Bootloader: Add API to create GUID from string

This commit is contained in:
Bananymous 2023-11-13 18:52:41 +02:00
parent 1a75262b04
commit 8a5753b0fe
2 changed files with 53 additions and 1 deletions

View File

@ -3,6 +3,54 @@
#include <iomanip>
#include <cstring>
std::optional<uint64_t> parse_hex(std::string_view hex_string)
{
uint64_t result = 0;
for (char c : hex_string)
{
if (!isxdigit(c))
return {};
uint8_t nibble = 0;
if ('0' <= c && c <= '9')
nibble = c - '0';
else if ('a' <= c && c <= 'f')
nibble = c - 'a' + 10;
else
nibble = c - 'A' + 10;
result = (result << 4) | nibble;
}
return result;
}
std::optional<GUID> GUID::from_string(std::string_view guid_string)
{
if (guid_string.size() != 36)
return {};
if (guid_string[8] != '-' || guid_string[13] != '-' || guid_string[18] != '-' || guid_string[23] != '-')
return {};
auto comp1 = parse_hex(guid_string.substr(0, 8));
auto comp2 = parse_hex(guid_string.substr(9, 4));
auto comp3 = parse_hex(guid_string.substr(14, 4));
auto comp4 = parse_hex(guid_string.substr(19, 4));
auto comp5 = parse_hex(guid_string.substr(24, 12));
if (!comp1.has_value() || !comp2.has_value() || !comp3.has_value() || !comp4.has_value() || !comp5.has_value())
return {};
GUID result;
result.component1 = *comp1;
result.component2 = *comp2;
result.component3 = *comp3;
for (int i = 0; i < 2; i++)
result.component45[i + 0] = *comp4 >> ((2-1) * 8 - i * 8);
for (int i = 0; i < 6; i++)
result.component45[i + 2] = *comp5 >> ((6-1) * 8 - i * 8);
return result;
}
bool GUID::operator==(const GUID& other) const
{
return std::memcmp(this, &other, sizeof(GUID)) == 0;
@ -19,7 +67,7 @@ std::ostream& operator<<(std::ostream& out, const GUID& guid)
out << std::setw(2);
for (int i = 0; i < 2; i++) out << +guid.component45[i];
out << '-';
for (int i = 2; i < 6; i++) out << +guid.component45[i];
for (int i = 2; i < 8; i++) out << +guid.component45[i];
out.flags(flags);
return out;

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@ -1,10 +1,14 @@
#pragma once
#include <cstdint>
#include <optional>
#include <ostream>
#include <string_view>
struct GUID
{
static std::optional<GUID> from_string(std::string_view);
uint32_t component1;
uint16_t component2;
uint16_t component3;