encodedstream.h
// Copyright (C) 2011 Milo Yip
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#ifndef RAPIDJSON_ENCODEDSTREAM_H_
#define RAPIDJSON_ENCODEDSTREAM_H_
#include "rapidjson.h"
#ifdef __GNUC__
RAPIDJSON_DIAG_PUSH
RAPIDJSON_DIAG_OFF(effc++)
#endif
namespace rapidjson {
//! 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_;
};
//! 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:
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); }
Ch Take() { RAPIDJSON_ASSERT(false); }
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) {
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 = (const unsigned char *)is_->Peek4();
if (!c)
return;
unsigned bom = 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_) {
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.
switch (type_) {
case kUTF8:
// Do nothing
break;
case kUTF16LE:
case kUTF16BE:
RAPIDJSON_ASSERT(sizeof(Ch) >= 2);
break;
case kUTF32LE:
case kUTF32BE:
RAPIDJSON_ASSERT(sizeof(Ch) >= 4);
break;
default:
RAPIDJSON_ASSERT(false); // Invalid type
}
}
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 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) {
// RUntime check whether the size of character type is sufficient. It only perform checks with assertion.
switch (type_) {
case kUTF16LE:
case kUTF16BE:
RAPIDJSON_ASSERT(sizeof(Ch) >= 2);
break;
case kUTF32LE:
case kUTF32BE:
RAPIDJSON_ASSERT(sizeof(Ch) >= 4);
break;
case kUTF8:
// Do nothing
break;
default:
RAPIDJSON_ASSERT(false); // Invalid UTFType
}
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); }
Ch Take() { RAPIDJSON_ASSERT(false); }
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
} // namespace rapidjson
#ifdef __GNUC__
RAPIDJSON_DIAG_POP
#endif
#endif // RAPIDJSON_FILESTREAM_H_
rapidjson::kUTF16LE
UTF-16 little endian.
Definition: encodings.h:545
rapidjson::AutoUTFOutputStream::AutoUTFOutputStream
AutoUTFOutputStream(OutputByteStream &os, UTFType type, bool putBOM)
Constructor.
Definition: encodedstream.h:228
rapidjson::kUTF32LE
UTF-32 little endian.
Definition: encodings.h:547
rapidjson::EncodedOutputStream
Output byte stream wrapper with statically bound encoding.
Definition: encodedstream.h:72
rapidjson::AutoUTFInputStream
Input stream wrapper with dynamically bound encoding and automatic encoding detection.
Definition: encodedstream.h:107
rapidjson::kUTF8
UTF-8.
Definition: encodings.h:544
rapidjson
main RapidJSON namespace
Definition: rapidjson.h:241
rapidjson::AutoUTFInputStream::AutoUTFInputStream
AutoUTFInputStream(InputByteStream &is, UTFType type=kUTF8)
Constructor.
Definition: encodedstream.h:117
rapidjson::EncodedInputStream
Input byte stream wrapper with a statically bound encoding.
Definition: encodedstream.h:39
rapidjson::kUTF16BE
UTF-16 big endian.
Definition: encodings.h:546
rapidjson.h
common definitions and configuration
rapidjson::AutoUTFOutputStream
Output stream wrapper with dynamically bound encoding and automatic encoding detection.
Definition: encodedstream.h:217
rapidjson::kUTF32BE
UTF-32 big endian.
Definition: encodings.h:548
RAPIDJSON_ASSERT
#define RAPIDJSON_ASSERT(x)
Assertion.
Definition: rapidjson.h:269
rapidjson::UTFType
UTFType
Runtime-specified UTF encoding type of a stream.
Definition: encodings.h:543