Metadatum List¶

typedef struct cardano_metadatum_list_t cardano_metadatum_list_t¶

Represents a list of metadatum.

cardano_error_t cardano_metadatum_list_new(cardano_metadatum_list_t **metadatum_list)¶

Creates and initializes a new instance of a metadatum_list.

This function allocates and initializes a new instance of cardano_metadatum_list_t. It returns an error code to indicate success or failure of the operation.

Usage Example:

cardano_metadatum_list_t* metadatum_list = NULL;

// Attempt to create a new metadatum_list
cardano_error_t result = cardano_metadatum_list_new(&metadatum_list);

if (result == CARDANO_SUCCESS)
{
  // Use the metadatum_list

  // Once done, ensure to clean up and release the metadatum_list
  cardano_metadatum_list_unref(&metadatum_list);
}

Parameters:¶

cardano_metadatum_list_t **metadatum_list¶

[out] On successful initialization, this will point to a newly created cardano_metadatum_list_t object. This object represents a “strong reference” to the metadatum_list, meaning that it is fully initialized and ready for use. The caller is responsible for managing the lifecycle of this object. Specifically, once the metadatum_list is no longer needed, the caller must release it by calling cardano_metadatum_list_unref.

Returns:¶

CARDANO_SUCCESS if the metadatum_list was successfully created, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_metadatum_list_from_cbor(cardano_cbor_reader_t *reader, cardano_metadatum_list_t **metadatum_list)¶

Creates a metadatum_list from a CBOR reader.

This function parses CBOR data using a provided cardano_cbor_reader_t and constructs a cardano_metadatum_list_t object. It assumes that the CBOR reader is set up correctly and that the CBOR data corresponds to the structure expected for a metadatum_list.

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_metadatum_list_t* metadatum_list = NULL;

cardano_error_t result = cardano_metadatum_list_from_cbor(reader, &metadatum_list);

if (result == CARDANO_SUCCESS)
{
  // Use the metadatum_list

  // Once done, ensure to clean up and release the metadatum_list
  cardano_metadatum_list_unref(&metadatum_list);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode metadatum_list: %s\n", error);
}

cardano_cbor_reader_unref(&reader); // Cleanup the CBOR reader

Note

If the function fails, the last error can be retrieved by calling cardano_cbor_reader_get_last_error with the reader. The caller is responsible for freeing the created cardano_metadatum_list_t object by calling cardano_metadatum_list_unref when it is no longer needed.

Parameters:¶

cardano_cbor_reader_t *reader¶

[in] A pointer to an initialized cardano_cbor_reader_t that is ready to read the CBOR-encoded metadatum_list data.

cardano_metadatum_list_t **metadatum_list¶

[out] A pointer to a pointer of cardano_metadatum_list_t that will be set to the address of the newly created metadatum_list object upon successful decoding.

Returns:¶

A cardano_error_t value indicating the outcome of the operation. Returns CARDANO_SUCCESS if the metadatum_list was successfully created, or an appropriate error code if an error occurred.

cardano_error_t cardano_metadatum_list_to_cbor(const cardano_metadatum_list_t *metadatum_list, cardano_cbor_writer_t *writer)¶

Serializes a metadatum_list into CBOR format using a CBOR writer.

This function serializes the given cardano_metadatum_list_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_metadatum_list_t* metadatum_list = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_metadatum_list_to_cbor(metadatum_list, writer);

  if (result == CARDANO_SUCCESS)
  {
    // Use the writer's buffer containing the serialized data
  }
  else
  {
    const char* error_message = cardano_cbor_writer_get_last_error(writer);
    printf("Serialization failed: %s\n", error_message);
  }

  cardano_cbor_writer_unref(&writer);
}

cardano_metadatum_list_unref(&metadatum_list);

Parameters:¶

const cardano_metadatum_list_t *metadatum_list¶

[in] A constant pointer to the cardano_metadatum_list_t object that is to be serialized.

cardano_cbor_writer_t *writer¶

[out] A pointer to a cardano_cbor_writer_t where the CBOR serialized data will be written. The writer must already be initialized and ready to accept the data.

Returns:¶

Returns CARDANO_SUCCESS if the serialization is successful. If the metadatum_list or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_metadatum_list_to_cip116_json(const cardano_metadatum_list_t *list, cardano_json_writer_t *writer)¶

Serializes a cardano_metadatum_list_t to CIP-116 JSON.

Produces a single JSON object.

Each element in contents is itself a full CIP-116 metadatum object as written by cardano_metadatum_to_cip116_json.

The function always writes a complete JSON object (it begins with { and ends with }). It assumes writer is positioned where a value is valid (root, array element, or after a property name).

Note

Property order (“tag” then “contents”) is stable for readability, but not required by CIP-116.

Parameters:¶

const cardano_metadatum_list_t *list¶

[in] A valid metadatum list to serialize.

cardano_json_writer_t *writer¶

[in] A valid JSON writer.

Returns:¶

CARDANO_SUCCESS on success.

Returns:¶

CARDANO_ERROR_POINTER_IS_NULL if any pointer parameter is NULL.

Returns:¶

CARDANO_ERROR_ENCODING if an element cannot be retrieved or serialized.

size_t cardano_metadatum_list_get_length(const cardano_metadatum_list_t *metadatum_list)¶

Retrieves the length of a metadatum list.

This function retrieves the number of elements in the provided cardano_metadatum_list_t object.

Usage Example:

cardano_metadatum_list_t* metadatum_list = cardano_metadatum_list_new();

// Populate metadatum_list with elements

size_t length = cardano_metadatum_list_get_length(metadatum_list);
printf("Length of the metadatum_list: %zu\n", length);

// Clean up the metadatum_list object once done
cardano_metadatum_list_unref(&metadatum_list);

Parameters:¶

const cardano_metadatum_list_t *metadatum_list¶

[in] A constant pointer to the cardano_metadatum_list_t object whose length is to be retrieved.

Returns:¶

The number of elements in the metadatum_list. Return 0 if the metadatum_list is NULL.

cardano_error_t cardano_metadatum_list_get(const cardano_metadatum_list_t *metadatum_list, size_t index, cardano_metadatum_t **element)¶

Retrieves an element from a metadatum list by index.

This function retrieves the element at the specified index from the provided cardano_metadatum_list_t object and stores it in the output parameter.

Usage Example:

cardano_metadatum_list_t* metadatum_list = cardano_metadatum_list_new();

// Populate metadatum_list with elements

cardano_metadatum_t* element = NULL;
cardano_error_t result = cardano_metadatum_list_get(metadatum_list, 2, &element);

if (result == CARDANO_SUCCESS)
{
  // Use the retrieved element
  // Remember to unreference the element once done if it's no longer needed
  cardano_metadatum_unref(&element);
}

// Clean up the metadatum_list object once done
cardano_metadatum_list_unref(&metadatum_list);

Parameters:¶

const cardano_metadatum_list_t *metadatum_list¶

[in] A constant pointer to the cardano_metadatum_list_t object from which the element is to be retrieved.

size_t index¶

[in] The index of the element to retrieve from the metadatum list. Indexing starts at 0.

cardano_metadatum_t **element¶

[out] Pointer to a variable where the retrieved element will be stored. This variable will point to the retrieved cardano_metadatum_t object. The caller is responsible for managing the lifecycle of the element by calling cardano_metadatum_unref when it is no longer needed.

Returns:¶

CARDANO_SUCCESS if the element was successfully retrieved, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_metadatum_list_add(cardano_metadatum_list_t *metadatum_list, cardano_metadatum_t *element)¶

Adds an element to a metadatum list.

This function adds the specified element to the end of the provided cardano_metadatum_list_t object.

Usage Example:

cardano_metadatum_list_t* metadatum_list = cardano_metadatum_list_new();

// Create and initialize a new metadatum element
cardano_metadatum_t* element = { ... };

// Add the element to the metadatum_list
cardano_error_t result = cardano_metadatum_list_add(metadatum_list, element);

if (result == CARDANO_SUCCESS)
{
  // Element added successfully
}

// Clean up the metadatum_list object once done
cardano_metadatum_list_unref(&metadatum_list);

Parameters:¶

cardano_metadatum_list_t *metadatum_list¶

[in] A constant pointer to the cardano_metadatum_list_t object to which the element is to be added.

cardano_metadatum_t *element¶

[in] Pointer to the cardano_metadatum_t object that is to be added to the metadatum_list. The element will be referenced by the metadatum_list after addition.

Returns:¶

CARDANO_SUCCESS if the element was successfully added to the metadatum_list, or an appropriate error code indicating the failure reason.

bool cardano_metadatum_list_equals(const cardano_metadatum_list_t *lhs, const cardano_metadatum_list_t *rhs)¶

Checks if two metadatum lists are equal.

This function compares two cardano_metadatum_list_t objects to determine if they are equal. Two metadatum lists are considered equal if they have the same number of elements and each corresponding pair of elements is equal according to the cardano_metadatum_equals function.

Usage Example:

cardano_metadatum_list_t* list1 = { ... };  // Assume list1 is initialized here
cardano_metadatum_list_t* list2 = { ... };  // Assume list2 is initialized here

if (cardano_metadatum_list_equals(list1, list2))
{
  // The two metadatum_lists are equal
}
else
{
  // The two metadatum_lists are not equal
}

Parameters:¶

const cardano_metadatum_list_t *lhs¶

[in] A constant pointer to the first cardano_metadatum_list_t object to be compared.

const cardano_metadatum_list_t *rhs¶

[in] A constant pointer to the second cardano_metadatum_list_t object to be compared.

Returns:¶

true if the two metadatum_lists are equal, false otherwise.

void cardano_metadatum_list_unref(cardano_metadatum_list_t **metadatum_list)¶

Decrements the reference count of a metadatum_list object.

This function is responsible for managing the lifecycle of a cardano_metadatum_list_t object by decreasing its reference count. When the reference count reaches zero, the metadatum_list is finalized; its associated resources are released, and its memory is deallocated.

Usage Example:

cardano_metadatum_list_t* metadatum_list = cardano_metadatum_list_new();

// Perform operations with the metadatum_list...

cardano_metadatum_list_unref(&metadatum_list);
// At this point, metadatum_list is NULL and cannot be used.

Note

After calling cardano_metadatum_list_unref, the pointer to the cardano_metadatum_list_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_metadatum_list_t **metadatum_list¶

[inout] A pointer to the pointer of the metadatum_list object. This double indirection allows the function to set the caller’s pointer to NULL, avoiding dangling pointer issues after the object has been freed.

void cardano_metadatum_list_ref(cardano_metadatum_list_t *metadatum_list)¶

Increases the reference count of the cardano_metadatum_list_t object.

This function is used to manually increment the reference count of a metadatum_list object, indicating that another part of the code has taken ownership of it. This ensures the object remains allocated and valid until all owners have released their reference by calling cardano_metadatum_list_unref.

Usage Example:

// Assuming metadatum_list is a previously created metadatum_list object

cardano_metadatum_list_ref(metadatum_list);

// Now metadatum_list can be safely used elsewhere without worrying about premature deallocation

Note

Always ensure that for every call to cardano_metadatum_list_ref there is a corresponding call to cardano_metadatum_list_unref to prevent memory leaks.

Parameters:¶

cardano_metadatum_list_t *metadatum_list¶

A pointer to the metadatum_list object whose reference count is to be incremented.

size_t cardano_metadatum_list_refcount(const cardano_metadatum_list_t *metadatum_list)¶

Retrieves the current reference count of the cardano_metadatum_list_t object.

This function returns the number of active references to a metadatum_list object. It’s useful for debugging purposes or managing the lifecycle of the object in complex scenarios.

Usage Example:

// Assuming metadatum_list is a previously created metadatum_list object

size_t ref_count = cardano_metadatum_list_refcount(metadatum_list);

printf("Reference count: %zu\n", ref_count);

Warning

This function does not account for transitive references. A transitive reference occurs when an object holds a reference to another object, rather than directly to the cardano_metadatum_list_t. As such, the reported count may not fully represent the total number of conceptual references in cases where such transitive relationships exist.

Parameters:¶

const cardano_metadatum_list_t *metadatum_list¶

A pointer to the metadatum_list object whose reference count is queried. The object must not be NULL.

Returns:¶

The number of active references to the specified metadatum_list object. If the object is properly managed (i.e., every cardano_metadatum_list_ref call is matched with a cardano_metadatum_list_unref call), this count should reach zero right before the object is deallocated.

void cardano_metadatum_list_set_last_error(cardano_metadatum_list_t *metadatum_list, const char *message)¶

Sets the last error message for a given metadatum_list object.

Records an error message in the metadatum_list’s last_error buffer, overwriting any existing message. This is useful for storing descriptive error information that can be later retrieved. The message is truncated if it exceeds the buffer’s capacity.

Note

The error message is limited to 1023 characters, including the null terminator, due to the fixed size of the last_error buffer.

Parameters:¶

cardano_metadatum_list_t *metadatum_list¶

[in] A pointer to the cardano_metadatum_list_t instance whose last error message is to be set. If NULL, the function does nothing.

const char *message¶

[in] A null-terminated string containing the error message. If NULL, the metadatum_list’s last_error is set to an empty string, indicating no error.

const char *cardano_metadatum_list_get_last_error(const cardano_metadatum_list_t *metadatum_list)¶

Retrieves the last error message recorded for a specific metadatum_list.

This function returns a pointer to the null-terminated string containing the last error message set by cardano_metadatum_list_set_last_error for the given metadatum_list. If no error message has been set, or if the last_error buffer was explicitly cleared, an empty string is returned, indicating no error.

Note

The returned string points to internal storage within the object and must not be modified by the caller. The string remains valid until the next call to cardano_metadatum_list_set_last_error for the same metadatum_list, or until the metadatum_list is deallocated.

Parameters:¶

const cardano_metadatum_list_t *metadatum_list¶

[in] A pointer to the cardano_metadatum_list_t instance whose last error message is to be retrieved. If the metadatum_list is NULL, the function returns a generic error message indicating the null metadatum_list.

Returns:¶

A pointer to a null-terminated string containing the last error message for the specified metadatum_list. If the metadatum_list is NULL, “Object is NULL.” is returned to indicate the error.