// Tencent is pleased to support the open source community by making RapidJSON available. // // Copyright (C) 2015 THL A29 Limited, a Tencent company, and Milo Yip. // // Licensed under the MIT License (the "License"); you may not use this file except // in compliance with the License. You may obtain a copy of the License at // // http://opensource.org/licenses/MIT // // Unless required by applicable law or agreed to in writing, software distributed // under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR // CONDITIONS OF ANY KIND, either express or implied. See the License for the // specific language governing permissions and limitations under the License. #ifndef RAPIDJSON_ENCODEDSTREAM_H_ #define RAPIDJSON_ENCODEDSTREAM_H_ #include "stream.h" #include "memorystream.h" #ifdef __GNUC__ RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_OFF(effc++) #endif #ifdef __clang__ RAPIDJSON_DIAG_PUSH RAPIDJSON_DIAG_OFF(padded) #endif RAPIDJSON_NAMESPACE_BEGIN //! Input byte stream wrapper with a statically bound encoding. /*! \tparam Encoding The interpretation of encoding of the stream. Either UTF8, UTF16LE, UTF16BE, UTF32LE, UTF32BE. \tparam InputByteStream Type of input byte stream. For example, FileReadStream. */ template <typename Encoding, typename InputByteStream> class EncodedInputStream { RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1); public: typedef typename Encoding::Ch Ch; EncodedInputStream(InputByteStream& is) : is_(is) { current_ = Encoding::TakeBOM(is_); } Ch Peek() const { return current_; } Ch Take() { Ch c = current_; current_ = Encoding::Take(is_); return c; } size_t Tell() const { return is_.Tell(); } // Not implemented void Put(Ch) { RAPIDJSON_ASSERT(false); } void Flush() { RAPIDJSON_ASSERT(false); } Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; } size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; } private: EncodedInputStream(const EncodedInputStream&); EncodedInputStream& operator=(const EncodedInputStream&); InputByteStream& is_; Ch current_; }; //! Specialized for UTF8 MemoryStream. template <> class EncodedInputStream<UTF8<>, MemoryStream> { public: typedef UTF8<>::Ch Ch; EncodedInputStream(MemoryStream& is) : is_(is) { if (static_cast<unsigned char>(is_.Peek()) == 0xEFu) is_.Take(); if (static_cast<unsigned char>(is_.Peek()) == 0xBBu) is_.Take(); if (static_cast<unsigned char>(is_.Peek()) == 0xBFu) is_.Take(); } Ch Peek() const { return is_.Peek(); } Ch Take() { return is_.Take(); } size_t Tell() const { return is_.Tell(); } // Not implemented void Put(Ch) {} void Flush() {} Ch* PutBegin() { return 0; } size_t PutEnd(Ch*) { return 0; } MemoryStream& is_; private: EncodedInputStream(const EncodedInputStream&); EncodedInputStream& operator=(const EncodedInputStream&); }; //! Output byte stream wrapper with statically bound encoding. /*! \tparam Encoding The interpretation of encoding of the stream. Either UTF8, UTF16LE, UTF16BE, UTF32LE, UTF32BE. \tparam OutputByteStream Type of input byte stream. For example, FileWriteStream. */ template <typename Encoding, typename OutputByteStream> class EncodedOutputStream { RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1); public: typedef typename Encoding::Ch Ch; EncodedOutputStream(OutputByteStream& os, bool putBOM = true) : os_(os) { if (putBOM) Encoding::PutBOM(os_); } void Put(Ch c) { Encoding::Put(os_, c); } void Flush() { os_.Flush(); } // Not implemented Ch Peek() const { RAPIDJSON_ASSERT(false); return 0;} Ch Take() { RAPIDJSON_ASSERT(false); return 0;} size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; } Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; } size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; } private: EncodedOutputStream(const EncodedOutputStream&); EncodedOutputStream& operator=(const EncodedOutputStream&); OutputByteStream& os_; }; #define RAPIDJSON_ENCODINGS_FUNC(x) UTF8<Ch>::x, UTF16LE<Ch>::x, UTF16BE<Ch>::x, UTF32LE<Ch>::x, UTF32BE<Ch>::x //! Input stream wrapper with dynamically bound encoding and automatic encoding detection. /*! \tparam CharType Type of character for reading. \tparam InputByteStream type of input byte stream to be wrapped. */ template <typename CharType, typename InputByteStream> class AutoUTFInputStream { RAPIDJSON_STATIC_ASSERT(sizeof(typename InputByteStream::Ch) == 1); public: typedef CharType Ch; //! Constructor. /*! \param is input stream to be wrapped. \param type UTF encoding type if it is not detected from the stream. */ AutoUTFInputStream(InputByteStream& is, UTFType type = kUTF8) : is_(&is), type_(type), hasBOM_(false) { RAPIDJSON_ASSERT(type >= kUTF8 && type <= kUTF32BE); DetectType(); static const TakeFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Take) }; takeFunc_ = f[type_]; current_ = takeFunc_(*is_); } UTFType GetType() const { return type_; } bool HasBOM() const { return hasBOM_; } Ch Peek() const { return current_; } Ch Take() { Ch c = current_; current_ = takeFunc_(*is_); return c; } size_t Tell() const { return is_->Tell(); } // Not implemented void Put(Ch) { RAPIDJSON_ASSERT(false); } void Flush() { RAPIDJSON_ASSERT(false); } Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; } size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; } private: AutoUTFInputStream(const AutoUTFInputStream&); AutoUTFInputStream& operator=(const AutoUTFInputStream&); // Detect encoding type with BOM or RFC 4627 void DetectType() { // BOM (Byte Order Mark): // 00 00 FE FF UTF-32BE // FF FE 00 00 UTF-32LE // FE FF UTF-16BE // FF FE UTF-16LE // EF BB BF UTF-8 const unsigned char* c = reinterpret_cast<const unsigned char *>(is_->Peek4()); if (!c) return; unsigned bom = static_cast<unsigned>(c[0] | (c[1] << 8) | (c[2] << 16) | (c[3] << 24)); hasBOM_ = false; if (bom == 0xFFFE0000) { type_ = kUTF32BE; hasBOM_ = true; is_->Take(); is_->Take(); is_->Take(); is_->Take(); } else if (bom == 0x0000FEFF) { type_ = kUTF32LE; hasBOM_ = true; is_->Take(); is_->Take(); is_->Take(); is_->Take(); } else if ((bom & 0xFFFF) == 0xFFFE) { type_ = kUTF16BE; hasBOM_ = true; is_->Take(); is_->Take(); } else if ((bom & 0xFFFF) == 0xFEFF) { type_ = kUTF16LE; hasBOM_ = true; is_->Take(); is_->Take(); } else if ((bom & 0xFFFFFF) == 0xBFBBEF) { type_ = kUTF8; hasBOM_ = true; is_->Take(); is_->Take(); is_->Take(); } // RFC 4627: Section 3 // "Since the first two characters of a JSON text will always be ASCII // characters [RFC0020], it is possible to determine whether an octet // stream is UTF-8, UTF-16 (BE or LE), or UTF-32 (BE or LE) by looking // at the pattern of nulls in the first four octets." // 00 00 00 xx UTF-32BE // 00 xx 00 xx UTF-16BE // xx 00 00 00 UTF-32LE // xx 00 xx 00 UTF-16LE // xx xx xx xx UTF-8 if (!hasBOM_) { int pattern = (c[0] ? 1 : 0) | (c[1] ? 2 : 0) | (c[2] ? 4 : 0) | (c[3] ? 8 : 0); switch (pattern) { case 0x08: type_ = kUTF32BE; break; case 0x0A: type_ = kUTF16BE; break; case 0x01: type_ = kUTF32LE; break; case 0x05: type_ = kUTF16LE; break; case 0x0F: type_ = kUTF8; break; default: break; // Use type defined by user. } } // Runtime check whether the size of character type is sufficient. It only perform checks with assertion. if (type_ == kUTF16LE || type_ == kUTF16BE) RAPIDJSON_ASSERT(sizeof(Ch) >= 2); if (type_ == kUTF32LE || type_ == kUTF32BE) RAPIDJSON_ASSERT(sizeof(Ch) >= 4); } typedef Ch (*TakeFunc)(InputByteStream& is); InputByteStream* is_; UTFType type_; Ch current_; TakeFunc takeFunc_; bool hasBOM_; }; //! Output stream wrapper with dynamically bound encoding and automatic encoding detection. /*! \tparam CharType Type of character for writing. \tparam OutputByteStream type of output byte stream to be wrapped. */ template <typename CharType, typename OutputByteStream> class AutoUTFOutputStream { RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1); public: typedef CharType Ch; //! Constructor. /*! \param os output stream to be wrapped. \param type UTF encoding type. \param putBOM Whether to write BOM at the beginning of the stream. */ AutoUTFOutputStream(OutputByteStream& os, UTFType type, bool putBOM) : os_(&os), type_(type) { RAPIDJSON_ASSERT(type >= kUTF8 && type <= kUTF32BE); // Runtime check whether the size of character type is sufficient. It only perform checks with assertion. if (type_ == kUTF16LE || type_ == kUTF16BE) RAPIDJSON_ASSERT(sizeof(Ch) >= 2); if (type_ == kUTF32LE || type_ == kUTF32BE) RAPIDJSON_ASSERT(sizeof(Ch) >= 4); static const PutFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Put) }; putFunc_ = f[type_]; if (putBOM) PutBOM(); } UTFType GetType() const { return type_; } void Put(Ch c) { putFunc_(*os_, c); } void Flush() { os_->Flush(); } // Not implemented Ch Peek() const { RAPIDJSON_ASSERT(false); return 0;} Ch Take() { RAPIDJSON_ASSERT(false); return 0;} size_t Tell() const { RAPIDJSON_ASSERT(false); return 0; } Ch* PutBegin() { RAPIDJSON_ASSERT(false); return 0; } size_t PutEnd(Ch*) { RAPIDJSON_ASSERT(false); return 0; } private: AutoUTFOutputStream(const AutoUTFOutputStream&); AutoUTFOutputStream& operator=(const AutoUTFOutputStream&); void PutBOM() { typedef void (*PutBOMFunc)(OutputByteStream&); static const PutBOMFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(PutBOM) }; f[type_](*os_); } typedef void (*PutFunc)(OutputByteStream&, Ch); OutputByteStream* os_; UTFType type_; PutFunc putFunc_; }; #undef RAPIDJSON_ENCODINGS_FUNC RAPIDJSON_NAMESPACE_END #ifdef __clang__ RAPIDJSON_DIAG_POP #endif #ifdef __GNUC__ RAPIDJSON_DIAG_POP #endif #endif // RAPIDJSON_FILESTREAM_H_