1 files changed, 78 insertions, 0 deletions
diff --git a/vendor/base16ct/src/lower.rs b/vendor/base16ct/src/lower.rs
new file mode 100644
index 0000000..63aa74d
--- /dev/null
+++ b/vendor/base16ct/src/lower.rs
@@ -0,0 +1,78 @@
+use crate::{decode_inner, encoded_len, Error};
+#[cfg(feature = "alloc")]
+use crate::{decoded_len, String, Vec};
+
+/// Decode a lower Base16 (hex) string into the provided destination buffer.
+pub fn decode(src: impl AsRef<[u8]>, dst: &mut [u8]) -> Result<&[u8], Error> {
+    decode_inner(src.as_ref(), dst, decode_nibble)
+}
+
+/// Decode a lower Base16 (hex) string into a byte vector.
+#[cfg(feature = "alloc")]
+pub fn decode_vec(input: impl AsRef<[u8]>) -> Result<Vec<u8>, Error> {
+    let mut output = vec![0u8; decoded_len(input.as_ref())?];
+    decode(input, &mut output)?;
+    Ok(output)
+}
+
+/// Encode the input byte slice as lower Base16.
+///
+/// Writes the result into the provided destination slice, returning an
+/// ASCII-encoded lower Base16 (hex) string value.
+pub fn encode<'a>(src: &[u8], dst: &'a mut [u8]) -> Result<&'a [u8], Error> {
+    let dst = dst
+        .get_mut(..encoded_len(src))
+        .ok_or(Error::InvalidLength)?;
+    for (src, dst) in src.iter().zip(dst.chunks_exact_mut(2)) {
+        dst[0] = encode_nibble(src >> 4);
+        dst[1] = encode_nibble(src & 0x0f);
+    }
+    Ok(dst)
+}
+
+/// Encode input byte slice into a [`&str`] containing lower Base16 (hex).
+pub fn encode_str<'a>(src: &[u8], dst: &'a mut [u8]) -> Result<&'a str, Error> {
+    encode(src, dst).map(|r| unsafe { core::str::from_utf8_unchecked(r) })
+}
+
+/// Encode input byte slice into a [`String`] containing lower Base16 (hex).
+///
+/// # Panics
+/// If `input` length is greater than `usize::MAX/2`.
+#[cfg(feature = "alloc")]
+pub fn encode_string(input: &[u8]) -> String {
+    let elen = encoded_len(input);
+    let mut dst = vec![0u8; elen];
+    let res = encode(input, &mut dst).expect("dst length is correct");
+
+    debug_assert_eq!(elen, res.len());
+    unsafe { String::from_utf8_unchecked(dst) }
+}
+
+/// Decode a single nibble of lower hex
+#[inline(always)]
+fn decode_nibble(src: u8) -> u16 {
+    // 0-9  0x30-0x39
+    // A-F  0x41-0x46 or a-f  0x61-0x66
+    let byte = src as i16;
+    let mut ret: i16 = -1;
+
+    // 0-9  0x30-0x39
+    // if (byte > 0x2f && byte < 0x3a) ret += byte - 0x30 + 1; // -47
+    ret += (((0x2fi16 - byte) & (byte - 0x3a)) >> 8) & (byte - 47);
+    // a-f  0x61-0x66
+    // if (byte > 0x60 && byte < 0x67) ret += byte - 0x61 + 10 + 1; // -86
+    ret += (((0x60i16 - byte) & (byte - 0x67)) >> 8) & (byte - 86);
+
+    ret as u16
+}
+
+/// Encode a single nibble of hex
+#[inline(always)]
+fn encode_nibble(src: u8) -> u8 {
+    let mut ret = src as i16 + 0x30;
+    // 0-9  0x30-0x39
+    // a-f  0x61-0x66
+    ret += ((0x39i16 - ret) >> 8) & (0x61i16 - 0x3a);
+    ret as u8
+}