jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, Itamar S. <itamar8910@gmail.com>
3 * Copyright (c) 2021-2022, the SerenityOS developers.
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8#pragma once
9
10#include <AK/DeprecatedString.h>
11#include <AK/EnumBits.h>
12#include <AK/Function.h>
13#include <AK/Noncopyable.h>
14#include <AK/NonnullRefPtr.h>
15#include <AK/RefCounted.h>
16#include <LibCore/Notifier.h>
17
18namespace Core {
19
20struct FileWatcherEvent {
21 enum class Type {
22 Invalid = 0,
23 MetadataModified = 1 << 0,
24 ContentModified = 1 << 1,
25 Deleted = 1 << 2,
26 ChildCreated = 1 << 3,
27 ChildDeleted = 1 << 4,
28 };
29 Type type { Type::Invalid };
30 DeprecatedString event_path;
31};
32
33AK_ENUM_BITWISE_OPERATORS(FileWatcherEvent::Type);
34
35enum class FileWatcherFlags : u32 {
36 None = 0,
37 Nonblock = 1 << 0,
38 CloseOnExec = 1 << 1,
39};
40
41AK_ENUM_BITWISE_OPERATORS(FileWatcherFlags);
42
43class FileWatcherBase {
44public:
45 virtual ~FileWatcherBase() = default;
46
47 ErrorOr<bool> add_watch(DeprecatedString path, FileWatcherEvent::Type event_mask);
48 ErrorOr<bool> remove_watch(DeprecatedString path);
49 bool is_watching(DeprecatedString const& path) const { return m_path_to_wd.find(path) != m_path_to_wd.end(); }
50
51protected:
52 FileWatcherBase(int watcher_fd)
53 : m_watcher_fd(watcher_fd)
54 {
55 }
56
57 int m_watcher_fd { -1 };
58 HashMap<DeprecatedString, unsigned> m_path_to_wd;
59 HashMap<unsigned, DeprecatedString> m_wd_to_path;
60};
61
62class BlockingFileWatcher final : public FileWatcherBase {
63 AK_MAKE_NONCOPYABLE(BlockingFileWatcher);
64
65public:
66 explicit BlockingFileWatcher(FileWatcherFlags = FileWatcherFlags::None);
67 ~BlockingFileWatcher();
68
69 Optional<FileWatcherEvent> wait_for_event();
70};
71
72class FileWatcher : public FileWatcherBase
73 , public RefCounted<FileWatcher> {
74 AK_MAKE_NONCOPYABLE(FileWatcher);
75
76public:
77 static ErrorOr<NonnullRefPtr<FileWatcher>> create(FileWatcherFlags = FileWatcherFlags::None);
78 ~FileWatcher();
79
80 Function<void(FileWatcherEvent const&)> on_change;
81
82protected:
83 FileWatcher(int watcher_fd, NonnullRefPtr<Notifier>);
84
85 NonnullRefPtr<Notifier> m_notifier;
86};
87
88}
89
90namespace AK {
91
92template<>
93struct Formatter<Core::FileWatcherEvent> : Formatter<FormatString> {
94 ErrorOr<void> format(FormatBuilder& builder, Core::FileWatcherEvent const& value)
95 {
96 return Formatter<FormatString>::format(builder, "FileWatcherEvent(\"{}\", {})"sv, value.event_path, value.type);
97 }
98};
99
100template<>
101struct Formatter<Core::FileWatcherEvent::Type> : Formatter<FormatString> {
102 ErrorOr<void> format(FormatBuilder& builder, Core::FileWatcherEvent::Type const& value)
103 {
104 bool had_any_flag = false;
105
106 auto put_string_if_has_flag = [&](auto mask, auto name) -> ErrorOr<void> {
107 if (!has_flag(value, mask))
108 return {};
109
110 if (had_any_flag)
111 TRY(builder.put_string(", "sv));
112 TRY(builder.put_string(name));
113
114 had_any_flag = true;
115 return {};
116 };
117
118 TRY(builder.put_string("["sv));
119 TRY(put_string_if_has_flag(Core::FileWatcherEvent::Type::ChildCreated, "ChildCreated"sv));
120 TRY(put_string_if_has_flag(Core::FileWatcherEvent::Type::ChildDeleted, "ChildDeleted"sv));
121 TRY(put_string_if_has_flag(Core::FileWatcherEvent::Type::Deleted, "Deleted"sv));
122 TRY(put_string_if_has_flag(Core::FileWatcherEvent::Type::ContentModified, "ContentModified"sv));
123 TRY(put_string_if_has_flag(Core::FileWatcherEvent::Type::MetadataModified, "MetadataModified"sv));
124 TRY(builder.put_string("]"sv));
125
126 VERIFY(had_any_flag);
127 return {};
128 }
129};
130
131}