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