github.com/jbendotnet/noms@v0.0.0-20190904222105-c43e4293ea92/go/perf/hash-perf-rig/main.go (about)

     1  // Copyright 2016 Attic Labs, Inc. All rights reserved.
     2  // Licensed under the Apache License, version 2.0:
     3  // http://www.apache.org/licenses/LICENSE-2.0
     4  
     5  package main
     6  
     7  import (
     8  	"crypto/sha1"
     9  	"crypto/sha256"
    10  	"crypto/sha512"
    11  	"fmt"
    12  	"hash"
    13  	"io"
    14  	"os"
    15  	"time"
    16  
    17  	"github.com/attic-labs/kingpin"
    18  	"github.com/codahale/blake2"
    19  	humanize "github.com/dustin/go-humanize"
    20  	"github.com/kch42/buzhash"
    21  )
    22  
    23  func main() {
    24  	useSHA := kingpin.Flag("use-sha", "<default>=no hashing, 1=sha1, 256=sha256, 512=sha512, blake=blake2b").String()
    25  	useBH := kingpin.Flag("use-bh", "whether we buzhash the bytes").Bool()
    26  	bigFile := kingpin.Arg("bigfile", "input file to chunk").Required().String()
    27  
    28  	kingpin.Parse()
    29  
    30  	bh := buzhash.NewBuzHash(64 * 8)
    31  	f, _ := os.Open(*bigFile)
    32  	defer f.Close()
    33  	t0 := time.Now()
    34  	buf := make([]byte, 4*1024)
    35  	l := uint64(0)
    36  
    37  	var h hash.Hash
    38  	if *useSHA == "1" {
    39  		h = sha1.New()
    40  	} else if *useSHA == "256" {
    41  		h = sha256.New()
    42  	} else if *useSHA == "512" {
    43  		h = sha512.New()
    44  	} else if *useSHA == "blake" {
    45  		h = blake2.NewBlake2B()
    46  	}
    47  
    48  	for {
    49  		n, err := f.Read(buf)
    50  		l += uint64(n)
    51  		if err == io.EOF {
    52  			break
    53  		}
    54  		s := buf[:n]
    55  		if h != nil {
    56  			h.Write(s)
    57  		}
    58  		if *useBH {
    59  			bh.Write(s)
    60  		}
    61  	}
    62  
    63  	t1 := time.Now()
    64  	d := t1.Sub(t0)
    65  	fmt.Printf("Read  %s in %s (%s/s)\n", humanize.Bytes(l), d, humanize.Bytes(uint64(float64(l)/d.Seconds())))
    66  	digest := []byte{}
    67  	if h != nil {
    68  		fmt.Printf("%x\n", h.Sum(digest))
    69  	}
    70  }