Struct Ledger 

pub struct Ledger { /* private fields */ }

A per-job checkpoint ledger, backed by a single SQLite file.

The connection is behind a Mutex purely to make Ledger: Sync — rusqlite::Connection is Send but not Sync (its statement cache uses unsynchronized interior mutability), and run_job holds a &Ledger across .await points in a task spawned onto a multi-threaded runtime, which requires the held reference to be Send, which in turn requires Ledger: Sync. There is normally only ever one writer (the job that owns this ledger), so contention is not a real concern; the lock exists to satisfy the type system’s threading rules, not to arbitrate real concurrent access.

Implementations

impl Ledger

pub fn open(path: &Path, graph_fingerprint: &str) -> Result<Self>

Open (creating if absent) a job’s ledger at path, ensuring both tables exist and job_status has its single row.

graph_fingerprint is recorded only when job_status doesn’t exist yet (a fresh job) — reopening an existing ledger leaves the originally-recorded fingerprint untouched, since comparing old vs. new fingerprint is a resume endpoint’s job, not open’s.

pub fn graph_fingerprint(&self) -> Result<String>

The fingerprint recorded when this job was first submitted — compare against a freshly computed one before resuming.

pub fn get_completed(&self, node_name: &str) -> Result<Option<Value>>

The recorded output of node_name, if it completed successfully. None for a node that never ran, is still pending, or was skipped.

pub fn is_skipped(&self, node_name: &str) -> Result<bool>

Whether node_name was recorded as skipped (e.g. excluded by a branch decision).

pub fn write_completed(&self, node_name: &str, output: &Value) -> Result<()>

Record node_name as completed with output, overwriting any prior checkpoint for that node.

pub fn write_skipped(&self, node_name: &str) -> Result<()>

Record node_name as skipped, overwriting any prior checkpoint for that node.

pub fn job_status(&self) -> Result<LedgerJobStatus>

The job’s own terminal status. Running until Ledger::finish is called.

pub fn finish(&self, status: &str) -> Result<()>

Record the job’s terminal status (e.g. "completed", "failed", "cancelled").