File content as of revision 11:e1bee9a77652:

/*
 * Parser.cpp
 *
 * Created on: Nov 1, 2013
 * * Authors: Vincent Wochnik <v.wochnik@gmail.com>
 *
 * Copyright (c) 2013 Cumulocity GmbH
 *
 * 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.
 */

#include "Parser.h"
#include <assert.h>

#define STATE_BLANK 0
#define STATE_STRUCTURE 1
#define STATE_VALUE 2
#define STATE_INQUOTES 3
#define STATE_AFTERQUOTE 4
#define STATE_COMPLETE 5
#define STATE_ERROR 6


/*-------------------------------------------------------------------------*/
Parser::Parser()
{
	reset();
}
/*-------------------------------------------------------------------------*/
uint8_t Parser::readFrom(AbstractDataSource& source, ParsedRecord& record)
{
	int status = -1;
	char read;

	reset();
	record.clear();

	while ((_state < STATE_COMPLETE) &&
			(((read = source.read()) > 0) ||
			 ((status = source.status()) == DS_STATUS_OK)))
		parse(read);

	// successfully read record
	if (_state == STATE_COMPLETE)
	{
		if (!record.set(_buffer, _count))
			return PARSER_INTERNAL_ERROR;
		return PARSER_SUCCESS;
	}

	if (_state == STATE_BLANK)
	{
		assert(status >= 0);
		if (status == DS_STATUS_CLOSED)
			return PARSER_END_OF_RESPONSE;
		else if (status == DS_STATUS_TIMEOUT)
			return PARSER_TIMEOUT_ERROR;
		else
			return PARSER_INTERNAL_ERROR;
	}

	assert(status >= 0);
	if (status == DS_STATUS_TIMEOUT)
		return PARSER_TIMEOUT_ERROR;
	else if (status == DS_STATUS_ERROR)
		return PARSER_INTERNAL_ERROR;
	else
		return PARSER_PARSE_ERROR;
}
/*-------------------------------------------------------------------------*/
void Parser::parse(char c)
{
	if (_ptr-_buffer >= SMARTREST_PARSER_BUFFER_SIZE)
	{
		_state = STATE_ERROR;
		return;
	}

	switch (_state)
	{
		case STATE_BLANK:
			_state = STATE_STRUCTURE;
		case STATE_STRUCTURE:
			switch (c)
			{
				case ' ':
				case '\t':
				case '\r':
					break;
				case '"':
					_state = STATE_INQUOTES;
					break;
				case ',':
					close();
					break;
				case '\0':
				case '\n':
					if ((_count == 0) && (_length == 0))
					{
						_state = STATE_BLANK;
					}
					else
					{
						close();
						_state = STATE_COMPLETE;
					}
					break;
				default:
					if (_length > 0)
					{
						_state = STATE_ERROR;
					}
					else
					{
						_state = STATE_VALUE;
						parse(c);
					}
					break;
			}
			break;
		case STATE_VALUE:
			switch (c)
			{
				case ',':
				case '\n':
					_state = STATE_STRUCTURE;
					parse(c);
					break;
				case '"':
					_state = STATE_ERROR;
					break;
				default:
					if ((c == ' ') || (c == '\t') || (c == '\r'))
						_trailing++;
					else
						_trailing = 0;
					append(c);
					break;
			}
			break;
		case STATE_INQUOTES:
			switch (c)
			{
				case '"':
					_state = STATE_AFTERQUOTE;
					break;
				default:
					append(c);
					break;
			}
			break;
		case STATE_AFTERQUOTE:
			switch (c)
			{
				case '"':
					append(c);
					_state = STATE_INQUOTES;
					break;
				default:
					_state = STATE_STRUCTURE;
					parse(c);
					break;
			}
			break;
	}
}
/*-------------------------------------------------------------------------*/
void Parser::append(char c)
{
	*_ptr++ = c;
	_length++;
}
/*-------------------------------------------------------------------------*/
void Parser::close()
{
	_ptr -= _trailing;
	*_ptr++ = 0;
	_trailing = 0;
	_length = 0;
	_count++;
}
/*-------------------------------------------------------------------------*/
void Parser::reset()
{
	_state = STATE_BLANK;
	_ptr = _buffer;
	_count = 0;
	_trailing = 0;
	_length = 0;
}
/*-------------------------------------------------------------------------*/