Struct ProvenanceLog 

pub struct ProvenanceLog { /* private fields */ }

Append-only writer with in-process serialization.

Implementations

impl ProvenanceLog

pub fn open( path: impl Into<Utf8PathBuf>, session_id: String, ) -> Result<Self, LogError>

Open or create the log at path, stamping every row with session_id.

session_id MUST be a 26-char ULID generated once per process invocation by the caller. Re-opening the log within the same process reuses the same session_id; re-opening in a new process gets a new one. This crate intentionally does NOT generate the ULID itself — callers are responsible for creating one (e.g. via the ulid crate already present in the workspace) and threading it through.

If the file exists, scan it once to recover the last ts_seq and this_hash. If the file is missing or empty, the first row will use prev_hash = "GENESIS" and ts_seq = 1.

Errors

Returns LogError::Io for I/O failures or if any line fails to parse as a LogRow (synthetic message: "corrupted log at line N: …"). The writer never silently truncates a corrupt log.

Returns LogError::NotARegularFile if path exists but is not a regular file (e.g. a directory).

pub fn append(&self, input: RowInput<'_>) -> Result<u64, LogError>

Append a row. Computes prev_hash, ts_seq, ts, session_id, and this_hash; the caller only supplies the semantic fields via RowInput.

Returns the assigned ts_seq on success.

Errors

Returns LogError on serialization, I/O, or fsync failure. Callers MUST treat this as fail-closed and abort the surrounding fetch.

pub fn path(&self) -> &Utf8Path

Returns the path the log was opened at. Useful for tests and audit tooling.

pub fn session_id(&self) -> &str

Returns the session id stamped into every row written through this writer.

Trait Implementations

impl Debug for ProvenanceLog

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

Formats the value using the given formatter.