43 lines
935 B
V
43 lines
935 B
V
// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module rand
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import time
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// Commonly used constants across RNGs
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const (
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lower_mask = u64(0x00000000ffffffff)
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)
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// Constants taken from Numerical Recipes
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[inline]
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fn nr_next(prev u32) u32 {
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return prev * 1664525 + 1013904223
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}
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// utility function that return the required number of u32s generated from system time
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[inline]
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pub fn time_seed_array(count int) []u32 {
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mut seed := u32(time.now().unix_time())
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mut seed_data := []u32{cap: count}
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for _ in 0 .. count {
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seed = nr_next(seed)
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seed_data << nr_next(seed)
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}
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return seed_data
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}
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[inline]
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fn time_seed_32() u32 {
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return time_seed_array(1)[0]
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}
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[inline]
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fn time_seed_64() u64 {
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seed_data := time_seed_array(2)
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lower := u64(seed_data[0])
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upper := u64(seed_data[1])
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return lower | (upper << 32)
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}
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