ceph/src/rapidjson/include/rapidjson/stringbuffer.h

   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 "stream.h"
  19 #include "internal/stack.h"
  20
  21 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
  22 #include <utility> // std::move
  23 #endif
  24
  25 #include "internal/stack.h"
  26
  27 #if defined(__clang__)
  28 RAPIDJSON_DIAG_PUSH
  29 RAPIDJSON_DIAG_OFF(c++98-compat)
  30 #endif
  31
  32 RAPIDJSON_NAMESPACE_BEGIN
  33
  34 //! Represents an in-memory output stream.
  35 /*!
  36     \tparam Encoding Encoding of the stream.
  37     \tparam Allocator type for allocating memory buffer.
  38     \note implements Stream concept
  39 */
  40 template <typename Encoding, typename Allocator = CrtAllocator>
  41 class GenericStringBuffer {
  42 public:
  43     typedef typename Encoding::Ch Ch;
  44
  45     GenericStringBuffer(Allocator* allocator = 0, size_t capacity = kDefaultCapacity) : stack_(allocator, capacity) {}
  46
  47 #if RAPIDJSON_HAS_CXX11_RVALUE_REFS
  48     GenericStringBuffer(GenericStringBuffer&& rhs) : stack_(std::move(rhs.stack_)) {}
  49     GenericStringBuffer& operator=(GenericStringBuffer&& rhs) {
  50         if (&rhs != this)
  51             stack_ = std::move(rhs.stack_);
  52         return *this;
  53     }
  54 #endif
  55
  56     void Put(Ch c) { *stack_.template Push<Ch>() = c; }
  57     void PutUnsafe(Ch c) { *stack_.template PushUnsafe<Ch>() = c; }
  58     void Flush() {}
  59
  60     void Clear() { stack_.Clear(); }
  61     void ShrinkToFit() {
  62         // Push and pop a null terminator. This is safe.
  63         *stack_.template Push<Ch>() = '\0';
  64         stack_.ShrinkToFit();
  65         stack_.template Pop<Ch>(1);
  66     }
  67
  68     void Reserve(size_t count) { stack_.template Reserve<Ch>(count); }
  69     Ch* Push(size_t count) { return stack_.template Push<Ch>(count); }
  70     Ch* PushUnsafe(size_t count) { return stack_.template PushUnsafe<Ch>(count); }
  71     void Pop(size_t count) { stack_.template Pop<Ch>(count); }
  72
  73     const Ch* GetString() const {
  74         // Push and pop a null terminator. This is safe.
  75         *stack_.template Push<Ch>() = '\0';
  76         stack_.template Pop<Ch>(1);
  77
  78         return stack_.template Bottom<Ch>();
  79     }
  80
  81     size_t GetSize() const { return stack_.GetSize(); }
  82
  83     static const size_t kDefaultCapacity = 256;
  84     mutable internal::Stack<Allocator> stack_;
  85
  86 private:
  87     // Prohibit copy constructor & assignment operator.
  88     GenericStringBuffer(const GenericStringBuffer&);
  89     GenericStringBuffer& operator=(const GenericStringBuffer&);
  90 };
  91
  92 //! String buffer with UTF8 encoding
  93 typedef GenericStringBuffer<UTF8<> > StringBuffer;
  94
  95 template<typename Encoding, typename Allocator>
  96 inline void PutReserve(GenericStringBuffer<Encoding, Allocator>& stream, size_t count) {
  97     stream.Reserve(count);
  98 }
  99
 100 template<typename Encoding, typename Allocator>
 101 inline void PutUnsafe(GenericStringBuffer<Encoding, Allocator>& stream, typename Encoding::Ch c) {
 102     stream.PutUnsafe(c);
 103 }
 104
 105 //! Implement specialized version of PutN() with memset() for better performance.
 106 template<>
 107 inline void PutN(GenericStringBuffer<UTF8<> >& stream, char c, size_t n) {
 108     std::memset(stream.stack_.Push<char>(n), c, n * sizeof(c));
 109 }
 110
 111 RAPIDJSON_NAMESPACE_END
 112
 113 #if defined(__clang__)
 114 RAPIDJSON_DIAG_POP
 115 #endif
 116
 117 #endif // RAPIDJSON_STRINGBUFFER_H_