Update¶

typedef struct cardano_update_t cardano_update_t¶

When stakeholders wish to propose changes to the system’s parameters, they submit an update proposal.

Such proposals are then voted on by the community. If approved, the protocol parameters are adjusted accordingly in the specified epoch.

cardano_error_t cardano_update_new(uint64_t epoch, cardano_proposed_param_updates_t *updates, cardano_update_t **update)¶

Creates and initializes a new instance of the update.

This function allocates and initializes a new instance of the update, representing an update proposal for the Cardano protocol.

Usage Example:

cardano_update_t* update = NULL;
uint64_t epoch = 123; // Example epoch number
cardano_proposed_param_updates_t* proposed_updates = NULL;

// Initialize proposed_updates properly before using

// Attempt to create a new update object
cardano_error_t result = cardano_update_new(epoch, proposed_updates, &update);

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

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

Parameters:¶

uint64_t epoch¶

[in] The epoch number in which the proposal will come into effect if accepted.

cardano_proposed_param_updates_t *updates¶

[in] A pointer to the proposed protocol parameter updates.

cardano_update_t **update¶

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

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the update was successfully created, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_update_from_cbor(cardano_cbor_reader_t *reader, cardano_update_t **update)¶

Creates a cardano_update_t from a CBOR reader.

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

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_update_t* update = NULL;

cardano_error_t result = cardano_update_from_cbor(reader, &update);

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

  // Once done, ensure to clean up and release the update
  cardano_update_unref(&update);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode update: %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_update_t object by calling cardano_update_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 data.

cardano_update_t **update¶

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

Returns:¶

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

cardano_error_t cardano_update_to_cbor(const cardano_update_t *update, cardano_cbor_writer_t *writer)¶

Serializes protocol version into CBOR format using a CBOR writer.

This function serializes the given cardano_update_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_update_t* update = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_update_to_cbor(update, 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_update_unref(&update);

Parameters:¶

const cardano_update_t *update¶

[in] A constant pointer to the cardano_update_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 update or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_update_to_cip116_json(const cardano_update_t *update, cardano_json_writer_t *writer)¶

Serializes an update to CIP-116 JSON.

The function writes the full JSON object, including the surrounding braces. Keys are written in the order: “epoch”, “proposed_protocol_parameter_updates”.

Parameters:¶

const cardano_update_t *update¶

[in] Pointer to a valid cardano_update_t.

cardano_json_writer_t *writer¶

[in] Pointer to a valid cardano_json_writer_t.

Returns:¶

CARDANO_SUCCESS On success. CARDANO_ERROR_POINTER_IS_NULL If update or writer is NULL. Other Any error propagated from nested writers.

cardano_error_t cardano_update_get_epoch(const cardano_update_t *update, uint64_t *epoch)¶

Retrieves the epoch number from the update.

This function returns the epoch number in which the proposal will come into effect if accepted.

Usage Example:

cardano_update_t* update = NULL;
uint64_t epoch = 0;

// Assume update is initialized properly

cardano_error_t result = cardano_update_get_epoch(update, &epoch);

if (result == CARDANO_SUCCESS)
{
  printf("Epoch: %lu\n", epoch);
}

Parameters:¶

const cardano_update_t *update¶

[in] Pointer to the update object.

uint64_t *epoch¶

[out] On successful retrieval, this will point to the epoch number.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the epoch number was successfully retrieved, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_update_get_proposed_parameters(const cardano_update_t *update, cardano_proposed_param_updates_t **proposed_parameters)¶

Retrieves the proposed parameters from the update.

This function returns the proposed protocol parameter updates from the update object.

Usage Example:

cardano_update_t* update = NULL;
cardano_proposed_param_updates_t* proposed_parameters = NULL;

// Assume update is initialized properly

cardano_error_t result = cardano_update_get_proposed_parameters(update, &proposed_parameters);

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

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

Parameters:¶

const cardano_update_t *update¶

[in] Pointer to the update object.

cardano_proposed_param_updates_t **proposed_parameters¶

[out] On successful retrieval, this will point to the proposed protocol parameter updates.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the proposed parameters were successfully retrieved, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_update_set_epoch(cardano_update_t *update, uint64_t epoch)¶

Sets the epoch in the update object.

This function sets the epoch in the given update object, specifying when the proposed protocol parameter updates will take effect if accepted.

Usage Example:

cardano_update_t* update = NULL;
uint64_t epoch = 300; // Example epoch number

// Assume update is initialized properly

cardano_error_t result = cardano_update_set_epoch(update, epoch);

if (result == CARDANO_SUCCESS)
{
  // The epoch has been successfully set
}

Parameters:¶

cardano_update_t *update¶

[in] Pointer to the update object.

uint64_t epoch¶

[in] The epoch number to set.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the epoch was successfully set, or an appropriate error code indicating the failure reason.

cardano_error_t cardano_update_set_proposed_parameters(cardano_update_t *update, cardano_proposed_param_updates_t *proposed_parameters)¶

Sets the proposed protocol parameters in the update object.

This function sets the proposed protocol parameter updates in the given update object. These parameters will take effect in the specified epoch if the proposal is accepted.

Usage Example:

cardano_update_t* update = NULL;
cardano_proposed_param_updates_t* proposed_parameters = NULL;

// Assume update and proposed_parameters are initialized properly

cardano_error_t result = cardano_update_set_proposed_parameters(update, proposed_parameters);

if (result == CARDANO_SUCCESS)
{
  // The proposed parameters have been successfully set
}

// Clean up
cardano_update_unref(&update);
cardano_proposed_param_updates_unref(&proposed_parameters);

Parameters:¶

cardano_update_t *update¶

[in] Pointer to the update object.

cardano_proposed_param_updates_t *proposed_parameters¶

[in] Pointer to the proposed protocol parameter updates to set.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the proposed parameters were successfully set, or an appropriate error code indicating the failure reason.

void cardano_update_unref(cardano_update_t **update)¶

Decrements the reference count of a cardano_update_t object.

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

Usage Example:

cardano_update_t* update = cardano_update_new(major, minor);

// Perform operations with the update...

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

Note

After calling cardano_update_unref, the pointer to the cardano_update_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_update_t **update¶

[inout] A pointer to the pointer of the update 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_update_ref(cardano_update_t *update)¶

Increases the reference count of the cardano_update_t object.

This function is used to manually increment the reference count of an cardano_update_t 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_update_unref.

Usage Example:

// Assuming update is a previously created update object

cardano_update_ref(update);

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

Note

Always ensure that for every call to cardano_update_ref there is a corresponding call to cardano_update_unref to prevent memory leaks.

Parameters:¶

cardano_update_t *update¶

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

size_t cardano_update_refcount(const cardano_update_t *update)¶

Retrieves the current reference count of the cardano_update_t object.

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

Usage Example:

// Assuming update is a previously created update object

size_t ref_count = cardano_update_refcount(update);

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_update_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_update_t *update¶

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

Returns:¶

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

void cardano_update_set_last_error(cardano_update_t *update, const char *message)¶

Sets the last error message for a given cardano_update_t object.

Records an error message in the update’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_update_t *update¶

[in] A pointer to the cardano_update_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 update’s last_error is set to an empty string, indicating no error.

const char *cardano_update_get_last_error(const cardano_update_t *update)¶

Retrieves the last error message recorded for a specific update.

This function returns a pointer to the null-terminated string containing the last error message set by cardano_update_set_last_error for the given update. 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_update_set_last_error for the same update, or until the update is deallocated.

Parameters:¶

const cardano_update_t *update¶

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

Returns:¶

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