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.
Closes#4300.
The TypeScript `BlobFile` only had `size()`, `read()` and `readRange()`,
while the Rust `BlobFile` behind it also has `seek`, `tell`,
`read_up_to`, `read_ranges` and `close`. This exposes those on the Node
binding:
- `read(maxBytes?)` reads at most `maxBytes` from the cursor (Rust
`read_up_to`). Without the argument it reads to the end, as before.
- `readRanges([{ start, end }, ...])` reads several half-open ranges and
returns one buffer per range, in order. Like `readRange`, it does not
move the cursor.
- `seek(position)` and `tell()` move and report the cursor.
- `close()` releases the handle, and `isClosed()` reports it. Every
read, `seek` and `tell` after `close()` fails with "blob file is already
closed". A second `close()` does nothing. The binding keeps its own
`closed` flag, the same way the Python `BlobFile` does.
Offsets and lengths are `bigint`, like `readRange` and `size()`.
`BlobRange` is exported as a type.
The new tests in `table.test.ts` cover chunked reads with
`read(maxBytes)`, `seek` and `tell`, a negative seek position,
`readRanges` order and cursor, a `readRanges` end past the blob size,
and reads after `close()`. The Node docs under `docs/src/js` are
regenerated with `pnpm run docs`.
I left the `ReadableStream`/async iterator idea from the issue out of
this PR. The AbortSignal work in #4288 touches the same methods, so it
can follow on top of this.
this PR blob v2 field helpers and reads to the Node SDK.
`blob()` marks a field as blob v2 and lets you set the storage
thresholds. Inputs can be bytes, a URI, or a data/uri struct.
Queries return descriptors. `fetchBlobs()` reads the bytes by row ID,
and `fetchBlobFiles()` gives you lazy handles for full or range reads.
`blobColumns()` lists the blob fields, including nested ones.
Fetch uses the table’s current checkout. It preserves order, duplicates,
and nulls. Holding row IDs across compaction still requires stable row
IDs.
```javascript
const db = await connect("./data");
const video = await readFile("clip.mp4");
const table = await db.createTable(
"videos",
[{ id: 1n, video }],
{
schema: new Schema([
new Field("id", new Int64()),
blob("video"),
]),
},
);
const rows = await table.query().select(["id"]).withRowId().toArray();
const rowIds = rows.map((row) => row._rowid as bigint);
const bytes = await table.fetchBlobs("video", rowIds);
const [handle] = await table.fetchBlobFiles("video", rowIds);
const header = await handle!.readRange(0n, 65536n);
```
### Testing
- cover input validation, thresholds, nested fields, fetch ordering,
nulls, and range reads.
Bilal Atique
Drew