File content as of revision 19:81dfc04ce0bb:

/*
 * HTTPResponseFilter.cpp
 *
 * Created on: Feb 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 "HTTPResponseFilter.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <stdio.h>

const char *cExpectedStatus = "HTTP/1.* ";
const char *cContentLength = "Content-Length: ";

HTTPResponseFilter::HTTPResponseFilter(AbstractDataSource& source) : _source(source), _state(RESPF_STATE_INIT)
{
    _length = _read = 0;
}

HTTPResponseFilter::~HTTPResponseFilter()
{
}

char HTTPResponseFilter::read()
{
    if (_state != RESPF_STATE_READ_HEADERS)
        return 0;
    if ((_length > 0) && (_length == _read))
        return 0;
    _read++;
    return _source.read();
}

uint8_t HTTPResponseFilter::status()
{
    if (_state != RESPF_STATE_READ_HEADERS)
        return DS_STATUS_ERROR;
    if ((_length > 0) && (_length == _read))
        return DS_STATUS_CLOSED;
    return _source.status();
}

uint16_t HTTPResponseFilter::readStatus()
{
    uint16_t res = 0;
    uint8_t state = 0;
    char c;
    size_t offset = 0;
    uint8_t status = DS_STATUS_OK;
    
    if (_state != RESPF_STATE_INIT)
        return 0;
        
    while ((state < 3) && (((c = _source.read()) > 0) || ((status = _source.status()) == DS_STATUS_OK))) {
        switch (state) {
        case 0: // read expected status line
            if ((cExpectedStatus[offset] != c) && (cExpectedStatus[offset] != '*'))
                state = 3;
            offset++;
            if (offset == strlen(cExpectedStatus)) {
                state = 1;
            }
            break;
        case 1:
            if (isspace(c))
                state = 2;
            if (isdigit(c))
                res = (res * 10) + (c - '0');
            break;
        case 2:
            if (c == '\n')
                state = 3;
            break;
        }
    }

    if ((status != DS_STATUS_OK) || (state != 3))
        return 0;

    _state = RESPF_STATE_READ_STATUS;        
    return res;
}

bool HTTPResponseFilter::skipHeaders()
{
    uint8_t state = 0;
    char c;
    size_t offset = 0;
    uint8_t status = DS_STATUS_OK;

    if (_state != RESPF_STATE_READ_STATUS)
        return false;

    while ((state < 5) && (((c = _source.read()) > 0) || ((status = _source.status()) == DS_STATUS_OK))) {
        switch (state) {
        case 0: // start of line
            if (offset == 0) {
                if (cContentLength[0] == c)
                    state = 1;
                if (c == '\r')
                    state = 4;
            } else {
                if (c == '\r')
                    state = 3;
            }
            offset++;
            break;
        case 1:
            if (c == '\r')
                state = 3;
            else if (cContentLength[offset] != c)
                state = 0;
            else if (offset == strlen(cContentLength)-1)
                state = 2;
            offset++;
            break;
        case 2:
            if (isdigit(c))
                _length = (_length * 10) + (c - '0');
            else if (c == '\r')
                state = 3;
            else
                state = 0;
            offset++;
            break;
        case 3:
            if (c == '\n') {
                state = 0;
                offset = 0;
            }
            break;
        case 4:
            if (c == '\n')
                state = 5;
            break;
        }
    }

    if ((status != DS_STATUS_OK) || (state != 5))
        return false;
        
    _state = RESPF_STATE_READ_HEADERS;
    return true;
}

void HTTPResponseFilter::reset()
{
    _state = RESPF_STATE_INIT;
    _length = _read = 0;
}