oxgraph-layout-util

Shared layout primitives for oxgraph: builder helpers + offset-integrity validation.

The support crate every concrete oxgraph layout reuses. no_std (+ alloc for build-time helpers), unsafe-free, no dependency on any other oxgraph crate.

What it is

Three responsibilities live here, one namespace each:

Index/word vocabulary (crate root): LayoutIndex, LayoutWord, LayoutSnapshotWord, and SnapshotWidth, the single sealed set of dense index widths, native and little-endian storage words, and the width-to-LE-word bijection shared by every layout and snapshot crate. LocalId is the one generic local-handle newtype layout crates alias for their node/edge/vertex/hyperedge/incidence identities, and IdSlice is the one slice-to-handle iterator they all reuse.
Build-time (build module): validate dense IDs against a known count, flatten per-bucket payloads into CSR-style (offsets, items) pairs, and lower native index slices into explicit little-endian words.
Read-time (integrity module): walk borrowed offset arrays at view-open time and convert already-validated indexes infallibly.

The crate also provides the CRC-32C (Castagnoli) checksum function (crc32c_append) that oxgraph-snapshot writers and verified readers plug in. No public domain semantics: this crate knows nothing about graphs or hypergraphs.

Where it sits

oxgraph-layout-util             ← this crate
├── oxgraph-snapshot              byte container (no-alloc dependency)
├── oxgraph-csr / oxgraph-csc     borrowed graph layouts
└── oxgraph-hyper-bcsr            borrowed hypergraph layout

Features

Feature	Effect
`alloc` (default)	Enables the build-time primitives that allocate (`build_offset_index`, `slice_to_le`).
none (`default-features = false`)	Keeps the index/word vocabulary, `LocalId`, `IdSlice`, and the offset-integrity checks, with no allocation.

Documentation

See docs.rs/oxgraph-layout-util for the full API and the oxgraph family README for how the layers fit together. Also available through the umbrella crate: cargo add oxgraph --features layout.

License