Enum ProjectionKind 

pub enum ProjectionKind {
    Row,
    Graph,
    Unrecognized(u8),
}

Global reusable projection definition. Names the extraction rules that turn a payload into a queryable row. Not attached to a topic on its own: bindings (ProjectionBinding) declare where projections may apply.

Storage model

A published record lives in up to three places, controlled by the projection:

1. Iggy log (always): the original wire bytes, partitioned, replayable from offset 0. The source of truth.
2. Indexed columns (always): the scalar fields declared via field / field_at, extracted from the payload at materialize time and stored in the row. These drive filters, ordering, and aggregates.
3. Inline body (opt-in via inline_payload, on by default through Projection::builder): a copy of the full original payload alongside the row, so typed fetches can decode it without going back to the log.

The body may carry fields that are not indexed. Only the declared fields are queryable. Everything else rides through as part of the inlined body (when on) or is reachable only by Iggy replay (when off). What a projection materializes: queryable rows, or a knowledge graph of nodes and edges. Rides the wire as a u8 code (the growable-dictionary pattern) so a future kind flows through an old reader as Unrecognized rather than failing the listing.

Variants

Row

Materialize queryable rows (the default).

Graph

Materialize a knowledge graph (nodes, edges, triplets).

Unrecognized(u8)

A code this build does not know, passed through.

Implementations

impl ProjectionKind

pub const fn code(self) -> u8

The pinned wire code.

pub const fn from_code(code: u8) -> Self

The kind for a wire code (unknown codes become Unrecognized).

pub const fn is_row(&self) -> bool

Whether this is the default Row kind (omitted on the wire).

Trait Implementations

impl Clone for ProjectionKind

fn clone(&self) -> ProjectionKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ProjectionKind

impl Debug for ProjectionKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ProjectionKind

fn default() -> ProjectionKind

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ProjectionKind

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ProjectionKind

impl From<ProjectionKind> for u8

fn from(kind: ProjectionKind) -> u8

Converts to this type from the input type.

impl From<u8> for ProjectionKind

fn from(code: u8) -> Self

Converts to this type from the input type.

impl Hash for ProjectionKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ProjectionKind

fn eq(&self, other: &ProjectionKind) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for ProjectionKind

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ProjectionKind