Struct NoteMetadata 

pub struct NoteMetadata { /* private fields */ }

Protocol-level note metadata that combines PartialNoteMetadata with attachment information.

This type wraps PartialNoteMetadata together with attachment headers and an attachment commitment, and knows how to encode them into a Word and compute commitments.

The metadata word is encoded as a single Word (4 felts) with the following layout:

0th felt: [sender_id_suffix (56 bits) | reserved (3 bits) | note_type (1 bit) | version (4 bits)]
1st felt: [sender_id_prefix (64 bits)]
2nd felt: [reserved (32 bits) | note_tag (32 bits)]
3rd felt: [attachment_3_scheme (16 bits) | attachment_2_scheme (16 bits) |
           attachment_1_scheme (16 bits) | attachment_0_scheme (16 bits)]

Felt validity is guaranteed:

• 0th felt: The lower 8 bits of the account ID suffix are 0 by construction, so they can be overwritten. The suffix’s MSB is zero so the felt stays valid when lower bits are set.
• 1st felt: Equivalent to the account ID prefix, so it inherits its validity.
• 2nd felt: The tag is a u32 and the reserved bits are currently set to zero, however users shouldn’t assume these are zero.
• 3rd felt: Max value is 0xFFFEFFFE_FFFEFFFE (schemes capped at 65534), which is less than p.

The version is hardcoded to 0 and is reserved for forward compatibility.

Implementations

impl NoteMetadata

pub fn new( partial_metadata: PartialNoteMetadata, attachments: &NoteAttachments, ) -> Self

Returns a new NoteMetadata derived from the given partial metadata and attachments.

The attachment headers and commitment are derived from the provided attachments.

pub fn from_parts( partial_metadata: PartialNoteMetadata, attachment_headers: [NoteAttachmentHeader; 4], attachments_commitment: Word, ) -> Self

Creates a NoteMetadata from its raw parts.

Prefer Self::new whenever possible.

pub fn partial_metadata(&self) -> &PartialNoteMetadata

Returns the inner PartialNoteMetadata.

pub fn sender(&self) -> AccountId

Returns the account which created the note.

pub fn note_type(&self) -> NoteType

Returns the note’s type.

pub fn tag(&self) -> NoteTag

Returns the tag associated with the note.

pub fn attachment_headers(&self) -> &[NoteAttachmentHeader; 4]

Returns the attachment headers.

pub fn attachments_commitment(&self) -> Word

Returns the attachments commitment.

pub fn has_attachments(&self) -> bool

Returns true if the metadata advertises at least one attachment.

The metadata carries only attachment scheme markers, not their content, so this does not imply the content is available locally.

pub fn is_private(&self) -> bool

Returns true if the note is private, false otherwise.

pub fn is_public(&self) -> bool

Returns true if the note is public, false otherwise.

pub fn to_metadata_word(&self) -> Word

Returns the metadata encoded as a Word.

See NoteMetadata docs for the layout.

pub fn to_commitment(&self) -> Word

Returns the commitment to the note metadata, which is defined as:

hash(NOTE_METADATA_WORD || ATTACHMENTS_COMMITMENT)

pub fn into_partial_metadata(self) -> PartialNoteMetadata

Consumes self and returns the inner PartialNoteMetadata.

Trait Implementations

impl Clone for NoteMetadata

fn clone(&self) -> NoteMetadata

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for NoteMetadata

impl Debug for NoteMetadata

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

Formats the value using the given formatter.

impl Deserializable for NoteMetadata

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 min_serialized_size() -> usize

Returns the minimum serialized size for one instance of this type.

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

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

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

Deserializes Self from bytes with a byte budget limit.

impl Eq for NoteMetadata

impl PartialEq for NoteMetadata

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

Equality operator ==.

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

Inequality operator !=.

impl Serializable for NoteMetadata

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 StructuralPartialEq for NoteMetadata