Module graph_integration 

Graph-level storage integration (M4.E2 — D170–D174).

Free functions (not Graph methods) because graphrefly-graph does not depend on graphrefly-storage — the dependency flows in the other direction. See D170.

Provided APIs

• GraphCheckpointRecord — portable baseline type wrapping a GraphPersistSnapshot + seq metadata + format_version (F7 close).
• diff_snapshots / decompose_diff_to_frames — snapshot diff → WAL frame generation engine (D172).
• attach_snapshot_storage + StorageHandle — wire observe subscription → snapshot diff → WAL frame writes.
• restore_snapshot — three-phase replay (baseline → checksum verify → lifecycle-scoped batch).

Manifest (D173 — F4 close)

F4 (cross-restart key recovery) is structurally closed by D174: at the attach boundary, key_of is derived deterministically from graph.name. On restore, the snapshot key is known without a separate manifest entry. The checkpoint record’s seq field serves as the WAL high-water mark.

Structs

AttachOptions

Options for attach_snapshot_storage.

AttachTierPair

Configuration for a single snapshot+WAL tier pair.

GraphCheckpointRecord

Portable baseline record written by attach_snapshot_storage on full-snapshot writes. Contains the full GraphPersistSnapshot plus metadata for WAL cursor alignment.

GraphSnapshotDiff

Structural diff between two GraphPersistSnapshots.

RestoreOptions

Options for restore_snapshot.

StorageHandle

Handle returned by attach_snapshot_storage.

ValueChange

A single node value change detected by diff_snapshots.

Enums

TornWritePolicy

Torn-write policy for mid-stream checksum failures.

Constants

SNAPSHOT_VERSION

Current snapshot format version. Embedded in GraphCheckpointRecord and in BaseChange.version within decomposed WAL frames (F7 close).

Functions

attach_snapshot_storage

Wire an observe subscription on graph that persists node changes to the provided snapshot+WAL tier pairs.

decompose_diff_to_frames

Convert a GraphSnapshotDiff into WAL frames ready for persistence.

diff_snapshots

Compare two snapshots and produce a structural diff.

restore_snapshot

Three-phase WAL replay: baseline load → checksum verify → lifecycle- scoped batch.

Type Aliases

ErrorCallback

Error callback for AttachOptions.

OnTornWrite

Callback for torn-write decisions. Receives the frame_seq and reason; returns the desired policy.

PathFilter

Filter predicate for AttachOptions.