Documentation / @super-line/core / RelayCollectionStore

Interface: RelayCollectionStore

Defined in: packages/core/src/collections.ts:100

A node-local replica. Core relays each batch across nodes over the Adapter and re-ingests remote batches through RelayCollectionStore.apply, so every node converges to the same rows.

Extends

• CollectionStoreBase

Properties

clustering

readonly clustering: "relay"

Defined in: packages/core/src/collections.ts:101

---

coordination

readonly coordination: "local"

Defined in: packages/core/src/collections.ts:102

Methods

apply()

apply(ops, origin): RowChange[]

Defined in: packages/core/src/collections.ts:118

See CollectionStore for the shared atomicity / error / timestamp contract. In relay mode apply also fires onChange once per resulting change before returning, and returns those changes.

The non-void return type is load-bearing — do not "simplify" it to void. It is the only thing making an async implementation a compile error, and that is the invariant which keeps a relayed write from echo-storming the cluster: the relay ingress fires-and-forgets (void apply(...)) so it can absorb a cross-node race in a try/catch, and the CRDT sibling clears a re-publish guard in finally. An async apply escapes that catch and clears that guard before the change is ever emitted. TypeScript's void-return rule accepts a function returning anything where void is declared, so apply(): void would silently permit async apply() again. RowChange[] does not.

(collections-crdt-libsql had to discover this constraint on its own — sync hot path, debounced onChange persistence — back when it lived only in prose. Now the compiler holds it.)

Parameters

ops

ResolvedRowOp[]

origin

string

Returns

RowChange[]

---

close()?

optional close(): Awaitable<void>

Defined in: packages/core/src/collections.ts:93

Release any resources held by the backend.

Returns

Awaitable<void>

Inherited from

CollectionStoreBase.close

---

conditionalApply()

conditionalApply(conditions, ops, origin): boolean

Defined in: packages/core/src/collections.ts:120

Atomically check every condition and apply ops; returns false without changing anything when one is stale.

Parameters

conditions

RowCondition[]

ops

ResolvedRowOp[]

origin

string

Returns

boolean

---

count()?

optional count(n, filter): Awaitable<number>

Defined in: packages/core/src/collections.ts:67

Rows of n matching filter (all rows when undefined), without materializing them. Absent ⇒ the server counts a snapshot.

Parameters

n

string

filter

Expr | undefined

Returns

Awaitable<number>

Inherited from

CollectionStoreBase.count

---

countBy()?

optional countBy(n, field, filter): Awaitable<ValueCount[]>

Defined in: packages/core/src/collections.ts:69

Every group of field over filter, unordered, as core's countValues forms them. Absent ⇒ the server groups a snapshot.

Parameters

n

string

field

string

filter

Expr | undefined

Returns

Awaitable<ValueCount[]>

Inherited from

CollectionStoreBase.countBy

---

fixedFields()?

optional fixedFields(n): readonly string[]

Defined in: packages/core/src/collections.ts:83

Fields of collection n whose value never changes for a key. An update without prev otherwise reaches every subscriber, a non-matching one as a data-less delete; the server skips a subscriber whose filter rules the new row out on these fields, since no version of the row ever matched it. Absent ⇒ none.

Parameters

n

string

Returns

readonly string[]

Inherited from

CollectionStoreBase.fixedFields

---

onChange()

onChange(cb): () => void

Defined in: packages/core/src/collections.ts:91

Subscribe to every applied row change across all collections — core's single fan-out source. Returns an unsubscribe fn. Who fires it depends on the mode: a RelayCollectionStore fires it from apply; a SelfCollectionStore fires it from its replication feed instead. That difference is the one thing this seam cannot state in its types (the signature is identical either way), so it is stated here and pinned by the conformance suite.

Parameters

cb

(change) => void

Returns

() => void

Inherited from

CollectionStoreBase.onChange

---

read()

read(n, id): unknown

Defined in: packages/core/src/collections.ts:71

Read one row by primary key — for write-policy prev and advisory FK checks. Undefined if absent.

Parameters

n

string

id

string

Returns

unknown

Inherited from

CollectionStoreBase.read

---

rowMeta()?

optional rowMeta(n, ids): Awaitable<Record<string, RowTimestamps>>

Defined in: packages/core/src/collections.ts:77

Inspector-only: per-row RowTimestamps keyed by row id, for ids in collection n. The client subscribe path never sees these (rows stay exactly your schema) — timestamps are surfaced solely by the Control Center. Absent ⇒ the backend doesn't track row timestamps; the inspector shows no created/updated.

Parameters

n

string

ids

string[]

Returns

Awaitable<Record<string, RowTimestamps>>

Inherited from

CollectionStoreBase.rowMeta

---

snapshot()

snapshot(n, query): Awaitable<unknown[]>

Defined in: packages/core/src/collections.ts:65

Materialize a collection's snapshot for the initial subscribe: filter → sort → offset/limit (core injects the policy filter).

Parameters

n

string

query

CollectionQuery

Returns

Awaitable<unknown[]>

Inherited from

CollectionStoreBase.snapshot