File content as of revision 4:059b8b90e0d9:

/*
 * 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"

#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)
{
    uint8_t status; char read;

    reset();
    record.clear();

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

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

    if (_state == STATE_COMPLETE)
        return PARSER_SUCCESS;
    else if (_state == STATE_BLANK)
        if (status == DS_STATUS_CLOSED)
            return PARSER_END_OF_RESPONSE;
        else
            return PARSER_TIMEOUT_ERROR;
    else
        if (status == DS_STATUS_TIMEOUT)
            return PARSER_TIMEOUT_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;
}