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