Struct LaneChain 

pub struct LaneChain {
    pub chain_root: B256,
    pub chunk_price: U256,
    pub verified_index: u8,
    pub tip: B256,
}

One metering epoch’s hash-chain state on a lane (ADR 003 §Hash-chain metering (PayWord)).

chain_root is the head the payer signed into the epoch’s voucher, and (verified_index, tip) is the deepest preimage the node has verified under it — the frontier that turns into money at redemption. tip is the preimage bytes, not just the depth: only the payer can produce a value at a given depth, so a node that kept the index alone would hold an unprovable claim after a restart, in exactly the abandonment case the chain exists to cover.

A sealed epoch (chain_root == B256::ZERO) meters nothing: chunk_price is zero, verified_index stays 0, and tip is zero. Nothing hashes to zero, so no index above 0 can ever be verified against it.

Fields

chain_root: B256

Head of this epoch’s chain; zero seals the epoch at its anchor amount.

chunk_price: U256

What one chunk adds over the anchor, in token base units. Zero on a sealed epoch.

verified_index: u8

Deepest chain index verified under chain_root; 0 until the first preimage lands.

tip: B256

The preimage bytes at verified_index, or chain_root itself at index 0 — which is what makes the walk uniform with no branch.

Implementations

impl LaneChain

pub const NONE: Self

The empty chain: no root, no price, nothing verified. What a lane holds before its first voucher, and what a sealed voucher installs.

pub const fn opened(chain_root: B256, chunk_price: U256) -> Self

A fresh epoch at index 0: the root is its own tip, so a claim settling at exactly the anchor amount submits a value the payer already holds and walks nothing.

pub fn accrued(&self) -> U256

What the verified frontier adds over its anchor: verified_index × chunk_price.

pub fn accrued_bytes(&self) -> U256

What the verified frontier adds over its anchor on the byte axis: verified_index × CHUNK_BYTES.

Trait Implementations

impl Clone for LaneChain

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for LaneChain

impl Debug for LaneChain

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

Formats the value using the given formatter.

impl Eq for LaneChain

impl PartialEq for LaneChain

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for LaneChain