Committee¶

typedef struct cardano_committee_t cardano_committee_t¶

The constitutional committee represents a set of individuals or entities (each associated with a pair of Ed25519 credentials) that are collectively responsible for ensuring that the Constitution is respected.

Though it cannot be enforced on-chain, the constitutional committee is only supposed to vote on the constitutionality of governance actions (which should thus ensure the long-term sustainability of the blockchain) and should be replaced (via the no confidence action) if they overstep this boundary.

cardano_error_t cardano_committee_new(cardano_unit_interval_t *quorum_threshold, cardano_committee_t **committee)¶

Creates and initializes a new instance of a constitutional committee.

This function allocates and initializes a new instance of a cardano_committee_t object, which represents a constitutional committee responsible for overseeing the constitutionality of governance actions. The function requires a quorum threshold, represented as a cardano_unit_interval_t object, defining the minimum percentage of committee members that must participate in a vote for it to be valid.

Usage Example:

cardano_unit_interval_t* quorum_threshold = ...; // Assume quorum_threshold is already initialized
cardano_committee_t* committee = NULL;
cardano_error_t result = cardano_committee_new(&quorum_threshold, &committee);

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

Parameters:¶

cardano_unit_interval_t *quorum_threshold¶: [in] A pointer to a cardano_unit_interval_t object specifying the minimum percentage of committee members required to participate in a vote for it to be valid.
cardano_committee_t **committee¶: [out] On successful initialization, this will point to a newly created cardano_committee_t object. This object represents a “strong reference” to the committee, meaning that it is fully initialized and ready for use. The caller is responsible for managing the lifecycle of this object, specifically, once the committee is no longer needed, the caller must release it by calling cardano_committee_unref.

Returns:¶

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

cardano_error_t cardano_committee_from_cbor(cardano_cbor_reader_t *reader, cardano_committee_t **committee)¶

Creates a cardano_committee_t from a CBOR reader.

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

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_committee_t* committee = NULL;

cardano_error_t result = cardano_committee_from_cbor(reader, &committee);

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

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

Serializes the certificate into CBOR format using a CBOR writer.

This function serializes the given cardano_committee_t object using a cardano_cbor_writer_t.

Usage Example:

cardano_committee_t* committee = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_committee_to_cbor(committee, 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_committee_unref(&committee);

Parameters:¶

const cardano_committee_t *committee¶: [in] A constant pointer to the cardano_committee_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 committee or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

cardano_error_t cardano_committee_set_quorum_threshold(cardano_committee_t *committee, cardano_unit_interval_t *quorum_threshold)¶

Sets the quorum threshold in the committee.

This function updates the quorum threshold of a cardano_committee_t object. The quorum threshold is a cardano_unit_interval_t object representing the minimum percentage of committee members that must participate for a vote to be valid.

Usage Example:

cardano_committee_t* committee = ...; // Assume committee is already initialized
cardano_unit_interval_t quorum_threshold = { .numerator = 60, .denominator = 100 }; // 60% quorum

cardano_error_t result = cardano_committee_set_quorum_threshold(committee, &quorum_threshold);
if (result == CARDANO_SUCCESS)
{
  // The quorum threshold is now set for the committee
}
else
{
  printf("Failed to set the quorum threshold.\n");
}
// The committee needs to be managed and eventually unreferenced by the caller
cardano_committee_unref(&committee);

Parameters:¶

cardano_committee_t *committee¶: [inout] A pointer to an initialized cardano_committee_t object to which the quorum threshold will be set.
cardano_unit_interval_t *quorum_threshold¶: [in] A pointer to an initialized cardano_unit_interval_t object representing the new quorum threshold.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the quorum threshold 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_unit_interval_t *cardano_committee_get_quorum_threshold(cardano_committee_t *committee)¶

Gets the quorum threshold from a committee.

This function retrieves the quorum threshold from a given cardano_committee_t object. The quorum threshold is represented as a cardano_unit_interval_t object which details the minimum percentage of committee members required to validate a vote.

Usage Example:

cardano_committee_t* committee = ...; // Assume initialized
cardano_unit_interval_t* quorum_threshold = cardano_committee_get_quorum_threshold(committee);

if (quorum_threshold != NULL)
{
  printf("Quorum Threshold: %u/%u\n", quorum_threshold->numerator, quorum_threshold->denominator);
  // Use the quorum threshold data

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

Parameters:¶

cardano_committee_t *committee¶: [in] A pointer to an initialized cardano_committee_t object from which the quorum threshold is retrieved.

Returns:¶

A pointer to the retrieved cardano_unit_interval_t object representing the quorum threshold. This will be a new reference, and the caller is responsible for releasing it with cardano_unit_interval_unref when it is no longer needed.

cardano_error_t cardano_committee_members_keys(cardano_committee_t *committee, cardano_credential_set_t **credentials)¶

Retrieves a set of credentials for all members of a committee.

This function fetches all member credentials from a given cardano_committee_t object. It returns a set of credentials, each representing a committee member. The function allocates memory for a cardano_credential_set_t object, and the caller is responsible for releasing this resource using cardano_credential_set_unref when it is no longer needed.

Usage Example:

cardano_committee_t* committee = ...; // Assume committee is already initialized
cardano_credential_set_t* credentials = NULL;

cardano_error_t result = cardano_committee_members_keys(committee, &credentials);
if (result == CARDANO_SUCCESS)
{
  // Process the set of credentials
  // ...

  // Once done, ensure to clean up and release the list
  cardano_credential_set_unref(&credentials);
}
else
{
  printf("Failed to retrieve committee members' credentials: %s\n", cardano_error_to_string(result));
}

Parameters:¶

cardano_committee_t *committee¶: [in] A pointer to an initialized cardano_committee_t object.
cardano_credential_set_t **credentials¶: [out] On successful execution, this will point to a newly created cardano_credential_set_t object containing the credentials of all committee members. If the committee has no members, the returned list will be empty but not NULL.

Returns:¶

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

cardano_error_t cardano_committee_add_member(cardano_committee_t *committee, cardano_credential_t *credential, uint64_t epoch)¶

Adds a member to a committee.

This function adds a new member to the specified cardano_committee_t object using a given cardano_credential_t object and epoch. The function assumes ownership of the credential reference passed to it, which means that the caller should not unreference the credential after calling this function unless it retains another reference for its own use.

Usage Example:

cardano_committee_t* committee = ...; // Assume committee is already initialized
cardano_credential_t* credential = ...; // Assume credential is already initialized
uint64_t epoch = 250; // Example epoch number

cardano_error_t result = cardano_committee_add_member(committee, credential, epoch);
if (result == CARDANO_SUCCESS)
{
  // The member has been successfully added to the committee
}
else
{
  printf("Failed to add member to the committee: %s\n", cardano_error_to_string(result));
}
// Clean up resources, if no longer used elsewhere
cardano_credential_unref(&credential);
cardano_committee_unref(&committee);

Parameters:¶

cardano_committee_t *committee¶: [inout] A pointer to an initialized cardano_committee_t object to which the member will be added.
cardano_credential_t *credential¶: [in] A pointer to an initialized cardano_credential_t object representing the member’s credential. This function increments the reference count of the credential, ensuring it remains valid for the duration of its association with the committee.
uint64_t epoch¶: [in] The epoch number from which the member’s participation in the committee becomes effective.

Returns:¶

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

uint64_t cardano_committee_get_member_epoch(cardano_committee_t *committee, cardano_credential_t *credential)¶

Retrieves the epoch at which the term of a specific committee member will end.

This function fetches the epoch number indicating when a committee member’s term will end based on their credential. It searches the committee’s records for the specified cardano_credential_t object and returns the associated epoch. If the credential is not found, or if the member has no specified end term, the function returns 0.

Usage Example:

cardano_committee_t* committee = ...; // Assume committee is already initialized
const cardano_credential_t* credential = ...; // Assume credential represents a committee member

uint64_t ending_epoch = cardano_committee_get_member_epoch(committee, credential);
if (ending_epoch > 0)
{
  printf("Member's term will end at epoch: %llu\n", ending_epoch);
}
else
{
  printf("Credential not found or no end term set for the committee member.\n");
}

Parameters:¶

cardano_committee_t *committee¶: [in] A pointer to an initialized cardano_committee_t object containing the committee data.
cardano_credential_t *credential¶: [in] A constant pointer to an initialized cardano_credential_t object representing the committee member’s credential.

Returns:¶

The epoch number at which the committee member’s term will end, or 0 if the member’s credential is not found or no end term is set.

cardano_error_t cardano_committee_get_key_at(const cardano_committee_t *committee, size_t index, cardano_credential_t **credential)¶

Retrieves the credential at a specific index from the committee.

This function retrieves the credential at the specified index from the committee.

Usage Example:

cardano_committee_t* committee = NULL;
cardano_credential_t* credential = NULL;
size_t index = 0; // Index of the credential to retrieve

// Assume committee is initialized properly

cardano_error_t result = cardano_committee_get_key_at(committee, index, &credential);

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

  // Once done, ensure to clean up and release the credential
  cardano_credential_unref(&credential);
}
else
{
  // Handle the error
}

Parameters:¶

const cardano_committee_t *committee¶: [in] Pointer to the committee object.
size_t index¶: [in] The index of the credential to retrieve.
cardano_credential_t **credential¶: [out] On successful retrieval, this will point to the credential at the specified index. The caller is responsible for managing the lifecycle of this object. Specifically, once the credential is no longer needed, the caller must release it by calling cardano_credential_unref.

Returns:¶

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

cardano_error_t cardano_committee_get_value_at(const cardano_committee_t *committee, size_t index, uint64_t *epoch)¶

Retrieves the committee member epoch at a specific index from the committee.

This function retrieves the committee member epoch at the specified index from the committee.

Usage Example:

cardano_committee_t* committee = NULL;
uint64_t epoch = 0;
size_t index = 0; // Index of the committee member epoch to retrieve

// Assume committee is initialized properly

cardano_error_t result = cardano_committee_get_value_at(committee, index, &epoch);

if (result == CARDANO_SUCCESS)
{
  // Use the epoch
}
else
{
  // Handle the error
}

Parameters:¶

const cardano_committee_t *committee¶: [in] Pointer to the committee object.
size_t index¶: [in] The index of the committee member epoch to retrieve.
uint64_t *epoch¶: [out] On successful retrieval, this will point to the committee member epoch at the specified index.

Returns:¶

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

cardano_error_t cardano_committee_get_key_value_at(const cardano_committee_t *committee, size_t index, cardano_credential_t **credential, uint64_t *epoch)¶

Retrieves the credential and committee member epoch at the specified index.

This function retrieves the credential and committee member epoch from the proposed committee member epochs at the specified index.

Usage Example:

cardano_committee_t* committee = NULL;
// Assume committee is initialized properly

size_t index = 0;
cardano_credential_t* credential = NULL;
uint64_t epoch = 0;

cardano_error_t result = cardano_committee_get_key_value_at(committee, index, &credential, &epoch);

if (result == CARDANO_SUCCESS)
{
  if (credential != NULL && epoch != NULL)
  {
    // Use the credential and committee member epoch
  }
  else
  {
    printf("Key-value pair not set at index %zu.\n", index);
  }
}
else
{
  // Handle error
  printf("Failed to get key-value pair at index %zu.\n", index);
}

// Clean up
cardano_committee_unref(&committee);
cardano_credential_unref(&credential);

Parameters:¶

const cardano_committee_t *committee¶: [in] Pointer to the proposed committee member epochs object.
size_t index¶: [in] The index at which to retrieve the key-value pair.
cardano_credential_t **credential¶: [out] On successful retrieval, this will point to the credential at the specified index. The caller is responsible for managing the lifecycle of this object and should release it using cardano_credential_unref when it is no longer needed.
uint64_t *epoch¶: [out] On successful retrieval, this will point to the committee member epoch at the specified index.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the key-value pair was successfully retrieved, or an appropriate error code indicating the failure reason.

void cardano_committee_unref(cardano_committee_t **committee)¶

Decrements the reference count of a cardano_committee_t object.

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

Usage Example:

cardano_committee_t* committee = cardano_committee_new(major, minor);

// Perform operations with the committee...

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

Note

After calling cardano_committee_unref, the pointer to the cardano_committee_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_committee_t **committee¶: [inout] A pointer to the pointer of the committee 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_committee_ref(cardano_committee_t *committee)¶

Increases the reference count of the cardano_committee_t object.

This function is used to manually increment the reference count of an cardano_committee_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_committee_unref.

Usage Example:

// Assuming committee is a previously created committee object

cardano_committee_ref(committee);

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

Note

Always ensure that for every call to cardano_committee_ref there is a corresponding call to cardano_committee_unref to prevent memory leaks.

Parameters:¶

cardano_committee_t *committee¶: A pointer to the cardano_committee_t object whose reference count is to be incremented.

size_t cardano_committee_refcount(const cardano_committee_t *committee)¶

Retrieves the current reference count of the cardano_committee_t object.

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

Usage Example:

// Assuming committee is a previously created committee object

size_t ref_count = cardano_committee_refcount(committee);

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_committee_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_committee_t *committee¶: A pointer to the cardano_committee_t object whose reference count is queried. The object must not be NULL.

Returns:¶

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

void cardano_committee_set_last_error(cardano_committee_t *committee, const char *message)¶

Sets the last error message for a given cardano_committee_t object.

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

const char *cardano_committee_get_last_error(const cardano_committee_t *committee)¶

Retrieves the last error message recorded for a specific committee.

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

Parameters:¶

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

Returns:¶

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