vendor: Update everything

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4620

vendor/github.com/chmduquesne/rollinghash/roll/main.go

@@ -0,0 +1,126 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"time"
+
+	"code.cloudfoundry.org/bytefmt"
+	//rollsum "github.com/chmduquesne/rollinghash/adler32"
+	//rollsum "github.com/chmduquesne/rollinghash/buzhash32"
+	rollsum "github.com/chmduquesne/rollinghash/buzhash64"
+	//rollsum "github.com/chmduquesne/rollinghash/bozo32"
+)
+
+const (
+	KiB = 1024
+	MiB = 1024 * KiB
+	GiB = 1024 * MiB
+
+	clearscreen = "\033[2J\033[1;1H"
+	clearline   = "\x1b[2K"
+)
+
+func genMasks() (res []uint64) {
+	res = make([]uint64, 64)
+	ones := ^uint64(0) // 0xffffffffffffffff
+	for i := 0; i < 64; i++ {
+		res[i] = ones >> uint(63-i)
+	}
+	return
+}
+
+func hash2uint64(s []byte) (res uint64) {
+	for _, b := range s {
+		res <<= 8
+		res |= uint64(b)
+	}
+	return
+}
+
+func main() {
+	dostats := flag.Bool("stats", false, "Do some stats about the rolling sum")
+	size := flag.String("size", "256M", "How much data to read")
+	flag.Parse()
+
+	fileSize, err := bytefmt.ToBytes(*size)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	bufsize := 16 * MiB
+	rbuf := make([]byte, bufsize)
+	hbuf := make([]byte, 0, 8)
+	t := time.Now()
+
+	f, err := os.Open("/dev/urandom")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		if err := f.Close(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+
+	io.ReadFull(f, rbuf)
+
+	roll := rollsum.New()
+	roll.Write(rbuf[:64])
+
+	masks := genMasks()
+	hits := make(map[uint64]uint64)
+	for _, m := range masks {
+		hits[m] = 0
+	}
+
+	n := uint64(0)
+	k := 0
+	for n < fileSize {
+		if k >= bufsize {
+			status := fmt.Sprintf("Byte count: %s", bytefmt.ByteSize(n))
+			if *dostats {
+				fmt.Printf(clearscreen)
+				fmt.Println(status)
+				for i, m := range masks {
+					frequency := "NaN"
+					if hits[m] != 0 {
+						frequency = bytefmt.ByteSize(n / hits[m])
+					}
+					fmt.Printf("0x%016x (%02d bits): every %s\n", m, i+1, frequency)
+				}
+			} else {
+				fmt.Printf(clearline)
+				fmt.Printf(status)
+				fmt.Printf("\r")
+			}
+			_, err := io.ReadFull(f, rbuf)
+			if err != nil {
+				panic(err)
+			}
+			k = 0
+		}
+		roll.Roll(rbuf[k])
+		if *dostats {
+			s := hash2uint64(roll.Sum(hbuf))
+			for _, m := range masks {
+				if s&m == m {
+					hits[m] += 1
+				} else {
+					break
+				}
+			}
+		}
+		k++
+		n++
+	}
+	duration := time.Since(t)
+	fmt.Printf("Rolled %s of data in %v (%s/s).\n",
+		bytefmt.ByteSize(n),
+		duration,
+		bytefmt.ByteSize(n*1e9/uint64(duration)),
+	)
+}