Custody.h

/*
 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <AK/Badge.h>
#include <AK/InlineLinkedList.h>
#include <AK/RefCounted.h>
#include <AK/RefPtr.h>
#include <AK/String.h>

namespace Kernel {

class Inode;
class VFS;

// FIXME: Custody needs some locking.

class Custody : public RefCounted<Custody>
    , public InlineLinkedListNode<Custody> {
public:
    static Custody* get_if_cached(Custody* parent, const StringView& name);
    static NonnullRefPtr<Custody> get_or_create(Custody* parent, const StringView& name, Inode&, int mount_flags);
    static NonnullRefPtr<Custody> create(Custody* parent, const StringView& name, Inode& inode, int mount_flags)
    {
        return adopt(*new Custody(parent, name, inode, mount_flags));
    }

    ~Custody();

    Custody* parent() { return m_parent.ptr(); }
    const Custody* parent() const { return m_parent.ptr(); }
    Inode& inode() { return *m_inode; }
    const Inode& inode() const { return *m_inode; }
    const String& name() const { return m_name; }
    String absolute_path() const;

    bool is_deleted() const { return m_deleted; }
    bool is_mounted_on() const { return m_mounted_on; }

    int mount_flags() const { return m_mount_flags; }

    void did_delete(Badge<VFS>);
    void did_mount_on(Badge<VFS>);
    void did_rename(Badge<VFS>, const String& name);

    // For InlineLinkedListNode.
    Custody* m_next { nullptr };
    Custody* m_prev { nullptr };

private:
    Custody(Custody* parent, const StringView& name, Inode&, int mount_flags);

    RefPtr<Custody> m_parent;
    String m_name;
    NonnullRefPtr<Inode> m_inode;
    bool m_deleted { false };
    bool m_mounted_on { false };
    int m_mount_flags { 0 };
};

}