Struct SnapshotHeader 

pub struct SnapshotHeader {
    pub format_version: u32,
    pub bytecode_hash: String,
    pub state_contract: Option<SnapshotContract>,
    pub projection_contract: Option<SnapshotContract>,
    pub program_ids: Vec<String>,
    pub resume_watermark: u64,
    pub observed_slot: u64,
    pub created_at_epoch_ms: u64,
    pub entry_counts: BTreeMap<String, u64>,
    pub trigger: Option<SnapshotTrigger>,
}

Plain-JSON metadata used to validate a snapshot before decompressing it.

Fields

format_version: u32

arete_interpreter::snapshot::SNAPSHOT_FORMAT_VERSION at write time.

bytecode_hash: String

Fingerprint of the compiled MultiEntityBytecode. A mismatch means the stack’s logic changed; the snapshot is discarded (cold start).

state_contract: Option<SnapshotContract>

Durable entity structure, independent of handler opcode ordering. Absent on snapshots written before contract-aware restore.

projection_contract: Option<SnapshotContract>

Runtime view/cache structure. Kept separate so a future migration can make an explicit decision about rebuilding projections.

program_ids: Vec<String>

resume_watermark: u64

Highest slot among mutation batches the projector had applied when the VM was dumped. Safe from_slot resume point.

observed_slot: u64

Slot-subscription tip at dump time (diagnostics / staleness clamping).

created_at_epoch_ms: u64

entry_counts: BTreeMap<String, u64>

Entity-name -> row count, for logging and debugging.

trigger: Option<SnapshotTrigger>

What wrote this snapshot. A shutdown snapshot is taken at a consistency cut with nothing in flight, so its offsets are exactly what was published; a periodic one can be behind by up to the write interval. Absent in snapshots written before the distinction mattered, which are treated as the unclean case.

Trait Implementations

impl Clone for SnapshotHeader

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SnapshotHeader

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SnapshotHeader

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SnapshotHeader

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

where __S: Serializer,

Serialize this value into the given Serde serializer.