Struct OpLog 

pub struct OpLog { /* private fields */ }

Implementations

impl OpLog

pub fn open(root: &Path) -> Result<Self>

pub fn put(&self, rec: &OperationRecord) -> Result<()>

Persist a record. Idempotent on existing op_ids (the bytes must match by content addressing).

Crash safety: the tempfile’s data is fsync’d before rename, so a successful return implies a durable file at the final path. The containing directory is not fsync’d; on a crash between rename and the directory’s metadata flush, the file can be lost. For a content-addressed log this is acceptable — a lost record can be re-derived from the same source — but callers that also persist references to the op_id (e.g. branch heads) should fsync those refs after put returns.

pub fn get(&self, op_id: &OpId) -> Result<Option<OperationRecord>>

pub fn walk_back( &self, head: &OpId, limit: Option<usize>, ) -> Result<Vec<OperationRecord>>

Walk parents transitively. Newest-first, BFS, dedup’d by op_id. Stops at parentless ops or after limit records.

pub fn walk_forward( &self, head: &OpId, limit: Option<usize>, ) -> Result<Vec<OperationRecord>>

Same set as walk_back but oldest-first. Used by branch_head for left-to-right transition replay.

pub fn lca(&self, a: &OpId, b: &OpId) -> Result<Option<OpId>>

Common ancestor of two op_ids in the DAG.

On tree-shaped histories and chain merges this is the lowest common ancestor — the closest shared op. On criss-cross merges (two ops each with two parents from independent histories) there can be multiple incomparable common ancestors; this picks one deterministically (the first hit when traversing b’s ancestors newest-first), but not via a recursive merge. None if no shared ancestor exists.

Tier-1 merge in #129 covers linear and tree-shaped histories; criss-cross resolution is deferred to a future tier (Git’s recursive strategy is the reference).

pub fn list_all(&self) -> Result<Vec<OperationRecord>>

Every record in the log. Order is whatever the directory listing produces — undefined and not stable. Used by the [crate::predicate] evaluator when no narrower candidate set is available.

pub fn ops_since( &self, head: &OpId, base: Option<&OpId>, ) -> Result<Vec<OperationRecord>>

Ops in head’s history that are not in base’s history. base = None means “include all of head’s history” (used for independent-histories case where the LCA is None).