file.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2020, Google Inc.
 *
 * File I/O operations
 */

#pragma once

#include <map>
#include <stdint.h>
#include <string>
#include <sys/types.h>

#include <libcamera/base/private.h>

#include <libcamera/base/class.h>
#include <libcamera/base/flags.h>
#include <libcamera/base/span.h>
#include <libcamera/base/unique_fd.h>

namespace libcamera {

class File
{
public:
    enum class MapFlag {
        NoOption = 0,
        Private = (1 << 0),
    };

    using MapFlags = Flags<MapFlag>;

    enum class OpenModeFlag {
        NotOpen = 0,
        ReadOnly = (1 << 0),
        WriteOnly = (1 << 1),
        ReadWrite = ReadOnly | WriteOnly,
    };

    using OpenMode = Flags<OpenModeFlag>;

    File(const std::string &name);
    File();
    ~File();

    const std::string &fileName() const { return name_; }
    void setFileName(const std::string &name);
    bool exists() const;

    bool open(OpenMode mode);
    bool isOpen() const { return fd_.isValid(); }
    OpenMode openMode() const { return mode_; }
    void close();

    int error() const { return error_; }
    ssize_t size() const;

    off_t pos() const;
    off_t seek(off_t pos);

    ssize_t read(const Span<uint8_t> &data);
    ssize_t write(const Span<const uint8_t> &data);

    Span<uint8_t> map(off_t offset = 0, ssize_t size = -1,
              MapFlags flags = MapFlag::NoOption);
    bool unmap(uint8_t *addr);

    static bool exists(const std::string &name);

private:
    LIBCAMERA_DISABLE_COPY(File)

    void unmapAll();

    std::string name_;
    UniqueFD fd_;
    OpenMode mode_;

    int error_;
    std::map<void *, size_t> maps_;
};

LIBCAMERA_FLAGS_ENABLE_OPERATORS(File::MapFlag)
LIBCAMERA_FLAGS_ENABLE_OPERATORS(File::OpenModeFlag)

} /* namespace libcamera */