diff options
author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
---|---|---|
committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/old/vlib/rand/rand.v | |
download | cli-tools-windows-master.tar.gz cli-tools-windows-master.tar.bz2 cli-tools-windows-master.zip |
Diffstat (limited to 'v_windows/v/old/vlib/rand/rand.v')
-rw-r--r-- | v_windows/v/old/vlib/rand/rand.v | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/v_windows/v/old/vlib/rand/rand.v b/v_windows/v/old/vlib/rand/rand.v new file mode 100644 index 0000000..0136ec1 --- /dev/null +++ b/v_windows/v/old/vlib/rand/rand.v @@ -0,0 +1,317 @@ +// Copyright (c) 2019-2021 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.seed +import rand.wyrand +import time + +// PRNGConfigStruct is a configuration struct for creating a new instance of the default RNG. +// Note that the RNGs may have a different number of u32s required for seeding. The default +// generator WyRand used 64 bits, ie. 2 u32s so that is the default. In case your desired generator +// uses a different number of u32s, use the `seed.time_seed_array()` method with the correct +// number of u32s. +pub struct PRNGConfigStruct { + seed []u32 = seed.time_seed_array(2) +} + +// PRNG is a common interface for all PRNGs that can be used seamlessly with the rand +// modules's API. It defines all the methods that a PRNG (in the vlib or custom made) must +// implement in order to ensure that _all_ functions can be used with the generator. +pub interface PRNG { + seed(seed_data []u32) + u32() u32 + u64() u64 + u32n(max u32) u32 + u64n(max u64) u64 + u32_in_range(min u32, max u32) u32 + u64_in_range(min u64, max u64) u64 + int() int + i64() i64 + int31() int + int63() i64 + intn(max int) int + i64n(max i64) i64 + int_in_range(min int, max int) int + i64_in_range(min i64, max i64) i64 + f32() f32 + f64() f64 + f32n(max f32) f32 + f64n(max f64) f64 + f32_in_range(min f32, max f32) f32 + f64_in_range(min f64, max f64) f64 +} + +__global ( + default_rng &PRNG +) + +// init initializes the default RNG. +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) &PRNG { + mut rng := &wyrand.WyRandRNG{} + rng.seed(config.seed) + return rng +} + +// get_current_rng returns the PRNG instance currently in use. If it is not changed, it will be an instance of wyrand.WyRandRNG. +pub fn get_current_rng() &PRNG { + return default_rng +} + +// set_rng changes the default RNG from wyrand.WyRandRNG (or whatever the last RNG was) to the one +// provided by the user. Note that this new RNG must be seeded manually with a constant seed or the +// `seed.time_seed_array()` method. Also, it is recommended to store the old RNG in a variable and +// should be restored if work with the custom RNG is complete. It is not necessary to restore if the +// program terminates soon afterwards. +pub fn set_rng(rng &PRNG) { + default_rng = unsafe { rng } +} + +// seed sets the given array of `u32` values as the seed for the `default_rng`. The default_rng is +// an instance of WyRandRNG which takes 2 u32 values. When using a custom RNG, make sure to use +// the correct number of u32s. +pub fn seed(seed []u32) { + default_rng.seed(seed) +} + +// u32 returns a uniformly distributed `u32` in range `[0, 2³²)`. +pub fn u32() u32 { + return default_rng.u32() +} + +// u64 returns a uniformly distributed `u64` in range `[0, 2⁶⁴)`. +pub fn u64() u64 { + return default_rng.u64() +} + +// u32n returns a uniformly distributed pseudorandom 32-bit signed positive `u32` in range `[0, max)`. +pub fn u32n(max u32) u32 { + return default_rng.u32n(max) +} + +// u64n returns a uniformly distributed pseudorandom 64-bit signed positive `u64` in range `[0, max)`. +pub fn u64n(max u64) u64 { + return default_rng.u64n(max) +} + +// u32_in_range returns a uniformly distributed pseudorandom 32-bit unsigned `u32` in range `[min, max)`. +pub fn u32_in_range(min u32, max u32) u32 { + return default_rng.u32_in_range(min, max) +} + +// u64_in_range returns a uniformly distributed pseudorandom 64-bit unsigned `u64` in range `[min, max)`. +pub fn u64_in_range(min u64, 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 returns a uniformly distributed pseudorandom 32-bit signed positive `int` in range `[0, max)`. +pub fn intn(max int) int { + return default_rng.intn(max) +} + +// byte returns a uniformly distributed pseudorandom 8-bit unsigned positive `byte`. +pub fn byte() byte { + return byte(default_rng.u32() & 0xff) +} + +// int_in_range returns a uniformly distributed pseudorandom 32-bit signed int in range `[min, max)`. +// Both `min` and `max` can be negative, but we must have `min < max`. +pub fn int_in_range(min int, 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 returns a uniformly distributed pseudorandom 64-bit signed positive `i64` in range `[0, max)`. +pub fn i64n(max i64) i64 { + return default_rng.i64n(max) +} + +// i64_in_range returns a uniformly distributed pseudorandom 64-bit signed `i64` in range `[min, max)`. +pub fn i64_in_range(min i64, max i64) i64 { + return default_rng.i64_in_range(min, max) +} + +// int63 returns a uniformly distributed pseudorandom 63-bit signed positive `i64`. +pub fn int63() i64 { + return default_rng.int63() +} + +// f32 returns a uniformly distributed 32-bit floating point in range `[0, 1)`. +pub fn f32() f32 { + return default_rng.f32() +} + +// f64 returns a uniformly distributed 64-bit floating point in range `[0, 1)`. +pub fn f64() f64 { + return default_rng.f64() +} + +// f32n returns a uniformly distributed 32-bit floating point in range `[0, max)`. +pub fn f32n(max f32) f32 { + return default_rng.f32n(max) +} + +// f64n returns a uniformly distributed 64-bit floating point in range `[0, max)`. +pub fn f64n(max f64) f64 { + return default_rng.f64n(max) +} + +// f32_in_range returns a uniformly distributed 32-bit floating point in range `[min, max)`. +pub fn f32_in_range(min f32, max f32) f32 { + return default_rng.f32_in_range(min, max) +} + +// f64_in_range returns a uniformly distributed 64-bit floating point in range `[min, max)`. +pub fn f64_in_range(min f64, max f64) f64 { + return default_rng.f64_in_range(min, max) +} + +const ( + english_letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' + hex_chars = 'abcdef0123456789' + ascii_chars = '!"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ\\^_`abcdefghijklmnopqrstuvwxyz{|}~' +) + +// string_from_set returns a string of length `len` containing random characters sampled from the given `charset` +pub fn string_from_set(charset string, len int) string { + if len == 0 { + return '' + } + mut buf := unsafe { malloc_noscan(len + 1) } + for i in 0 .. len { + unsafe { + buf[i] = charset[intn(charset.len)] + } + } + unsafe { + buf[len] = 0 + } + return unsafe { buf.vstring_with_len(len) } +} + +// string returns a string of length `len` containing random characters in range `[a-zA-Z]`. +pub fn string(len int) string { + return string_from_set(rand.english_letters, len) +} + +// hex returns a hexadecimal number of length `len` containing random characters in range `[a-f0-9]`. +pub fn hex(len int) string { + return string_from_set(rand.hex_chars, len) +} + +// ascii returns a random string of the printable ASCII characters with length `len`. +pub fn ascii(len int) string { + return string_from_set(rand.ascii_chars, len) +} + +// uuid_v4 generates a random (v4) UUID +// See https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_(random) +pub fn uuid_v4() string { + buflen := 36 + mut buf := unsafe { malloc_noscan(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 buf.vstring_with_len(buflen) + } +} + +const ( + ulid_encoding = '0123456789ABCDEFGHJKMNPQRSTVWXYZ' +) + +// 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()) +} + +// 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 { + buflen := 26 + mut buf := unsafe { malloc_noscan(27) } + mut t := unix_time_milli + mut i := 9 + for i >= 0 { + unsafe { + buf[i] = rand.ulid_encoding[t & 0x1F] + } + t = t >> 5 + i-- + } + // first rand set + mut x := default_rng.u64() + i = 10 + for i < 19 { + unsafe { + buf[i] = rand.ulid_encoding[x & 0x1F] + } + x = x >> 5 + i++ + } + // second rand set + x = default_rng.u64() + for i < 26 { + unsafe { + buf[i] = rand.ulid_encoding[x & 0x1F] + } + x = x >> 5 + i++ + } + unsafe { + buf[26] = 0 + return buf.vstring_with_len(buflen) + } +} |