1 | // Copyright (C) 2024 The Qt Company Ltd. |
---|---|
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #ifndef QPROTOBUFREPEATEDITERATOR_H |
5 | #define QPROTOBUFREPEATEDITERATOR_H |
6 | |
7 | #include <QtProtobuf/qprotobufmessage.h> |
8 | #include <QtProtobuf/qtprotobuftypes.h> |
9 | #include <QtProtobuf/qtprotobufexports.h> |
10 | |
11 | #include <QtCore/qhash.h> |
12 | #include <QtCore/qlist.h> |
13 | |
14 | QT_BEGIN_NAMESPACE |
15 | |
16 | class QProtobufMessage; |
17 | class QProtobufRepeatedIterator; |
18 | |
19 | namespace QtProtobufPrivate { |
20 | template <typename T, QtProtobuf::if_protobuf_message<T> = true> |
21 | class ListIterator |
22 | { |
23 | public: |
24 | ~ListIterator() = default; |
25 | |
26 | bool hasNext() const noexcept { return m_it != m_list->end(); } |
27 | QProtobufMessage *next() |
28 | { |
29 | Q_ASSERT(m_it != m_list->end()); |
30 | return &*m_it++; |
31 | } |
32 | |
33 | QProtobufMessage *addNext() { return &m_list->emplace_back(); } |
34 | |
35 | /* protobuf allows having elements in the repeated fields that are failed to deserialize */ |
36 | void push() noexcept { } |
37 | |
38 | private: |
39 | Q_DISABLE_COPY_MOVE(ListIterator) |
40 | |
41 | friend class QT_PREPEND_NAMESPACE(QProtobufRepeatedIterator); |
42 | |
43 | explicit ListIterator(QList<T> &list) : m_list(&list), m_it(m_list->begin()) { } |
44 | QList<T> *m_list = nullptr; |
45 | typename QList<T>::Iterator m_it; |
46 | }; |
47 | |
48 | template <typename K, typename V, QtProtobuf::if_protobuf_map<K, V> = true> |
49 | class MapIterator |
50 | { |
51 | using MapEntry = QProtobufMapEntry<K, V>; |
52 | static_assert(!std::is_pointer_v<typename MapEntry::KeyType>, "Map key must not be message"); |
53 | |
54 | public: |
55 | ~MapIterator() { delete m_mapEntry; } |
56 | |
57 | bool hasNext() const noexcept { return m_it != m_hash->end(); } |
58 | QProtobufMessage *next() |
59 | { |
60 | Q_ASSERT(m_it != m_hash->end()); |
61 | m_mapEntry->setKey(m_it.key()); |
62 | if constexpr (std::is_pointer_v<typename MapEntry::ValueType>) |
63 | m_mapEntry->setValue(&m_it.value()); |
64 | else |
65 | m_mapEntry->setValue(m_it.value()); |
66 | ++m_it; |
67 | return m_mapEntry; |
68 | } |
69 | |
70 | QProtobufMessage *addNext() |
71 | { |
72 | m_mapEntry->setKey({}); |
73 | m_mapEntry->setValue({}); |
74 | return m_mapEntry; |
75 | } |
76 | void push() |
77 | { |
78 | auto it = m_hash->emplace(m_mapEntry->key()); |
79 | if constexpr (std::is_pointer_v<typename MapEntry::ValueType>) |
80 | *it = std::move(*m_mapEntry->value()); |
81 | else |
82 | *it = m_mapEntry->value(); |
83 | } |
84 | |
85 | private: |
86 | Q_DISABLE_COPY_MOVE(MapIterator) |
87 | |
88 | friend class QT_PREPEND_NAMESPACE(QProtobufRepeatedIterator); |
89 | |
90 | explicit MapIterator(QHash<K, V> &hash) |
91 | : m_hash(&hash), m_it(m_hash->begin()), m_mapEntry(new MapEntry) |
92 | { |
93 | } |
94 | QHash<K, V> *m_hash = nullptr; |
95 | typename QHash<K, V>::Iterator m_it; |
96 | MapEntry *m_mapEntry; |
97 | }; |
98 | } |
99 | |
100 | class QProtobufRepeatedIterator |
101 | { |
102 | enum class Operation { HasNext, Next, AddNext, Push, Deleter }; |
103 | using ImplFn = void (*)(Operation op, void *data, void **args, void *ret); |
104 | |
105 | template <typename T> |
106 | static constexpr ImplFn MakeImpl() |
107 | { |
108 | return [](Operation op, void *data, void **, void *ret) { |
109 | switch (op) { |
110 | case Operation::HasNext: |
111 | *static_cast<bool *>(ret) = static_cast<const T *>(data)->hasNext(); |
112 | break; |
113 | case Operation::Next: |
114 | *static_cast<QProtobufMessage **>(ret) = static_cast<T *>(data)->next(); |
115 | break; |
116 | case Operation::AddNext: |
117 | *static_cast<QProtobufMessage **>(ret) = static_cast<T *>(data)->addNext(); |
118 | break; |
119 | case Operation::Push: |
120 | static_cast<T *>(data)->push(); |
121 | break; |
122 | case Operation::Deleter: |
123 | static_cast<T *>(data)->~T(); |
124 | break; |
125 | } |
126 | }; |
127 | } |
128 | public: |
129 | QProtobufRepeatedIterator() = default; |
130 | ~QProtobufRepeatedIterator() |
131 | { |
132 | if (m_impl) |
133 | m_impl(Operation::Deleter, &m_data, nullptr, nullptr); |
134 | } |
135 | |
136 | QProtobufRepeatedIterator(QProtobufRepeatedIterator &&other) noexcept |
137 | : m_data(std::exchange(obj&: other.m_data, new_val: {})), m_impl(std::exchange(obj&: other.m_impl, new_val: nullptr)) |
138 | { |
139 | } |
140 | QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QProtobufRepeatedIterator) |
141 | void swap(QProtobufRepeatedIterator &other) noexcept |
142 | { |
143 | std::swap(a&: m_data, b&: other.m_data); |
144 | qt_ptr_swap(lhs&: m_impl, rhs&: other.m_impl); |
145 | }; |
146 | |
147 | [[nodiscard]] bool isValid() const noexcept { return m_impl != nullptr; } |
148 | |
149 | [[nodiscard]] bool hasNext() const noexcept |
150 | { |
151 | bool ret = false; |
152 | if (m_impl) |
153 | m_impl(Operation::HasNext, &m_data, nullptr, &ret); |
154 | return ret; |
155 | } |
156 | |
157 | [[nodiscard]] QProtobufMessage *next() |
158 | { |
159 | Q_ASSERT(m_impl); |
160 | |
161 | QProtobufMessage *ret; |
162 | m_impl(Operation::Next, &m_data, nullptr, &ret); |
163 | return ret; |
164 | } |
165 | |
166 | [[nodiscard]] QProtobufMessage *addNext() |
167 | { |
168 | Q_ASSERT(m_impl); |
169 | |
170 | QProtobufMessage *ret; |
171 | m_impl(Operation::AddNext, &m_data, nullptr, &ret); |
172 | return ret; |
173 | } |
174 | |
175 | void push() |
176 | { |
177 | Q_ASSERT(m_impl); |
178 | |
179 | m_impl(Operation::Push, &m_data, nullptr, nullptr); |
180 | } |
181 | |
182 | template<typename T> |
183 | static QProtobufRepeatedIterator fromList(QList<T> &list) |
184 | { |
185 | return QProtobufRepeatedIterator(list); |
186 | } |
187 | |
188 | template<typename K, typename V> |
189 | static QProtobufRepeatedIterator fromHash(QHash<K, V> &hash) |
190 | { |
191 | return QProtobufRepeatedIterator(hash); |
192 | } |
193 | |
194 | private: |
195 | Q_DISABLE_COPY(QProtobufRepeatedIterator) |
196 | |
197 | template<typename K, typename V, typename Iterator = QtProtobufPrivate::MapIterator<K, V>> |
198 | explicit QProtobufRepeatedIterator(QHash<K, V> &data) noexcept : m_impl(MakeImpl<Iterator>()) |
199 | { |
200 | ::new (static_cast<void *>(&m_data)) Iterator(data); |
201 | } |
202 | |
203 | template<typename T, typename Iterator = QtProtobufPrivate::ListIterator<T>> |
204 | explicit QProtobufRepeatedIterator(QList<T> &data) noexcept : m_impl(MakeImpl<Iterator>()) |
205 | { |
206 | ::new (static_cast<void *>(&m_data)) Iterator(data); |
207 | } |
208 | |
209 | mutable struct { alignas(sizeof(void *)) unsigned char data[sizeof(void *) * 4]; } m_data; |
210 | ImplFn m_impl = nullptr; |
211 | |
212 | static_assert(sizeof(QHash<int, int>::const_iterator) <= sizeof(m_data)); |
213 | static_assert(alignof(decltype(m_data)) == alignof(void *)); |
214 | }; |
215 | |
216 | QT_END_NAMESPACE |
217 | |
218 | #endif // QPROTOBUFREPEATEDITERATOR_H |
219 |
Definitions
- ListIterator
- ~ListIterator
- hasNext
- next
- addNext
- push
- ListIterator
- ListIterator
- ListIterator
- MapIterator
- ~MapIterator
- hasNext
- next
- addNext
- push
- MapIterator
- MapIterator
- MapIterator
- QProtobufRepeatedIterator
- Operation
- MakeImpl
- QProtobufRepeatedIterator
- ~QProtobufRepeatedIterator
- QProtobufRepeatedIterator
- swap
- isValid
- hasNext
- next
- addNext
- push
- fromList
- fromHash
- QProtobufRepeatedIterator
- QProtobufRepeatedIterator
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