Struct AcknowledgedStoreSnapshot 

pub struct AcknowledgedStoreSnapshot {
    pub authority: RetainedReplaySnapshotAuthority,
    pub acknowledgements: BTreeMap<StoreDeviceId, RetainedAcknowledgementChain>,
}

One snapshot every device active at its cut has acknowledged.

This is the unanimity proof, and it answers only one question: may history behind this snapshot be deleted? It may, because every device that could still need that history has said in a signed acknowledgement — activated by a commit in the verified closure — that it holds this snapshot.

Installing a snapshot asks a different question and does not need this. A device joining or restoring wants a signed, owner-authored, history- consistent image; whether some other device has caught up has no bearing on that, and a device that is behind converges through an ordinary pull no matter which image the joiner installed. Requiring unanimity there made a store with one joined-and-idle device fall back to its generation-zero image forever.

Fields

authority: RetainedReplaySnapshotAuthority

acknowledgements: BTreeMap<StoreDeviceId, RetainedAcknowledgementChain>

One chain per device that had to acknowledge, which is a subset of the devices active at the coverage: those still active now. Which subset is a question about the current device state, so it is decided by the builder against verified history and recorded here — validate can check that these devices were active at the coverage and that each chain proves what it claims, but not that the set is the right one to have asked. See the reclaim module for why the set is what it is.

Implementations

impl AcknowledgedStoreSnapshot

pub fn acknowledgement_refs( &self, ) -> Result<Vec<StoreAckRef>, StoreProtocolError>

The latest acknowledgement each active device signed for this snapshot, in a stable order. This is the evidence a reclaim claim carries: the devices are named by what they signed, not by the chains behind it.

pub fn validate(&self) -> Result<(), StoreProtocolError>

The installable authority, plus proof that every device active at its cut acknowledged this exact snapshot. Reclaim deletes history behind a snapshot only against this.

Trait Implementations

impl Clone for AcknowledgedStoreSnapshot

fn clone(&self) -> AcknowledgedStoreSnapshot

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AcknowledgedStoreSnapshot

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AcknowledgedStoreSnapshot

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for AcknowledgedStoreSnapshot

fn eq(&self, other: &AcknowledgedStoreSnapshot) -> 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 Serialize for AcknowledgedStoreSnapshot

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for AcknowledgedStoreSnapshot

impl StructuralPartialEq for AcknowledgedStoreSnapshot