osd-contiki/apps/rest-engine/rest-engine.h

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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
* An abstraction layer for RESTful Web services (Erbium).
* Inspired by RESTful Contiki by Dogan Yazar.
* \author
* Matthias Kovatsch <kovatsch@inf.ethz.ch>
*/
#ifndef REST_ENGINE_H_
#define REST_ENGINE_H_
#include <stdio.h>
#include "contiki.h"
#include "contiki-lib.h"
#include "rest-constants.h"
/* list of valid REST Enigne implementations */
#define REGISTERED_ENGINE_ERBIUM coap_rest_implementation
#define REGISTERED_ENGINE_HELIUM http_rest_implementation
/* sanity check for configured implementation */
#if !defined(REST) || (REST != REGISTERED_ENGINE_ERBIUM && REST != REGISTERED_ENGINE_HELIUM)
#error "Define a valid REST Engine implementation (REST define)!"
#endif
/*
* The maximum buffer size that is provided for resource responses and must be respected due to the limited IP buffer.
* Larger data must be handled by the resource and will be sent chunk-wise through a TCP stream or CoAP blocks.
*/
#ifndef REST_MAX_CHUNK_SIZE
#define REST_MAX_CHUNK_SIZE 64
#endif
#ifndef MIN
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#endif /* MIN */
struct resource_s;
struct periodic_resource_s;
/* signatures of handler functions */
typedef void (*restful_handler)(void *request, void *response,
uint8_t *buffer, uint16_t preferred_size,
int32_t *offset);
typedef void (*restful_final_handler)(struct resource_s *resource,
void *request, void *response);
typedef void (*restful_periodic_handler)(void);
typedef void (*restful_response_handler)(void *data, void *response);
typedef void (*restful_trigger_handler)(void);
/* signature of the rest-engine service function */
typedef int (*service_callback_t)(void *request, void *response,
uint8_t *buffer, uint16_t preferred_size,
int32_t *offset);
/* data structure representing a resource in REST */
struct resource_s {
struct resource_s *next; /* for LIST, points to next resource defined */
const char *url; /*handled URL */
rest_resource_flags_t flags; /* handled RESTful methods */
const char *attributes; /* link-format attributes */
restful_handler get_handler; /* handler function */
restful_handler post_handler; /* handler function */
restful_handler put_handler; /* handler function */
restful_handler delete_handler; /* handler function */
union {
struct periodic_resource_s *periodic; /* special data depending on flags */
restful_trigger_handler trigger;
restful_trigger_handler resume;
};
};
typedef struct resource_s resource_t;
struct periodic_resource_s {
struct periodic_resource_s *next; /* for LIST, points to next resource defined */
const resource_t *resource;
uint32_t period;
struct etimer periodic_timer;
const restful_periodic_handler periodic_handler;
};
typedef struct periodic_resource_s periodic_resource_t;
/*
* Macro to define a RESTful resource.
* Resources are statically defined for the sake of efficiency and better memory management.
*/
#define RESOURCE(name, attributes, get_handler, post_handler, put_handler, delete_handler) \
resource_t name = { NULL, NULL, NO_FLAGS, attributes, get_handler, post_handler, put_handler, delete_handler, { NULL } }
#define PARENT_RESOURCE(name, attributes, get_handler, post_handler, put_handler, delete_handler) \
resource_t name = { NULL, NULL, HAS_SUB_RESOURCES, attributes, get_handler, post_handler, put_handler, delete_handler, { NULL } }
#define SEPARATE_RESOURCE(name, attributes, get_handler, post_handler, put_handler, delete_handler, resume_handler) \
resource_t name = { NULL, NULL, IS_SEPARATE, attributes, get_handler, post_handler, put_handler, delete_handler, { .resume = resume_handler } }
#define EVENT_RESOURCE(name, attributes, get_handler, post_handler, put_handler, delete_handler, event_handler) \
resource_t name = { NULL, NULL, IS_OBSERVABLE, attributes, get_handler, post_handler, put_handler, delete_handler, { .trigger = event_handler } }
/*
* Macro to define a periodic resource.
* The corresponding [name]_periodic_handler() function will be called every period.
* For instance polling a sensor and publishing a changed value to subscribed clients would be done there.
* The subscriber list will be maintained by the final_handler rest_subscription_handler() (see rest-mapping header file).
*/
#define PERIODIC_RESOURCE(name, attributes, get_handler, post_handler, put_handler, delete_handler, period, periodic_handler) \
periodic_resource_t periodic_##name; \
resource_t name = { NULL, NULL, IS_OBSERVABLE | IS_PERIODIC, attributes, get_handler, post_handler, put_handler, delete_handler, { .periodic = &periodic_##name } }; \
periodic_resource_t periodic_##name = { NULL, &name, period, { { 0 } }, periodic_handler };
struct rest_implementation {
char *name;
/** Initialize the REST implementation. */
void (*init)(void);
/** Register the RESTful service callback at implementation. */
void (*set_service_callback)(service_callback_t callback);
/** Get request URI path. */
int (*get_url)(void *request, const char **url);
/** Get the method of a request. */
rest_resource_flags_t (*get_method_type)(void *request);
/** Set the status code of a response. */
int (*set_response_status)(void *response, unsigned int code);
/** Get the content-type of a request. */
int (*get_header_content_type)(void *request,
unsigned int *content_format);
/** Set the Content-Type of a response. */
int (*set_header_content_type)(void *response,
unsigned int content_format);
/** Get the Accept types of a request. */
int (*get_header_accept)(void *request, unsigned int *accept);
/** Get the Length option of a request. */
int (*get_header_length)(void *request, uint32_t *size);
/** Set the Length option of a response. */
int (*set_header_length)(void *response, uint32_t size);
/** Get the Max-Age option of a request. */
int (*get_header_max_age)(void *request, uint32_t *age);
/** Set the Max-Age option of a response. */
int (*set_header_max_age)(void *response, uint32_t age);
/** Set the ETag option of a response. */
int (*set_header_etag)(void *response, const uint8_t *etag,
size_t length);
/** Get the If-Match option of a request. */
int (*get_header_if_match)(void *request, const uint8_t **etag);
/** Get the If-Match option of a request. */
int (*get_header_if_none_match)(void *request);
/** Get the Host option of a request. */
int (*get_header_host)(void *request, const char **host);
/** Set the location option of a response. */
int (*set_header_location)(void *response, const char *location);
/** Get the payload option of a request. */
int (*get_request_payload)(void *request, const uint8_t **payload);
/** Set the payload option of a response. */
int (*set_response_payload)(void *response, const void *payload,
size_t length);
/** Get the query string of a request. */
int (*get_query)(void *request, const char **value);
/** Get the value of a request query key-value pair. */
int (*get_query_variable)(void *request, const char *name,
const char **value);
/** Get the value of a request POST key-value pair. */
int (*get_post_variable)(void *request, const char *name,
const char **value);
/** Send the payload to all subscribers of the resource at url. */
void (*notify_subscribers)(resource_t *resource);
/** The handler for resource subscriptions. */
restful_final_handler subscription_handler;
/* REST status codes. */
const struct rest_implementation_status status;
/* REST content-types. */
const struct rest_implementation_type type;
};
/* instance of REST implementation */
extern const struct rest_implementation REST;
/*
* To be called by HTTP/COAP server as a callback function when a new service request appears.
* This function dispatches the corresponding RESTful service.
*/
int rest_invoke_restful_service(void *request, void *response,
uint8_t *buffer, uint16_t buffer_size,
int32_t *offset);
/*---------------------------------------------------------------------------*/
/**
* \brief Initializes REST framework and starts the HTTP or CoAP process.
*/
void rest_init_engine(void);
/*---------------------------------------------------------------------------*/
/**
*
* \brief Resources wanted to be accessible should be activated with the following code.
* \param resource
* A RESTful resource defined through the RESOURCE macros.
* \param path
* The local URI path where to provide the resource.
*/
void rest_activate_resource(resource_t *resource, char *path);
/*---------------------------------------------------------------------------*/
/**
* \brief Returns the list of registered RESTful resources.
* \return The resource list.
*/
list_t rest_get_resources(void);
/*---------------------------------------------------------------------------*/
#endif /*REST_ENGINE_H_ */