79 lines
1.9 KiB
Go
79 lines
1.9 KiB
Go
package main
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import (
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"fmt"
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"log"
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math_rand "math/rand"
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"time"
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"github.com/schollz/peerdiscovery"
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"github.com/schollz/progressbar"
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)
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func main() {
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fmt.Println("Scanning for 10 seconds to find LAN peers")
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// show progress bar
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go func() {
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bar := progressbar.New(10)
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for i := 0; i < 10; i++ {
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bar.Add(1)
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time.Sleep(1 * time.Second)
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}
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fmt.Print("\n")
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}()
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// discover peers
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p, err := peerdiscovery.New(peerdiscovery.Settings{
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Limit: -1,
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Payload: []byte(randStringBytesMaskImprSrc(10)),
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Delay: 500 * time.Millisecond,
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TimeLimit: 10 * time.Second,
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})
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if err != nil {
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log.Fatal(err)
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}
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discoveries, err := p.Discover()
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if err != nil {
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log.Fatal(err)
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} else {
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if len(discoveries) > 0 {
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fmt.Printf("Found %d other computers\n", len(discoveries))
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for i, d := range discoveries {
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fmt.Printf("%d) '%s' with payload '%s'\n", i, d.Address, d.Payload)
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}
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} else {
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fmt.Println("Found no devices. You need to run this on another computer at the same time.")
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}
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}
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}
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// src is seeds the random generator for generating random strings
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var src = math_rand.NewSource(time.Now().UnixNano())
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const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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const (
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letterIdxBits = 6 // 6 bits to represent a letter index
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letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
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letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
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)
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// RandStringBytesMaskImprSrc prints a random string
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func randStringBytesMaskImprSrc(n int) string {
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b := make([]byte, n)
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// A src.Int63() generates 63 random bits, enough for letterIdxMax characters!
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for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {
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if remain == 0 {
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cache, remain = src.Int63(), letterIdxMax
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}
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if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
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b[i] = letterBytes[idx]
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i--
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}
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cache >>= letterIdxBits
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remain--
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}
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return string(b)
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}
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