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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#pragma once
28
29#include <AK/Badge.h>
30#include <AK/CircularQueue.h>
31#include <AK/WeakPtr.h>
32#include <Kernel/FileSystem/File.h>
33
34namespace Kernel {
35
36class Inode;
37
38class InodeWatcher final : public File {
39public:
40 static NonnullRefPtr<InodeWatcher> create(Inode&);
41 virtual ~InodeWatcher() override;
42
43 struct Event {
44 enum class Type {
45 Invalid = 0,
46 Modified,
47 };
48
49 Type type { Type::Invalid };
50 };
51
52 virtual bool can_read(const FileDescription&) const override;
53 virtual bool can_write(const FileDescription&) const override;
54 virtual ssize_t read(FileDescription&, u8*, ssize_t) override;
55 virtual ssize_t write(FileDescription&, const u8*, ssize_t) override;
56 virtual String absolute_path(const FileDescription&) const override;
57 virtual const char* class_name() const override { return "InodeWatcher"; };
58
59 void notify_inode_event(Badge<Inode>, Event::Type);
60
61private:
62 explicit InodeWatcher(Inode&);
63
64 WeakPtr<Inode> m_inode;
65 CircularQueue<Event, 32> m_queue;
66};
67
68}