Unit Interval¶

typedef struct cardano_unit_interval_t cardano_unit_interval_t¶

Represents a rational number as a ratio of two integers.

Unit intervals are serialized as Rational Numbers (Tag 30). Rational numbers are numbers that can be expressed as a ratio of two integers: a numerator, written as the top part of a fraction, and the denominator, the bottom part. The value of a rational number is the numerator divided by the denominator.

cardano_error_t cardano_unit_interval_new(uint64_t numerator, uint64_t denominator, cardano_unit_interval_t **unit_interval)¶

Creates and initializes a new instance of a unit interval.

This function allocates and initializes a new instance of a unit interval, representing a rational number where the numerator and denominator are both unsigned 64-bit integers. Unit intervals are serialized as Rational Numbers (Tag 30). Rational numbers are numbers that can be expressed as a ratio of two integers: a numerator, usually written as the top part of a fraction, and the denominator, the bottom part. The value of a rational number is the numerator divided by the denominator.

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
uint64_t numerator = 3;
uint64_t denominator = 4;

// Attempt to create a new unit interval object
cardano_error_t result = cardano_unit_interval_new(numerator, denominator, &unit_interval);

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

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

Parameters:¶

uint64_t numerator¶: [in] The numerator of the unit interval.
uint64_t denominator¶: [in] The denominator of the unit interval.
cardano_unit_interval_t **unit_interval¶: [out] On successful initialization, this will point to a newly created unit interval 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 unit interval is no longer needed, the caller must release it by calling cardano_unit_interval_unref.

Returns:¶

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

cardano_error_t cardano_unit_interval_from_double(double value, cardano_unit_interval_t **unit_interval)¶

Creates and initializes a new instance of a unit interval from a floating-point value.

This function creates a new instance of a unit interval from a floating-point value, representing a rational number. The floating-point value is converted into a fraction where the numerator and denominator are both unsigned 64-bit integers.

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
double value = 0.25; // Example floating-point value

// Attempt to create a new unit interval object from the floating-point value
cardano_error_t result = cardano_unit_interval_from_double(value, &unit_interval);

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

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

Parameters:¶

double value¶: [in] The floating-point value from which to create the unit interval.
cardano_unit_interval_t **unit_interval¶: [out] On successful initialization, this will point to a newly created unit interval 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 unit interval is no longer needed, the caller must release it by calling cardano_unit_interval_unref.

Returns:¶

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

cardano_error_t cardano_unit_interval_from_cbor(cardano_cbor_reader_t *reader, cardano_unit_interval_t **unit_interval)¶

Creates a cardano_unit_interval_t from a CBOR reader.

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

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_unit_interval_t* unit_interval = NULL;

cardano_error_t result = cardano_unit_interval_from_cbor(reader, &unit_interval);

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

  // Once done, ensure to clean up and release the unit_interval
  cardano_unit_interval_unref(&unit_interval);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode unit_interval: %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_unit_interval_t object by calling cardano_unit_interval_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_unit_interval_t **unit_interval¶: [out] A pointer to a pointer of cardano_unit_interval_t that will be set to the address of the newly created unit_interval 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_unit_interval_to_cbor(const cardano_unit_interval_t *unit_interval, cardano_cbor_writer_t *writer)¶

Serializes protocol version into CBOR format using a CBOR writer.

This function serializes the given cardano_unit_interval_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_unit_interval_t* unit_interval = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_unit_interval_to_cbor(unit_interval, 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_unit_interval_unref(&unit_interval);

Parameters:¶

const cardano_unit_interval_t *unit_interval¶: [in] A constant pointer to the cardano_unit_interval_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 unit_interval or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_unit_interval_to_cip116_json(const cardano_unit_interval_t *interval, cardano_json_writer_t *writer)¶

Serializes a unit interval to CIP-116 JSON.

The function writes the full JSON object, including the surrounding braces. Keys are written in the order: “numerator”, “denominator”. Both values are encoded as strings to ensure precision for 64-bit integers in JSON.

Parameters:¶

const cardano_unit_interval_t *interval¶: [in] Pointer to a valid cardano_unit_interval_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 interval or writer is NULL. Other Any error propagated from nested writers.

uint64_t cardano_unit_interval_get_numerator(const cardano_unit_interval_t *unit_interval)¶

Retrieves the numerator of the Unit Interval.

This function returns the numerator of the Unit Interval,

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
// Assume unit_interval is initialized properly

uint64_t numerator_version = cardano_unit_interval_get_numerator(unit_interval);
printf("Major Version: %lu\n", numerator_version);

Parameters:¶

const cardano_unit_interval_t *unit_interval¶: [in] Pointer to the Unit Interval object.

Returns:¶

The numerator of the Unit Interval.

cardano_error_t cardano_unit_interval_set_numerator(cardano_unit_interval_t *unit_interval, uint64_t numerator)¶

Sets the numerator of the Unit Interval.

This function sets the numerator of the Unit Interval,

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
// Assume unit_interval is initialized properly

cardano_error_t result = cardano_unit_interval_set_numerator(unit_interval, 2);

if (result == CARDANO_SUCCESS)
{
  printf("Major version set successfully.\n");
}
else
{
  printf("Failed to set numerator version: %d\n", result);
}

Parameters:¶

cardano_unit_interval_t *unit_interval¶: [in] Pointer to the Unit Interval object.
uint64_t numerator¶: [in] The numerator to set.

Returns:¶

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

uint64_t cardano_unit_interval_get_denominator(const cardano_unit_interval_t *unit_interval)¶

Retrieves the denominator of the Unit Interval.

This function returns the denominator of the Unit Interval.

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
// Assume unit_interval is initialized properly

uint64_t denominator_version = cardano_unit_interval_get_denominator(unit_interval);
printf("Minor Version: %lu\n", denominator_version);

Parameters:¶

const cardano_unit_interval_t *unit_interval¶: [in] Pointer to the Unit Interval object.

Returns:¶

The denominator of the Unit Interval.

double cardano_unit_interval_to_double(const cardano_unit_interval_t *unit_interval)¶

Converts a unit interval to a double-precision floating-point value.

This function converts a unit interval, representing a rational number, to a double-precision floating-point value. The rational number is converted into a floating-point representation, providing a decimal approximation of the value.

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
// Assume unit_interval is initialized properly

double result = cardano_unit_interval_to_double(unit_interval);
printf("Result: %f\n", result);

Parameters:¶

const cardano_unit_interval_t *unit_interval¶: [in] Pointer to the unit interval object to be converted.

Returns:¶

The double-precision floating-point value representing the unit interval.

cardano_error_t cardano_unit_interval_set_denominator(cardano_unit_interval_t *unit_interval, uint64_t denominator)¶

Sets the denominator of the Unit Interval.

This function sets the denominator of the Unit Interval.

Usage Example:

cardano_unit_interval_t* unit_interval = NULL;
// Assume unit_interval is initialized properly

cardano_error_t result = cardano_unit_interval_set_denominator(unit_interval, 1);

if (result == CARDANO_SUCCESS)
{
  printf("Minor version set successfully.\n");
}
else
{
  printf("Failed to set denominator version: %d\n", result);
}

Parameters:¶

cardano_unit_interval_t *unit_interval¶: [in] Pointer to the Unit Interval object.
uint64_t denominator¶: [in] The denominator to set.

Returns:¶

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

void cardano_unit_interval_unref(cardano_unit_interval_t **unit_interval)¶

Decrements the reference count of a cardano_unit_interval_t object.

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

Usage Example:

cardano_unit_interval_t* unit_interval = cardano_unit_interval_new(numerator, denominator);

// Perform operations with the unit_interval...

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

Note

After calling cardano_unit_interval_unref, the pointer to the cardano_unit_interval_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_unit_interval_t **unit_interval¶: [inout] A pointer to the pointer of the unit_interval 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_unit_interval_ref(cardano_unit_interval_t *unit_interval)¶

Increases the reference count of the cardano_unit_interval_t object.

This function is used to manually increment the reference count of an cardano_unit_interval_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_unit_interval_unref.

Usage Example:

// Assuming unit_interval is a previously created unit_interval object

cardano_unit_interval_ref(unit_interval);

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

Note

Always ensure that for every call to cardano_unit_interval_ref there is a corresponding call to cardano_unit_interval_unref to prevent memory leaks.

Parameters:¶

cardano_unit_interval_t *unit_interval¶: A pointer to the cardano_unit_interval_t object whose reference count is to be incremented.

size_t cardano_unit_interval_refcount(const cardano_unit_interval_t *unit_interval)¶

Retrieves the current reference count of the cardano_unit_interval_t object.

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

Usage Example:

// Assuming unit_interval is a previously created unit_interval object

size_t ref_count = cardano_unit_interval_refcount(unit_interval);

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_unit_interval_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_unit_interval_t *unit_interval¶: A pointer to the cardano_unit_interval_t object whose reference count is queried. The object must not be NULL.

Returns:¶

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

void cardano_unit_interval_set_last_error(cardano_unit_interval_t *unit_interval, const char *message)¶

Sets the last error message for a given cardano_unit_interval_t object.

Records an error message in the unit_interval’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_unit_interval_t *unit_interval¶: [in] A pointer to the cardano_unit_interval_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 unit_interval’s last_error is set to an empty string, indicating no error.

const char *cardano_unit_interval_get_last_error(const cardano_unit_interval_t *unit_interval)¶

Retrieves the last error message recorded for a specific unit_interval.

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

Parameters:¶

const cardano_unit_interval_t *unit_interval¶: [in] A pointer to the cardano_unit_interval_t instance whose last error message is to be retrieved. If the unit_interval is NULL, the function returns a generic error message indicating the null unit_interval.

Returns:¶

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