Constitution¶

typedef struct cardano_constitution_t cardano_constitution_t¶

The Cardano Constitution is a text document that defines Cardano’s shared values and guiding principles.

At this stage, the Constitution is an informational document that unambiguously captures the core values of Cardano and acts to ensure its long-term sustainability. At a later stage, we can imagine the Constitution perhaps evolving into a smart-contract based set of rules that drives the entire governance framework.

For now, however, the Constitution will remain an off-chain document whose hash digest value will be recorded on-chain.

cardano_error_t cardano_constitution_new(cardano_anchor_t *anchor, cardano_blake2b_hash_t *script_hash, cardano_constitution_t **constitution)¶

Creates and initializes a new instance of the Cardano Constitution.

This function allocates and initializes a new instance of a cardano_constitution_t object, which represents the Cardano Constitution, a guiding document that defines Cardano’s shared values and principles. It ensures the long-term sustainability of the Cardano ecosystem by capturing these core values in a form that is potentially verifiable on-chain through its hash.

Usage Example:

cardano_anchor_t* anchor = cardano_anchor_new(...); // Assume anchor is already initialized
cardano_blake2b_hash_t* script_hash = cardano_blake2b_hash_new(...); // Optionally initialized
cardano_constitution_t* constitution = NULL;
cardano_error_t result = cardano_constitution_new(anchor, script_hash, &constitution);

if (result == CARDANO_SUCCESS)
{
  // Use the constitution
  // Free resources when done
  cardano_constitution_unref(&constitution);
}
else
{
  printf("Failed to create the constitution: %s\n", cardano_error_to_string(result));
}

// Cleanup the anchor and optionally the script hash
cardano_anchor_unref(&anchor);

if (script_hash)
{
  cardano_blake2b_hash_unref(&script_hash);
}

Parameters:¶

cardano_anchor_t *anchor¶

[in] A pointer to a cardano_anchor_t object that links to the off-chain content of the constitution.

cardano_blake2b_hash_t *script_hash¶

[in] An optional pointer to a cardano_blake2b_hash_t object representing the hash of the constitution’s script. This parameter can be NULL if no hash is to be associated.

cardano_constitution_t **constitution¶

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

Returns:¶

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

cardano_error_t cardano_constitution_from_cbor(cardano_cbor_reader_t *reader, cardano_constitution_t **constitution)¶

Creates a cardano_constitution_t from a CBOR reader.

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

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_constitution_t* constitution = NULL;

cardano_error_t result = cardano_constitution_from_cbor(reader, &constitution);

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

  // Once done, ensure to clean up and release the constitution
  cardano_constitution_unref(&constitution);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode constitution: %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_constitution_t object by calling cardano_constitution_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_constitution_t **constitution¶

[out] A pointer to a pointer of cardano_constitution_t that will be set to the address of the newly created constitution 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_constitution_to_cbor(const cardano_constitution_t *constitution, cardano_cbor_writer_t *writer)¶

Serializes the certificate into CBOR format using a CBOR writer.

This function serializes the given cardano_constitution_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_constitution_t* constitution = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_constitution_to_cbor(constitution, 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_constitution_unref(&constitution);

Parameters:¶

const cardano_constitution_t *constitution¶

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

cardano_error_t cardano_constitution_to_cip116_json(const cardano_constitution_t *constitution, cardano_json_writer_t *writer)¶

Serializes a constitution object to CIP-116 JSON.

The function writes the full JSON object, including the surrounding braces. Keys are written in the order: “anchor”, then “script_hash” (if present).

Parameters:¶

const cardano_constitution_t *constitution¶

[in] Pointer to a valid cardano_constitution_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 constitution or writer is NULL. CARDANO_ERROR_MEMORY_ALLOCATION_FAILED If memory allocation fails. Other Any error propagated from nested writers.

cardano_error_t cardano_constitution_set_anchor(cardano_constitution_t *constitution, cardano_anchor_t *anchor)¶

Sets the anchor in the constitution.

This function updates the anchor of a cardano_constitution_t object. The anchor is used to link to the off-chain content of the constitution.

Usage Example:

cardano_constitution_t* constitution = ...; // Assume constitution is already initialized
cardano_anchor_t* anchor = cardano_anchor_new(...); // Assume anchor is already initialized

cardano_error_t result = cardano_constitution_set_anchor(constitution, anchor);
if (result == CARDANO_SUCCESS)
{
  // The anchor is now set for the constitution
}
else
{
  printf("Failed to set the anchor.\n");
}
// Clean up the constitution and anchor after use
cardano_constitution_unref(&constitution);
cardano_anchor_unref(&anchor);

Parameters:¶

cardano_constitution_t *constitution¶

[inout] A pointer to an initialized cardano_constitution_t object to which the anchor will be set.

cardano_anchor_t *anchor¶

[in] A pointer to an initialized cardano_anchor_t object representing the new anchor.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the anchor was successfully set, or an appropriate error code indicating the failure reason, such as CARDANO_ERROR_POINTER_IS_NULL if any of the input pointers are NULL.

cardano_anchor_t *cardano_constitution_get_anchor(cardano_constitution_t *constitution)¶

Gets the anchor from a constitution.

This function retrieves the anchor from a given cardano_constitution_t object. The anchor links to the off-chain content of the constitution.

Usage Example:

cardano_constitution_t* constitution = ...; // Assume initialized
cardano_anchor_t* anchor = cardano_constitution_get_anchor(constitution);

if (anchor != NULL)
{
  // Use the anchor

  // Once done, ensure to clean up and release the anchor
  cardano_anchor_unref(&anchor);
}
else
{
  printf("ERROR: No anchor set for this constitution.\n");
}

Parameters:¶

cardano_constitution_t *constitution¶

[in] A pointer to an initialized cardano_constitution_t object from which the anchor is retrieved.

Returns:¶

A pointer to the retrieved cardano_anchor_t object representing the anchor. This will be a new reference, and the caller is responsible for releasing it with cardano_anchor_unref when it is no longer needed. If the constitution does not have an anchor set, NULL is returned.

cardano_error_t cardano_constitution_set_script_hash(cardano_constitution_t *constitution, cardano_blake2b_hash_t *script_hash)¶

Sets the script hash in the constitution.

This function updates the script hash of a cardano_constitution_t object. The script hash is a cardano_blake2b_hash_t object representing the hash of the off-chain constitution content.

Usage Example:

cardano_constitution_t* constitution = ...; // Assume constitution is already initialized
cardano_blake2b_hash_t* script_hash = cardano_blake2b_hash_new(...); // Assume script_hash is initialized

cardano_error_t result = cardano_constitution_set_script_hash(constitution, script_hash);
if (result == CARDANO_SUCCESS)
{
  // The script hash is now set for the constitution
}
else
{
  printf("Failed to set the script hash.\n");
}

// Free resources when done
cardano_blake2b_hash_unref(script_hash);
cardano_constitution_unref(&constitution);

Parameters:¶

cardano_constitution_t *constitution¶

[inout] A pointer to an initialized cardano_constitution_t object to which the script hash will be set.

cardano_blake2b_hash_t *script_hash¶

[in] A pointer to an initialized cardano_blake2b_hash_t object representing the new script hash. This parameter can be NULL if the script hash is to be unset.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the script hash was successfully set, or an appropriate error code indicating the failure reason, such as CARDANO_ERROR_POINTER_IS_NULL if the constitution pointer is NULL.

cardano_blake2b_hash_t *cardano_constitution_get_script_hash(cardano_constitution_t *constitution)¶

Retrieves the script hash from a constitution.

This function retrieves the script hash from a given cardano_constitution_t object. The script hash is represented as a cardano_blake2b_hash_t object.

Usage Example:

cardano_constitution_t* constitution = ...; // Assume initialized
cardano_blake2b_hash_t* script_hash = cardano_constitution_get_script_hash(constitution);

if (script_hash != NULL)
{
  printf("Script Hash: %s\n", cardano_blake2b_hash_to_string(script_hash));
  // Use the script hash data

  // Once done, ensure to clean up and release the script hash
  cardano_blake2b_hash_unref(&script_hash);
}

Parameters:¶

cardano_constitution_t *constitution¶

[in] A pointer to an initialized cardano_constitution_t object from which the script hash is retrieved.

Returns:¶

A pointer to the retrieved cardano_blake2b_hash_t object representing the script hash. This will be a new reference, and the caller is responsible for releasing it with cardano_blake2b_hash_unref when it is no longer needed.

void cardano_constitution_unref(cardano_constitution_t **constitution)¶

Decrements the reference count of a cardano_constitution_t object.

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

Usage Example:

cardano_constitution_t* constitution = cardano_constitution_new(major, minor);

// Perform operations with the constitution...

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

Note

After calling cardano_constitution_unref, the pointer to the cardano_constitution_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_constitution_t **constitution¶

[inout] A pointer to the pointer of the constitution 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_constitution_ref(cardano_constitution_t *constitution)¶

Increases the reference count of the cardano_constitution_t object.

This function is used to manually increment the reference count of an cardano_constitution_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_constitution_unref.

Usage Example:

// Assuming constitution is a previously created constitution object

cardano_constitution_ref(constitution);

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

Note

Always ensure that for every call to cardano_constitution_ref there is a corresponding call to cardano_constitution_unref to prevent memory leaks.

Parameters:¶

cardano_constitution_t *constitution¶

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

size_t cardano_constitution_refcount(const cardano_constitution_t *constitution)¶

Retrieves the current reference count of the cardano_constitution_t object.

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

Usage Example:

// Assuming constitution is a previously created constitution object

size_t ref_count = cardano_constitution_refcount(constitution);

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_constitution_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_constitution_t *constitution¶

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

Returns:¶

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

void cardano_constitution_set_last_error(cardano_constitution_t *constitution, const char *message)¶

Sets the last error message for a given cardano_constitution_t object.

Records an error message in the constitution’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_constitution_t *constitution¶

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

const char *cardano_constitution_get_last_error(const cardano_constitution_t *constitution)¶

Retrieves the last error message recorded for a specific constitution.

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

Parameters:¶

const cardano_constitution_t *constitution¶

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

Returns:¶

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