Module cypher_value_codec

Expand description

MessagePack-based binary encoding for CypherValue (uni_common::Value).

§Design

All property values are stored as self-describing binary blobs in Arrow LargeBinary columns. Each blob has the format:

[tag_byte: u8][msgpack_payload: bytes]

The tag byte provides O(1) type identification without deserialization. MessagePack preserves int/float distinction natively (unlike JSON).

Tag	Type	Payload
0	Null	empty
1	Bool	msgpack bool
2	Int	msgpack i64
3	Float	msgpack f64
4	String	msgpack string
5	List	msgpack array of recursively-encoded blobs
6	Map	msgpack map of string → recursively-encoded blobs
7	Bytes	msgpack binary
8	Node	msgpack {vid, label, props}
9	Edge	msgpack {eid, type, src, dst, props}
10	Path	msgpack {nodes, rels}
11	Date	msgpack i32 (days since epoch)
12	Time	msgpack i64 (nanoseconds since midnight)
13	DateTime	msgpack i64 (nanoseconds since epoch)
14	Duration	msgpack {months, days, nanos}
15	Point	msgpack {srid, coords}
16	Vector	msgpack array of f32

Nested values (List elements, Map values, Node/Edge properties) are recursively encoded as [tag][payload] blobs.

decode: Decode tagged MessagePack bytes to a Value.
decode_bool: Decode a bool directly without constructing a Value.
decode_float: Decode a float directly without constructing a Value.
decode_int: Decode an int directly without constructing a Value.
decode_string: Decode a string directly without constructing a Value.
encode: Encode a Value to tagged MessagePack bytes.
encode_bool: Encode a bool directly without constructing a Value.
encode_float: Encode a float directly without constructing a Value.
encode_int: Encode an int directly without constructing a Value.
encode_null: Encode null directly.
encode_string: Encode a string directly without constructing a Value.
extract_map_entry_raw: Extract a map entry as raw bytes without decoding the entire map.
is_null: Fast null check.
peek_tag: Peek at the tag byte without deserializing.