ladybird/AK/Hex.cpp
Idan Horowitz 2ab292f381 AK: Expose the decode_hex_digit helper
This helper is useful on its own for things like uri encoding/decoding,
so this commit exposes it via the AK/Hex header
2021-04-14 13:30:10 +02:00

82 lines
2.5 KiB
C++

/*
* Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Array.h>
#include <AK/ByteBuffer.h>
#include <AK/Hex.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <AK/Vector.h>
namespace AK {
u8 decode_hex_digit(char digit)
{
if (digit >= '0' && digit <= '9')
return digit - '0';
if (digit >= 'a' && digit <= 'f')
return 10 + (digit - 'a');
if (digit >= 'A' && digit <= 'F')
return 10 + (digit - 'A');
return 255;
}
Optional<ByteBuffer> decode_hex(const StringView& input)
{
if ((input.length() % 2) != 0)
return {};
auto output = ByteBuffer::create_zeroed(input.length() / 2);
for (long unsigned int i = 0; i < input.length() / 2; i++) {
auto c1 = decode_hex_digit(input[i * 2]);
if (c1 >= 16)
return {};
auto c2 = decode_hex_digit(input[i * 2 + 1]);
if (c2 >= 16)
return {};
output[i] = (c1 << 4) + c2;
}
return output;
}
String encode_hex(ReadonlyBytes input)
{
StringBuilder output(input.size() * 2);
for (auto ch : input)
output.appendff("{:02x}", ch);
return output.build();
}
}