| 1 | /** |
| 2 | * Bun stream interoperability for Effect streams. |
| 3 | * |
| 4 | * This module is the Bun entry point for adapting runtime streams into Effect's |
| 5 | * streaming model. It re-exports the shared Node stream adapters for Bun's |
| 6 | * Node-compatible stream APIs and adds {@link fromReadableStream}, a Web |
| 7 | * `ReadableStream` adapter that uses Bun's `readMany` reader method to pull |
| 8 | * batches of values into an Effect `Stream`. |
| 9 | * |
| 10 | * @since 4.0.0 |
| 11 | */ |
| 12 | import * as Arr from "effect/Array" |
| 13 | import * as Cause from "effect/Cause" |
| 14 | import * as Channel from "effect/Channel" |
| 15 | import * as Effect from "effect/Effect" |
| 16 | import { constVoid, type LazyArg } from "effect/Function" |
| 17 | import type * as Pull from "effect/Pull" |
| 18 | import * as Scope from "effect/Scope" |
| 19 | import * as Stream from "effect/Stream" |
| 20 | |
| 21 | /** |
| 22 | * @since 4.0.0 |
| 23 | */ |
| 24 | export * from "@effect/platform-node-shared/NodeStream" |
| 25 | |
| 26 | /** |
| 27 | * Creates a stream from a `ReadableStream` using Bun's optimized `.readMany` |
| 28 | * API. |
| 29 | * |
| 30 | * @category constructors |
| 31 | * @since 4.0.0 |
| 32 | */ |
| 33 | export const fromReadableStream = <A, E>( |
| 34 | options: { |
| 35 | readonly evaluate: LazyArg<ReadableStream<A>> |
| 36 | readonly onError: (error: unknown) => E |
| 37 | readonly releaseLockOnEnd?: boolean | undefined |
| 38 | } |
| 39 | ): Stream.Stream<A, E> => |
| 40 | Stream.fromChannel(Channel.fromTransform(Effect.fnUntraced(function*(_, scope) { |
| 41 | const reader = options.evaluate().getReader() |
| 42 | yield* Scope.addFinalizer( |
| 43 | scope, |
| 44 | options.releaseLockOnEnd |
| 45 | ? Effect.sync(() => reader.releaseLock()) |
| 46 | : Effect.promise(() => reader.cancel().catch(constVoid)) |
| 47 | ) |
| 48 | function readMany(): Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E> { |
| 49 | let result: |
| 50 | | Bun.ReadableStreamDefaultReadManyResult<A> |
| 51 | | Promise<Bun.ReadableStreamDefaultReadManyResult<A>> |
| 52 | try { |
| 53 | result = reader.readMany() |
| 54 | } catch (error) { |
| 55 | return Effect.fail(options.onError(error)) |
| 56 | } |
| 57 | if ("then" in result) { |
| 58 | return Effect.callback<Arr.NonEmptyReadonlyArray<A>, E | Cause.Done>((resume) => { |
| 59 | result.then((_) => resume(handleResult(_)), (e) => resume(Effect.fail(options.onError(e)))) |
| 60 | }) |
| 61 | } |
| 62 | return handleResult(result) |
| 63 | } |
| 64 | function handleResult( |
| 65 | result: Bun.ReadableStreamDefaultReadManyResult<A> |
| 66 | ): Pull.Pull<Arr.NonEmptyReadonlyArray<A>, E> { |
| 67 | if (result.done) { |
| 68 | return Cause.done() |
| 69 | } else if (!Arr.isReadonlyArrayNonEmpty(result.value)) { |
| 70 | return readMany() |
| 71 | } |
| 72 | return Effect.succeed(result.value) |
| 73 | } |
| 74 | // @effect-diagnostics-next-line returnEffectInGen:off |
| 75 | return Effect.suspend(readMany) |
| 76 | }))) |