unique_fd.h

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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2021, Google Inc.
 *
 * unique_fd.h - File descriptor wrapper that owns a file descriptor.
 */
 
#pragma once
 
#include <utility>
 
#include <libcamera/base/class.h>
#include <libcamera/base/compiler.h>
 
namespace libcamera {
 
class UniqueFD final
{
public:
    UniqueFD()
        : fd_(-1)
    {
    }
 
    explicit UniqueFD(int fd)
        : fd_(fd)
    {
    }
 
    UniqueFD(UniqueFD &&other)
        : fd_(other.release())
    {
    }
 
    ~UniqueFD()
    {
        reset();
    }
 
    UniqueFD &operator=(UniqueFD &&other)
    {
        reset(other.release());
        return *this;
    }
 
    __nodiscard int release()
    {
        int fd = fd_;
        fd_ = -1;
        return fd;
    }
 
    void reset(int fd = -1);
 
    void swap(UniqueFD &other)
    {
        std::swap(fd_, other.fd_);
    }
 
    int get() const { return fd_; }
    bool isValid() const { return fd_ >= 0; }
 
private:
    LIBCAMERA_DISABLE_COPY(UniqueFD)
 
    int fd_;
};
 
} /* namespace libcamera */