Struct MmrFrontier 

pub struct MmrFrontier { /* private fields */ }

A peaks-only MMR frontier: the O(log n) state a stream continues from, and the accumulator that continues it. leaf_count fixes where an extension proof’s connecting nodes go.

Peak hashes equal mmr_lib’s, so root is mmr_lib::MMR::get_root bound to the leaf count, and proofs from a full mmr_lib::MMR over the same leaves verify against it.

Fields are private. new, from_parts and Decode are the only constructors, and each enforces one peak per set bit of leaf_count and leaf_count <= MAX_MMR_LEAF_COUNT.

Encodes as leaf_count ‖ peaks. A decoder reads the count first, and the BoundedVec rejects an over-long length prefix before any peak is read.

Implementations

impl MmrFrontier

pub fn new() -> Self

pub fn from_parts(peaks: Vec<Hash>, leaf_count: u64) -> Option<Self>

A frontier from (peaks, leaf_count). None unless there is one peak per set bit of leaf_count and leaf_count <= MAX_MMR_LEAF_COUNT.

pub fn peaks(&self) -> &[Hash]

The peaks, highest to lowest.

pub fn leaf_count(&self) -> u64

pub fn try_append(&mut self, leaf: Hash) -> Result<(), FrontierFull>

Append a leaf, merging equal-height peaks as mmr_lib does. At MAX_MMR_LEAF_COUNT the leaf is refused and the frontier left unchanged, so every frontier still decodes.

pub fn append(&mut self, leaf: Hash)

try_append for a frontier this chain built itself, from the empty frontier one leaf at a time.

Panics

At MAX_MMR_LEAF_COUNT, which no stream reaches: 2^48 leaves are beyond any chain’s lifetime. Never call it on a frontier built from untrusted parts.

pub fn root(&self) -> MmrRoot

The root: the leaf count bound over the bagged peaks (MmrRoot::from_bag). The empty frontier bags to zero (empty_root), so a frontier that has consumed nothing compares and extends like any other.

Trait Implementations

impl Clone for MmrFrontier

fn clone(&self) -> MmrFrontier

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MmrFrontier

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

Formats the value using the given formatter.

impl Decode for MmrFrontier

Field order matches the derived Encode. The decoded pair goes through from_parts, so a frontier off the wire holds the same invariants as one built here.

fn decode<I: Input>(input: &mut I) -> Result<Self, CodecError>

Attempt to deserialise the value from input.

fn decode_into<I>( input: &mut I, dst: &mut MaybeUninit<Self>, ) -> Result<DecodeFinished, Error>

where I: Input,

Attempt to deserialize the value from input into a pre-allocated piece of memory.

fn skip<I>(input: &mut I) -> Result<(), Error>

where I: Input,

Attempt to skip the encoded value from input.

fn encoded_fixed_size() -> Option<usize>

Returns the fixed encoded size of the type.

impl Default for MmrFrontier

fn default() -> MmrFrontier

Returns the “default value” for a type.

impl Encode for MmrFrontier

fn size_hint(&self) -> usize

If possible give a hint of expected size of the encoding.

fn encode_to<__CodecOutputEdqy: Output + ?Sized>( &self, __codec_dest_edqy: &mut __CodecOutputEdqy, )

Convert self to a slice and append it to the destination.

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

Convert self to an owned vector.

fn using_encoded<R, F>(&self, f: F) -> R

where F: FnOnce(&[u8]) -> R,

Convert self to a slice and then invoke the given closure with it.

fn encoded_size(&self) -> usize

Calculates the encoded size.

impl PartialEq for MmrFrontier

fn eq(&self, other: &MmrFrontier) -> 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 TypeInfo for MmrFrontier

type Identity = MmrFrontier

The type identifying for which type info is provided.

fn type_info() -> Type

Returns the static type identifier for Self.

impl DecodeWithMemTracking for MmrFrontier

impl EncodeLike for MmrFrontier

impl Eq for MmrFrontier

impl StructuralPartialEq for MmrFrontier