libcoap  4.2.0
resource.h File Reference

Generic resource handling. More...

#include <assert.h>
#include "uthash.h"
#include "async.h"
#include "str.h"
#include "pdu.h"
#include "net.h"
#include "subscribe.h"
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Go to the source code of this file.

Data Structures

struct  coap_attr_t
 
struct  coap_resource_t
 

Macros

#define COAP_RESOURCE_CHECK_TIME   2
 The interval in seconds to check if resources have changed. More...
 
#define COAP_ATTR_FLAGS_RELEASE_NAME   0x1
 
#define COAP_ATTR_FLAGS_RELEASE_VALUE   0x2
 
#define COAP_RESOURCE_FLAGS_RELEASE_URI   0x1
 The URI passed to coap_resource_init() is free'd by coap_delete_resource(). More...
 
#define COAP_RESOURCE_FLAGS_NOTIFY_NON   0x0
 Notifications will be sent non-confirmable by default. More...
 
#define COAP_RESOURCE_FLAGS_NOTIFY_CON   0x2
 Notifications will be sent confirmable by default. More...
 
#define COAP_PRINT_STATUS_MASK   0xF0000000u
 
#define COAP_PRINT_OUTPUT_LENGTH(v)   ((v) & ~COAP_PRINT_STATUS_MASK)
 
#define COAP_PRINT_STATUS_ERROR   0x80000000u
 
#define COAP_PRINT_STATUS_TRUNC   0x40000000u
 
#define RESOURCES_ADD(r, obj)   HASH_ADD(hh, (r), uri_path->s[0], (obj)->uri_path->length, (obj))
 
#define RESOURCES_DELETE(r, obj)   HASH_DELETE(hh, (r), (obj))
 
#define RESOURCES_ITER(r, tmp)
 
#define RESOURCES_FIND(r, k, res)
 

Typedefs

typedef void(* coap_method_handler_t) (coap_context_t *, struct coap_resource_t *, coap_session_t *, coap_pdu_t *, coap_binary_t *, coap_string_t *, coap_pdu_t *)
 Definition of message handler function (. More...
 
typedef struct coap_attr_t coap_attr_t
 
typedef struct coap_resource_t coap_resource_t
 
typedef unsigned int coap_print_status_t
 Status word to encode the result of conditional print or copy operations such as coap_print_link(). More...
 

Functions

coap_resource_tcoap_resource_init (coap_str_const_t *uri_path, int flags)
 Creates a new resource object and initializes the link field to the string uri_path. More...
 
coap_resource_tcoap_resource_unknown_init (coap_method_handler_t put_handler)
 Creates a new resource object for the unknown resource handler with support for PUT. More...
 
COAP_STATIC_INLINE void coap_resource_set_mode (coap_resource_t *resource, int mode)
 Sets the notification message type of resource resource to given mode. More...
 
COAP_STATIC_INLINE void coap_resource_set_userdata (coap_resource_t *r, void *data)
 Sets the user_data. More...
 
COAP_STATIC_INLINE void * coap_resource_get_userdata (coap_resource_t *r)
 Gets the user_data. More...
 
void coap_add_resource (coap_context_t *context, coap_resource_t *resource)
 Registers the given resource for context. More...
 
int coap_delete_resource (coap_context_t *context, coap_resource_t *resource)
 Deletes a resource identified by resource. More...
 
void coap_delete_all_resources (coap_context_t *context)
 Deletes all resources from given context and frees their storage. More...
 
coap_attr_tcoap_add_attr (coap_resource_t *resource, coap_str_const_t *name, coap_str_const_t *value, int flags)
 Registers a new attribute with the given resource. More...
 
coap_attr_tcoap_find_attr (coap_resource_t *resource, coap_str_const_t *name)
 Returns resource's coap_attr_t object with given name if found, NULL otherwise. More...
 
void coap_delete_attr (coap_attr_t *attr)
 Deletes an attribute. More...
 
coap_print_status_t coap_print_link (const coap_resource_t *resource, unsigned char *buf, size_t *len, size_t *offset)
 Writes a description of this resource in link-format to given text buffer. More...
 
void coap_register_handler (coap_resource_t *resource, unsigned char method, coap_method_handler_t handler)
 Registers the specified handler as message handler for the request type method. More...
 
coap_resource_tcoap_get_resource_from_uri_path (coap_context_t *context, coap_str_const_t *uri_path)
 Returns the resource identified by the unique string uri_path. More...
 
coap_subscription_tcoap_add_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token, coap_string_t *query, int has_block2, coap_block_t block2)
 Adds the specified peer as observer for resource. More...
 
coap_subscription_tcoap_find_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token)
 Returns a subscription object for given peer. More...
 
void coap_touch_observer (coap_context_t *context, coap_session_t *session, const coap_binary_t *token)
 Marks an observer as alive. More...
 
int coap_delete_observer (coap_resource_t *resource, coap_session_t *session, const coap_binary_t *token)
 Removes any subscription for observer from resource and releases the allocated storage. More...
 
void coap_delete_observers (coap_context_t *context, coap_session_t *session)
 Removes any subscription for session and releases the allocated storage. More...
 
void coap_check_notify (coap_context_t *context)
 Checks for all known resources, if they are dirty and notifies subscribed observers. More...
 
coap_print_status_t coap_print_wellknown (coap_context_t *, unsigned char *, size_t *, size_t, coap_opt_t *)
 Prints the names of all known resources to buf. More...
 
void coap_handle_failed_notify (coap_context_t *, coap_session_t *, const coap_binary_t *)
 
COAP_STATIC_INLINE void coap_resource_set_get_observable (coap_resource_t *resource, int mode)
 Set whether a resource is observable. More...
 
int coap_resource_notify_observers (coap_resource_t *resource, const coap_string_t *query)
 Initiate the sending of an Observe packet for all observers of resource, optionally matching query if not NULL. More...
 
COAP_STATIC_INLINE coap_str_const_tcoap_resource_get_uri_path (coap_resource_t *resource)
 Get the UriPath from a resource. More...
 
COAP_DEPRECATED int coap_resource_set_dirty (coap_resource_t *r, const coap_string_t *query)
 

Detailed Description

Generic resource handling.

Definition in file resource.h.

Macro Definition Documentation

◆ COAP_ATTR_FLAGS_RELEASE_NAME

#define COAP_ATTR_FLAGS_RELEASE_NAME   0x1

Definition at line 44 of file resource.h.

◆ COAP_ATTR_FLAGS_RELEASE_VALUE

#define COAP_ATTR_FLAGS_RELEASE_VALUE   0x2

Definition at line 45 of file resource.h.

◆ COAP_PRINT_OUTPUT_LENGTH

#define COAP_PRINT_OUTPUT_LENGTH (   v)    ((v) & ~COAP_PRINT_STATUS_MASK)

Definition at line 314 of file resource.h.

◆ COAP_PRINT_STATUS_ERROR

#define COAP_PRINT_STATUS_ERROR   0x80000000u

Definition at line 315 of file resource.h.

◆ COAP_PRINT_STATUS_MASK

#define COAP_PRINT_STATUS_MASK   0xF0000000u

Definition at line 313 of file resource.h.

◆ COAP_PRINT_STATUS_TRUNC

#define COAP_PRINT_STATUS_TRUNC   0x40000000u

Definition at line 316 of file resource.h.

◆ COAP_RESOURCE_CHECK_TIME

#define COAP_RESOURCE_CHECK_TIME   2

The interval in seconds to check if resources have changed.

Definition at line 22 of file resource.h.

◆ COAP_RESOURCE_FLAGS_NOTIFY_CON

#define COAP_RESOURCE_FLAGS_NOTIFY_CON   0x2

Notifications will be sent confirmable by default.

RFC 7641 Section 4.5 https://tools.ietf.org/html/rfc7641#section-4.5

Definition at line 67 of file resource.h.

◆ COAP_RESOURCE_FLAGS_NOTIFY_NON

#define COAP_RESOURCE_FLAGS_NOTIFY_NON   0x0

Notifications will be sent non-confirmable by default.

RFC 7641 Section 4.5 https://tools.ietf.org/html/rfc7641#section-4.5

Definition at line 61 of file resource.h.

◆ COAP_RESOURCE_FLAGS_RELEASE_URI

#define COAP_RESOURCE_FLAGS_RELEASE_URI   0x1

The URI passed to coap_resource_init() is free'd by coap_delete_resource().

Definition at line 55 of file resource.h.

◆ RESOURCES_ADD

#define RESOURCES_ADD (   r,
  obj 
)    HASH_ADD(hh, (r), uri_path->s[0], (obj)->uri_path->length, (obj))

Definition at line 449 of file resource.h.

◆ RESOURCES_DELETE

#define RESOURCES_DELETE (   r,
  obj 
)    HASH_DELETE(hh, (r), (obj))

Definition at line 452 of file resource.h.

◆ RESOURCES_FIND

#define RESOURCES_FIND (   r,
  k,
  res 
)
Value:
{ \
HASH_FIND(hh, (r), (k)->s, (k)->length, (res)); \
}

Definition at line 459 of file resource.h.

◆ RESOURCES_ITER

#define RESOURCES_ITER (   r,
  tmp 
)
Value:
coap_resource_t *tmp, *rtmp; \
HASH_ITER(hh, (r), tmp, rtmp)

Definition at line 455 of file resource.h.

Typedef Documentation

◆ coap_attr_t

typedef struct coap_attr_t coap_attr_t

◆ coap_method_handler_t

typedef void(* coap_method_handler_t) (coap_context_t *, struct coap_resource_t *, coap_session_t *, coap_pdu_t *, coap_binary_t *, coap_string_t *, coap_pdu_t *)

Definition of message handler function (.

See also
coap_resource_t).

Definition at line 36 of file resource.h.

◆ coap_print_status_t

typedef unsigned int coap_print_status_t

Status word to encode the result of conditional print or copy operations such as coap_print_link().

The lower 28 bits of coap_print_status_t are used to encode the number of characters that has actually been printed, bits 28 to 31 encode the status. When COAP_PRINT_STATUS_ERROR is set, an error occurred during output. In this case, the other bits are undefined. COAP_PRINT_STATUS_TRUNC indicates that the output is truncated, i.e. the printing would have exceeded the current buffer.

Definition at line 311 of file resource.h.

◆ coap_resource_t

Function Documentation

◆ coap_add_attr()

coap_attr_t* coap_add_attr ( coap_resource_t resource,
coap_str_const_t name,
coap_str_const_t value,
int  flags 
)

Registers a new attribute with the given resource.

As the attribute's coap_str_const_ fields will point to name and value the caller must ensure that these pointers are valid during the attribute's lifetime.

If the name and/or value string is going to be freed off at attribute removal time by the setting of COAP_ATTR_FLAGS_RELEASE_NAME or COAP_ATTR_FLAGS_RELEASE_VALUE in flags, then either the 's' variable of coap_str_const_t has to point to constant text, or point to data within the allocated coap_str_const_t parameter.

Parameters
resourceThe resource to register the attribute with.
nameThe attribute's name as a string.
valueThe attribute's value as a string or NULL if none.
flagsFlags for memory management (in particular release of memory). Possible values:
COAP_ATTR_FLAGS_RELEASE_NAME If this flag is set, the name passed to coap_add_attr_release() is free'd when the attribute is deleted
COAP_ATTR_FLAGS_RELEASE_VALUE If this flag is set, the value passed to coap_add_attr_release() is free'd when the attribute is deleted
Returns
A pointer to the new attribute or NULL on error.

Definition at line 352 of file resource.c.

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◆ coap_add_observer()

coap_subscription_t* coap_add_observer ( coap_resource_t resource,
coap_session_t session,
const coap_binary_t token,
coap_string_t query,
int  has_block2,
coap_block_t  block2 
)

Adds the specified peer as observer for resource.

The subscription is identified by the given token. This function returns the registered subscription information if the observer has been added, or NULL on error.

Parameters
resourceThe observed resource.
sessionThe observer's session
tokenThe token that identifies this subscription.
queryThe query string, if any. subscription will take ownership of the string.
has_block2If Option Block2 defined.
block2Contents of Block2 if Block 2 defined.
Returns
A pointer to the added/updated subscription information or NULL on error.

Definition at line 623 of file resource.c.

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◆ coap_add_resource()

void coap_add_resource ( coap_context_t context,
coap_resource_t resource 
)

Registers the given resource for context.

The resource must have been created by coap_resource_init() or coap_resource_unknown_init(), the storage allocated for the resource will be released by coap_delete_resource().

Parameters
contextThe context to use.
resourceThe resource to store.

Definition at line 452 of file resource.c.

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◆ coap_check_notify()

void coap_check_notify ( coap_context_t context)

Checks for all known resources, if they are dirty and notifies subscribed observers.

Definition at line 869 of file resource.c.

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◆ coap_delete_all_resources()

void coap_delete_all_resources ( coap_context_t context)

Deletes all resources from given context and frees their storage.

Parameters
contextThe CoAP context with the resources to be deleted.

Definition at line 494 of file resource.c.

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◆ coap_delete_attr()

void coap_delete_attr ( coap_attr_t attr)

Deletes an attribute.

Note: This is for internal use only, as it is not deleted from its chain.

Parameters
attrPointer to a previously created attribute.

Definition at line 406 of file resource.c.

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◆ coap_delete_observer()

int coap_delete_observer ( coap_resource_t resource,
coap_session_t session,
const coap_binary_t token 
)

Removes any subscription for observer from resource and releases the allocated storage.

The result is 1 if an observation relationship with observer and token existed, 0 otherwise.

Parameters
resourceThe observed resource.
sessionThe observer's session.
tokenThe token that identifies this subscription or NULL for any token.
Returns
1 if the observer has been deleted, 0 otherwise.

Definition at line 703 of file resource.c.

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◆ coap_delete_observers()

void coap_delete_observers ( coap_context_t context,
coap_session_t session 
)

Removes any subscription for session and releases the allocated storage.

Parameters
contextThe CoAP context to use.
sessionThe observer's session.

Definition at line 729 of file resource.c.

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◆ coap_delete_resource()

int coap_delete_resource ( coap_context_t context,
coap_resource_t resource 
)

Deletes a resource identified by resource.

The storage allocated for that resource is freed, and removed from the context.

Parameters
contextThe context where the resources are stored.
resourceThe resource to delete.
Returns
1 if the resource was found (and destroyed), 0 otherwise.

Definition at line 474 of file resource.c.

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◆ coap_find_attr()

coap_attr_t* coap_find_attr ( coap_resource_t resource,
coap_str_const_t name 
)

Returns resource's coap_attr_t object with given name if found, NULL otherwise.

Parameters
resourceThe resource to search for attribute name.
nameName of the requested attribute as a string.
Returns
The first attribute with specified name or NULL if none was found.

Definition at line 389 of file resource.c.

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◆ coap_find_observer()

coap_subscription_t* coap_find_observer ( coap_resource_t resource,
coap_session_t session,
const coap_binary_t token 
)

Returns a subscription object for given peer.

Parameters
resourceThe observed resource.
sessionThe observer's session
tokenThe token that identifies this subscription or NULL for any token.
Returns
A valid subscription if exists or NULL otherwise.

Definition at line 587 of file resource.c.

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◆ coap_get_resource_from_uri_path()

coap_resource_t* coap_get_resource_from_uri_path ( coap_context_t context,
coap_str_const_t uri_path 
)

Returns the resource identified by the unique string uri_path.

If no resource was found, this function returns NULL.

Parameters
contextThe context to look for this resource.
uri_pathThe unique string uri of the resource.
Returns
A pointer to the resource or NULL if not found.

Definition at line 515 of file resource.c.

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◆ coap_handle_failed_notify()

void coap_handle_failed_notify ( coap_context_t ,
coap_session_t ,
const coap_binary_t  
)

Definition at line 930 of file resource.c.

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◆ coap_print_link()

coap_print_status_t coap_print_link ( const coap_resource_t resource,
unsigned char *  buf,
size_t *  len,
size_t *  offset 
)

Writes a description of this resource in link-format to given text buffer.

len must be initialized to the maximum length of buf and will be set to the number of characters actually written if successful. This function returns 1 on success or 0 on error.

Parameters
resourceThe resource to describe.
bufThe output buffer to write the description to.
lenMust be initialized to the length of buf and will be set to the length of the printed link description.
offsetThe offset within the resource description where to start writing into buf. This is useful for dealing with the Block2 option. offset is updated during output as it is consumed.
Returns
If COAP_PRINT_STATUS_ERROR is set, an error occured. Otherwise, the lower 28 bits will indicate the number of characters that have actually been output into buffer. The flag COAP_PRINT_STATUS_TRUNC indicates that the output has been truncated.

Definition at line 524 of file resource.c.

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◆ coap_print_wellknown()

coap_print_status_t coap_print_wellknown ( coap_context_t context,
unsigned char *  buf,
size_t *  buflen,
size_t  offset,
coap_opt_t query_filter 
)

Prints the names of all known resources to buf.

This function sets buflen to the number of bytes actually written and returns 1 on succes. On error, the value in buflen is undefined and the return value will be 0.

Parameters
contextThe context with the resource map.
bufThe buffer to write the result.
buflenMust be initialized to the maximum length of buf and will be set to the length of the well-known response on return.
offsetThe offset in bytes where the output shall start and is shifted accordingly with the characters that have been processed. This parameter is used to support the block option.
query_filterA filter query according to Link Format
Returns
COAP_PRINT_STATUS_ERROR on error. Otherwise, the lower 28 bits are set to the number of bytes that have actually been written to buf. COAP_PRINT_STATUS_TRUNC is set when the output has been truncated.

Definition at line 169 of file resource.c.

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◆ coap_register_handler()

void coap_register_handler ( coap_resource_t resource,
unsigned char  method,
coap_method_handler_t  handler 
)

Registers the specified handler as message handler for the request type method.

Parameters
resourceThe resource for which the handler shall be registered.
methodThe CoAP request method to handle.
handlerThe handler to register with resource.

Definition at line 577 of file resource.c.

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◆ coap_resource_get_uri_path()

COAP_STATIC_INLINE coap_str_const_t* coap_resource_get_uri_path ( coap_resource_t resource)

Get the UriPath from a resource.

Parameters
resourceThe CoAP resource to check.
Returns
The UriPath if it exists or NULL otherwise.

Definition at line 511 of file resource.h.

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◆ coap_resource_get_userdata()

COAP_STATIC_INLINE void* coap_resource_get_userdata ( coap_resource_t r)

Gets the user_data.

The user_data is exclusively used by the library-user and can be used as context in the handler functions.

Parameters
rResource to retrieve the user_darta from
Returns
The user_data pointer

Definition at line 213 of file resource.h.

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◆ coap_resource_init()

coap_resource_t* coap_resource_init ( coap_str_const_t uri_path,
int  flags 
)

Creates a new resource object and initializes the link field to the string uri_path.

This function returns the new coap_resource_t object.

If the string is going to be freed off by coap_delete_resource() when COAP_RESOURCE_FLAGS_RELEASE_URI is set in flags, then either the 's' variable of coap_str_const_t has to point to constant text, or point to data within the allocated coap_str_const_t parameter.

Parameters
uri_pathThe string URI path of the new resource.
flagsFlags for memory management (in particular release of memory). Possible values:
COAP_RESOURCE_FLAGS_RELEASE_URI If this flag is set, the URI passed to coap_resource_init() is free'd by coap_delete_resource()
COAP_RESOURCE_FLAGS_NOTIFY_CON If this flag is set, coap-observe notifications will be sent confirmable by default.
COAP_RESOURCE_FLAGS_NOTIFY_NON (default) If this flag is set, coap-observe notifications will be sent non-confirmable by default.
If flags is set to 0 then the COAP_RESOURCE_FLAGS_NOTIFY_NON is considered.
Returns
A pointer to the new object or NULL on error.

Definition at line 300 of file resource.c.

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◆ coap_resource_notify_observers()

int coap_resource_notify_observers ( coap_resource_t resource,
const coap_string_t query 
)

Initiate the sending of an Observe packet for all observers of resource, optionally matching query if not NULL.

Parameters
resourceThe CoAP resource to use.
queryThe Query to match against or NULL
Returns
1 if the Observe has been triggered, 0 otherwise.

Definition at line 837 of file resource.c.

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◆ coap_resource_set_dirty()

COAP_DEPRECATED int coap_resource_set_dirty ( coap_resource_t r,
const coap_string_t query 
)
Deprecated:
use coap_resource_notify_observers() instead.

Definition at line 832 of file resource.c.

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◆ coap_resource_set_get_observable()

COAP_STATIC_INLINE void coap_resource_set_get_observable ( coap_resource_t resource,
int  mode 
)

Set whether a resource is observable.

If the resource is observable and the client has set the COAP_OPTION_OBSERVE in a request packet, then whenever the state of the resource changes (a call to coap_resource_trigger_observe()), an Observer response will get sent.

Parameters
resourceThe CoAP resource to use.
mode1 if Observable is to be set, 0 otherwise.

Definition at line 486 of file resource.h.

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◆ coap_resource_set_mode()

COAP_STATIC_INLINE void coap_resource_set_mode ( coap_resource_t resource,
int  mode 
)

Sets the notification message type of resource resource to given mode.

Parameters
resourceThe resource to update.
modeMust be one of COAP_RESOURCE_FLAGS_NOTIFY_NON or COAP_RESOURCE_FLAGS_NOTIFY_CON.

Definition at line 185 of file resource.h.

◆ coap_resource_set_userdata()

COAP_STATIC_INLINE void coap_resource_set_userdata ( coap_resource_t r,
void *  data 
)

Sets the user_data.

The user_data is exclusively used by the library-user and can be used as context in the handler functions.

Parameters
rResource to attach the data to
dataData to attach to the user_data field. This pointer is only used for storage, the data remains under user control

Definition at line 200 of file resource.h.

◆ coap_resource_unknown_init()

coap_resource_t* coap_resource_unknown_init ( coap_method_handler_t  put_handler)

Creates a new resource object for the unknown resource handler with support for PUT.

In the same way that additional handlers can be added to the resource created by coap_resource_init() by using coap_register_handler(), POST, GET, DELETE etc. handlers can be added to this resource. It is the responsibility of the application to manage the unknown resources by either creating new resources with coap_resource_init() (which should have a DELETE handler specified for the resource removal) or by maintaining an active resource list.

Note: There can only be one unknown resource handler per context - attaching a new one overrides the previous definition.

Note: It is not possible to observe the unknown resource with a GET request

  • a separate resource needs to be reated by the PUT (or POST) handler, and make that resource observable.

This function returns the new coap_resource_t object.

Parameters
put_handlerThe PUT handler to register with resource for unknown Uri-Path.
Returns
A pointer to the new object or NULL on error.

Definition at line 334 of file resource.c.

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◆ coap_touch_observer()

void coap_touch_observer ( coap_context_t context,
coap_session_t session,
const coap_binary_t token 
)

Marks an observer as alive.

Parameters
contextThe CoAP context to use.
sessionThe observer's session
tokenThe corresponding token that has been used for the subscription.

Definition at line 690 of file resource.c.

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