark_PJW
Benchmark_PJW-12       	42439626	        27.85 ns/op
Benchmark_PJW64
Benchmark_PJW64-12     	37491696	        33.28 ns/op
Benchmark_ELF
Benchmark_ELF-12       	38034584	        31.74 ns/op
Benchmark_ELF64
Benchmark_ELF64-12     	44047201	        27.58 ns/op
Benchmark_DJB
Benchmark_DJB-12       	46994352	        22.60 ns/op
Benchmark_DJB64
Benchmark_DJB64-12     	61980186	        19.19 ns/op
Benchmark_AP
Benchmark_AP-12        	29544234	        40.58 ns/op
Benchmark_AP64
Benchmark_AP64-12      	28123783	        42.48 ns/op

package main

import (
	"encoding/binary"
	"fmt"
	"math"

	"github.com/gogf/gf/v2/encoding/ghash"
)

func main() {
	var (
		m    = make(map[uint64]struct{})
		b    = make([]byte, 8)
		ok   bool
		hash uint64
	)
	for i := uint64(0); i < math.MaxUint64; i++ {
		binary.LittleEndian.PutUint64(b, i)
		hash = ghash.PJW64(b)
		if _, ok = m[hash]; ok {
			fmt.Println("repeated found:", i)
			break
		}
		m[hash] = struct{}{}
	}
}