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Refactor encoding concept to use stream for encoding and validation.

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git-svn-id: https://rapidjson.googlecode.com/svn/trunk@32 c5894555-1306-4e8d-425f-1f6f381ee07c
This commit is contained in:
miloyip@gmail.com 2011-11-23 09:46:14 +00:00
parent b9d932ac9a
commit 25eeff24f3
2 changed files with 113 additions and 101 deletions
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159
include/rapidjson/rapidjson.h
View File

@ -303,11 +303,19 @@ private:
concept Encoding {
typename Ch; //! Type of character.
//! \brief Encode a Unicode codepoint to a buffer.
//! \param buffer pointer to destination buffer to store the result. It should have sufficient size of encoding one character.
//! \brief Encode a Unicode codepoint to a stream.
//! \param os Output stream.
//! \param codepoint An unicode codepoint, ranging from 0x0 to 0x10FFFF inclusively.
//! \returns the pointer to the next character after the encoded data.
static Ch* Encode(Ch *buffer, unsigned codepoint);
template<typename OutputStream>
static void Encode(OutputStream& os, unsigned codepoint) {
//! \brief Validate one Unicode codepoint from an encoded stream.
//! \param is Input stream to obtain codepoint.
//! \param os Output for copying one codepoint.
//! \return true if it is valid.
//! \note This function just validating and copying the codepoint without actually decode it.
template <typename InputStream, typename OutputStream>
RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
};
\endcode
*/
@ -317,6 +325,7 @@ concept Encoding {
//! UTF-8 encoding.
/*! http://en.wikipedia.org/wiki/UTF-8
http://tools.ietf.org/html/rfc3629
\tparam CharType Type for storing 8-bit UTF-8 data. Default is char.
\implements Encoding
*/
@ -324,67 +333,70 @@ template<typename CharType = char>
struct UTF8 {
typedef CharType Ch;
static Ch* Encode(Ch *buffer, unsigned codepoint) {
template<typename OutputStream>
static void Encode(OutputStream& os, unsigned codepoint) {
if (codepoint <= 0x7F)
*buffer++ = codepoint & 0xFF;
os.Put(codepoint & 0xFF);
else if (codepoint <= 0x7FF) {
*buffer++ = 0xC0 | ((codepoint >> 6) & 0xFF);
*buffer++ = 0x80 | ((codepoint & 0x3F));
os.Put(0xC0 | ((codepoint >> 6) & 0xFF));
os.Put(0x80 | ((codepoint & 0x3F)));
}
else if (codepoint <= 0xFFFF) {
*buffer++ = 0xE0 | ((codepoint >> 12) & 0xFF);
*buffer++ = 0x80 | ((codepoint >> 6) & 0x3F);
*buffer++ = 0x80 | (codepoint & 0x3F);
os.Put(0xE0 | ((codepoint >> 12) & 0xFF));
os.Put(0x80 | ((codepoint >> 6) & 0x3F));
os.Put(0x80 | (codepoint & 0x3F));
}
else {
RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
*buffer++ = 0xF0 | ((codepoint >> 18) & 0xFF);
*buffer++ = 0x80 | ((codepoint >> 12) & 0x3F);
*buffer++ = 0x80 | ((codepoint >> 6) & 0x3F);
*buffer++ = 0x80 | (codepoint & 0x3F);
os.Put(0xF0 | ((codepoint >> 18) & 0xFF));
os.Put(0x80 | ((codepoint >> 12) & 0x3F));
os.Put(0x80 | ((codepoint >> 6) & 0x3F));
os.Put(0x80 | (codepoint & 0x3F));
}
return buffer;
}
template <typename Stream>
RAPIDJSON_FORCEINLINE static Ch* Validate(Ch *buffer, Stream& s) {
#define X1 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1
#define X5 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5
static const char utf8[256] = {
X1,X1,X1,X1,X1,X1,X1,X1, // 00-7F 1 byte
X5,X5,X5,X5, // 80-BF Continuation
0,0,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // C0-C1: invalid, C2-CF: 2 bytes
2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, // D0-DF: 2 bytes
3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3, // E0-EF: 3 bytes
4,4,4,4,4,0,0,0,0,0,0,0,0,0,0,0, // F0-F4: 4 bytes
template <typename InputStream, typename OutputStream>
RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
// http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
static const unsigned char utf8d[] = {
//! \todo optimization
// The first part of the table maps bytes to character classes that
// to reduce the size of the transition table and create bitmasks.
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,9,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
8,8,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
10,3,3,3,3,3,3,3,3,3,3,3,3,4,3,3, 11,6,6,6,5,8,8,8,8,8,8,8,8,8,8,8,
// The second part is a transition table that maps a combination
// of a state of the automaton and a character class to a state.
0,12,24,36,60,96,84,12,12,12,48,72, 12,12,12,12,12,12,12,12,12,12,12,12,
12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
12,36,12,12,12,12,12,12,12,12,12,12,
};
#undef X1
#undef X5
Ch c;
os.Put(c = is.Take());
if ((unsigned char) c <= 0x80)
return true;
#define TAIL() c = *buffer++ = s.Take(); if ((c & 0xC0) != 0x80) return NULL;
unsigned type = utf8d[(unsigned char)c];
unsigned state = utf8d[256 + type];
if (state == 12)
return false;
Ch c = *buffer++ = s.Take();
if ((unsigned char)c < 0x80u)
return buffer;
switch(utf8[(unsigned char)c]) {
case 2:
TAIL();
return buffer;
case 3:
TAIL();
TAIL();
return buffer;
case 4:
TAIL();
TAIL();
TAIL();
return buffer;
}
return NULL;
#undef TAIL
while (state) {
os.Put(c = is.Take());
unsigned type = utf8d[(unsigned char)c];
state = utf8d[256 + state + type];
if (state == 12)
return false;
};
return true;
}
};
@ -393,6 +405,7 @@ struct UTF8 {
//! UTF-16 encoding.
/*! http://en.wikipedia.org/wiki/UTF-16
http://tools.ietf.org/html/rfc2781
\tparam CharType Type for storing 16-bit UTF-16 data. Default is wchar_t. C++11 may use char16_t instead.
\implements Encoding
*/
@ -400,33 +413,32 @@ template<typename CharType = wchar_t>
struct UTF16 {
typedef CharType Ch;
static Ch* Encode(Ch* buffer, unsigned codepoint) {
template<typename OutputStream>
static void Encode(OutputStream& os, unsigned codepoint) {
if (codepoint <= 0xFFFF) {
RAPIDJSON_ASSERT(codepoint < 0xD800 || codepoint > 0xDFFF); // Code point itself cannot be surrogate pair
*buffer++ = codepoint;
os.Put(codepoint);
}
else {
RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
unsigned v = codepoint - 0x10000;
*buffer++ = (v >> 10) + 0xD800;
*buffer++ = (v & 0x3FF) + 0xDC00;
os.Put((v >> 10) + 0xD800);
os.Put((v & 0x3FF) + 0xDC00);
}
return buffer;
}
template <typename Stream>
static Ch* Validate(Ch *buffer, Stream& s) {
Ch c = *buffer++ = s.Take();
template <typename InputStream, typename OutputStream>
RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
Ch c;
os.Put(c = is.Take());
if (c < 0xD800 || c > 0xDFFF)
;
return true;
else if (c < 0xDBFF) {
Ch c = *buffer++ = s.Take();
if (c < 0xDC00 || c > 0xDFFF)
return NULL;
os.Put(c = is.Take());
return c >= 0xDC00 && c <= 0xDFFF;
}
else
return NULL;
return buffer;
return false;
}
};
@ -442,16 +454,17 @@ template<typename CharType = unsigned>
struct UTF32 {
typedef CharType Ch;
static Ch *Encode(Ch* buffer, unsigned codepoint) {
template<typename OutputStream>
static void Encode(OutputStream& os, unsigned codepoint) {
RAPIDJSON_ASSERT(codepoint <= 0x10FFFF);
*buffer++ = codepoint;
return buffer;
os.Put(codepoint);
}
template <typename Stream>
static Ch* Validate(Ch *buffer, Stream& s) {
Ch c = *buffer++ = s.Take();
return c <= 0x10FFFF ? buffer : 0;
template <typename InputStream, typename OutputStream>
RAPIDJSON_FORCEINLINE static bool Validate(InputStream& is, OutputStream& os) {
Ch c;
os.Put(c = is.Take());
return c <= 0x10FFFF;
}
};

55
include/rapidjson/reader.h
View File

@ -368,6 +368,16 @@ private:
return codepoint;
}
struct StackStream {
StackStream(internal::Stack<Allocator>& stack) : stack_(stack), length_(0) {}
void Put(Ch c) {
*stack_.template Push<Ch>() = c;
++length_;
}
internal::Stack<Allocator>& stack_;
SizeType length_;
};
// Parse string, handling the prefix and suffix double quotes and escaping.
template<unsigned parseFlags, typename Stream, typename Handler>
void ParseString(Stream& stream, Handler& handler) {
@ -391,13 +401,13 @@ private:
else
len = 0;
StackStream stackStream(stack_);
#define RAPIDJSON_PUT(x) \
do { \
if (parseFlags & kParseInsituFlag) \
s.Put(x); \
else { \
*stack_.template Push<Ch>() = x; \
++len; \
stackStream.Put(x); \
} \
} while(false)
@ -423,16 +433,10 @@ private:
codepoint = (((codepoint - 0xD800) << 10) | (codepoint2 - 0xDC00)) + 0x10000;
}
Ch buffer[4];
SizeType count = SizeType(Encoding::Encode(buffer, codepoint) - &buffer[0]);
if (parseFlags & kParseInsituFlag)
for (SizeType i = 0; i < count; i++)
s.Put(buffer[i]);
else {
memcpy(stack_.template Push<Ch>(count), buffer, count * sizeof(Ch));
len += count;
}
Encoding::Encode(s, codepoint);
else
Encoding::Encode(stackStream, codepoint);
}
else {
RAPIDJSON_PARSE_ERROR("Unknown escape character", stream.Tell() - 1);
@ -449,7 +453,7 @@ private:
}
else {
RAPIDJSON_PUT('\0');
handler.String(stack_.template Pop<Ch>(len), len - 1, true);
handler.String(stack_.template Pop<Ch>(stackStream.length_), stackStream.length_ - 1, true);
}
stream = s; // restore stream
return;
@ -463,24 +467,19 @@ private:
return;
}
else if (parseFlags & kParseValidateEncodingFlag) {
Ch buffer[4];
Ch* end = Encoding::Validate(&buffer[0], s);
if (end == NULL) {
RAPIDJSON_PARSE_ERROR("Invalid encoding", s.Tell());
return;
if (parseFlags & kParseInsituFlag) {
if (!Encoding::Validate(s, s)) {
RAPIDJSON_PARSE_ERROR("Invalid encoding", s.Tell());
return;
}
}
if (parseFlags & kParseInsituFlag)
for (Ch* p = &buffer[0]; p != end; ++p)
s.Put(*p);
else {
SizeType l = SizeType(end - &buffer[0]);
Ch* q = stack_.template Push<Ch>(l);
for (Ch* p = &buffer[0]; p != end; ++p)
*q++ = *p;
len += l;
else
{
if (!Encoding::Validate(s, stackStream)) {
RAPIDJSON_PARSE_ERROR("Invalid encoding", s.Tell());
return;
}
}
}
else {
RAPIDJSON_PUT(s.Take()); // Normal character, just copy