nes-proj/examples/er-rest-example/resources/res-event.c

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/*
* 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"
#define DEBUG 0
#if DEBUG
#include <stdio.h>
#define PRINTF(...) printf(__VA_ARGS__)
#define PRINT6ADDR(addr) PRINTF("[%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x]", ((uint8_t *)addr)[0], ((uint8_t *)addr)[1], ((uint8_t *)addr)[2], ((uint8_t *)addr)[3], ((uint8_t *)addr)[4], ((uint8_t *)addr)[5], ((uint8_t *)addr)[6], ((uint8_t *)addr)[7], ((uint8_t *)addr)[8], ((uint8_t *)addr)[9], ((uint8_t *)addr)[10], ((uint8_t *)addr)[11], ((uint8_t *)addr)[12], ((uint8_t *)addr)[13], ((uint8_t *)addr)[14], ((uint8_t *)addr)[15])
#define PRINTLLADDR(lladdr) PRINTF("[%02x:%02x:%02x:%02x:%02x:%02x]", (lladdr)->addr[0], (lladdr)->addr[1], (lladdr)->addr[2], (lladdr)->addr[3], (lladdr)->addr[4], (lladdr)->addr[5])
#else
#define PRINTF(...)
#define PRINT6ADDR(addr)
#define PRINTLLADDR(addr)
#endif
static void res_get_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
static void res_event_handler();
/*
* 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(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
{
REST.set_header_content_type(response, REST.type.TEXT_PLAIN);
REST.set_response_payload(response, buffer, snprintf((char *)buffer, preferred_size, "EVENT %lu", 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()
{
/* 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) {
PRINTF("TICK %u for /%s\n", event_counter, res_event.url);
/* Notify the registered observers which will trigger the res_get_handler to create the response. */
REST.notify_subscribers(&res_event);
}
}