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//
// Parser.cpp
//
// $Id$
//
// Library: JSON
// Package: JSON
// Module: Parser
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// 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, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
#include "Poco/JSON/Parser.h"
#include "Poco/JSON/JSONException.h"
#include "Poco/Ascii.h"
#include "Poco/Token.h"
#include "Poco/UTF8Encoding.h"
#undef min
#undef max
#include <limits>
#include <clocale>
#include <istream>
namespace Poco {
namespace JSON {
#ifndef IS_HIGH_SURROGATE
#define IS_HIGH_SURROGATE(uc) (((uc) & 0xFC00) == 0xD800)
#endif
#ifndef IS_LOW_SURROGATE
#define IS_LOW_SURROGATE(uc) (((uc) & 0xFC00) == 0xDC00)
#endif
#ifndef DECODE_SURROGATE_PAIR
#define DECODE_SURROGATE_PAIR(hi,lo) ((((hi) & 0x3FF) << 10) + ((lo) & 0x3FF) + 0x10000)
#endif
#define COUNTOF(x) (sizeof(x)/sizeof(x[0]))
static unsigned char utf8_lead_bits[4] = { 0x00, 0xC0, 0xE0, 0xF0 };
const int Parser::_asciiClass[] = {
xx, xx, xx, xx, xx, xx, xx, xx,
xx, C_WHITE, C_WHITE, xx, xx, C_WHITE, xx, xx,
xx, xx, xx, xx, xx, xx, xx, xx,
xx, xx, xx, xx, xx, xx, xx, xx,
C_SPACE, C_ETC, C_QUOTE, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_STAR, C_PLUS, C_COMMA, C_MINUS, C_POINT, C_SLASH,
C_ZERO, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT, C_DIGIT,
C_DIGIT, C_DIGIT, C_COLON, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ABCDF, C_ABCDF, C_ABCDF, C_ABCDF, C_E, C_ABCDF, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_LSQRB, C_BACKS, C_RSQRB, C_ETC, C_ETC,
C_ETC, C_LOW_A, C_LOW_B, C_LOW_C, C_LOW_D, C_LOW_E, C_LOW_F, C_ETC,
C_ETC, C_ETC, C_ETC, C_ETC, C_LOW_L, C_ETC, C_LOW_N, C_ETC,
C_ETC, C_ETC, C_LOW_R, C_LOW_S, C_LOW_T, C_LOW_U, C_ETC, C_ETC,
C_ETC, C_ETC, C_ETC, C_LCURB, C_ETC, C_RCURB, C_ETC, C_ETC
};
const int Parser::_stateTransitionTable[NR_STATES][NR_CLASSES] = {
/*
white 1-9 ABCDF etc
space | { } [ ] : , " \ / + - . 0 | a b c d e f l n r s t u | E | * */
/*start GO*/ {GO,GO,-6,xx,-5,xx,xx,xx,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*ok OK*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*object OB*/ {OB,OB,xx,-9,xx,xx,xx,xx,SB,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*key KE*/ {KE,KE,xx,xx,xx,xx,xx,xx,SB,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*colon CO*/ {CO,CO,xx,xx,xx,xx,-2,xx,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*value VA*/ {VA,VA,-6,xx,-5,xx,xx,xx,SB,xx,CB,xx,MX,xx,ZX,IX,xx,xx,xx,xx,xx,FA,xx,NU,xx,xx,TR,xx,xx,xx,xx,xx},
/*array AR*/ {AR,AR,-6,xx,-5,-7,xx,xx,SB,xx,CB,xx,MX,xx,ZX,IX,xx,xx,xx,xx,xx,FA,xx,NU,xx,xx,TR,xx,xx,xx,xx,xx},
/*string ST*/ {ST,xx,ST,ST,ST,ST,ST,ST,-4,EX,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST,ST},
/*escape EC*/ {xx,xx,xx,xx,xx,xx,xx,xx,ST,ST,ST,xx,xx,xx,xx,xx,xx,ST,xx,xx,xx,ST,xx,ST,ST,xx,ST,U1,xx,xx,xx,xx},
/*u1 U1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,U2,U2,U2,U2,U2,U2,U2,U2,xx,xx,xx,xx,xx,xx,U2,U2,xx,xx},
/*u2 U2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,U3,U3,U3,U3,U3,U3,U3,U3,xx,xx,xx,xx,xx,xx,U3,U3,xx,xx},
/*u3 U3*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,U4,U4,U4,U4,U4,U4,U4,U4,xx,xx,xx,xx,xx,xx,U4,U4,xx,xx},
/*u4 U4*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,UC,UC,UC,UC,UC,UC,UC,UC,xx,xx,xx,xx,xx,xx,UC,UC,xx,xx},
/*minus MI*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,ZE,IT,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*zero ZE*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,CB,xx,xx,DF,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*int IT*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,CB,xx,xx,DF,IT,IT,xx,xx,xx,xx,DE,xx,xx,xx,xx,xx,xx,xx,xx,DE,xx,xx},
/*frac FR*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,CB,xx,xx,xx,FR,FR,xx,xx,xx,xx,E1,xx,xx,xx,xx,xx,xx,xx,xx,E1,xx,xx},
/*e E1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,E2,E2,xx,E3,E3,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*ex E2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,E3,E3,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*exp E3*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,xx,xx,xx,xx,E3,E3,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*tr T1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,T2,xx,xx,xx,xx,xx,xx,xx},
/*tru T2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,T3,xx,xx,xx,xx},
/*1 T3*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,OK,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*fa F1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,F2,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*fal F2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,F3,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*fals F3*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,F4,xx,xx,xx,xx,xx,xx},
/*0 F4*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,OK,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*nu N1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,N2,xx,xx,xx,xx},
/*nul N2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,N3,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*null N3*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,CB,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,OK,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*/ C1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,C2},
/*/* C2*/ {C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C3},
/** C3*/ {C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,CE,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C2,C3},
/*_. FX*/ {OK,OK,xx,-8,xx,-7,xx,-3,xx,xx,xx,xx,xx,xx,FR,FR,xx,xx,xx,xx,E1,xx,xx,xx,xx,xx,xx,xx,xx,E1,xx,xx},
/*\ D1*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,D2,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx},
/*\ D2*/ {xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,xx,U1,xx,xx,xx,xx},
};
Parser::Parser(const Handler::Ptr& pHandler, std::size_t bufSize) :
_pHandler(pHandler),
_state(GO),
_beforeCommentState(0),
_type(JSON_T_NONE),
_escaped(0),
_comment(0),
_utf16HighSurrogate(0),
_depth(JSON_UNLIMITED_DEPTH),
_top(-1),
_stack(JSON_PARSER_STACK_SIZE),
_parseBuffer(bufSize),
_decimalPoint('.'),
_allowNullByte(true),
_allowComments(false)
{
_parseBuffer.resize(0);
push(MODE_DONE);
}
Parser::~Parser()
{
}
void Parser::reset()
{
_state = GO;
_beforeCommentState = 0;
_type = JSON_T_NONE;
_escaped = 0;
_utf16HighSurrogate = 0;
_top = -1;
_stack.clear();
_parseBuffer.resize(0);
push(MODE_DONE);
if (_pHandler) _pHandler->reset();
}
Dynamic::Var Parser::parse(const std::string& json)
{
std::string::const_iterator it = json.begin();
std::string::const_iterator end = json.end();
Source<std::string::const_iterator> source(it, end);
int c = 0;
while(source.nextChar(c))
{
if (0 == parseChar(c, source)) throw SyntaxException("JSON syntax error");
}
if (!done())
throw JSONException("JSON syntax error");
return asVar();
}
Dynamic::Var Parser::parse(std::istream& in)
{
std::istreambuf_iterator<char> it(in.rdbuf());
std::istreambuf_iterator<char> end;
Source<std::istreambuf_iterator<char> > source(it, end);
int c = 0;
while(source.nextChar(c))
{
if (0 == parseChar(c, source)) throw JSONException("JSON syntax error");
}
if (!done())
throw JSONException("JSON syntax error");
return asVar();
}
bool Parser::push(int mode)
{
_top += 1;
if (_depth < 0)
{
if (_top >= _stack.size())
_stack.resize(_stack.size() * 2, true);
}
else
{
if (_top >= _depth) return false;
}
_stack[_top] = mode;
return true;
}
bool Parser::pop(int mode)
{
if (_top < 0 || _stack[_top] != mode)
return false;
_top -= 1;
return true;
}
void Parser::clearBuffer()
{
_parseBuffer.resize(0);
}
void Parser::parseBufferPopBackChar()
{
poco_assert(_parseBuffer.size() >= 1);
_parseBuffer.resize(_parseBuffer.size() - 1);
}
void Parser::parseBufferPushBackChar(char c)
{
if (_parseBuffer.size() + 1 >= _parseBuffer.capacity())
_parseBuffer.resize(_parseBuffer.capacity() * 2);
_parseBuffer.append(c);
}
void Parser::addEscapedCharToParseBuffer(CharIntType nextChar)
{
_escaped = 0;
// remove the backslash
parseBufferPopBackChar();
switch(nextChar)
{
case 'b':
parseBufferPushBackChar('\b');
break;
case 'f':
parseBufferPushBackChar('\f');
break;
case 'n':
parseBufferPushBackChar('\n');
break;
case 'r':
parseBufferPushBackChar('\r');
break;
case 't':
parseBufferPushBackChar('\t');
break;
case '"':
parseBufferPushBackChar('"');
break;
case '\\':
parseBufferPushBackChar('\\');
break;
case '/':
parseBufferPushBackChar('/');
break;
case 'u':
parseBufferPushBackChar('\\');
parseBufferPushBackChar('u');
break;
default:
break;
}
}
void Parser::addCharToParseBuffer(CharIntType nextChar, int nextClass)
{
if (_escaped)
{
addEscapedCharToParseBuffer(nextChar);
return;
}
else if (!_comment)
{
if ((_type != JSON_T_NONE) ||
!((nextClass == C_SPACE) || (nextClass == C_WHITE)))
{
parseBufferPushBackChar((char) nextChar);
}
}
}
Parser::CharIntType Parser::decodeUnicodeChar()
{
int i;
unsigned uc = 0;
char* p;
int trail_bytes;
poco_assert(_parseBuffer.size() >= 6);
p = &_parseBuffer[_parseBuffer.size() - 4];
for (i = 12; i >= 0; i -= 4, ++p) {
unsigned x = *p;
if (x >= 'a') {
x -= ('a' - 10);
} else if (x >= 'A') {
x -= ('A' - 10);
} else {
x &= ~0x30u;
}
poco_assert(x < 16);
uc |= x << i;
}
if ( !_allowNullByte && uc == 0 ) return 0; // Null byte not allowed
// clear UTF-16 char from buffer
_parseBuffer.resize(_parseBuffer.size() - 6);
// attempt decoding
if (_utf16HighSurrogate)
{
if (IS_LOW_SURROGATE(uc))
{
uc = DECODE_SURROGATE_PAIR(_utf16HighSurrogate, uc);
trail_bytes = 3;
_utf16HighSurrogate = 0;
}
else
{
// high surrogate without a following low surrogate
return 0;
}
}
else
{
if (uc < 0x80)
{
trail_bytes = 0;
}
else if (uc < 0x800)
{
trail_bytes = 1;
}
else if (IS_HIGH_SURROGATE(uc))
{
// save the high surrogate and wait for the low surrogate
_utf16HighSurrogate = uc;
return 1;
}
else if (IS_LOW_SURROGATE(uc))
{
// low surrogate without a preceding high surrogate
return 0;
}
else
{
trail_bytes = 2;
}
}
_parseBuffer.append((char) ((uc >> (trail_bytes * 6)) | utf8_lead_bits[trail_bytes]));
for (i = trail_bytes * 6 - 6; i >= 0; i -= 6)
{
_parseBuffer.append((char) (((uc >> i) & 0x3F) | 0x80));
}
return 1;
}
void Parser::parseBuffer()
{
if (_pHandler)
{
int type = _type; // just to silence g++
if (type != JSON_T_NONE)
{
assertNonContainer();
switch(type)
{
case JSON_T_TRUE:
{
_pHandler->value(true);
break;
}
case JSON_T_FALSE:
{
_pHandler->value(false);
break;
}
case JSON_T_NULL:
{
_pHandler->null();
break;
}
case JSON_T_FLOAT:
{
// Float can't end with a dot
if (_parseBuffer[_parseBuffer.size() - 1] == '.' ) throw SyntaxException("JSON syntax error");
double float_value = NumberParser::parseFloat(std::string(_parseBuffer.begin(), _parseBuffer.size()));
_pHandler->value(float_value);
break;
}
case JSON_T_INTEGER:
{
#if defined(POCO_HAVE_INT64)
try
{
Int64 value = NumberParser::parse64(std::string(_parseBuffer.begin(), _parseBuffer.size()));
// if number is 32-bit, then handle as such
if (value > std::numeric_limits<int>::max()
|| value < std::numeric_limits<int>::min() )
{
_pHandler->value(value);
}
else
{
_pHandler->value(static_cast<int>(value));
}
}
// try to handle error as unsigned in case of overflow
catch ( const SyntaxException& )
{
UInt64 value = NumberParser::parseUnsigned64(std::string(_parseBuffer.begin(), _parseBuffer.size()));
// if number is 32-bit, then handle as such
if ( value > std::numeric_limits<unsigned>::max() )
{
_pHandler->value(value);
}
else
{
_pHandler->value(static_cast<unsigned>(value));
}
}
#else
try
{
int value = NumberParser::parse(std::string(_parseBuffer.begin(), _parseBuffer.size()));
_pHandler->value(value);
}
// try to handle error as unsigned in case of overflow
catch ( const SyntaxException& )
{
unsigned value = NumberParser::parseUnsigned(std::string(_parseBuffer.begin(), _parseBuffer.size()));
_pHandler->value(value);
}
#endif
}
break;
case JSON_T_STRING:
{
_pHandler->value(std::string(_parseBuffer.begin(), _parseBuffer.size()));
break;
}
}
}
}
clearBuffer();
}
int Parser::utf8CheckFirst(char byte)
{
unsigned char u = (unsigned char) byte;
if(u < 0x80)
return 1;
if (0x80 <= u && u <= 0xBF)
{
// second, third or fourth byte of a multi-byte
// sequence, i.e. a "continuation byte"
return 0;
}
else if(u == 0xC0 || u == 0xC1)
{
// overlong encoding of an ASCII byte
return 0;
}
else if(0xC2 <= u && u <= 0xDF)
{
// 2-byte sequence
return 2;
}
else if(0xE0 <= u && u <= 0xEF)
{
// 3-byte sequence
return 3;
}
else if(0xF0 <= u && u <= 0xF4)
{
// 4-byte sequence
return 4;
}
else
{
// u >= 0xF5
// Restricted (start of 4-, 5- or 6-byte sequence) or invalid UTF-8
return 0;
}
}
} } // namespace Poco::JSON