116 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			116 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C++
		
	
	
	
| // Tencent is pleased to support the open source community by making RapidJSON available.
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| // 
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| // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. All rights reserved.
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| //
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| // Licensed under the MIT License (the "License"); you may not use this file except
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| // in compliance with the License. You may obtain a copy of the License at
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| //
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| // http://opensource.org/licenses/MIT
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| //
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| // Unless required by applicable law or agreed to in writing, software distributed 
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| // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR 
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| // CONDITIONS OF ANY KIND, either express or implied. See the License for the 
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| // specific language governing permissions and limitations under the License.
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| 
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| #ifndef RAPIDJSON_ISTREAMWRAPPER_H_
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| #define RAPIDJSON_ISTREAMWRAPPER_H_
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| 
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| #include "stream.h"
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| #include <iosfwd>
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| 
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| #ifdef __clang__
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| RAPIDJSON_DIAG_PUSH
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| RAPIDJSON_DIAG_OFF(padded)
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| #endif
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| 
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| #ifdef _MSC_VER
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| RAPIDJSON_DIAG_PUSH
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| RAPIDJSON_DIAG_OFF(4351) // new behavior: elements of array 'array' will be default initialized
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| #endif
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| 
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| RAPIDJSON_NAMESPACE_BEGIN
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| 
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| //! Wrapper of \c std::basic_istream into RapidJSON's Stream concept.
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| /*!
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|     The classes can be wrapped including but not limited to:
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| 
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|     - \c std::istringstream
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|     - \c std::stringstream
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|     - \c std::wistringstream
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|     - \c std::wstringstream
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|     - \c std::ifstream
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|     - \c std::fstream
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|     - \c std::wifstream
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|     - \c std::wfstream
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| 
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|     \tparam StreamType Class derived from \c std::basic_istream.
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| */
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|    
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| template <typename StreamType>
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| class BasicIStreamWrapper {
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| public:
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|     typedef typename StreamType::char_type Ch;
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|     BasicIStreamWrapper(StreamType& stream) : stream_(stream), count_(), peekBuffer_() {}
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| 
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|     Ch Peek() const { 
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|         typename StreamType::int_type c = stream_.peek();
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|         return RAPIDJSON_LIKELY(c != StreamType::traits_type::eof()) ? static_cast<Ch>(c) : '\0';
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|     }
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| 
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|     Ch Take() { 
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|         typename StreamType::int_type c = stream_.get();
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|         if (RAPIDJSON_LIKELY(c != StreamType::traits_type::eof())) {
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|             count_++;
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|             return static_cast<Ch>(c);
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|         }
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|         else
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|             return '\0';
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|     }
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| 
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|     // tellg() may return -1 when failed. So we count by ourself.
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|     size_t Tell() const { return count_; }
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| 
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|     Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; }
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|     void Put(Ch) { RAPIDJSON_ASSERT(false); }
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|     void Flush() { RAPIDJSON_ASSERT(false); }
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|     size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; }
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| 
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|     // For encoding detection only.
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|     const Ch* Peek4() const {
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|         RAPIDJSON_ASSERT(sizeof(Ch) == 1); // Only usable for byte stream.
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|         int i;
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|         bool hasError = false;
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|         for (i = 0; i < 4; ++i) {
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|             typename StreamType::int_type c = stream_.get();
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|             if (c == StreamType::traits_type::eof()) {
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|                 hasError = true;
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|                 stream_.clear();
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|                 break;
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|             }
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|             peekBuffer_[i] = static_cast<Ch>(c);
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|         }
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|         for (--i; i >= 0; --i)
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|             stream_.putback(peekBuffer_[i]);
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|         return !hasError ? peekBuffer_ : 0;
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|     }
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| 
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| private:
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|     BasicIStreamWrapper(const BasicIStreamWrapper&);
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|     BasicIStreamWrapper& operator=(const BasicIStreamWrapper&);
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| 
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|     StreamType& stream_;
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|     size_t count_;  //!< Number of characters read. Note:
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|     mutable Ch peekBuffer_[4];
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| };
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| 
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| typedef BasicIStreamWrapper<std::istream> IStreamWrapper;
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| typedef BasicIStreamWrapper<std::wistream> WIStreamWrapper;
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| 
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| #if defined(__clang__) || defined(_MSC_VER)
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| RAPIDJSON_DIAG_POP
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| #endif
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| 
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| RAPIDJSON_NAMESPACE_END
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| 
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| #endif // RAPIDJSON_ISTREAMWRAPPER_H_
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