84 lines
2.1 KiB
Go
84 lines
2.1 KiB
Go
// linear congruential generator written in go
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// by darkmage
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// https://www.evildojo.com
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// https://www.twitter.com/evildojo666
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package main
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import (
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"fmt"
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"time"
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"os"
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"math"
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"math/rand"
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"strconv"
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"sync"
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)
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// define a global sieve
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var sieve []bool
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var wg sync.WaitGroup
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func run_sieve(max int64, start int64, move int64, shard_num int64, shard_count int64) {
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var current int64 = start + shard_num
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if current > max-1 {
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current = current % max
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}
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for i := int64(0); i <= max/shard_count; i++ {
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sieve[current] = true
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current = current + move
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if current > max-1 {
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current = current % max
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}
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}
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defer wg.Done()
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}
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func main() {
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if len(os.Args) != 3 {
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fmt.Println("Usage: go run main.go <seed> <shard_count>")
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os.Exit(1)
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}
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seed, err := strconv.ParseInt(os.Args[1], 10, 64)
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if err != nil {
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fmt.Println("Error: ", err)
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os.Exit(1)
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}
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rand := rand.New(rand.NewSource(seed))
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var max int64 = 256*256*256*256
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var start int64 = rand.Int63n(max)
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fmt.Println("start:", start)
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shard_count, err := strconv.ParseInt(os.Args[2], 10, 64)
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if err != nil {
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fmt.Println("Error: ", err)
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os.Exit(1)
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}
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fmt.Println("shard_count:", shard_count)
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var move int64 = (int64(math.Sqrt(float64(max))) + 1) * shard_count
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fmt.Println("move:", move)
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sieve = make([]bool, max)
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start_time := time.Now()
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for i := int64(0); i < shard_count; i++ {
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fmt.Println("shard:", i)
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wg.Add(1)
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go run_sieve(max, start, move, i, shard_count)
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}
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wg.Wait()
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end_time := time.Now()
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fmt.Println("Completed iterating numbers")
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fmt.Println("Time elapsed:", end_time.Sub(start_time))
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fmt.Println("Checking sieve")
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start_time = time.Now()
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for i := int64(0); i < max; i++ {
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if !sieve[i] {
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fmt.Println(os.Stderr, "Error, not all numbers flipped")
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os.Exit(1)
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}
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}
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end_time = time.Now()
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fmt.Println("Time elapsed:", end_time.Sub(start_time))
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}
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