Module index 

Secondary indexes (L6) — index B+trees layered over the M4 B+tree.

M7 adds secondary indexes: per-collection B+trees keyed by an order-preserving encoding of one or more document fields, valued by the document’s Id. See docs/format.md § Indexes for the authoritative on-disk layout.

Each declared index lives in its own B+tree (M4 — no new on-disk page types). The index’s root page-id is persisted inside the owning CollectionDescriptor as an IndexDescriptor entry (M5 reserved the field; M7 fills it).

Module split

• spec — runtime declaration shapes: IndexKind, IndexSpec, constructors. The descriptor on-disk shape lives in crate::catalog because the catalog owns the wire row.
• key — order-preserving byte encoding for Dynamic values plus the composite envelope. The encoding contract is documented in docs/format.md § Index key encoding.

Power-of-ten posture

• Rule 1. No recursion: the encoder walks the input &[Dynamic] with a single bounded for loop.
• Rule 2. Per-encode loops are bounded by the input slice length, which the caller has already validated against IndexSpec::key_paths.len().
• Rule 5. Field count is checked against IndexSpec’s key_paths at the encode-time runtime boundary; type-level invariants (kind enum, non-empty key_paths for composite, single-field for Each) sit on the constructors.
• Rule 7. No unwrap / expect on the production path. The encoder returns Err(Error::Codec) on String fields that contain an embedded 0x00 (the terminator would split the key — see docs/format.md).
• Rule 9. All dispatch is static — IndexKind is an enum matched at every call site; no dyn, no macro generation.

Re-exports

pub use crate::index::extract::extract_index_keys;

pub use crate::index::extract::MAX_EACH_ENTRIES;

pub use crate::index::key::encode_field;

pub use crate::index::key::encode_index_key;

pub use crate::index::key::encode_index_key_parts;

pub use crate::index::key::encoded_id_suffix_len;

pub use crate::index::key::EncodedIndexKey;

pub use crate::index::key::COMPOSITE_TAG;

pub use crate::index::spec::IndexKind;

pub use crate::index::spec::IndexSpec;

Modules

extract

Field extraction: Document → encoded index keys.

key

Order-preserving byte encoding for index keys.

spec

IndexKind + IndexSpec — runtime declaration of a secondary index.