1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 // This header file is protobuf internal. Users should not include this 32 // file directly. 33 #ifndef GOOGLE_PROTOBUF_REPEATED_FIELD_REFLECTION_H__ 34 #define GOOGLE_PROTOBUF_REPEATED_FIELD_REFLECTION_H__ 35 36 #include <memory> 37 #ifndef _SHARED_PTR_H 38 #include <google/protobuf/stubs/shared_ptr.h> 39 #endif 40 41 #include <google/protobuf/generated_enum_reflection.h> 42 43 namespace google { 44 namespace protobuf { 45 namespace internal { 46 // Interfaces used to implement reflection RepeatedFieldRef API. 47 // Reflection::GetRepeatedAccessor() should return a pointer to an singleton 48 // object that implements the below interface. 49 // 50 // This interface passes/returns values using void pointers. The actual type 51 // of the value depends on the field's cpp_type. Following is a mapping from 52 // cpp_type to the type that should be used in this interface: 53 // 54 // field->cpp_type() T Actual type of void* 55 // CPPTYPE_INT32 int32 int32 56 // CPPTYPE_UINT32 uint32 uint32 57 // CPPTYPE_INT64 int64 int64 58 // CPPTYPE_UINT64 uint64 uint64 59 // CPPTYPE_DOUBLE double double 60 // CPPTYPE_FLOAT float float 61 // CPPTYPE_BOOL bool bool 62 // CPPTYPE_ENUM generated enum type int32 63 // CPPTYPE_STRING string string 64 // CPPTYPE_MESSAGE generated message type google::protobuf::Message 65 // or google::protobuf::Message 66 // 67 // Note that for enums we use int32 in the interface. 68 // 69 // You can map from T to the actual type using RefTypeTraits: 70 // typedef RefTypeTraits<T>::AccessorValueType ActualType; 71 class LIBPROTOBUF_EXPORT RepeatedFieldAccessor { 72 public: 73 // Typedefs for clarity. 74 typedef void Field; 75 typedef void Value; 76 typedef void Iterator; 77 78 virtual ~RepeatedFieldAccessor(); 79 virtual bool IsEmpty(const Field* data) const = 0; 80 virtual int Size(const Field* data) const = 0; 81 // Depends on the underlying representation of the repeated field, this 82 // method can return a pointer to the underlying object if such an object 83 // exists, or fill the data into scratch_space and return scratch_space. 84 // Callers of this method must ensure scratch_space is a valid pointer 85 // to a mutable object of the correct type. 86 virtual const Value* Get( 87 const Field* data, int index, Value* scratch_space) const = 0; 88 89 virtual void Clear(Field* data) const = 0; 90 virtual void Set(Field* data, int index, const Value* value) const = 0; 91 virtual void Add(Field* data, const Value* value) const = 0; 92 virtual void RemoveLast(Field* data) const = 0; 93 virtual void SwapElements(Field* data, int index1, int index2) const = 0; 94 virtual void Swap(Field* data, const RepeatedFieldAccessor* other_mutator, 95 Field* other_data) const = 0; 96 97 // Create an iterator that points at the begining of the repeated field. 98 virtual Iterator* BeginIterator(const Field* data) const = 0; 99 // Create an iterator that points at the end of the repeated field. 100 virtual Iterator* EndIterator(const Field* data) const = 0; 101 // Make a copy of an iterator and return the new copy. 102 virtual Iterator* CopyIterator(const Field* data, 103 const Iterator* iterator) const = 0; 104 // Move an iterator to point to the next element. 105 virtual Iterator* AdvanceIterator(const Field* data, 106 Iterator* iterator) const = 0; 107 // Compare whether two iterators point to the same element. 108 virtual bool EqualsIterator(const Field* data, const Iterator* a, 109 const Iterator* b) const = 0; 110 // Delete an iterator created by BeginIterator(), EndIterator() and 111 // CopyIterator(). 112 virtual void DeleteIterator(const Field* data, Iterator* iterator) const = 0; 113 // Like Get() but for iterators. 114 virtual const Value* GetIteratorValue(const Field* data, 115 const Iterator* iterator, 116 Value* scratch_space) const = 0; 117 118 // Templated methods that make using this interface easier for non-message 119 // types. 120 template<typename T> Get(const Field * data,int index)121 T Get(const Field* data, int index) const { 122 typedef typename RefTypeTraits<T>::AccessorValueType ActualType; 123 ActualType scratch_space; 124 return static_cast<T>( 125 *reinterpret_cast<const ActualType*>( 126 Get(data, index, static_cast<Value*>(&scratch_space)))); 127 } 128 129 template<typename T, typename ValueType> Set(Field * data,int index,const ValueType & value)130 void Set(Field* data, int index, const ValueType& value) const { 131 typedef typename RefTypeTraits<T>::AccessorValueType ActualType; 132 // In this RepeatedFieldAccessor interface we pass/return data using 133 // raw pointers. Type of the data these raw pointers point to should 134 // be ActualType. Here we have a ValueType object and want a ActualType 135 // pointer. We can't cast a ValueType pointer to an ActualType pointer 136 // directly because their type might be different (for enums ValueType 137 // may be a generated enum type while ActualType is int32). To be safe 138 // we make a copy to get a temporary ActualType object and use it. 139 ActualType tmp = static_cast<ActualType>(value); 140 Set(data, index, static_cast<const Value*>(&tmp)); 141 } 142 143 template<typename T, typename ValueType> Add(Field * data,const ValueType & value)144 void Add(Field* data, const ValueType& value) const { 145 typedef typename RefTypeTraits<T>::AccessorValueType ActualType; 146 // In this RepeatedFieldAccessor interface we pass/return data using 147 // raw pointers. Type of the data these raw pointers point to should 148 // be ActualType. Here we have a ValueType object and want a ActualType 149 // pointer. We can't cast a ValueType pointer to an ActualType pointer 150 // directly because their type might be different (for enums ValueType 151 // may be a generated enum type while ActualType is int32). To be safe 152 // we make a copy to get a temporary ActualType object and use it. 153 ActualType tmp = static_cast<ActualType>(value); 154 Add(data, static_cast<const Value*>(&tmp)); 155 } 156 }; 157 158 // Implement (Mutable)RepeatedFieldRef::iterator 159 template<typename T> 160 class RepeatedFieldRefIterator 161 : public std::iterator<std::forward_iterator_tag, T> { 162 typedef typename RefTypeTraits<T>::AccessorValueType AccessorValueType; 163 typedef typename RefTypeTraits<T>::IteratorValueType IteratorValueType; 164 typedef typename RefTypeTraits<T>::IteratorPointerType IteratorPointerType; 165 166 public: 167 // Constructor for non-message fields. RepeatedFieldRefIterator(const void * data,const RepeatedFieldAccessor * accessor,bool begin)168 RepeatedFieldRefIterator(const void* data, 169 const RepeatedFieldAccessor* accessor, 170 bool begin) 171 : data_(data), accessor_(accessor), 172 iterator_(begin ? accessor->BeginIterator(data) : 173 accessor->EndIterator(data)), 174 scratch_space_(new AccessorValueType) { 175 } 176 // Constructor for message fields. RepeatedFieldRefIterator(const void * data,const RepeatedFieldAccessor * accessor,bool begin,AccessorValueType * scratch_space)177 RepeatedFieldRefIterator(const void* data, 178 const RepeatedFieldAccessor* accessor, 179 bool begin, 180 AccessorValueType* scratch_space) 181 : data_(data), accessor_(accessor), 182 iterator_(begin ? accessor->BeginIterator(data) : 183 accessor->EndIterator(data)), 184 scratch_space_(scratch_space) { 185 } ~RepeatedFieldRefIterator()186 ~RepeatedFieldRefIterator() { 187 accessor_->DeleteIterator(data_, iterator_); 188 } 189 RepeatedFieldRefIterator operator++(int) { 190 RepeatedFieldRefIterator tmp(*this); 191 iterator_ = accessor_->AdvanceIterator(data_, iterator_); 192 return tmp; 193 } 194 RepeatedFieldRefIterator& operator++() { 195 iterator_ = accessor_->AdvanceIterator(data_, iterator_); 196 return *this; 197 } 198 IteratorValueType operator*() const { 199 return static_cast<IteratorValueType>( 200 *static_cast<const AccessorValueType*>( 201 accessor_->GetIteratorValue( 202 data_, iterator_, scratch_space_.get()))); 203 } 204 IteratorPointerType operator->() const { 205 return static_cast<IteratorPointerType>( 206 accessor_->GetIteratorValue( 207 data_, iterator_, scratch_space_.get())); 208 } 209 bool operator!=(const RepeatedFieldRefIterator& other) const { 210 assert(data_ == other.data_); 211 assert(accessor_ == other.accessor_); 212 return !accessor_->EqualsIterator(data_, iterator_, other.iterator_); 213 } 214 bool operator==(const RepeatedFieldRefIterator& other) const { 215 return !this->operator!=(other); 216 } 217 RepeatedFieldRefIterator(const RepeatedFieldRefIterator & other)218 RepeatedFieldRefIterator(const RepeatedFieldRefIterator& other) 219 : data_(other.data_), accessor_(other.accessor_), 220 iterator_(accessor_->CopyIterator(data_, other.iterator_)) { 221 } 222 RepeatedFieldRefIterator& operator=(const RepeatedFieldRefIterator& other) { 223 if (this != &other) { 224 accessor_->DeleteIterator(data_, iterator_); 225 data_ = other.data_; 226 accessor_ = other.accessor_; 227 iterator_ = accessor_->CopyIterator(data_, other.iterator_); 228 } 229 return *this; 230 } 231 232 protected: 233 const void* data_; 234 const RepeatedFieldAccessor* accessor_; 235 void* iterator_; 236 google::protobuf::scoped_ptr<AccessorValueType> scratch_space_; 237 }; 238 239 // TypeTraits that maps the type parameter T of RepeatedFieldRef or 240 // MutableRepeatedFieldRef to corresponding iterator type, 241 // RepeatedFieldAccessor type, etc. 242 template<typename T> 243 struct PrimitiveTraits { 244 static const bool is_primitive = false; 245 }; 246 #define DEFINE_PRIMITIVE(TYPE, type) \ 247 template<> struct PrimitiveTraits<type> { \ 248 static const bool is_primitive = true; \ 249 static const FieldDescriptor::CppType cpp_type = \ 250 FieldDescriptor::CPPTYPE_ ## TYPE; \ 251 }; 252 DEFINE_PRIMITIVE(INT32, int32) 253 DEFINE_PRIMITIVE(UINT32, uint32) 254 DEFINE_PRIMITIVE(INT64, int64) 255 DEFINE_PRIMITIVE(UINT64, uint64) 256 DEFINE_PRIMITIVE(FLOAT, float) 257 DEFINE_PRIMITIVE(DOUBLE, double) 258 DEFINE_PRIMITIVE(BOOL, bool) 259 #undef DEFINE_PRIMITIVE 260 261 template<typename T> 262 struct RefTypeTraits< 263 T, typename internal::enable_if<PrimitiveTraits<T>::is_primitive>::type> { 264 typedef RepeatedFieldRefIterator<T> iterator; 265 typedef RepeatedFieldAccessor AccessorType; 266 typedef T AccessorValueType; 267 typedef T IteratorValueType; 268 typedef T* IteratorPointerType; 269 static const FieldDescriptor::CppType cpp_type = 270 PrimitiveTraits<T>::cpp_type; 271 static const Descriptor* GetMessageFieldDescriptor() { 272 return NULL; 273 } 274 }; 275 276 template<typename T> 277 struct RefTypeTraits< 278 T, typename internal::enable_if<is_proto_enum<T>::value>::type> { 279 typedef RepeatedFieldRefIterator<T> iterator; 280 typedef RepeatedFieldAccessor AccessorType; 281 // We use int32 for repeated enums in RepeatedFieldAccessor. 282 typedef int32 AccessorValueType; 283 typedef T IteratorValueType; 284 typedef int32* IteratorPointerType; 285 static const FieldDescriptor::CppType cpp_type = 286 FieldDescriptor::CPPTYPE_ENUM; 287 static const Descriptor* GetMessageFieldDescriptor() { 288 return NULL; 289 } 290 }; 291 292 template<typename T> 293 struct RefTypeTraits< 294 T, typename internal::enable_if<internal::is_same<string, T>::value>::type> { 295 typedef RepeatedFieldRefIterator<T> iterator; 296 typedef RepeatedFieldAccessor AccessorType; 297 typedef string AccessorValueType; 298 typedef string IteratorValueType; 299 typedef string* IteratorPointerType; 300 static const FieldDescriptor::CppType cpp_type = 301 FieldDescriptor::CPPTYPE_STRING; 302 static const Descriptor* GetMessageFieldDescriptor() { 303 return NULL; 304 } 305 }; 306 307 template<typename T> 308 struct MessageDescriptorGetter { 309 static const Descriptor* get() { 310 return T::default_instance().GetDescriptor(); 311 } 312 }; 313 template<> 314 struct MessageDescriptorGetter<Message> { 315 static const Descriptor* get() { 316 return NULL; 317 } 318 }; 319 320 template<typename T> 321 struct RefTypeTraits< 322 T, typename internal::enable_if<internal::is_base_of<Message, T>::value>::type> { 323 typedef RepeatedFieldRefIterator<T> iterator; 324 typedef RepeatedFieldAccessor AccessorType; 325 typedef Message AccessorValueType; 326 typedef const T& IteratorValueType; 327 typedef const T* IteratorPointerType; 328 static const FieldDescriptor::CppType cpp_type = 329 FieldDescriptor::CPPTYPE_MESSAGE; 330 static const Descriptor* GetMessageFieldDescriptor() { 331 return MessageDescriptorGetter<T>::get(); 332 } 333 }; 334 } // namespace internal 335 } // namespace protobuf 336 } // namespace google 337 #endif // GOOGLE_PROTOBUF_REPEATED_FIELD_REFLECTION_H__ 338