Required Guards Map¶

typedef struct cardano_required_guards_map_t cardano_required_guards_map_t¶

Represents a map of credentials to an optional plutus datum.

A sub transaction uses this map to restrict which top-level guards must be present; a top-level transaction body may also carry it as a self assertion. Each entry maps a credential to either a plutus datum or to no datum at all (encoded as CBOR null on the wire).

cardano_error_t cardano_required_guards_map_new(cardano_required_guards_map_t **required_guards_map)¶

Creates and initializes a new instance of a required guards map.

This function allocates and initializes a new instance of cardano_required_guards_map_t, representing a map structure. It returns an error code to indicate the success or failure of the operation.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;

// Attempt to create a new required_guards_map
cardano_error_t result = cardano_required_guards_map_new(&required_guards_map);

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

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

Parameters:¶

cardano_required_guards_map_t **required_guards_map¶: [out] A pointer to a pointer to a cardano_required_guards_map_t object. Upon successful initialization, this will point to a newly created cardano_required_guards_map_t object. This object represents a “strong reference” to the required_guards_map, fully initialized and ready for use. The caller is responsible for managing the lifecycle of this object. Specifically, once the required_guards_map is no longer needed, the caller must release it by calling cardano_required_guards_map_unref.

Returns:¶

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

cardano_error_t cardano_required_guards_map_from_cbor(cardano_cbor_reader_t *reader, cardano_required_guards_map_t **required_guards_map)¶

Creates a required guards map from a CBOR reader.

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

The map must not be empty on the wire; decoding an empty map fails with CARDANO_ERROR_INVALID_CBOR_MAP_SIZE. An entry whose value is CBOR null is decoded as a credential without a datum.

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_required_guards_map_t* required_guards_map = NULL;

cardano_error_t result = cardano_required_guards_map_from_cbor(reader, &required_guards_map);

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

  // Once done, ensure to clean up and release the required_guards_map
  cardano_required_guards_map_unref(&required_guards_map);
}
else
{
  const char* error = cardano_cbor_reader_get_last_error(reader);
  printf("Failed to decode required_guards_map: %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_required_guards_map_t object by calling cardano_required_guards_map_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 required guards map data.
cardano_required_guards_map_t **required_guards_map¶: [out] A pointer to a pointer of cardano_required_guards_map_t that will be set to the address of the newly created required guards map object upon successful decoding.

Returns:¶

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

cardano_error_t cardano_required_guards_map_to_cbor(const cardano_required_guards_map_t *required_guards_map, cardano_cbor_writer_t *writer)¶

Serializes a required guards map into CBOR format using a CBOR writer.

This function serializes the given cardano_required_guards_map_t object using a cardano_cbor_writer_t. Entries are written in insertion order. An entry without a datum is written with a CBOR null value.

Usage Example:

cardano_required_guards_map_t* required_guards_map = ...;
cardano_cbor_writer_t* writer = cardano_cbor_writer_new();

if (writer)
{
  cardano_error_t result = cardano_required_guards_map_to_cbor(required_guards_map, 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_required_guards_map_unref(&required_guards_map);

Parameters:¶

const cardano_required_guards_map_t *required_guards_map¶: [in] A constant pointer to the cardano_required_guards_map_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 required_guards_map or writer is NULL, returns CARDANO_ERROR_POINTER_IS_NULL.

size_t cardano_required_guards_map_get_length(const cardano_required_guards_map_t *required_guards_map)¶

Retrieves the length of the required_guards_map.

This function returns the number of key-value pairs contained in the specified required_guards_map.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_error_t result = cardano_required_guards_map_new(&required_guards_map);

// Populate the required_guards_map with key-value pairs

size_t length = cardano_required_guards_map_get_length(required_guards_map);
printf("The length of the required_guards_map is: %zu\n", length);

cardano_required_guards_map_unref(&required_guards_map);

Parameters:¶

const cardano_required_guards_map_t *required_guards_map¶: [in] A constant pointer to the cardano_required_guards_map_t object for which the length is to be retrieved.

Returns:¶

The number of key-value pairs in the required_guards_map. Returns 0 if the required_guards_map is NULL.

cardano_error_t cardano_required_guards_map_get(const cardano_required_guards_map_t *required_guards_map, cardano_credential_t *key, cardano_plutus_data_t **element)¶

Retrieves the datum associated with a given credential in the required guards map.

This function retrieves the datum associated with the specified credential in the provided required guards map. It returns the datum through the output parameter element. Entries without a datum yield NULL through element while still returning CARDANO_SUCCESS. If the credential is not found in the map, the function returns CARDANO_ERROR_ELEMENT_NOT_FOUND.

Usage Example:

cardano_required_guards_map_t* required_guards_map = ...;
cardano_credential_t* key = ...; // Create a credential object representing the key
cardano_plutus_data_t* datum = NULL;

cardano_error_t result = cardano_required_guards_map_get(required_guards_map, key, &datum);

if (result == CARDANO_SUCCESS)
{
  if (datum != NULL)
  {
    // Use the retrieved datum
    cardano_plutus_data_unref(&datum);
  }
}
else
{
  // Handle error or key not found
}

cardano_credential_unref(&key); // Clean up the key resource
cardano_required_guards_map_unref(&required_guards_map);

Parameters:¶

const cardano_required_guards_map_t *required_guards_map¶: [in] A constant pointer to the cardano_required_guards_map_t object from which the datum is to be retrieved.
cardano_credential_t *key¶: [in] The credential whose associated datum is to be retrieved from the required_guards_map.
cardano_plutus_data_t **element¶: [out] A pointer to a variable where the retrieved datum will be stored. If the credential is found and has a datum, this variable will be set to the associated datum, and the caller must release it by calling cardano_plutus_data_unref. If the credential is found but has no datum, this variable will be set to NULL.

Returns:¶

CARDANO_SUCCESS if the credential was found, CARDANO_ERROR_ELEMENT_NOT_FOUND if the credential is not present in the map, or an appropriate error code if the input parameters are invalid.

cardano_error_t cardano_required_guards_map_insert(cardano_required_guards_map_t *required_guards_map, cardano_credential_t *key, cardano_plutus_data_t *value)¶

Inserts a key-value pair into the required guards map.

This function inserts the specified credential and its optional datum into the provided required guards map. Entries keep their insertion order when the map is serialized. Inserting a credential that is already present in the map fails with CARDANO_ERROR_DUPLICATED_KEY.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_error_t result = cardano_required_guards_map_new(&required_guards_map);

// Create key and value objects
cardano_credential_t* key = ...;
cardano_plutus_data_t* value = ...; // May be NULL for an entry without a datum

// Insert the key-value pair into the required_guards_map
result = cardano_required_guards_map_insert(required_guards_map, key, value);

if (result != CARDANO_SUCCESS)
{
  // Handle insertion failure
}

// Clean up key and value objects
cardano_credential_unref(&key);
cardano_plutus_data_unref(&value);

cardano_required_guards_map_unref(&required_guards_map);

Parameters:¶

cardano_required_guards_map_t *required_guards_map¶: [in] A constant pointer to the cardano_required_guards_map_t object where the key-value pair is to be inserted.
cardano_credential_t *key¶: [in] The credential to be inserted into the required guards map. The caller is responsible for managing the lifecycle of the key object.
cardano_plutus_data_t *value¶: [in] The datum to be associated with the credential, or NULL if the entry has no datum. The caller is responsible for managing the lifecycle of the value object.

Returns:¶

CARDANO_SUCCESS if the key-value pair was successfully inserted, or an appropriate error code if the input parameters are invalid or any other error occurs.

cardano_error_t cardano_required_guards_map_get_keys(cardano_required_guards_map_t *required_guards_map, cardano_credential_set_t **keys)¶

Retrieves the keys from the required guards map.

This function retrieves all the keys from the provided required guards map and returns them as a set. The caller is responsible for managing the lifecycle of the returned set by calling cardano_credential_set_unref when it is no longer needed.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_error_t result = cardano_required_guards_map_new(&required_guards_map);

// Populate the required_guards_map with key-value pairs

cardano_credential_set_t* keys = NULL;
result = cardano_required_guards_map_get_keys(required_guards_map, &keys);

if (result == CARDANO_SUCCESS)
{
  // Use the set of keys
  // Keys must also be freed if retrieved from the set

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

cardano_required_guards_map_unref(&required_guards_map);

Note

The returned set is canonically ordered (by credential type, then hash bytes) and may not match the map’s insertion-order iteration via the index based accessors.

Parameters:¶

cardano_required_guards_map_t *required_guards_map¶: [in] A pointer to the cardano_required_guards_map_t object from which the keys are to be retrieved.
cardano_credential_set_t **keys¶: [out] A pointer to a variable where the retrieved keys will be stored as a set. If successful, this variable will be set to point to the set of keys. The caller is responsible for managing the lifecycle of this set. It must be released by calling cardano_credential_set_unref when no longer needed.

Returns:¶

CARDANO_SUCCESS if the keys were successfully retrieved, or an appropriate error code if the input parameters are invalid or any other error occurs.

cardano_error_t cardano_required_guards_map_get_key_at(const cardano_required_guards_map_t *required_guards_map, size_t index, cardano_credential_t **credential)¶

Retrieves the credential at a specific index from the required guards map.

This function retrieves the credential at the specified index from the required guards map.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_credential_t* credential = NULL;
size_t index = 0; // Index of the credential to retrieve

// Assume required_guards_map is initialized properly

cardano_error_t result = cardano_required_guards_map_get_key_at(required_guards_map, 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_required_guards_map_t *required_guards_map¶: [in] Pointer to the required guards map 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_required_guards_map_get_value_at(const cardano_required_guards_map_t *required_guards_map, size_t index, cardano_plutus_data_t **datum)¶

Retrieves the datum at a specific index from the required guards map.

This function retrieves the datum at the specified index from the required guards map. Entries without a datum yield NULL through the output parameter.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_plutus_data_t* datum = NULL;
size_t index = 0; // Index of the datum to retrieve

// Assume required_guards_map is initialized properly

cardano_error_t result = cardano_required_guards_map_get_value_at(required_guards_map, index, &datum);

if (result == CARDANO_SUCCESS)
{
  if (datum != NULL)
  {
    // Use the datum
    cardano_plutus_data_unref(&datum);
  }
}
else
{
  // Handle the error
}

Parameters:¶

const cardano_required_guards_map_t *required_guards_map¶: [in] Pointer to the required guards map object.
size_t index¶: [in] The index of the datum to retrieve.
cardano_plutus_data_t **datum¶: [out] On successful retrieval, this will point to the datum at the specified index, or be set to NULL if the entry has no datum. When a datum is returned, the caller is responsible for managing its lifecycle and must release it by calling cardano_plutus_data_unref.

Returns:¶

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

cardano_error_t cardano_required_guards_map_get_key_value_at(const cardano_required_guards_map_t *required_guards_map, size_t index, cardano_credential_t **credential, cardano_plutus_data_t **datum)¶

Retrieves the credential and datum at the specified index.

This function retrieves the credential and its optional datum from the required guards map at the specified index.

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
// Assume required_guards_map is initialized properly

size_t index = 0;
cardano_credential_t* credential = NULL;
cardano_plutus_data_t* datum = NULL;

cardano_error_t result = cardano_required_guards_map_get_key_value_at(required_guards_map, index, &credential, &datum);

if (result == CARDANO_SUCCESS)
{
  // Use the credential and the datum (the datum is NULL for entries without one)
}
else
{
  // Handle error
  printf("Failed to get key-value pair at index %zu.\n", index);
}

// Clean up
cardano_required_guards_map_unref(&required_guards_map);
cardano_credential_unref(&credential);
cardano_plutus_data_unref(&datum);

Parameters:¶

const cardano_required_guards_map_t *required_guards_map¶: [in] Pointer to the required guards map 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.
cardano_plutus_data_t **datum¶: [out] On successful retrieval, this will point to the datum at the specified index, or be set to NULL if the entry has no datum. When a datum is returned, the caller is responsible for managing its lifecycle and must release it by calling cardano_plutus_data_unref.

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_required_guards_map_unref(cardano_required_guards_map_t **required_guards_map)¶

Decrements the reference count of a required_guards_map object.

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

Usage Example:

cardano_required_guards_map_t* required_guards_map = NULL;
cardano_error_t result = cardano_required_guards_map_new(&required_guards_map);

// Perform operations with the required_guards_map...

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

Note

After calling cardano_required_guards_map_unref, the pointer to the cardano_required_guards_map_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_required_guards_map_t **required_guards_map¶: [inout] A pointer to the pointer of the required_guards_map 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_required_guards_map_ref(cardano_required_guards_map_t *required_guards_map)¶

Increases the reference count of the cardano_required_guards_map_t object.

This function is used to manually increment the reference count of a required_guards_map 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_required_guards_map_unref.

Usage Example:

// Assuming required_guards_map is a previously created required_guards_map object

cardano_required_guards_map_ref(required_guards_map);

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

Note

Always ensure that for every call to cardano_required_guards_map_ref there is a corresponding call to cardano_required_guards_map_unref to prevent memory leaks.

Parameters:¶

cardano_required_guards_map_t *required_guards_map¶: A pointer to the required_guards_map object whose reference count is to be incremented.

size_t cardano_required_guards_map_refcount(const cardano_required_guards_map_t *required_guards_map)¶

Retrieves the current reference count of the cardano_required_guards_map_t object.

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

Usage Example:

// Assuming required_guards_map is a previously created required_guards_map object

size_t ref_count = cardano_required_guards_map_refcount(required_guards_map);

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_required_guards_map_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_required_guards_map_t *required_guards_map¶: A pointer to the required_guards_map object whose reference count is queried. The object must not be NULL.

Returns:¶

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

void cardano_required_guards_map_set_last_error(cardano_required_guards_map_t *required_guards_map, const char *message)¶

Sets the last error message for a given required_guards_map object.

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

const char *cardano_required_guards_map_get_last_error(const cardano_required_guards_map_t *required_guards_map)¶

Retrieves the last error message recorded for a specific required_guards_map.

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

Parameters:¶

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

Returns:¶

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