e_utils/algorithm/random/
random.rs

1use rand::{
2  rngs::{SmallRng, StdRng},
3  Rng, SeedableRng,
4};
5
6/// URL safe symbols.
7///
8/// An array of characters which can be safely used in urls.
9/// Alphabet default for Rand. Is alphabet by default for Rand
10///
11/// # Example
12///
13/// ```
14/// let id = Rand::Rand!(10, &Rand::alphabet::NID_SAFE);
15/// ```
16pub const NID_SAFE: [char; 64] = [
17  '_', '-', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g',
18  'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
19  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S',
20  'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
21];
22
23///
24#[derive(Debug)]
25pub enum Rand {
26  ///Safe
27  Safe,
28  ///
29  UnSafe,
30}
31impl Rand {
32  ///
33  pub fn random_type<T>(&self) -> T
34  where
35    rand::distributions::Standard: rand::prelude::Distribution<T>,
36  {
37    match &self {
38      Rand::Safe => StdRng::from_entropy().gen::<T>(),
39      Rand::UnSafe => SmallRng::from_entropy().gen::<T>(),
40    }
41  }
42  ///
43  pub fn random_bool(&self) -> bool {
44    match &self {
45      Rand::Safe => StdRng::from_entropy().gen_range(1u8..=2) == 1,
46      Rand::UnSafe => SmallRng::from_entropy().gen_range(1u8..=2) == 1,
47    }
48  }
49  ///
50  pub fn rgb_range(&self, min: u8, max: u8) -> (u8, u8, u8) {
51    match &self {
52      Rand::Safe => {
53        let mut rng = StdRng::from_entropy();
54        (
55          rng.gen_range(min..max),
56          rng.gen_range(min..max),
57          rng.gen_range(min..max),
58        )
59      }
60      Rand::UnSafe => {
61        let mut rng = SmallRng::from_entropy();
62        (
63          rng.gen_range(min..max),
64          rng.gen_range(min..max),
65          rng.gen_range(min..max),
66        )
67      }
68    }
69  }
70  ///
71  pub fn random_range<T, R>(&self, range: R) -> T
72  where
73    T: rand::distributions::uniform::SampleUniform,
74    R: rand::distributions::uniform::SampleRange<T>,
75  {
76    match &self {
77      Rand::Safe => StdRng::from_entropy().gen_range(range),
78      Rand::UnSafe => SmallRng::from_entropy().gen_range(range),
79    }
80  }
81  ///
82  pub fn random_rng(&self, step: usize) -> Vec<u8> {
83    match &self {
84      Rand::Safe => {
85        let mut rng = StdRng::from_entropy();
86        let mut result = vec![0u8; step];
87        rng.fill(&mut result[..]);
88        result
89      }
90      Rand::UnSafe => {
91        let mut rng = SmallRng::from_entropy();
92        let mut result = vec![0u8; step];
93        rng.fill(&mut result[..]);
94        result
95      }
96    }
97  }
98  /// Nanoid
99  pub fn nanoid_format(&self, alphabet: &[char], size: usize) -> String {
100    assert!(
101      alphabet.len() <= u8::max_value() as usize,
102      "The alphabet cannot be longer than a `u8` (to comply with the `random` function)"
103    );
104    let mask = alphabet.len().next_power_of_two() - 1;
105    let step: usize = 8 * size / 5;
106    // Assert that the masking does not truncate the alphabet. (See #9)
107    debug_assert!(alphabet.len() <= mask + 1);
108    let mut id = String::with_capacity(size);
109    loop {
110      let bytes = self.random_rng(step);
111      for &byte in &bytes {
112        let byte = byte as usize & mask;
113
114        if alphabet.len() > byte {
115          id.push(alphabet[byte]);
116
117          if id.len() == size {
118            return id;
119          }
120        }
121      }
122    }
123  }
124}
e_utils/algorithm/random/random.rs

e_utils/algorithm/random/
random.rs
