binascii.hexlify by youknowone · Pull Request #5820 · RustPython/RustPython
#[pyfunction(name = "b2a_hex")] #[pyfunction] fn hexlify(data: ArgBytesLike) -> Vec<u8> { fn hexlify( data: ArgBytesLike, sep: OptionalArg<ArgAsciiBuffer>, bytes_per_sep: OptionalArg<isize>, vm: &VirtualMachine, ) -> PyResult<Vec<u8>> { let bytes_per_sep = bytes_per_sep.unwrap_or(1);
data.with_ref(|bytes| { let mut hex = Vec::<u8>::with_capacity(bytes.len() * 2); for b in bytes { hex.push(hex_nibble(b >> 4)); hex.push(hex_nibble(b & 0xf)); // Get separator character if provided let sep_char = if let OptionalArg::Present(sep_buf) = sep { sep_buf.with_ref(|sep_bytes| { if sep_bytes.len() != 1 { return Err(vm.new_value_error("sep must be length 1.".to_owned())); } let sep_char = sep_bytes[0]; if !sep_char.is_ascii() { return Err(vm.new_value_error("sep must be ASCII.".to_owned())); } Ok(Some(sep_char)) })? } else { None };
// If no separator or bytes_per_sep is 0, use simple hexlify if sep_char.is_none() || bytes_per_sep == 0 || bytes.is_empty() { let mut hex = Vec::<u8>::with_capacity(bytes.len() * 2); for b in bytes { hex.push(hex_nibble(b >> 4)); hex.push(hex_nibble(b & 0xf)); } return Ok(hex); }
let sep_char = sep_char.unwrap(); let abs_bytes_per_sep = bytes_per_sep.unsigned_abs();
// If separator interval is >= data length, no separators needed if abs_bytes_per_sep >= bytes.len() { let mut hex = Vec::<u8>::with_capacity(bytes.len() * 2); for b in bytes { hex.push(hex_nibble(b >> 4)); hex.push(hex_nibble(b & 0xf)); } return Ok(hex); }
// Calculate result length let num_separators = (bytes.len() - 1) / abs_bytes_per_sep; let result_len = bytes.len() * 2 + num_separators; let mut hex = vec![0u8; result_len];
if bytes_per_sep < 0 { // Left-to-right processing (negative bytes_per_sep) let mut i = 0; // input index let mut j = 0; // output index let chunks = bytes.len() / abs_bytes_per_sep;
// Process complete chunks for _ in 0..chunks { for _ in 0..abs_bytes_per_sep { let b = bytes[i]; hex[j] = hex_nibble(b >> 4); hex[j + 1] = hex_nibble(b & 0xf); i += 1; j += 2; } if i < bytes.len() { hex[j] = sep_char; j += 1; } }
// Process remaining bytes while i < bytes.len() { let b = bytes[i]; hex[j] = hex_nibble(b >> 4); hex[j + 1] = hex_nibble(b & 0xf); i += 1; j += 2; } } else { // Right-to-left processing (positive bytes_per_sep) let mut i = bytes.len() as isize - 1; // input index let mut j = result_len as isize - 1; // output index let chunks = bytes.len() / abs_bytes_per_sep;
// Process complete chunks from right for _ in 0..chunks { for _ in 0..abs_bytes_per_sep { let b = bytes[i as usize]; hex[j as usize] = hex_nibble(b & 0xf); hex[(j - 1) as usize] = hex_nibble(b >> 4); i -= 1; j -= 2; } if i >= 0 { hex[j as usize] = sep_char; j -= 1; } }
// Process remaining bytes while i >= 0 { let b = bytes[i as usize]; hex[j as usize] = hex_nibble(b & 0xf); hex[(j - 1) as usize] = hex_nibble(b >> 4); i -= 1; j -= 2; } } hex
Ok(hex) }) }