Struct Checkpoint 

pub struct Checkpoint {
    pub version: u32,
    pub session: String,
    pub started_at: String,
    pub checkpoint_at: String,
    pub invocation: u32,
    pub phases: Vec<PhaseEntry>,
}

In-memory checkpoint state — the fold of an append-only JSONL event stream at logs/<session>/checkpoint.jsonl. One per session. Per SRD-44a, the on-disk format is the event log; this struct is what consumers (resume planner, summary report) see after reading and folding.

Fields

version: u32

File-format version. 1 until we ship a 2. Each resume invocation refuses to read a checkpoint whose version it doesn’t recognise — fail fast over silent schema drift.

session: String

Session identifier — same string used in logs/<session>/. The resume CLI’s auto-detect picks the most-recent session; explicit --resume <id> names this directly.

started_at: String

RFC 3339 timestamp of session start — first invocation’s nmbrs run start.

checkpoint_at: String

RFC 3339 timestamp of this flush — updated on every successful write.

invocation: u32

1-based invocation counter. First nmbrs run is 1; each --resume increments by 1. Used in session.log separator lines (--- RESUMED <ts> [#N] ---) and in post-run summary diagnostics if needed.

phases: Vec<PhaseEntry>

One entry per pre-mapped phase. Order matches the scenario tree’s DFS — same order the post-run summary uses, same order the resume planner walks.

Trait Implementations

impl Clone for Checkpoint

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 Checkpoint

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Checkpoint

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Checkpoint

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

where __S: Serializer,

Serialize this value into the given Serde serializer.