90 lines
3.7 KiB
C
90 lines
3.7 KiB
C
/*
|
|
* Copyright (c) 2013, Institute for Pervasive Computing, ETH Zurich
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the Institute nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* This file is part of the Contiki operating system.
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
* Example resource
|
|
* \author
|
|
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include "rest-engine.h"
|
|
#include "er-coap.h"
|
|
|
|
static void res_get_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
|
|
static void res_periodic_handler(void);
|
|
|
|
PERIODIC_RESOURCE(res_push,
|
|
"title=\"Periodic demo\";obs",
|
|
res_get_handler,
|
|
NULL,
|
|
NULL,
|
|
NULL,
|
|
5 * CLOCK_SECOND,
|
|
res_periodic_handler);
|
|
|
|
/*
|
|
* Use local resource state that is accessed by res_get_handler() and altered by res_periodic_handler() or PUT or POST.
|
|
*/
|
|
static int32_t event_counter = 0;
|
|
|
|
static void
|
|
res_get_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
|
|
{
|
|
/*
|
|
* For minimal complexity, request query and options should be ignored for GET on observable resources.
|
|
* Otherwise the requests must be stored with the observer list and passed by REST.notify_subscribers().
|
|
* This would be a TODO in the corresponding files in contiki/apps/erbium/!
|
|
*/
|
|
REST.set_header_content_type(response, REST.type.TEXT_PLAIN);
|
|
REST.set_header_max_age(response, res_push.periodic->period / CLOCK_SECOND);
|
|
REST.set_response_payload(response, buffer, snprintf((char *)buffer, preferred_size, "VERY LONG EVENT %lu", event_counter));
|
|
|
|
/* The REST.subscription_handler() will be called for observable resources by the REST framework. */
|
|
}
|
|
/*
|
|
* Additionally, a handler function named [resource name]_handler must be implemented for each PERIODIC_RESOURCE.
|
|
* It will be called by the REST manager process with the defined period.
|
|
*/
|
|
static void
|
|
res_periodic_handler()
|
|
{
|
|
/* Do a periodic task here, e.g., sampling a sensor. */
|
|
++event_counter;
|
|
|
|
/* Usually a condition is defined under with subscribers are notified, e.g., large enough delta in sensor reading. */
|
|
if(1) {
|
|
/* Notify the registered observers which will trigger the res_get_handler to create the response. */
|
|
REST.notify_subscribers(&res_push);
|
|
}
|
|
}
|