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Diffstat (limited to 'v_windows/v/old/vlib/rand/musl/musl_rng.v')
| -rw-r--r-- | v_windows/v/old/vlib/rand/musl/musl_rng.v | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/v_windows/v/old/vlib/rand/musl/musl_rng.v b/v_windows/v/old/vlib/rand/musl/musl_rng.v new file mode 100644 index 0000000..fdfb733 --- /dev/null +++ b/v_windows/v/old/vlib/rand/musl/musl_rng.v @@ -0,0 +1,241 @@ +// 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 musl + +import math.bits +import rand.seed +import rand.constants + +// MuslRNG ported from https://git.musl-libc.org/cgit/musl/tree/src/prng/rand_r.c +pub struct MuslRNG { +mut: + state u32 = seed.time_seed_32() +} + +// seed sets the current random state based on `seed_data`. +// seed expects `seed_data` to be only one `u32`. +pub fn (mut rng MuslRNG) seed(seed_data []u32) { + if seed_data.len != 1 { + eprintln('MuslRNG needs only one unsigned 32-bit integer as a seed.') + exit(1) + } + rng.state = seed_data[0] +} + +// temper returns a tempered value based on `prev` value. +[inline] +fn temper(prev u32) u32 { + mut x := prev + x ^= x >> 11 + x ^= (x << 7) & 0x9D2C5680 + x ^= (x << 15) & 0xEFC60000 + x ^= (x >> 18) + return x +} + +// u32 returns a pseudorandom 32-bit unsigned integer (`u32`). +[inline] +pub fn (mut rng MuslRNG) u32() u32 { + rng.state = rng.state * 1103515245 + 12345 + // We are not dividing by 2 (or shifting right by 1) + // because we want all 32-bits of random data + return temper(rng.state) +} + +// u64 returns a pseudorandom 64-bit unsigned integer (`u64`). +[inline] +pub fn (mut rng MuslRNG) u64() u64 { + return u64(rng.u32()) | (u64(rng.u32()) << 32) +} + +// u32n returns a pseudorandom 32-bit unsigned integer `u32` in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) u32n(max u32) u32 { + if max == 0 { + eprintln('max must be positive integer.') + exit(1) + } + // Check SysRNG in system_rng.c.v for explanation + bit_len := bits.len_32(max) + if bit_len == 32 { + for { + value := rng.u32() + if value < max { + return value + } + } + } else { + mask := (u32(1) << (bit_len + 1)) - 1 + for { + value := rng.u32() & mask + if value < max { + return value + } + } + } + return u32(0) +} + +// u64n returns a pseudorandom 64-bit unsigned integer (`u64`) in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) u64n(max u64) u64 { + if max == 0 { + eprintln('max must be positive integer.') + exit(1) + } + bit_len := bits.len_64(max) + if bit_len == 64 { + for { + value := rng.u64() + if value < max { + return value + } + } + } else { + mask := (u64(1) << (bit_len + 1)) - 1 + for { + value := rng.u64() & mask + if value < max { + return value + } + } + } + return u64(0) +} + +// u32_in_range returns a pseudorandom 32-bit unsigned integer (`u32`) in range `[min, max)`. +[inline] +pub fn (mut rng MuslRNG) u32_in_range(min u32, max u32) u32 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.u32n(u32(max - min)) +} + +// u64_in_range returns a pseudorandom 64-bit unsigned integer (`u64`) in range `[min, max)`. +[inline] +pub fn (mut rng MuslRNG) u64_in_range(min u64, max u64) u64 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.u64n(max - min) +} + +// int returns a 32-bit signed (possibly negative) integer (`int`). +[inline] +pub fn (mut rng MuslRNG) int() int { + return int(rng.u32()) +} + +// i64 returns a 64-bit signed (possibly negative) integer (`i64`). +[inline] +pub fn (mut rng MuslRNG) i64() i64 { + return i64(rng.u64()) +} + +// int31 returns a 31-bit positive pseudorandom integer (`int`). +[inline] +pub fn (mut rng MuslRNG) int31() int { + return int(rng.u32() >> 1) +} + +// int63 returns a 63-bit positive pseudorandom integer (`i64`). +[inline] +pub fn (mut rng MuslRNG) int63() i64 { + return i64(rng.u64() >> 1) +} + +// intn returns a 32-bit positive int in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) intn(max int) int { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return int(rng.u32n(u32(max))) +} + +// i64n returns a 64-bit positive integer `i64` in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) i64n(max i64) i64 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return i64(rng.u64n(u64(max))) +} + +// int_in_range returns a 32-bit positive integer `int` in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) int_in_range(min int, max int) int { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.intn(max - min) +} + +// i64_in_range returns a 64-bit positive integer `i64` in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) i64_in_range(min i64, max i64) i64 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.i64n(max - min) +} + +// f32 returns a pseudorandom `f32` value in range `[0, 1)`. +[inline] +pub fn (mut rng MuslRNG) f32() f32 { + return f32(rng.u32()) / constants.max_u32_as_f32 +} + +// f64 returns a pseudorandom `f64` value in range `[0, 1)`. +[inline] +pub fn (mut rng MuslRNG) f64() f64 { + return f64(rng.u64()) / constants.max_u64_as_f64 +} + +// f32n returns a pseudorandom `f32` value in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) f32n(max f32) f32 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return rng.f32() * max +} + +// f64n returns a pseudorandom `f64` value in range `[0, max)`. +[inline] +pub fn (mut rng MuslRNG) f64n(max f64) f64 { + if max <= 0 { + eprintln('max has to be positive.') + exit(1) + } + return rng.f64() * max +} + +// f32_in_range returns a pseudorandom `f32` in range `[min, max)`. +[inline] +pub fn (mut rng MuslRNG) f32_in_range(min f32, max f32) f32 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.f32n(max - min) +} + +// i64_in_range returns a pseudorandom `i64` in range `[min, max)`. +[inline] +pub fn (mut rng MuslRNG) f64_in_range(min f64, max f64) f64 { + if max <= min { + eprintln('max must be greater than min.') + exit(1) + } + return min + rng.f64n(max - min) +} |