RapidJSON: include/rapidjson/stringbuffer.h 源文件

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.
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 //! 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.
92 GenericStringBuffer(const GenericStringBuffer&);
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_
Allocator
Concept for allocating, resizing and freeing memory block.
rapidjson::GenericStringBuffer
Represents an in-memory output stream.
Definition: stringbuffer.h:41
rapidjson::PutUnsafe
void PutUnsafe(Stream &stream, typename Stream::Ch c)
Write character to a stream, presuming buffer is reserved.
Definition: stream.h:91
rapidjson::UTF8
UTF-8 encoding.
Definition: encodings.h:96
rapidjson::GenericStringBuffer::GetLength
size_t GetLength() const
Get the length of string in Ch in the string buffer.
Definition: stringbuffer.h:85
rapidjson::GenericStringBuffer::GetSize
size_t GetSize() const
Get the size of string in bytes in the string buffer.
Definition: stringbuffer.h:82
rapidjson::PutN
void PutN(FileWriteStream &stream, char c, size_t n)
Implement specialized version of PutN() with memset() for better performance.
Definition: filewritestream.h:94