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#include <cabinet/magic.hpp>
#include <magic.h>
#include <cerrno>
#include <cstddef>
#include <expected>
#include <filesystem>
#include <span>
#include <string>
#include <string_view>
#include <system_error>
#include <utility>
namespace cab
{
auto magic::open(magic::flags flags, std::string_view database) noexcept -> std::expected<magic, std::error_code>
{
auto cookie = magic_open(std::to_underlying(flags));
if (!cookie)
{
return std::unexpected{
std::error_code{errno, std::system_category()}
};
}
if (auto success = magic_load(cookie, database.data()); success < 0)
{
return std::unexpected{std::make_error_code(std::errc::invalid_argument)};
}
return magic{cookie};
}
magic::magic(::magic_t cookie) noexcept
: m_cookie{cookie}
{}
magic::magic(magic && other) noexcept
: m_cookie{std::exchange(other.m_cookie, nullptr)}
{}
magic::~magic()
{
if (m_cookie)
{
magic_close(m_cookie);
}
}
auto magic::operator=(magic && other) noexcept -> magic &
{
std::swap(m_cookie, other.m_cookie);
return *this;
}
auto magic::process(std::filesystem::path path) -> std::expected<std::string, std::error_code>
{
return handle_result(::magic_file(m_cookie, path.native().c_str()));
}
auto magic::process(int file_descriptor) -> std::expected<std::string, std::error_code>
{
if (file_descriptor < 0)
{
return std::unexpected{std::make_error_code(std::errc::invalid_argument)};
}
return handle_result(::magic_descriptor(m_cookie, file_descriptor));
}
auto magic::process(std::span<std::byte> data) -> std::expected<std::string, std::error_code>
{
return handle_result(::magic_buffer(m_cookie, data.data(), data.size_bytes()));
}
auto magic::handle_result(char const * result) -> std::expected<std::string, std::error_code>
{
auto errno_copy = errno;
if (!result)
{
auto magic_errno = ::magic_errno(m_cookie);
if (!magic_errno && !errno)
{
return std::unexpected{std::make_error_code(std::errc::invalid_argument)};
}
}
return std::string{result};
}
auto swap(magic & lhs, magic & rhs) noexcept -> void
{
auto temp = std::move(lhs);
lhs = std::move(rhs);
rhs = std::move(lhs);
}
} // namespace cab
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