Struct SnapshotChain 

pub struct SnapshotChain { /* private fields */ }

The home’s attestation chain, as far as a reader has read its log: each RecordRefSnapshot’s id and the id its prev_snapshot names.

Built from /api/log pages, which a reader holds, rather than from anything a seed says about itself.

Implementations

impl SnapshotChain

pub fn read_page(&mut self, entries: &[Value]) -> usize

Adds every attestation in a page of /api/log entries, and says how many it found.

pub fn insert(&mut self, id: String, prev: Option<String>)

Records one link: attestation id follows prev.

pub fn steps_back(&self, from: &str, to: &str) -> Option<u64>

How many prev_snapshot links lead from from back to to, or None when to is not an ancestor of from in what was read.

pub fn relate(&self, a: &str, b: &str) -> Relation

The fork rule: a and b agree when one is the other’s ancestor, or they are equal, and are a fork when neither is.

A statement over S endorses S and everything reachable from it by prev_snapshot, so how many attestations landed between two readers’ looks does not matter, and a seed need not race the home. For the walk to be complete, the chain must hold every attestation from the lower of the two positions onward.

Trait Implementations

impl Clone for SnapshotChain

fn clone(&self) -> SnapshotChain

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SnapshotChain

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

Formats the value using the given formatter.

impl Default for SnapshotChain

fn default() -> SnapshotChain

Returns the “default value” for a type.