/
lib.go
47 lines (40 loc) · 821 Bytes
/
lib.go
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package random
import (
"bytes"
randcrypto "crypto/rand"
"io"
randmath "math/rand"
)
func WriteRandomBytes(count int64, w io.Writer) error {
r := &io.LimitedReader{R: randcrypto.Reader, N: count}
_, err := io.Copy(w, r)
return err
}
func WritePseudoRandomBytes(count int64, w io.Writer, seed int64) error {
randmath.Seed(seed)
// Configurable buffer size
bufsize := int64(1024 * 1024 * 4)
b := make([]byte, bufsize)
for count > 0 {
if bufsize > count {
bufsize = count
b = b[:bufsize]
}
var n uint32
for i := int64(0); i < bufsize; {
n = randmath.Uint32()
for j := 0; j < 4 && i < bufsize; j++ {
b[i] = byte(n & 0xff)
n >>= 8
i++
}
}
count = count - bufsize
r := bytes.NewReader(b)
_, err := io.Copy(w, r)
if err != nil {
return err
}
}
return nil
}