Files
lancedb/nodejs/__test__/blob.test.ts
T
Drew 6702e3fec1 feat(node): add blob v2 fetch and field helpers (#4155)
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.
2026-09-11 14:46:27 -07:00

186 lines
5.8 KiB
TypeScript

// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The LanceDB Authors
import { Field, Int64, List, Schema, Struct, Utf8 } from "apache-arrow";
import { makeArrowTable } from "../lancedb/arrow";
import { BlobFile, blob, coerceBlobValue, isBlobField } from "../lancedb/blob";
describe("blob()", () => {
it("marks the field as lance.blob.v2", () => {
const field = blob("image", { nullable: false });
expect(field.nullable).toBe(false);
expect(isBlobField(field)).toBe(true);
expect(field.metadata.get("ARROW:extension:name")).toBe("lance.blob.v2");
});
it("writes encoding thresholds as field metadata", () => {
const field = blob("video", {
inlineSizeThreshold: 1024,
dedicatedSizeThreshold: 2 * 1024 * 1024,
packFileSizeThreshold: 64 * 1024 * 1024,
});
expect(
field.metadata.get("lance-encoding:blob-inline-size-threshold"),
).toBe("1024");
expect(
field.metadata.get("lance-encoding:blob-dedicated-size-threshold"),
).toBe(String(2 * 1024 * 1024));
expect(
field.metadata.get("lance-encoding:blob-pack-file-size-threshold"),
).toBe(String(64 * 1024 * 1024));
});
it("rejects invalid thresholds", () => {
expect(() => blob("image", { inlineSizeThreshold: -1 })).toThrow(
/inlineSizeThreshold must be non-negative/,
);
expect(() => blob("image", { dedicatedSizeThreshold: 0 })).toThrow(
/dedicatedSizeThreshold must be positive/,
);
expect(() => blob("image", { packFileSizeThreshold: 1.5 })).toThrow(
/packFileSizeThreshold must be a safe integer/,
);
expect(() =>
blob("image", { dedicatedSizeThreshold: Number.MAX_SAFE_INTEGER + 1 }),
).toThrow(/dedicatedSizeThreshold must be a safe integer/);
});
});
describe("coerceBlobValue", () => {
it.each([
["Buffer", Buffer.from("x"), { data: Buffer.from("x"), uri: null }],
[
"Uint8Array",
new Uint8Array([120]),
{ data: new Uint8Array([120]), uri: null },
],
["URI string", "s3://bucket/key", { data: null, uri: "s3://bucket/key" }],
[
"data struct",
{ data: Buffer.from("y") },
{ data: Buffer.from("y"), uri: null },
],
[
"uri struct",
{ uri: "s3://bucket/key" },
{ data: null, uri: "s3://bucket/key" },
],
["null", null, null],
])("accepts %s", (_name, input, expected) => {
expect(coerceBlobValue(input)).toEqual(expected);
});
it.each([
["empty URI", "", /uri cannot be empty/],
["object without data or uri", { position: 0 }, /data' or 'uri/],
[
"Int16Array",
new Int16Array([1]),
/Blob data must be Buffer or Uint8Array/,
],
[
"both data and uri",
{ data: Buffer.from("y"), uri: "s3://bucket/key" },
/exactly one of 'data' or 'uri'/,
],
[
"neither data nor uri",
{ data: null, uri: null },
/exactly one of 'data' or 'uri'/,
],
])("rejects %s", (_name, input, message) => {
expect(() => coerceBlobValue(input)).toThrow(message);
});
});
describe("BlobFile", () => {
it("rejects constructing BlobFile without a native handle", () => {
expect(() => new (BlobFile as unknown as { new (): BlobFile })()).toThrow(
/fetchBlobFiles/,
);
});
});
describe("makeArrowTable blob columns", () => {
it("coerces Buffer input onto a blob field", () => {
const schema = new Schema([
new Field("id", new Int64(), true),
blob("image"),
]);
const table = makeArrowTable([{ id: 1n, image: Buffer.from("hello") }], {
schema,
});
expect(isBlobField(table.schema.fields[1])).toBe(true);
const image = table.getChild("image")!;
expect(image.nullCount).toBe(0);
expect(image.getChild("uri")!.get(0)).toBeNull();
expect(image.getChild("data")!.nullCount).toBe(0);
expect(Buffer.from(image.getChild("data")!.get(0)!).toString()).toBe(
"hello",
);
});
it("coerces Buffer elements inside a list and keeps null slots", () => {
const schema = new Schema([
new Field("id", new Int64(), true),
new Field("images", new List(blob("image")), true),
]);
const table = makeArrowTable(
[
{ id: 1n, images: [Buffer.from("a"), Buffer.from("bb")] },
{ id: 2n, images: null },
{ id: 3n, images: [Buffer.from("c"), null] },
{ id: 4n, images: [] },
],
{ schema },
);
const images = table.getChild("images")!;
expect(images.nullCount).toBe(1);
const rows = images.toArray();
expect(rows[1]).toBeNull();
expect(Array.from(rows[3] as Iterable<unknown>)).toHaveLength(0);
const first = Array.from(rows[0] as Iterable<{ data: Uint8Array | null }>);
expect(Buffer.from(first[0].data!).toString()).toBe("a");
expect(Buffer.from(first[1].data!).toString()).toBe("bb");
const third = Array.from(
rows[2] as Iterable<{ data: Uint8Array | null } | null>,
);
expect(Buffer.from(third[0]!.data!).toString()).toBe("c");
expect(third[1]).toBeNull();
});
it("coerces Buffer fields inside list structs", () => {
const schema = new Schema([
new Field("id", new Int64(), true),
new Field(
"items",
new List(
new Field(
"item",
new Struct([new Field("name", new Utf8(), true), blob("image")]),
true,
),
),
true,
),
]);
const table = makeArrowTable(
[
{
id: 1n,
items: [{ name: "one", image: Buffer.from("alpha") }],
},
],
{ schema },
);
const items = Array.from(
table.getChild("items")!.toArray()[0] as Iterable<{
name: string;
image: { data: Uint8Array | null };
}>,
);
expect(items[0].name).toBe("one");
expect(Buffer.from(items[0].image.data!).toString()).toBe("alpha");
});
});