74 lines
1.6 KiB
V
74 lines
1.6 KiB
V
module rand
|
|
|
|
import time
|
|
|
|
// init initializes the default RNG.
|
|
fn init() {
|
|
default_rng = new_default()
|
|
}
|
|
|
|
pub fn string(len int) string {
|
|
result := ''
|
|
#
|
|
#const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
|
|
#const charactersLength = characters.length;
|
|
#for (let i = 0;i < len.val;i++)
|
|
#result.str += characters.charAt(Math.random() * charactersLength);
|
|
|
|
return result
|
|
}
|
|
|
|
const (
|
|
ulid_encoding = '0123456789ABCDEFGHJKMNPQRSTVWXYZ'
|
|
)
|
|
|
|
// ulid generates an Unique Lexicographically sortable IDentifier.
|
|
// See https://github.com/ulid/spec .
|
|
// Note: ULIDs can leak timing information, if you make them public, because
|
|
// you can infer the rate at which some resource is being created, like
|
|
// users or business transactions.
|
|
// (https://news.ycombinator.com/item?id=14526173)
|
|
pub fn ulid() string {
|
|
return ulid_at_millisecond(u64(time.utc().unix_time_milli()))
|
|
}
|
|
|
|
// ulid_at_millisecond does the same as `ulid` but takes a custom Unix millisecond timestamp via `unix_time_milli`.
|
|
pub fn ulid_at_millisecond(unix_time_milli u64) string {
|
|
mut buf := []byte{cap: 27}
|
|
mut t := unix_time_milli
|
|
mut i := 9
|
|
for i >= 0 {
|
|
buf[i] = rand.ulid_encoding[int(t & 0x1f)]
|
|
t = t >> 5
|
|
i--
|
|
}
|
|
|
|
mut x := default_rng.u64()
|
|
i = 10
|
|
for i < 19 {
|
|
buf[i] = rand.ulid_encoding[int(x & 0x1f)]
|
|
|
|
x = x >> 5
|
|
i++
|
|
}
|
|
|
|
x = default_rng.u64()
|
|
for i < 26 {
|
|
buf[i] = rand.ulid_encoding[int(x & 0x1f)]
|
|
x = x >> 5
|
|
i++
|
|
}
|
|
|
|
res := ''
|
|
println(buf)
|
|
#res.str = buf.arr.arr.map(String.fromCharCode).join('')
|
|
|
|
return res
|
|
}
|
|
|
|
fn read_internal(mut rng PRNG, mut buf []byte) {
|
|
for i in 0 .. buf.len {
|
|
buf[i] = rng.byte()
|
|
}
|
|
}
|