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基本介绍
常用经典哈希函数Go语言实现,提供uint32
及uint64
类型的哈希函数。
使用方式:
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import "github.com/gogf/gf/v2/encoding/ghash" |
接口文档:
https://pkg.go.dev/github.com/gogf/gf/v2/encoding/ghash
基准测试
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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_SRS64 Benchmark_SRS64-12 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 |
重复性测试
测试结果与测试内容有关联性,我这里通过uint64
数值的范围遍历来进行简单的重复性测试,仅供参考。
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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{}{} } } |
测试结果如下:
哈希函数 | 重复位置 | 备注 |
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AP64 | 8388640 | |
BKDR64 | 33536 | |
DJB64 | 8448 | |
ELF64 | 4096 | |
JS64 | ||
PJW64 | ||
RS64 | ||
SDBM64 |
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