Pool Metadata¶

typedef struct cardano_pool_metadata_t cardano_pool_metadata_t¶

The pool registration certificate can include a way to locate pool metadata.

This includes the hash of the metadata. This is not the metadata itself but a unique identifier that corresponds to the metadata. The hash function ensures that even a small change in the metadata leads to a completely different hash, securing the authenticity of the data.

Along with the hash of the metadata, the URL where the actual metadata file (in JSON format) is hosted is also included in the certificate. The combination of the URL and the hash allows wallets and other services to download the metadata file and verify it against the hash.

cardano_error_t cardano_pool_metadata_new(const char *url, size_t url_length, cardano_blake2b_hash_t *hash, cardano_pool_metadata_t **pool_metadata)¶

Creates and initializes a new pool metadata object.

This function allocates and initializes a new instance of cardano_pool_metadata_t. The pool metadata includes information such as a URL to the pool’s metadata file and its associated hash.

Usage Example:

const char* url = "https://example.com/poolmetadata.json";
size_t url_length = strlen(url);
cardano_blake2b_hash_t* hash = ...;  // Assume hash is initialized here
cardano_pool_metadata_t* pool_metadata = NULL;

cardano_error_t result = cardano_pool_metadata_new(url, url_length, hash, &pool_metadata);

if (result == CARDANO_SUCCESS)
{
  // Use the pool metadata

  // Once done, ensure to clean up and release the pool metadata
  cardano_pool_metadata_unref(&pool_metadata);
}
else
{
  printf("Failed to create pool metadata: %s\n", cardano_error_to_string(result));
}

Parameters:¶

const char *url¶

[in] A constant pointer to a character array containing the URL where the pool metadata is hosted.

size_t url_length¶

[in] The length of the URL character array.

cardano_blake2b_hash_t *hash¶

[in] A pointer to a cardano_blake2b_hash_t object representing the BLAKE2b hash of the metadata file. This hash is used to verify the integrity of the metadata once fetched.

cardano_pool_metadata_t **pool_metadata¶

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

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the pool metadata was successfully created, or an appropriate error code indicating the failure reason, such as invalid URL format, null pointers, or out of memory errors.

cardano_error_t cardano_pool_metadata_from_hash_hex(const char *url, size_t url_size, const char *hash, size_t hash_size, cardano_pool_metadata_t **pool_metadata)¶

Initializes pool metadata from a URL and a hexadecimal hash string.

This function creates a pool metadata object based on the provided URL and a BLAKE2b hash of the metadata content, given as a hexadecimal string. This approach is useful when the hash of the metadata is known in a string format, allowing for easy verification of metadata integrity after retrieval.

Usage Example:

const char* url = "https://example.com/poolmetadata.json";
size_t url_size = strlen(url);
const char* hash_hex = "abc123...";  // Example BLAKE2b hash in hexadecimal
size_t hash_size = strlen(hash_hex);
cardano_pool_metadata_t* pool_metadata = NULL;

cardano_error_t result = cardano_pool_metadata_from_hash_hex(url, url_size, hash_hex, hash_size, &pool_metadata);

if (result == CARDANO_SUCCESS)
{
  // Use the pool metadata

  // Once done, ensure to clean up and release the pool metadata
  cardano_pool_metadata_unref(&pool_metadata);
}
else
{
  printf("Failed to create pool metadata: %s\n", cardano_error_to_string(result));
}

Parameters:¶

const char *url¶

[in] A pointer to a character array containing the URL where the pool metadata is hosted.

size_t url_size¶

[in] The length of the URL character array.

const char *hash¶

[in] A pointer to a character array containing the hexadecimal representation of the BLAKE2b hash of the pool metadata. This hash is used to ensure the integrity of the downloaded metadata.

size_t hash_size¶

[in] The length of the hash character array.

cardano_pool_metadata_t **pool_metadata¶

[out] On successful initialization, this will point to the newly created cardano_pool_metadata_t object. This object represents a “strong reference” to the pool metadata, fully initialized and ready for use. The caller is responsible for managing the lifecycle of this object, specifically releasing it by calling cardano_pool_metadata_unref when it is no longer needed.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the pool metadata was successfully created, or an appropriate error code indicating the failure reason, such as invalid URL or hash format, null pointers, or memory allocation issues.

cardano_error_t cardano_pool_metadata_from_cbor(cardano_cbor_reader_t *reader, cardano_pool_metadata_t **pool_metadata)¶

Creates a cardano_pool_metadata_t from a CBOR reader.

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

Usage Example:

cardano_cbor_reader_t* reader = cardano_cbor_reader_new(cbor_data, data_size);
cardano_pool_metadata_t* pool_metadata = NULL;

cardano_error_t result = cardano_pool_metadata_from_cbor(reader, &pool_metadata);

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

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

[out] A pointer to a pointer of cardano_pool_metadata_t that will be set to the address of the newly created pool_metadata 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_pool_metadata_to_cip116_json(const cardano_pool_metadata_t *metadata, cardano_json_writer_t *writer)¶

Serializes pool metadata to CIP-116 JSON.

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

Parameters:¶

const cardano_pool_metadata_t *metadata¶

[in] Pointer to a valid cardano_pool_metadata_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 metadata or writer is NULL. CARDANO_ERROR_MEMORY_ALLOCATION_FAILED If memory allocation fails for hash conversion. Other Any error propagated from nested writers.

size_t cardano_pool_metadata_get_url_size(const cardano_pool_metadata_t *pool_metadata)¶

Retrieves the size of the URL string stored in the pool metadata object.

This function returns the length of the URL string contained within a cardano_pool_metadata_t object. This length does not include the null terminator of the string. This function is useful for determining the buffer size needed to store or manipulate the URL string outside of the pool metadata object.

Usage Example:

cardano_pool_metadata_t* pool_metadata = ...; // Assume pool_metadata is already initialized
size_t url_size = cardano_pool_metadata_get_url_size(pool_metadata);
printf("URL size: %zu bytes\n", url_size);

Parameters:¶

const cardano_pool_metadata_t *pool_metadata¶

[in] A constant pointer to an initialized cardano_pool_metadata_t object.

Returns:¶

The size of the URL string in bytes, excluding the null terminator. If the input pointer is NULL, returns 0 to indicate an error or uninitialized pool metadata object.

const char *cardano_pool_metadata_get_url(const cardano_pool_metadata_t *pool_metadata)¶

Retrieves the URL string from a pool metadata object.

This function provides access to the URL string stored within a cardano_pool_metadata_t object. The URL is associated with the metadata of a Cardano stake pool and is used for various network operations and identity verifications. The returned string is null-terminated.

Usage Example:

cardano_pool_metadata_t* pool_metadata = ...; // Assume pool_metadata is already initialized
const char* url = cardano_pool_metadata_get_url(pool_metadata);

if (url != NULL)
{
  printf("Pool URL: %s\n", url);
}
else
{
  printf("Failed to retrieve URL from pool metadata.\n");
}

Parameters:¶

const cardano_pool_metadata_t *pool_metadata¶

[in] A constant pointer to an initialized cardano_pool_metadata_t object.

Returns:¶

A constant pointer to a null-terminated string representing the URL of the pool metadata. If the input pointer is NULL, or if the pool metadata object is uninitialized, returns NULL. The caller should not attempt to modify or free the returned string, as it points to internal memory managed by the cardano_pool_metadata_t object. The memory for the string will be freed when the cardano_pool_metadata_t object is destroyed.

cardano_error_t cardano_pool_metadata_set_url(const char *url, size_t url_size, cardano_pool_metadata_t *pool_metadata)¶

Sets the URL string in a pool metadata object.

This function updates the URL string stored within a cardano_pool_metadata_t object. The URL is associated with the metadata of a Cardano stake pool and is used for various network operations and identity verifications. This function copies the URL from the provided string to the pool metadata object.

Usage Example:

const char* new_url = "https://newpoolmetadata.com";
cardano_pool_metadata_t* pool_metadata = ...; // Assume pool_metadata is already initialized
cardano_error_t result = cardano_pool_metadata_set_url(new_url, strlen(new_url) + 1, pool_metadata);

if (result == CARDANO_SUCCESS)
{
  printf("Pool URL updated successfully.\n");
}
else
{
  printf("Failed to update pool URL.\n");
}

Note

This function does not take ownership of the url parameter but copies its content. The caller is responsible for managing the memory of url. Ensure that the pool_metadata object is not NULL and properly initialized before calling this function.

Parameters:¶

const char *url¶

[in] A pointer to a character array containing the new URL to be set in the pool metadata.

size_t url_size¶

[in] The size of the URL character array, including the null terminator.

cardano_pool_metadata_t *pool_metadata¶

[inout] A pointer to an initialized cardano_pool_metadata_t object which will be updated.

Returns:¶

cardano_error_t indicating the outcome of the operation. Returns CARDANO_SUCCESS if the URL was successfully updated, or an appropriate error code indicating the failure reason, such as invalid parameters or out of memory errors.

cardano_error_t cardano_pool_metadata_get_hash(cardano_pool_metadata_t *pool_metadata, cardano_blake2b_hash_t **hash)¶

Retrieves the Blake2b hash from a pool metadata object.

This function provides access to the Blake2b hash stored within a cardano_pool_metadata_t object.

Usage Example:

cardano_pool_metadata_t* pool_metadata = ...; // Assume pool_metadata is already initialized
cardano_blake2b_hash_t* hash = NULL;
cardano_error_t result = cardano_pool_metadata_get_hash(pool_metadata, &hash);

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

  // Once done, ensure to clean up and release the hash
  cardano_blake2b_hash_unref(&hash);
}
else
{
  printf("Failed to retrieve hash from pool metadata.\n");
}

Parameters:¶

cardano_pool_metadata_t *pool_metadata¶

[in] A pointer to an initialized cardano_pool_metadata_t object.

cardano_blake2b_hash_t **hash¶

[out] On successful retrieval, this will point to a newly created cardano_blake2b_hash_t object containing the hash. The caller is responsible for managing the lifecycle of this object, and must release it by calling cardano_blake2b_hash_unref when it is no longer needed.

Returns:¶

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

cardano_error_t cardano_pool_metadata_set_hash(cardano_pool_metadata_t *pool_metadata, cardano_blake2b_hash_t *hash)¶

Sets the Blake2b hash for a pool metadata object.

This function sets the Blake2b hash within a cardano_pool_metadata_t object.

Usage Example:

cardano_pool_metadata_t* pool_metadata = ...; // Assume pool_metadata is already initialized
cardano_blake2b_hash_t* hash = ...; // Assume hash is already initialized
cardano_error_t result = cardano_pool_metadata_set_hash(pool_metadata, hash);

if (result == CARDANO_SUCCESS)
{
  // Hash was successfully set
}
else
{
  printf("Failed to set hash for pool metadata.\n");
}

Parameters:¶

cardano_pool_metadata_t *pool_metadata¶

[in] A pointer to an initialized cardano_pool_metadata_t object.

cardano_blake2b_hash_t *hash¶

[in] A pointer to an initialized cardano_blake2b_hash_t object containing the hash to be set. The caller is responsible for managing the lifecycle of the hash object, and must ensure that it remains valid for the duration of the operation. The function does not take ownership of the hash object.

Returns:¶

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

void cardano_pool_metadata_unref(cardano_pool_metadata_t **pool_metadata)¶

Decrements the reference count of a cardano_pool_metadata_t object.

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

Usage Example:

cardano_pool_metadata_t* pool_metadata = cardano_pool_metadata_new(major, minor);

// Perform operations with the pool_metadata...

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

Note

After calling cardano_pool_metadata_unref, the pointer to the cardano_pool_metadata_t object will be set to NULL to prevent its reuse.

Parameters:¶

cardano_pool_metadata_t **pool_metadata¶

[inout] A pointer to the pointer of the pool_metadata 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_pool_metadata_ref(cardano_pool_metadata_t *pool_metadata)¶

Increases the reference count of the cardano_pool_metadata_t object.

This function is used to manually increment the reference count of an cardano_pool_metadata_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_pool_metadata_unref.

Usage Example:

// Assuming pool_metadata is a previously created pool_metadata object

cardano_pool_metadata_ref(pool_metadata);

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

Note

Always ensure that for every call to cardano_pool_metadata_ref there is a corresponding call to cardano_pool_metadata_unref to prevent memory leaks.

Parameters:¶

cardano_pool_metadata_t *pool_metadata¶

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

size_t cardano_pool_metadata_refcount(const cardano_pool_metadata_t *pool_metadata)¶

Retrieves the current reference count of the cardano_pool_metadata_t object.

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

Usage Example:

// Assuming pool_metadata is a previously created pool_metadata object

size_t ref_count = cardano_pool_metadata_refcount(pool_metadata);

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_pool_metadata_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_pool_metadata_t *pool_metadata¶

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

Returns:¶

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

void cardano_pool_metadata_set_last_error(cardano_pool_metadata_t *pool_metadata, const char *message)¶

Sets the last error message for a given cardano_pool_metadata_t object.

Records an error message in the pool_metadata’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_pool_metadata_t *pool_metadata¶

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

const char *cardano_pool_metadata_get_last_error(const cardano_pool_metadata_t *pool_metadata)¶

Retrieves the last error message recorded for a specific pool_metadata.

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

Parameters:¶

const cardano_pool_metadata_t *pool_metadata¶

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

Returns:¶

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