flate2_crc/
lib.rs

1//! Deprecated crate, use `crc32fast`
2
3// Note that this isn't really intended to be a user-facing crate, that's
4// `flate2::Crc`
5
6#![deprecated(note = "use the `crc32fast` crate instead")]
7
8#[macro_use]
9extern crate cfg_if;
10
11#[cfg(test)]
12#[macro_use]
13extern crate quickcheck;
14
15cfg_if! {
16    if #[cfg(not(simd))] {
17        mod other;
18        use self::other as imp;
19    } else if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
20        mod x86;
21        use self::x86 as imp;
22    } else {
23        mod other;
24        use self::other as imp;
25    }
26}
27
28#[derive(Debug)]
29pub struct Hardware(bool);
30
31impl Hardware {
32    #[inline]
33    pub fn detect() -> Hardware {
34        Hardware(imp::detect())
35    }
36
37    #[inline]
38    pub fn calculate(
39        &self,
40        crc: u32,
41        data: &[u8],
42        fallback: fn(u32, &[u8]) -> u32,
43    ) -> u32 {
44        if self.0 {
45            unsafe { imp::calculate(crc, data, fallback) }
46        } else {
47            fallback(crc, data)
48        }
49    }
50}
51
52#[cfg(test)]
53mod tests {
54    extern crate miniz_sys;
55    extern crate rand;
56    extern crate rayon;
57
58    use self::rand::Rng;
59    use self::rayon::prelude::*;
60    use super::Hardware;
61
62    fn fallback(a: u32, b: &[u8]) -> u32 {
63        unsafe {
64            miniz_sys::mz_crc32(a as _, b.as_ptr(), b.len()) as u32
65        }
66    }
67
68    fn random_chunks(iters: usize, lo: usize, hi: usize) {
69        let hardware = Hardware::detect();
70
71        (0..iters)
72            .into_par_iter()
73            .for_each_with(Vec::new(), |data, _| {
74                let mut rng = rand::thread_rng();
75                let init = rng.gen::<u32>();
76                let len = rng.gen_range(lo, hi);
77                data.resize(len, 0u8);
78                rng.fill(&mut data[..]);
79
80                assert_eq!(
81                    fallback(init, &data),
82                    hardware.calculate(init, &data, fallback),
83                );
84            });
85    }
86
87    #[test]
88    fn random_small() {
89        random_chunks(1000, 0, 256);
90    }
91
92    #[test]
93    fn random_med() {
94        random_chunks(1000, 256, 16 * 1024);
95    }
96
97    #[test]
98    fn random_large() {
99        random_chunks(1000, 0, 1024 * 1024);
100    }
101
102    quickcheck! {
103        fn prop(crc: u32, xs: Vec<u8>) -> bool {
104            fallback(crc, &xs) == Hardware::detect().calculate(crc, &xs, fallback)
105        }
106    }
107}
flate2_crc/lib.rs

flate2_crc/
lib.rs
