FedP2P/internal/cmd/bloom-false-positives/main.go

34 lines
757 B
Go

package main
import (
"bufio"
"fmt"
"os"
"github.com/anacrolix/tagflag"
"github.com/willf/bloom"
)
func main() {
var args struct {
M uint `help:"num bits"`
K uint `help:"num hashing functions"`
}
tagflag.Parse(&args, tagflag.Description("adds lines from stdin to a bloom filter with the given configuration, and gives collision stats at EOF"))
filter := bloom.New(args.M, args.K)
scanner := bufio.NewScanner(os.Stdin)
n := 0
collisions := 0
for scanner.Scan() {
if filter.TestAndAdd(scanner.Bytes()) {
collisions++
}
n++
}
if err := scanner.Err(); err != nil {
fmt.Fprintf(os.Stderr, "error reading stdin: %s", err)
os.Exit(1)
}
fmt.Printf("collisions %d/%d (%f)\n", collisions, n, float64(collisions)/float64(n)*100)
}