237 lines
6.1 KiB
V
237 lines
6.1 KiB
V
// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
|
|
// Use of this source code is governed by an MIT license
|
|
// that can be found in the LICENSE file.
|
|
module rand
|
|
|
|
import rand.util
|
|
import rand.wyrand
|
|
import time
|
|
|
|
// Configuration struct for creating a new instance of the default RNG.
|
|
pub struct PRNGConfigStruct {
|
|
seed []u32 = util.time_seed_array(2)
|
|
}
|
|
|
|
__global ( default_rng &wyrand.WyRandRNG )
|
|
fn init() {
|
|
default_rng = new_default({})
|
|
}
|
|
|
|
// new_default returns a new instance of the default RNG. If the seed is not provided, the current time will be used to seed the instance.
|
|
pub fn new_default(config PRNGConfigStruct) &wyrand.WyRandRNG {
|
|
mut rng := &wyrand.WyRandRNG{}
|
|
rng.seed(config.seed)
|
|
return rng
|
|
}
|
|
|
|
// seed sets the given array of `u32` values as the seed for the `default_rng`.
|
|
pub fn seed(seed []u32) {
|
|
default_rng.seed(seed)
|
|
}
|
|
|
|
// u32() returns a uniformly distributed u32 in _[0, 2<sup>32</sup>)_
|
|
pub fn u32() u32 {
|
|
return default_rng.u32()
|
|
}
|
|
|
|
// u64() returns a uniformly distributed u64 in _[0, 2<sup>64</sup>)_
|
|
pub fn u64() u64 {
|
|
return default_rng.u64()
|
|
}
|
|
|
|
// u32n(max) returns a uniformly distributed pseudorandom 32-bit signed positive u32 in _[0, max)_
|
|
pub fn u32n(max u32) u32 {
|
|
return default_rng.u32n(max)
|
|
}
|
|
|
|
// u64n(max) returns a uniformly distributed pseudorandom 64-bit signed positive u64 in _[0, max)_
|
|
pub fn u64n(max u64) u64 {
|
|
return default_rng.u64n(max)
|
|
}
|
|
|
|
// u32_in_range(min, max) returns a uniformly distributed pseudorandom 32-bit unsigned u32 in _[min, max)_
|
|
pub fn u32_in_range(min, max u32) u32 {
|
|
return default_rng.u32_in_range(min, max)
|
|
}
|
|
|
|
// u64_in_range(min, max) returns a uniformly distributed pseudorandom 64-bit unsigned u64 in _[min, max)_
|
|
pub fn u64_in_range(min, max u64) u64 {
|
|
return default_rng.u64_in_range(min, max)
|
|
}
|
|
|
|
// int() returns a uniformly distributed pseudorandom 32-bit signed (possibly negative) int
|
|
pub fn int() int {
|
|
return default_rng.int()
|
|
}
|
|
|
|
// intn(max) returns a uniformly distributed pseudorandom 32-bit signed positive int in _[0, max)_
|
|
pub fn intn(max int) int {
|
|
return default_rng.intn(max)
|
|
}
|
|
|
|
// int_in_range(min, max) returns a uniformly distributed pseudorandom
|
|
// 32-bit signed int in [min, max). Both min and max can be negative, but we must have _min < max_.
|
|
pub fn int_in_range(min, max int) int {
|
|
return default_rng.int_in_range(min, max)
|
|
}
|
|
|
|
// int31() returns a uniformly distributed pseudorandom 31-bit signed positive int
|
|
pub fn int31() int {
|
|
return default_rng.int31()
|
|
}
|
|
|
|
// i64() returns a uniformly distributed pseudorandom 64-bit signed (possibly negative) i64
|
|
pub fn i64() i64 {
|
|
return default_rng.i64()
|
|
}
|
|
|
|
// i64n(max) returns a uniformly distributed pseudorandom 64-bit signed positive i64 in _[0, max)_
|
|
pub fn i64n(max i64) i64 {
|
|
return default_rng.i64n(max)
|
|
}
|
|
|
|
// i64_in_range(min, max) returns a uniformly distributed pseudorandom 64-bit signed int in _[min, max)_
|
|
pub fn i64_in_range(min, max i64) i64 {
|
|
return default_rng.i64_in_range(min, max)
|
|
}
|
|
|
|
// int63() returns a uniformly distributed pseudorandom 63-bit signed positive int
|
|
pub fn int63() i64 {
|
|
return default_rng.int63()
|
|
}
|
|
|
|
// f32() returns a uniformly distributed 32-bit floating point in _[0, 1)_
|
|
pub fn f32() f32 {
|
|
return default_rng.f32()
|
|
}
|
|
|
|
// f64() returns a uniformly distributed 64-bit floating point in _[0, 1)_
|
|
pub fn f64() f64 {
|
|
return default_rng.f64()
|
|
}
|
|
|
|
// f32n() returns a uniformly distributed 32-bit floating point in _[0, max)_
|
|
pub fn f32n(max f32) f32 {
|
|
return default_rng.f32n(max)
|
|
}
|
|
|
|
// f64n() returns a uniformly distributed 64-bit floating point in _[0, max)_
|
|
pub fn f64n(max f64) f64 {
|
|
return default_rng.f64n(max)
|
|
}
|
|
|
|
// f32_in_range(min, max) returns a uniformly distributed 32-bit floating point in _[min, max)_
|
|
pub fn f32_in_range(min, max f32) f32 {
|
|
return default_rng.f32_in_range(min, max)
|
|
}
|
|
|
|
// f64_in_range(min, max) returns a uniformly distributed 64-bit floating point in _[min, max)_
|
|
pub fn f64_in_range(min, max f64) f64 {
|
|
return default_rng.f64_in_range(min, max)
|
|
}
|
|
|
|
const (
|
|
chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
|
|
)
|
|
|
|
pub fn string(len int) string {
|
|
mut buf := malloc(len)
|
|
for i in 0 .. len {
|
|
unsafe {
|
|
buf[i] = chars[intn(chars.len)]
|
|
}
|
|
}
|
|
return unsafe { buf.vstring_with_len(len) }
|
|
}
|
|
|
|
// rand.uuid_v4 generate a completely random UUID (v4)
|
|
// See https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_(random)
|
|
pub fn uuid_v4() string {
|
|
buflen := 36
|
|
mut buf := malloc(37)
|
|
mut i_buf := 0
|
|
mut x := u64(0)
|
|
mut d := byte(0)
|
|
for i_buf < buflen {
|
|
mut c := 0
|
|
x = default_rng.u64()
|
|
// do most of the bit manipulation at once:
|
|
x &= 0x0F0F0F0F0F0F0F0F
|
|
x += 0x3030303030303030
|
|
// write the ASCII codes to the buffer:
|
|
for c < 8 && i_buf < buflen {
|
|
d = byte(x)
|
|
unsafe {
|
|
buf[i_buf] = if d > 0x39 { d + 0x27 } else { d }
|
|
}
|
|
i_buf++
|
|
c++
|
|
x = x >> 8
|
|
}
|
|
}
|
|
// there are still some random bits in x:
|
|
x = x >> 8
|
|
d = byte(x)
|
|
unsafe {
|
|
buf[19] = if d > 0x39 { d + 0x27 } else { d }
|
|
buf[8] = `-`
|
|
buf[13] = `-`
|
|
buf[18] = `-`
|
|
buf[23] = `-`
|
|
buf[14] = `4`
|
|
buf[buflen] = 0
|
|
}
|
|
return unsafe { buf.vstring_with_len(buflen) }
|
|
}
|
|
|
|
const(
|
|
ulid_encoding = "0123456789ABCDEFGHJKMNPQRSTVWXYZ"
|
|
)
|
|
|
|
// rand.ulid generates an Unique Lexicographically sortable IDentifier.
|
|
// See https://github.com/ulid/spec .
|
|
// NB: 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(time.utc().unix_time_milli())
|
|
}
|
|
|
|
pub fn ulid_at_millisecond(unix_time_milli u64) string {
|
|
buflen := 26
|
|
mut buf := malloc(27)
|
|
mut t := unix_time_milli
|
|
mut i := 9
|
|
for i >= 0 {
|
|
unsafe{
|
|
buf[i] = ulid_encoding[t & 0x1F]
|
|
}
|
|
t = t >> 5
|
|
i--
|
|
}
|
|
// first rand set
|
|
mut x := default_rng.u64()
|
|
i = 10
|
|
for i < 19 {
|
|
unsafe{
|
|
buf[i] = ulid_encoding[x & 0x1F]
|
|
}
|
|
x = x >> 5
|
|
i++
|
|
}
|
|
// second rand set
|
|
x = default_rng.u64()
|
|
for i < 26 {
|
|
unsafe{
|
|
buf[i] = ulid_encoding[x & 0x1F]
|
|
}
|
|
x = x >> 5
|
|
i++
|
|
}
|
|
unsafe{
|
|
buf[26] = 0
|
|
}
|
|
return unsafe { buf.vstring_with_len(buflen) }
|
|
}
|