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stringbuffer.h
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5 // Licensed under the MIT License (the "License"); you may not use this file except
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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  //! Get the size of string in bytes in the string buffer.
82  size_t GetSize() const { return stack_.GetSize(); }
83 
84  //! Get the length of string in Ch in the string buffer.
85  size_t GetLength() const { return stack_.GetSize() / sizeof(Ch); }
86 
87  static const size_t kDefaultCapacity = 256;
88  mutable internal::Stack<Allocator> stack_;
89 
90 private:
91  // Prohibit copy constructor & assignment operator.
93  GenericStringBuffer& operator=(const GenericStringBuffer&);
94 };
95 
96 //! String buffer with UTF8 encoding
97 typedef GenericStringBuffer<UTF8<> > StringBuffer;
98 
99 template<typename Encoding, typename Allocator>
100 inline void PutReserve(GenericStringBuffer<Encoding, Allocator>& stream, size_t count) {
101  stream.Reserve(count);
102 }
103 
104 template<typename Encoding, typename Allocator>
105 inline void PutUnsafe(GenericStringBuffer<Encoding, Allocator>& stream, typename Encoding::Ch c) {
106  stream.PutUnsafe(c);
107 }
108 
109 //! Implement specialized version of PutN() with memset() for better performance.
110 template<>
111 inline void PutN(GenericStringBuffer<UTF8<> >& stream, char c, size_t n) {
112  std::memset(stream.stack_.Push<char>(n), c, n * sizeof(c));
113 }
114 
115 RAPIDJSON_NAMESPACE_END
116 
117 #if defined(__clang__)
118 RAPIDJSON_DIAG_POP
119 #endif
120 
121 #endif // RAPIDJSON_STRINGBUFFER_H_
Represents an in-memory output stream.
Definition: fwd.h:59
size_t GetLength() const
Get the length of string in Ch in the string buffer.
Definition: stringbuffer.h:85
void PutN(FileWriteStream &stream, char c, size_t n)
Implement specialized version of PutN() with memset() for better performance.
Definition: filewritestream.h:94
size_t GetSize() const
Get the size of string in bytes in the string buffer.
Definition: stringbuffer.h:82
UTF-8 encoding.
Definition: encodings.h:96
void PutUnsafe(Stream &stream, typename Stream::Ch c)
Write character to a stream, presuming buffer is reserved.
Definition: stream.h:91