1 // Tencent is pleased to support the open source community by making RapidJSON available. 2 // 3 // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved. 4 // 5 // Licensed under the MIT License (the "License"); you may not use this file except 6 // in compliance with the License. You may obtain a copy of the License at 7 // 8 // http://opensource.org/licenses/MIT 9 // 10 // Unless required by applicable law or agreed to in writing, software distributed 11 // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 12 // CONDITIONS OF ANY KIND, either express or implied. See the License for the 13 // specific language governing permissions and limitations under the License. 14 15 #ifndef RAPIDJSON_STRINGBUFFER_H_ 16 #define RAPIDJSON_STRINGBUFFER_H_ 17 18 #include "rapidjson.h" 19 20 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS 21 #include <utility> // std::move 22 #endif 23 24 #include "internal/stack.h" 25 26 RAPIDJSON_NAMESPACE_BEGIN 27 28 //! Represents an in-memory output stream. 29 /*! 30 \tparam Encoding Encoding of the stream. 31 \tparam Allocator type for allocating memory buffer. 32 \note implements Stream concept 33 */ 34 template <typename Encoding, typename Allocator = CrtAllocator> 35 class GenericStringBuffer { 36 public: 37 typedef typename Encoding::Ch Ch; 38 39 explicit GenericStringBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {} 40 41 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS 42 GenericStringBuffer(GenericStringBuffer&& rhs) : stack_(std::move(rhs.stack_)) {} 43 GenericStringBuffer& operator=(GenericStringBuffer&& rhs) { 44 if (&rhs != this) 45 stack_ = std::move(rhs.stack_); 46 return *this; 47 } 48 #endif 49 50 void Put(Ch c) { *stack_.template Push<Ch>() = c; } 51 void Flush() {} 52 53 void Clear() { stack_.Clear(); } 54 void ShrinkToFit() { 55 // Push and pop a null terminator. This is safe. 56 *stack_.template Push<Ch>() = '\0'; 57 stack_.ShrinkToFit(); 58 stack_.template Pop<Ch>(1); 59 } 60 Ch* Push(size_t count) { return stack_.template Push<Ch>(count); } 61 void Pop(size_t count) { stack_.template Pop<Ch>(count); } 62 63 const Ch* GetString() const { 64 // Push and pop a null terminator. This is safe. 65 *stack_.template Push<Ch>() = '\0'; 66 stack_.template Pop<Ch>(1); 67 68 return stack_.template Bottom<Ch>(); 69 } 70 71 size_t GetSize() const { return stack_.GetSize(); } 72 73 static const size_t kDefaultCapacity = 256; 74 mutable internal::Stack<Allocator> stack_; 75 76 private: 77 // Prohibit copy constructor & assignment operator. 78 GenericStringBuffer(const GenericStringBuffer&); 79 GenericStringBuffer& operator=(const GenericStringBuffer&); 80 }; 81 82 //! String buffer with UTF8 encoding 83 typedef GenericStringBuffer<UTF8<> > StringBuffer; 84 85 //! Implement specialized version of PutN() with memset() for better performance. 86 template<> 87 inline void PutN(GenericStringBuffer<UTF8<> >& stream, char c, size_t n) { 88 std::memset(stream.stack_.Push<char>(n), c, n * sizeof(c)); 89 } 90 91 RAPIDJSON_NAMESPACE_END 92 93 #endif // RAPIDJSON_STRINGBUFFER_H_ 94
