Module codec 

Document codec (L4) — per-document header + postcard payload.

See docs/format.md § Document records for the authoritative byte-by-byte specification. This module is the reference implementation.

The codec sits between the typed Document API (this module) and the B+tree (L3): every stored value in a collection’s primary B-tree is the byte string produced by encode, and every Db::get decodes through decode. The catalog (L5) supplies the collection_id that the per-document header pins; the catalog itself stores CollectionDescriptors through this same codec (M5 issue #38).

Power-of-ten posture

• Rule 5. Encode and decode are runtime boundaries: every header field is validated explicitly before any postcard call touches caller-controlled bytes. CRC32C, collection-id, and version-range checks are the three layers of defense in decode.
• Rule 7. No unwrap / expect on any error-bearing path; postcard errors propagate via the ? operator into Error::Codec.
• Rule 9. Hot-path dispatch is static — all codec calls are monomorphised over T: Document. No dyn anywhere in this module.

Re-exports

pub use crate::codec::dynamic::Dynamic;

pub use crate::codec::header::DocumentHeader;

pub use crate::codec::header::DOC_HEADER_SIZE;

pub use crate::codec::header::MAX_INLINE_DOC;

pub use crate::codec::migrate::Migrate;

pub use crate::codec::schema::DynamicSchema;

pub use crate::codec::schema::EnumVariantSchema;

pub use crate::codec::schema::Schema;

pub use crate::codec::schema::MAX_SCHEMA_DEPTH;

Modules

dynamic

Dynamic — reflective value tree for schema migration.

header

Per-document record header — encode / decode.

migrate

Schema-evolution trait — Migrate.

schema

DynamicSchema — declarative description of a postcard-encoded payload’s shape.

Traits

Document

The trait every user document type implements.

Functions

decode

Decode an on-disk record into a T: Document instance.

encode

Encode doc into the on-disk record format.