Utils API Reference
The functions explained below are defined inside the file include/iowa_utils.h.
Data types
iowa_list_t
List structure used by the List APIs.
typedef struct _iowa_list_t
{
struct _iowa_list_t *nextP;
} iowa_list_t;
- nextP
- Pointer to the next element in the list.
Callbacks
iowa_list_node_free_callback_t
This is the list node free callback, called to free a node.
typedef void(*iowa_list_node_free_callback_t) (void *nodeP);
- nodeP
- The node to free.
iowa_list_node_find_callback_t
This is the list node find callback, called to find a node.
typedef bool(*iowa_list_node_find_callback_t) (void *nodeP,
void *criteria);
- nodeP
- The current node in the list.
- criteria
- The criteria to match.
API
iowa_utils_base64_get_encoded_size
Prototype
size_t iowa_utils_base64_get_encoded_size(size_t rawBufferLen);
iowa_utils_base64_get_encoded_size() calculates the length of a Base64 buffer based on a raw buffer represented by its length.
Arguments
- rawBufferLen
- The length of the raw buffer.
Return Value
The length of the Base64 buffer.
Header File
iowa_utils.h
iowa_utils_base64_get_decoded_size
Prototype
size_t iowa_utils_base64_get_decoded_size(uint8_t *base64Buffer,
size_t base64BufferLen);
iowa_utils_base64_get_decoded_size() calculates the length of a raw buffer based on a Base64 buffer.
Arguments
- base64Buffer
- The Base64 buffer.
- base64BufferLen
- The length of the Base64 buffer.
Return Value
The length of the raw buffer. If any error the length will be 0.
Header File
iowa_utils.h
iowa_utils_base64_encode
Prototype
size_t iowa_utils_base64_encode(uint8_t * rawBuffer,
size_t rawBufferLen,
uint8_t * base64Buffer,
size_t base64BufferLen);
Description
iowa_utils_base64_encode() encodes a raw buffer using Base64.
Arguments
- rawBuffer
- The raw buffer.
- rawBufferLen
- The length of the raw buffer.
- base64Buffer
- The preallocated Base64 buffer.
- base64BufferLen
- The length of the preallocated Base64 buffer.
Return Value
The length of the encoded buffer. If any error the length will be 0.
Header File
iowa_utils.h
iowa_utils_base64_decode
Prototype
size_t iowa_utils_base64_decode(uint8_t * base64Buffer,
size_t base64BufferLen,
uint8_t * rawBuffer,
size_t rawBufferLen);
Description
iowa_utils_base64_decode() decodes a Base64 buffer into a raw buffer.
Arguments
- base64Buffer
- The Base64 buffer.
- base64BufferLen
- The length of the Base64 buffer.
- rawBuffer
- The preallocated raw buffer.
- rawBufferLen
- The length of the preallocated raw buffer.
Return Value
The length of the decoded buffer. If any error the length will be 0.
Header File
iowa_utils.h
iowa_utils_uri_to_sensor
Prototype
iowa_sensor_t iowa_utils_uri_to_sensor(iowa_lwm2m_uri_t *uriP);
Description
iowa_utils_uri_to_sensor() converts an iowa_lwm2m_uri_t into an iowa_sensor_t.
Arguments
- uriP
- Uri to convert.
Return Value
The corresponding iowa_sensor_t or IOWA_INVALID_SENSOR_ID in case of error.
Header File
iowa_utils.h
iowa_utils_sensor_to_uri
Prototype
iowa_lwm2m_uri_t iowa_utils_sensor_to_uri(iowa_sensor_t id);
Description
iowa_utils_sensor_to_uri() converts an iowa_sensor_t into an iowa_lwm2m_uri_t.
Arguments
- id
- Id to convert.
Return Value
An iowa_lwm2m_uri_t.
Header File
iowa_utils.h
iowa_utils_list_add
Prototype
iowa_list_t * iowa_utils_list_add(iowa_list_t *headP,
iowa_list_t *nodeP);
Description
iowa_utils_list_add() adds a node to a list.
Arguments
- headP
- Head of the current list.
- nodeP
- Node to add to the list.
Return Value
The list with the new element.
Header File
iowa_utils.h
iowa_utils_list_remove
Prototype
iowa_list_t * iowa_utils_list_remove(iowa_list_t *headP,
iowa_list_t *nodeP);
Description
iowa_utils_list_remove() removes a node from a list.
Arguments
- headP
- Head of the current list.
- nodeP
- Node to remove from the list.
Return Value
The updated list.
Header File
iowa_utils.h
iowa_utils_list_free
Prototype
void iowa_utils_list_free(iowa_list_t *headP,
iowa_list_node_free_callback_t freeCb);
Description
iowa_utils_list_free() adds a node to a list.
Arguments
- headP
- List to free.
- freeCb
- Callback used to free the list.
Return Value
None.
Header File
iowa_utils.h
iowa_utils_list_find
Prototype
iowa_list_t * iowa_utils_list_find(iowa_list_t *headP,
iowa_list_node_find_callback_t findCb,
void *criteriaP);
Description
iowa_utils_list_find() finds a node in a list.
Arguments
- headP
- List to search on.
- findCb
- Callback used to find the node in the list.
- criteriaP
- Criteria used to find the node in the list.
Return Value
The node if found else NULL.
Header File
iowa_utils.h
iowa_utils_list_find_and_remove
Prototype
iowa_list_t * iowa_utils_list_find_and_remove(iowa_list_t *headP,
iowa_list_node_find_callback_t findCb,
void *criteriaP,
iowa_list_t **nodeP);
Description
iowa_utils_list_find_and_remove() finds a node in a list and removes it.
Arguments
- headP
- List to search on.
- findCb
- Callback used to find the node in the list.
- criteriaP
- Criteria used to find the node in the list.
- nodeP
- OUT. Node removed from the list. Can be nil.
Return Value
The updated list.
Header File
iowa_utils.h
Example: Linked List usage
When declaring the linked list data structure, the first member must be a pointer. This pointer will contain the address of the next element of the list.
Example:
struct myData
{
struct myData *nextP; // Used by the linked list functions
char *aString;
int anInt;
};
The head of the list is a pointer to your data structure.
Example:
struct myData *listHead;
You can now add or remove elements to the list by using the functions iowa_utils_list_add() and iowa_utils_list_remove().
But to avoid compiler warnings or multiple cast making the code unreadable, the following macros can be used:
- IOWA_UTILS_LIST_ADD(H, N)
- IOWA_UTILS_LIST_REMOVE(H, N)
- IOWA_UTILS_LIST_FREE(H, F)
- IOWA_UTILS_LIST_FIND(H, F, C)
- IOWA_UTILS_LIST_FIND_AND_REMOVE(H, F, C, N)
Instead of calling:
listHead = (struct myData *)iowa_utils_list_add((iowa_list_t *)listHead, (iowa_list_t *)newDataP);
You can use:
listHead = (struct myData *)IOWA_UTILS_LIST_ADD(listHead, newDataP);