nes-proj/examples/coap/coap-example-server/resources/res-event.c

96 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 <stdio.h>
#include <string.h>
#include "coap-engine.h"
#include "coap.h"
/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "App"
#define LOG_LEVEL LOG_LEVEL_APP
static void res_get_handler(coap_message_t *request, coap_message_t *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
static void res_event_handler(void);
/*
* Example for an event resource.
* Additionally takes a period parameter that defines the interval to call [name]_periodic_handler().
* A default post_handler takes care of subscriptions and manages a list of subscribers to notify.
*/
EVENT_RESOURCE(res_event,
"title=\"Event demo\";obs",
res_get_handler,
NULL,
NULL,
NULL,
res_event_handler);
/*
* Use local resource state that is accessed by res_get_handler() and altered by res_event_handler() or PUT or POST.
*/
static int32_t event_counter = 0;
static void
res_get_handler(coap_message_t *request, coap_message_t *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
{
coap_set_header_content_format(response, TEXT_PLAIN);
coap_set_payload(response, buffer, snprintf((char *)buffer, preferred_size, "EVENT %lu", (unsigned long) event_counter));
/* A post_handler that handles subscriptions/observing will be called for periodic resources by the framework. */
}
/*
* Additionally, res_event_handler must be implemented for each EVENT_RESOURCE.
* It is called through <res_name>.trigger(), usually from the server process.
*/
static void
res_event_handler(void)
{
/* Do the update triggered by the event here, e.g., sampling a sensor. */
++event_counter;
/* Usually a condition is defined under with subscribers are notified, e.g., event was above a threshold. */
if(1) {
LOG_DBG("TICK %u for /%s\n", (unsigned)event_counter, res_event.url);
/* Notify the registered observers which will trigger the res_get_handler to create the response. */
coap_notify_observers(&res_event);
}
}