Struct Mmr 

pub struct Mmr { /* private fields */ }

A fully materialized Merkle Mountain Range, with every tree in the forest and all their elements.

Since this is a full representation of the MMR, elements are never removed and the MMR will grow roughly O(2n) in number of leaf elements.

Cloning is cheap: the nodes are stored in chunks shared between clones, so a clone copies O(num_nodes / 1024) pointers instead of the full node buffer, and appending to the original after a clone copies at most one chunk.

Implementations

impl Mmr

pub fn new() -> Mmr

Constructor for an empty Mmr.

pub fn try_from_iter<T>(values: T) -> Result<Mmr, MmrError>

where T: IntoIterator<Item = Word>,

Constructs an MMR from an iterator of leaves.

Errors

Returns an error if the maximum forest size is exceeded.

pub fn from_nodes_unchecked( forest: Forest, nodes: impl IntoIterator<Item = Word>, ) -> Result<Mmr, MmrError>

Constructs an MMR from its forest and complete node array, in insertion (postorder) order, e.g. as previously obtained from mmr.nodes_from(0).copied() (see Mmr::nodes_from).

The only validation performed is structural: the node count must match forest. The nodes are otherwise taken verbatim — no hashes are recomputed or verified. Comparing the result’s Mmr::peaks against a trusted commitment checks the accumulator state, but because the peaks are read from the stored nodes rather than recomputed, it does not validate any non-peak nodes. The nodes must therefore come from a trusted source, e.g. the caller’s own previously validated state.

Errors

Returns an error if the number of nodes does not match the node count of forest.

pub const fn forest(&self) -> Forest

Returns the MMR forest representation. See Forest.

pub fn nodes_from(&self, start: usize) -> impl ExactSizeIterator + Clone

Returns an iterator over the MMR’s nodes at indices start.., in insertion (postorder) order. Returns an empty iterator if start is greater than or equal to the total node count, which is given by self.forest().num_nodes().

The node buffer is strictly append-only, so a consumer that has persisted the first start nodes can incrementally sync by appending only the nodes returned here.

Positioning is cheap: the iterator starts directly at start without walking the preceding nodes, and it knows its exact remaining length.

pub fn open(&self, pos: usize) -> Result<MmrProof, MmrError>

Returns an MmrProof for the leaf at the specified position.

Note: The leaf position is the 0-indexed number corresponding to the order the leaves were added, this corresponds to the MMR size prior to adding the element. So the 1st element has position 0, the second position 1, and so on.

Errors

Returns an error if the specified leaf position is out of bounds for this MMR.

pub fn open_at(&self, pos: usize, forest: Forest) -> Result<MmrProof, MmrError>

Returns an MmrProof for the leaf at the specified position using the state of the MMR at the specified forest.

Note: The leaf position is the 0-indexed number corresponding to the order the leaves were added, this corresponds to the MMR size prior to adding the element. So the 1st element has position 0, the second position 1, and so on.

Errors

Returns an error if:

• The specified leaf position is out of bounds for this MMR.
• The specified forest value is not valid for this MMR.

pub fn get(&self, pos: usize) -> Result<Word, MmrError>

Returns the leaf value at position pos.

Note: The leaf position is the 0-indexed number corresponding to the order the leaves were added, this corresponds to the MMR size prior to adding the element. So the 1st element has position 0, the second position 1, and so on.

pub fn add(&mut self, el: Word) -> Result<(), MmrError>

Adds a new element to the MMR.

Errors

Returns an error if the MMR exceeds the maximum supported forest size.

pub fn peaks(&self) -> MmrPeaks

Returns the current peaks of the MMR.

pub fn peaks_at(&self, forest: Forest) -> Result<MmrPeaks, MmrError>

Returns the peaks of the MMR at the state specified by forest.

Errors

Returns an error if the specified forest value is not valid for this MMR.

pub fn get_delta( &self, from_forest: Forest, to_forest: Forest, ) -> Result<MmrDelta, MmrError>

Compute the required update to original_forest.

The result is a packed sequence of the authentication elements required to update the trees that have been merged together, followed by the new peaks of the Mmr.

pub fn inner_nodes(&self) -> MmrNodes<'_>

An iterator over inner nodes in the MMR. The order of iteration is unspecified.

Trait Implementations

impl Clone for Mmr

fn clone(&self) -> Mmr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Mmr

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

Formats the value using the given formatter.

impl Default for Mmr

fn default() -> Mmr

Returns the “default value” for a type.

impl Deserializable for Mmr

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

where R: ByteReader,

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 From<&Mmr> for MerkleStore

fn from(value: &Mmr) -> MerkleStore

Converts to this type from the input type.

impl Serializable for Mmr

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

where W: ByteWriter,

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

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

Serializes self into a vector of bytes.

fn get_size_hint(&self) -> usize

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