1 // Tencent is pleased to support the open source community by making RapidJSON available.
3 // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
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
8 // http://opensource.org/licenses/MIT
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.
15 #ifndef RAPIDJSON_ISTREAMWRAPPER_H_
16 #define RAPIDJSON_ISTREAMWRAPPER_H_
23 RAPIDJSON_DIAG_OFF(padded)
24 #elif defined(_MSC_VER)
26 RAPIDJSON_DIAG_OFF(4351) // new behavior: elements of array 'array' will be default initialized
29 RAPIDJSON_NAMESPACE_BEGIN
31 //! Wrapper of \c std::basic_istream into RapidJSON's Stream concept.
33 The classes can be wrapped including but not limited to:
35 - \c std::istringstream
36 - \c std::stringstream
37 - \c std::wistringstream
38 - \c std::wstringstream
44 \tparam StreamType Class derived from \c std::basic_istream.
47 template <typename StreamType>
48 class BasicIStreamWrapper {
50 typedef typename StreamType::char_type Ch;
51 BasicIStreamWrapper(StreamType& stream) : stream_(stream), count_(), peekBuffer_() {}
54 typename StreamType::int_type c = stream_.peek();
55 return RAPIDJSON_LIKELY(c != StreamType::traits_type::eof()) ? static_cast<Ch>(c) : static_cast<Ch>('\0');
59 typename StreamType::int_type c = stream_.get();
60 if (RAPIDJSON_LIKELY(c != StreamType::traits_type::eof())) {
62 return static_cast<Ch>(c);
68 // tellg() may return -1 when failed. So we count by ourself.
69 size_t Tell() const { return count_; }
71 Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
72 void Put(Ch) { RAPIDJSON_ASSERT(false); }
73 void Flush() { RAPIDJSON_ASSERT(false); }
74 size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
76 // For encoding detection only.
77 const Ch* Peek4() const {
78 RAPIDJSON_ASSERT(sizeof(Ch) == 1); // Only usable for byte stream.
80 bool hasError = false;
81 for (i = 0; i < 4; ++i) {
82 typename StreamType::int_type c = stream_.get();
83 if (c == StreamType::traits_type::eof()) {
88 peekBuffer_[i] = static_cast<Ch>(c);
90 for (--i; i >= 0; --i)
91 stream_.putback(peekBuffer_[i]);
92 return !hasError ? peekBuffer_ : 0;
96 BasicIStreamWrapper(const BasicIStreamWrapper&);
97 BasicIStreamWrapper& operator=(const BasicIStreamWrapper&);
100 size_t count_; //!< Number of characters read. Note:
101 mutable Ch peekBuffer_[4];
104 typedef BasicIStreamWrapper<std::istream> IStreamWrapper;
105 typedef BasicIStreamWrapper<std::wistream> WIStreamWrapper;
107 #if defined(__clang__) || defined(_MSC_VER)
111 RAPIDJSON_NAMESPACE_END
113 #endif // RAPIDJSON_ISTREAMWRAPPER_H_