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__)
28RAPIDJSON_DIAG_PUSH
29RAPIDJSON_DIAG_OFF(c++98-compat)
30#endif
31
32RAPIDJSON_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*/
40template <typename Encoding, typename Allocator = CrtAllocator>
41class GenericStringBuffer {
42public:
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
86private:
87 // Prohibit copy constructor & assignment operator.
88 GenericStringBuffer(const GenericStringBuffer&);
89 GenericStringBuffer& operator=(const GenericStringBuffer&);
90};
91
92//! String buffer with UTF8 encoding
93typedef GenericStringBuffer<UTF8<> > StringBuffer;
94
95template<typename Encoding, typename Allocator>
96inline void PutReserve(GenericStringBuffer<Encoding, Allocator>& stream, size_t count) {
97 stream.Reserve(count);
98}
99
100template<typename Encoding, typename Allocator>
101inline 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.
106template<>
107inline void PutN(GenericStringBuffer<UTF8<> >& stream, char c, size_t n) {
108 std::memset(stream.stack_.Push<char>(n), c, n * sizeof(c));
109}
110
111RAPIDJSON_NAMESPACE_END
112
113#if defined(__clang__)
114RAPIDJSON_DIAG_POP
115#endif
116
117#endif // RAPIDJSON_STRINGBUFFER_H_
118