TxQueueStateRepresents the shared state of a transactional queue that can be inspected. This interface contains the core properties needed for queue state inspection operations like size, capacity, and completion status.
export interface TxQueueState extends import InspectableInspectable {
readonly TxQueueState.strategy: "bounded" | "unbounded" | "dropping" | "sliding"strategy: "bounded" | "unbounded" | "dropping" | "sliding"
readonly TxQueueState.capacity: numbercapacity: number
readonly TxQueueState.items: TxChunk.TxChunk<any>(property) TxQueueState.items: {
ref: TxRef.TxRef<Chunk.Chunk<A>>;
toString: () => string;
toJSON: () => unknown;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
import TxChunkTxChunk.type TxChunk.TxChunk = /*unresolved*/ anyTxChunk<any>
readonly TxQueueState.stateRef: TxRef.TxRef<State<any, any>>(property) TxQueueState.stateRef: {
version: number;
pending: Map<unknown, () => void>;
value: A;
pipe: { <A>(this: A): A; <A, B = never>(this: A, ab: (_: A) => B): B; <A, B = never, C = never>(this: A, ab: (_: A) => B, bc: (_: B) => C): C; <A, B = never, C = never, D = never>(this: A, ab: (_: A) => B, bc: (_: B) => C, cd: (_: C) => D): D; <…;
}
import TxRefTxRef.interface TxRef<in out A>TxRef is a transactional value, it can be read and modified within the body of a transaction.
When to use
Use to store mutable state that must be read and modified inside Effect
transactions.
Details
Accessed values are tracked by the transaction in order to detect conflicts and in order to
track changes, a transaction will retry whenever a conflict is detected or whenever the
transaction explicitely calls to Effect.txRetry and any of the accessed TxRef values
change.
Example (Using a transactional reference)
import { Effect, TxRef } from "effect"
const program = Effect.gen(function*() {
// Create a transactional reference
const ref: TxRef.TxRef<number> = yield* TxRef.make(0)
// Use within a transaction
yield* Effect.tx(Effect.gen(function*() {
const current = yield* TxRef.get(ref)
yield* TxRef.set(ref, current + 1)
}))
const final = yield* TxRef.get(ref)
console.log(final) // 1
})
TxRef<type State<_A, E> =
| {
readonly _tag: "Open"
}
| {
readonly _tag: "Closing"
readonly cause: Cause.Cause<E>
}
| {
readonly _tag: "Done"
readonly cause: Cause.Cause<E>
}
Represents the state of a transactional queue with sophisticated lifecycle management.
Details
The queue progresses through three states:
- Open: Accepting offers and serving takes normally
- Closing: No new offers accepted, serving remaining items until empty
- Done: Terminal state with completion cause, no further operations possible
Example (Inspecting queue lifecycle states)
import type { TxQueue } from "effect"
// State progression example
declare const state: TxQueue.State<string, Error>
if (state._tag === "Open") {
console.log("Queue is accepting new items")
} else if (state._tag === "Closing") {
console.log("Queue is draining, cause:", state.cause)
} else {
console.log("Queue is done, cause:", state.cause)
}
State<any, any>>
}