Enum Phase 

#[repr(u8)]
pub enum Phase {
    BoundaryStart = 0,
    SnapshotReady = 1,
    RequestBuilt = 2,
    FirstByte = 3,
    LastBlockEnd = 4,
    ToolsSpawned = 5,
    ToolsJoined = 6,
    BatchProposed = 7,
    WatermarkDurable = 8,
    BoundaryEnd = 9,
}

Re-exported so hotl_engine::LedgerSummary resolves alongside EngineEvent::LedgerReport — the loop-overhead instrument (§S1) lives in its own module ([ledger]) since it is self-contained (no dependency on the rest of the engine’s types) and independently unit-tested. The ten boundary events a turn’s sample passes through. Declaration order is the critical-path order the design doc’s per-phase deltas price (SnapshotReady−BoundaryStart prices the snapshot transport, etc.) — see [DELTA_PAIRS]. A doom-loop abort or a failed sample can legitimately skip phases past the point of failure; see [LoopLedger::stamp].

BatchProposed/WatermarkDurable are the one place the critical path forks: a sample proposes once (the model’s own assistant+usage entry) or twice (that entry, then — only when a tool phase runs — the tool-results entry). These two phases use [LoopLedger::restamp] (last-wins, not stamp’s first-wins), so their recorded position always tracks the sample’s REAL final commit — after ToolsJoined when a tool phase ran, otherwise right after LastBlockEnd. Every other phase is written exactly once by construction, so stamp’s first-wins rule is what applies to them.

Declaration order is stamp order, not wall order — and since S2c’s optimistic dispatch those two genuinely diverge. A sample whose request was dispatched at the previous boundary already had bytes on the wire before this sample’s BoundaryStart: its true first byte can precede the previous sample’s WatermarkDurable, which is the overlap the mechanism exists for, not a measurement error. Every stamp is taken when the turn observes the event, so the recorded sequence stays monotone and the summary needs no special case; what a reader must not do is treat RequestBuilt→FirstByte on an adopted sample as a round-trip measurement. It is the time to notice a byte that was already there, and it is legitimately near zero. ([width] saturates either way, so an out-of-order pair reports 0 rather than wrapping.)

Variants

BoundaryStart = 0

SnapshotReady = 1

RequestBuilt = 2

FirstByte = 3

LastBlockEnd = 4

ToolsSpawned = 5

ToolsJoined = 6

BatchProposed = 7

WatermarkDurable = 8

BoundaryEnd = 9

Trait Implementations

impl Clone for Phase

fn clone(&self) -> Phase

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Phase

impl Debug for Phase

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

Formats the value using the given formatter.

impl Eq for Phase

impl PartialEq for Phase

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Phase

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Phase