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Bilal Atique
0a1c1a04c7
Closes #4288. Blob reads in Node can now be cancelled. `BlobFile.read`, `readRange` and `readRanges`, and `Table.fetchBlobs` and `fetchBlobFiles` take an optional `{ signal?: AbortSignal }` (new `BlobReadOptions` type). When the signal aborts, the call rejects with `signal.reason` (an `AbortError` unless the caller gave a reason) and the native future is dropped, so the read stops instead of running to completion. A signal that is already aborted rejects before any read starts. How it works: - On the Rust side, these five methods are now sync `#[napi]` methods that return `env.spawn_future(...)`. The future is wrapped in `futures::future::abortable`, and the abort handle is registered with napi's `AbortSignal::on_abort`. napi's `AbortSignal` is `Rc`-based, so it can't be an argument of an `async fn`, which is why the methods changed shape. The TypeScript signatures are unchanged apart from the new optional argument. - napi-rs installs its own `onabort` on the signal it receives, which would overwrite a handler the caller set. So the TypeScript wrapper passes a private `AbortController` signal to the native call for each request, forwards the caller's abort to it with `addEventListener(..., { once: true })`, and removes the listener when the call settles. Tests in `table.test.ts`: - an already aborted signal rejects on all five methods, and the handle still reads afterwards - a custom abort reason is what the call rejects with - a read with a signal that never aborts returns normally and leaves no `abort` listener on the signal - aborting a 32 MiB `readRange` right after it starts rejects with `AbortError`, and the same handle reads again afterwards The Node docs under `docs/src/js` are regenerated. I didn't add a test for where the `read()` cursor ends up after a mid-flight abort on a local table. The remote `BlobFile` documents that a cancelled read leaves the cursor unchanged, but I haven't confirmed the same for the native Lance handle, so the docs don't claim it.
LanceDB JavaScript SDK
A JavaScript library for LanceDB.
Installation
npm install @lancedb/lancedb
This will download the appropriate native library for your platform. We currently support:
- Linux (x86_64 and aarch64 on glibc and musl)
- MacOS (Intel and ARM/M1/M2)
- Windows (x86_64 and aarch64)
Usage
Basic Example
import * as lancedb from "@lancedb/lancedb";
const db = await lancedb.connect("data/sample-lancedb");
const table = await db.createTable("my_table", [
{ id: 1, vector: [0.1, 1.0], item: "foo", price: 10.0 },
{ id: 2, vector: [3.9, 0.5], item: "bar", price: 20.0 },
]);
const results = await table.vectorSearch([0.1, 0.3]).limit(20).toArray();
console.log(results);
The quickstart contains more complete examples.
Development
See CONTRIBUTING.md for information on how to contribute to LanceDB.