// 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. All rights reserved. // // 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.
//! 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: typedeftypename Encoding::Ch Ch;
//! Output byte stream wrapper with 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, FileWriteStream.
*/ template <typename Encoding, typename OutputByteStream> class EncodedOutputStream {
RAPIDJSON_STATIC_ASSERT(sizeof(typename OutputByteStream::Ch) == 1); public: typedeftypename Encoding::Ch Ch;
//! 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(); staticconst TakeFunc f[] = { RAPIDJSON_ENCODINGS_FUNC(Take) };
takeFunc_ = f[type_];
current_ = takeFunc_(*is_);
}
// 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
constunsignedchar* c = (constunsignedchar *)is_->Peek4(); if (!c) return;
// 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_) { unsigned 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);
}
//! Output stream wrapper with dynamically bound encoding and automatic encoding detection. /*! \tparam CharType Type of character for writing. \tparam InputByteStream 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);
Die Informationen auf dieser Webseite wurden
nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit,
noch Qualität der bereit gestellten Informationen zugesichert.
Bemerkung:
Die farbliche Syntaxdarstellung ist noch experimentell.