aboutsummaryrefslogtreecommitdiff
path: root/vendor/rand_core/src/le.rs
diff options
context:
space:
mode:
authorValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
committerValentin Popov <valentin@popov.link>2024-01-08 00:21:28 +0300
commit1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch)
tree7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rand_core/src/le.rs
parent5ecd8cf2cba827454317368b68571df0d13d7842 (diff)
downloadfparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz
fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/rand_core/src/le.rs')
-rw-r--r--vendor/rand_core/src/le.rs68
1 files changed, 68 insertions, 0 deletions
diff --git a/vendor/rand_core/src/le.rs b/vendor/rand_core/src/le.rs
new file mode 100644
index 0000000..266651f
--- /dev/null
+++ b/vendor/rand_core/src/le.rs
@@ -0,0 +1,68 @@
+// Copyright 2018 Developers of the Rand project.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Little-Endian utilities
+//!
+//! Little-Endian order has been chosen for internal usage; this makes some
+//! useful functions available.
+
+use core::ptr;
+
+macro_rules! read_slice {
+ ($src:expr, $dst:expr, $size:expr, $which:ident) => {{
+ assert_eq!($src.len(), $size * $dst.len());
+
+ unsafe {
+ ptr::copy_nonoverlapping(
+ $src.as_ptr(),
+ $dst.as_mut_ptr() as *mut u8,
+ $src.len());
+ }
+ for v in $dst.iter_mut() {
+ *v = v.$which();
+ }
+ }};
+}
+
+/// Reads unsigned 32 bit integers from `src` into `dst`.
+/// Borrowed from the `byteorder` crate.
+#[inline]
+pub fn read_u32_into(src: &[u8], dst: &mut [u32]) {
+ read_slice!(src, dst, 4, to_le);
+}
+
+/// Reads unsigned 64 bit integers from `src` into `dst`.
+/// Borrowed from the `byteorder` crate.
+#[inline]
+pub fn read_u64_into(src: &[u8], dst: &mut [u64]) {
+ read_slice!(src, dst, 8, to_le);
+}
+
+#[test]
+fn test_read() {
+ let bytes = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16];
+
+ let mut buf = [0u32; 4];
+ read_u32_into(&bytes, &mut buf);
+ assert_eq!(buf[0], 0x04030201);
+ assert_eq!(buf[3], 0x100F0E0D);
+
+ let mut buf = [0u32; 3];
+ read_u32_into(&bytes[1..13], &mut buf); // unaligned
+ assert_eq!(buf[0], 0x05040302);
+ assert_eq!(buf[2], 0x0D0C0B0A);
+
+ let mut buf = [0u64; 2];
+ read_u64_into(&bytes, &mut buf);
+ assert_eq!(buf[0], 0x0807060504030201);
+ assert_eq!(buf[1], 0x100F0E0D0C0B0A09);
+
+ let mut buf = [0u64; 1];
+ read_u64_into(&bytes[7..15], &mut buf); // unaligned
+ assert_eq!(buf[0], 0x0F0E0D0C0B0A0908);
+}