1 // Copyright 2018 Brian Smith.
2 //
3 // Permission to use, copy, modify, and/or distribute this software for any
4 // purpose with or without fee is hereby granted, provided that the above
5 // copyright notice and this permission notice appear in all copies.
6 //
7 // THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
8 // WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 // MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
10 // SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 // WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
14 
15 use super::block::{Block, BLOCK_LEN};
16 
17 #[cfg(target_arch = "x86")]
shift_full_blocks<F>(in_out: &mut [u8], src: core::ops::RangeFrom<usize>, mut transform: F) where F: FnMut(&[u8; BLOCK_LEN]) -> Block,18 pub fn shift_full_blocks<F>(in_out: &mut [u8], src: core::ops::RangeFrom<usize>, mut transform: F)
19 where
20     F: FnMut(&[u8; BLOCK_LEN]) -> Block,
21 {
22     let in_out_len = in_out[src.clone()].len();
23 
24     for i in (0..in_out_len).step_by(BLOCK_LEN) {
25         let block = {
26             let input =
27                 <&[u8; BLOCK_LEN]>::try_from(&in_out[(src.start + i)..][..BLOCK_LEN]).unwrap();
28             transform(input)
29         };
30         let output = <&mut [u8; BLOCK_LEN]>::try_from(&mut in_out[i..][..BLOCK_LEN]).unwrap();
31         *output = *block.as_ref();
32     }
33 }
34 
shift_partial<F>((in_prefix_len, in_out): (usize, &mut [u8]), transform: F) where F: FnOnce(&[u8]) -> Block,35 pub fn shift_partial<F>((in_prefix_len, in_out): (usize, &mut [u8]), transform: F)
36 where
37     F: FnOnce(&[u8]) -> Block,
38 {
39     let (block, in_out_len) = {
40         let input = &in_out[in_prefix_len..];
41         let in_out_len = input.len();
42         if in_out_len == 0 {
43             return;
44         }
45         debug_assert!(in_out_len < BLOCK_LEN);
46         (transform(input), in_out_len)
47     };
48     in_out[..in_out_len].copy_from_slice(&block.as_ref()[..in_out_len]);
49 }
50