Access.hpp

/* Copyright 2017-2025 Fabian Koller and Franz Poeschel, Axel Huebl
 *
 * This file is part of openPMD-api.
 *
 * openPMD-api is free software: you can redistribute it and/or modify
 * it under the terms of of either the GNU General Public License or
 * the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * openPMD-api is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License and the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License
 * and the GNU Lesser General Public License along with openPMD-api.
 * If not, see <http://www.gnu.org/licenses/>.
 */
#pragma once
 
#include <stdexcept>
 
namespace openPMD
{
enum class Access
{
    READ_ONLY = 0,
    READ_LINEAR = 1,
    READ_WRITE = 2,
    CREATE_RANDOM_ACCESS = 3,
    CREATE_LINEAR = 4,
    APPEND_RANDOM_ACCESS = 5,
    APPEND_LINEAR = 6,
    READ_RANDOM_ACCESS = READ_ONLY, 
    CREATE = CREATE_RANDOM_ACCESS,
    APPEND = APPEND_RANDOM_ACCESS
}; // Access
 
std::ostream &operator<<(std::ostream &o, Access const &a);
 
namespace access
{
    inline bool readOnly(Access access)
    {
        switch (access)
        {
        case Access::READ_LINEAR:
        case Access::READ_ONLY:
            return true;
        case Access::READ_WRITE:
        case Access::CREATE_RANDOM_ACCESS:
        case Access::CREATE_LINEAR:
        case Access::APPEND_RANDOM_ACCESS:
        case Access::APPEND_LINEAR:
            return false;
        }
        throw std::runtime_error("Unreachable!");
    }
 
    inline bool write(Access access)
    {
        return !readOnly(access);
    }
 
    inline bool writeOnly(Access access)
    {
        switch (access)
        {
        case Access::READ_LINEAR:
        case Access::READ_ONLY:
        case Access::READ_WRITE:
            return false;
        case Access::CREATE_RANDOM_ACCESS:
        case Access::CREATE_LINEAR:
        case Access::APPEND_RANDOM_ACCESS:
        case Access::APPEND_LINEAR:
            return true;
        }
        throw std::runtime_error("Unreachable!");
    }
 
    inline bool read(Access access)
    {
        return !writeOnly(access);
    }
 
    inline bool random_access(Access access)
    {
        switch (access)
        {
 
        case Access::READ_ONLY:
        case Access::READ_WRITE:
        case Access::CREATE_RANDOM_ACCESS:
        case Access::APPEND_RANDOM_ACCESS:
            return true;
        case Access::READ_LINEAR:
        case Access::CREATE_LINEAR:
        case Access::APPEND_LINEAR:
            return false;
        }
        throw std::runtime_error("Unreachable");
    }
 
    inline bool linear(Access access)
    {
        return !random_access(access);
    }
 
    inline bool append(Access access)
    {
        switch (access)
        {
 
        case Access::READ_ONLY:
        case Access::READ_LINEAR:
        case Access::READ_WRITE:
        case Access::CREATE_RANDOM_ACCESS:
        case Access::CREATE_LINEAR:
            return false;
        case Access::APPEND_RANDOM_ACCESS:
        case Access::APPEND_LINEAR:
            return true;
        }
        throw std::runtime_error("Unreachable");
    }
 
    inline bool create(Access access)
    {
        switch (access)
        {
 
        case Access::READ_ONLY:
        case Access::READ_LINEAR:
        case Access::READ_WRITE:
        case Access::APPEND_RANDOM_ACCESS:
        case Access::APPEND_LINEAR:
            return false;
        case Access::CREATE_RANDOM_ACCESS:
        case Access::CREATE_LINEAR:
            return true;
        }
        throw std::runtime_error("Unreachable");
    }
} // namespace access
 
// deprecated name (used prior to 0.12.0)
// note: "using old [[deprecated(msg)]] = new;" is still badly supported, thus
// using typedef
//       https://en.cppreference.com/w/cpp/language/attributes/deprecated
//   - NVCC < 11.0.167 works but noisy "warning: attribute does not apply to any
//   entity"
//     Nvidia bug report: 2991260
//   - Intel C++ 19.1.0.20200306 bug report: 04651484
[[deprecated("AccessType is deprecated, use Access instead.")]] typedef Access
    AccessType;
} // namespace openPMD