osd-contiki/examples/osd/er-rest-example-merkurboard/resources/res-separate.c

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2014-11-19 22:06:38 +01:00
/*
* 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-separate.h"
#include "er-coap-transactions.h"
static void res_get_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset);
static void res_resume_handler(void);
SEPARATE_RESOURCE(res_separate,
"title=\"Separate demo\"",
res_get_handler,
NULL,
NULL,
NULL,
res_resume_handler);
/* A structure to store the information required for the separate handler */
typedef struct application_separate_store {
/* Provided by Erbium to store generic request information such as remote address and token. */
coap_separate_t request_metadata;
/* Add fields for addition information to be stored for finalizing, e.g.: */
char buffer[16];
} application_separate_store_t;
#define COAP_MAX_OPEN_SEPARATE 2
static uint8_t separate_active = 0;
static application_separate_store_t separate_store[COAP_MAX_OPEN_SEPARATE];
static void
res_get_handler(void *request, void *response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset)
{
/*
* Example allows only one open separate response.
* For multiple, the application must manage the list of stores.
*/
if(separate_active >= COAP_MAX_OPEN_SEPARATE) {
coap_separate_reject();
} else {
++separate_active;
/* Take over and skip response by engine. */
coap_separate_accept(request, &separate_store->request_metadata);
/* Be aware to respect the Block2 option, which is also stored in the coap_separate_t. */
/*
* At the moment, only the minimal information is stored in the store (client address, port, token, MID, type, and Block2).
* Extend the store, if the application requires additional information from this handler.
* buffer is an example field for custom information.
*/
snprintf(separate_store->buffer, sizeof(separate_store->buffer), "StoredInfo");
}
}
static void
res_resume_handler()
{
if(separate_active) {
coap_transaction_t *transaction = NULL;
if((transaction = coap_new_transaction(separate_store->request_metadata.mid, &separate_store->request_metadata.addr, separate_store->request_metadata.port))) {
coap_packet_t response[1]; /* This way the packet can be treated as pointer as usual. */
/* Restore the request information for the response. */
coap_separate_resume(response, &separate_store->request_metadata, REST.status.OK);
coap_set_payload(response, separate_store->buffer, strlen(separate_store->buffer));
/*
* Be aware to respect the Block2 option, which is also stored in the coap_separate_t.
* As it is a critical option, this example resource pretends to handle it for compliance.
*/
coap_set_header_block2(response, separate_store->request_metadata.block2_num, 0, separate_store->request_metadata.block2_size);
/* Warning: No check for serialization error. */
transaction->packet_len = coap_serialize_message(response, transaction->packet);
coap_send_transaction(transaction);
/* The engine will clear the transaction (right after send for NON, after acked for CON). */
/* FIXME there could me more! */
separate_active = 0;
} else {
/*
* Set timer for retry, send error message, ...
* The example simply waits for another button press.
*/
}
} /* if (separate_active) */
}