Enum AccountId 

pub enum AccountId {
    V0(AccountIdV0),
}

The identifier of an Account.

This enum is a wrapper around concrete versions of IDs. The following documents version 0.

Layout

An AccountId consists of two field elements, where the first is called the prefix and the second is called the suffix. It is laid out as follows:

prefix: [hash (56 bits) | storage mode (2 bits) | type (2 bits) | version (4 bits)]
suffix: [zero bit | hash (55 bits) | 8 zero bits]

Generation

An AccountId is a commitment to a user-generated seed and the code and storage of an account. An id is generated by first creating the account’s initial storage and code. Then a random seed is picked and the hash of (SEED, CODE_COMMITMENT, STORAGE_COMMITMENT, EMPTY_WORD) is computed. This process is repeated until the hash’s first element has the desired storage mode, account type and version and the suffix’ most significant bit is zero.

The prefix of the ID is exactly the first element of the hash. The suffix of the ID is the second element of the hash, but its lower 8 bits are zeroed. Thus, the prefix of the ID must derive exactly from the hash, while only the first 56 bits of the suffix are derived from the hash.

In total, due to requiring specific bits for storage mode, type, version and the most significant bit in the suffix, generating an ID requires 9 bits of Proof-of-Work.

Constraints

Constructors will return an error if:

• The prefix contains account ID metadata (storage mode, type or version) that does not match any of the known values.
• The most significant bit of the suffix is not zero.
• The lower 8 bits of the suffix are not zero, although AccountId::new ensures this is the case rather than return an error.

Design Rationale

The rationale behind the above layout is as follows.

• The prefix is the output of a hash function so it will be a valid field element without requiring additional constraints.
• The version is placed at a static offset such that future ID versions which may change the number of type or storage mode bits will not cause the version to be at a different offset. This is important so that a parser can always reliably read the version and then parse the remainder of the ID depending on the version. Having only 4 bits for the version is a trade off between future proofing to allow introducing more versions and the version requiring Proof of Work as part of the ID generation.
• The version, type and storage mode are part of the prefix which is included in the representation of a non-fungible asset. The prefix alone is enough to determine all of these properties about the ID.
• The most significant bit of the suffix must be zero to ensure the value of the suffix is always a valid felt, even if the lower 8 bits are all set to 1. The lower 8 bits of the suffix may be overwritten when the ID is embedded in other layouts such as the NoteMetadata. In that case, it can happen that all lower bits of the encoded suffix are one, so having the zero bit constraint is important for validity.

Variants

V0(AccountIdV0)

Implementations

impl AccountId

pub const SERIALIZED_SIZE: usize = 15usize

The serialized size of an AccountId in bytes.

pub fn new( seed: Word, version: AccountIdVersion, code_commitment: Word, storage_commitment: Word, ) -> Result<Self, AccountIdError>

Creates an AccountId by hashing the given seed, code_commitment, storage_commitment and using the resulting first and second element of the hash as the prefix and suffix felts of the ID.

See the documentation of the AccountId for more details on the generation.

Errors

Returns an error if any of the ID constraints are not met. See the constraints documentation for details.

pub fn new_unchecked(elements: [Felt; 2]) -> Self

Creates an AccountId from the given felts where the felt at index 0 is the prefix and the felt at index 1 is the suffix.

Warning

Validity of the ID must be ensured by the caller. An invalid ID may lead to panics.

Panics

Panics if the prefix does not contain a known account ID version.

If debug_assertions are enabled (e.g. in debug mode), this function panics if any of the ID constraints are not met. See the constraints documentation for details.

pub fn compute_account_seed( init_seed: [u8; 32], account_type: AccountType, storage_mode: AccountStorageMode, version: AccountIdVersion, code_commitment: Word, storage_commitment: Word, ) -> Result<Word, AccountError>

Grinds an account seed until its hash matches the given account_type, storage_mode and version and returns it as a Word. The input to the hash function next to the seed are the code_commitment and storage_commitment.

The grinding process is started from the given init_seed which should be a random seed generated from a cryptographically secure source.

pub const fn account_type(&self) -> AccountType

Returns the type of this account ID.

pub fn is_faucet(&self) -> bool

Returns true if an account with this ID is a faucet which can issue assets.

pub fn is_regular_account(&self) -> bool

Returns true if an account with this ID is a regular account.

pub fn storage_mode(&self) -> AccountStorageMode

Returns the storage mode of this account ID.

pub fn is_onchain(&self) -> bool

Returns true if the full state of the account is on chain, i.e. if the modes are AccountStorageMode::Public or AccountStorageMode::Network, false otherwise.

pub fn is_public(&self) -> bool

Returns true if the storage mode is AccountStorageMode::Public, false otherwise.

pub fn is_network(&self) -> bool

Returns true if the storage mode is AccountStorageMode::Network, false otherwise.

pub fn is_private(&self) -> bool

Returns true if the storage mode is AccountStorageMode::Private, false otherwise.

pub fn version(&self) -> AccountIdVersion

Returns the version of this account ID.

pub fn from_hex(hex_str: &str) -> Result<Self, AccountIdError>

Creates an AccountId from a hex string. Assumes the string starts with “0x” and that the hexadecimal characters are big-endian encoded.

pub fn to_hex(self) -> String

Returns a big-endian, hex-encoded string of length 32, including the 0x prefix. This means it encodes 15 bytes.

pub fn prefix(&self) -> AccountIdPrefix

Returns the AccountIdPrefix of this ID.

The prefix of an account ID is guaranteed to be unique.

pub const fn suffix(&self) -> Felt

Returns the suffix of this ID as a Felt.

Trait Implementations

impl Clone for AccountId

fn clone(&self) -> AccountId

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AccountId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deserializable for AccountId

fn read_from<R: ByteReader>( source: &mut R, ) -> Result<Self, DeserializationError>

Reads a sequence of bytes from the provided source, attempts to deserialize these bytes into Self, and returns the result.

fn read_from_bytes(bytes: &[u8]) -> Result<Self, DeserializationError>

Attempts to deserialize the provided bytes into Self and returns the result.

impl Display for AccountId

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<AccountId> for [Felt; 2]

fn from(id: AccountId) -> Self

Converts to this type from the input type.

impl From<AccountId> for [u8; 15]

fn from(id: AccountId) -> Self

Converts to this type from the input type.

impl From<AccountId> for u128

fn from(id: AccountId) -> Self

Converts to this type from the input type.

impl From<AccountIdV0> for AccountId

fn from(id: AccountIdV0) -> Self

Converts to this type from the input type.

impl Hash for AccountId

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for AccountId

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for AccountId

fn eq(&self, other: &AccountId) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for AccountId

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serializable for AccountId

fn write_into<W: ByteWriter>(&self, target: &mut W)

Serializes self into bytes and writes these bytes into the target.

fn get_size_hint(&self) -> usize

Returns an estimate of how many bytes are needed to represent self.

fn to_bytes(&self) -> Vec<u8>

Serializes self into a vector of bytes.

impl TryFrom<[BaseElement; 2]> for AccountId

fn try_from(elements: [Felt; 2]) -> Result<Self, Self::Error>

Returns an AccountId instantiated with the provided field elements where elements[0] is taken as the prefix and elements[1] is taken as the suffix.

Errors

Returns an error if any of the ID constraints are not met. See the constraints documentation for details.

type Error = AccountIdError

The type returned in the event of a conversion error.

impl TryFrom<[u8; 15]> for AccountId

fn try_from(bytes: [u8; 15]) -> Result<Self, Self::Error>

Tries to convert a byte array in big-endian order to an AccountId.

Errors

Returns an error if any of the ID constraints are not met. See the constraints documentation for details.

type Error = AccountIdError

The type returned in the event of a conversion error.

impl TryFrom<u128> for AccountId

fn try_from(int: u128) -> Result<Self, Self::Error>

Tries to convert a u128 into an AccountId.

Errors

Returns an error if any of the ID constraints are not met. See the constraints documentation for details.

type Error = AccountIdError

The type returned in the event of a conversion error.

impl Copy for AccountId

impl Eq for AccountId

impl StructuralPartialEq for AccountId