JavaScript / Node.js library for LanceDB

- Core rust library
- ffi bridge that exposes rust functionality to javascript
- npm package that provides a TypeScript / JavaScript library
- limitations: it only supports reading for now

node/src/index.ts

@@ -0,0 +1,134 @@
+// Copyright 2023 Lance Developers.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { tableFromIPC, Vector } from 'apache-arrow'
+
+// eslint-disable-next-line @typescript-eslint/no-var-requires
+const { databaseNew, databaseTableNames, databaseOpenTable, tableSearch } = require('../index.node')
+
+/**
+ * Connect to a LanceDB instance at the given URI
+ * @param uri The uri of the database.
+ */
+export function connect (uri: string): Connection {
+  return new Connection(uri)
+}
+
+/**
+ * A connection to a LanceDB database.
+ */
+export class Connection {
+  private readonly _uri: string
+  private readonly _db: any
+
+  constructor (uri: string) {
+    this._uri = uri
+    this._db = databaseNew(uri)
+  }
+
+  get uri (): string {
+    return this._uri
+  }
+
+  /**
+     * Get the names of all tables in the database.
+     */
+  tableNames (): string[] {
+    return databaseTableNames.call(this._db)
+  }
+
+  /**
+     * Open a table in the database.
+     * @param name The name of the table.
+     */
+  async openTable (name: string): Promise<Table> {
+    const tbl = await databaseOpenTable.call(this._db, name)
+    return new Table(tbl, name)
+  }
+}
+
+/**
+ * A table in a LanceDB database.
+ */
+export class Table {
+  private readonly _tbl: any
+  private readonly _name: string
+
+  constructor (tbl: any, name: string) {
+    this._tbl = tbl
+    this._name = name
+  }
+
+  get name (): string {
+    return this._name
+  }
+
+  /**
+     * Create a search query to find the nearest neighbors of the given query vector.
+     * @param queryVector The query vector.
+     */
+  search(queryVector: number[]): Query {
+    return new Query(this._tbl, queryVector)
+  }
+}
+
+/**
+ * A builder for nearest neighbor queries for LanceDB.
+ */
+export class Query {
+  private readonly _tbl: any
+  private readonly _query_vector: number[]
+  private readonly _limit: number
+  private readonly _refine_factor?: number
+  private readonly _nprobes: number
+  private readonly _columns?: string[]
+  private readonly _where?: string
+  private readonly _metric = 'L2'
+
+  constructor (tbl: any, queryVector: number[]) {
+    this._tbl = tbl
+    this._query_vector = queryVector
+    this._limit = 10
+    this._nprobes = 20
+    this._refine_factor = undefined
+    this._columns = undefined
+    this._where = undefined
+  }
+
+  /**
+     * Execute the query and return the results as an Array of Objects
+     */
+  async execute (): Promise<unknown[]> {
+    const buffer = await tableSearch.call(this._tbl, this._query_vector, this._limit)
+    const data = tableFromIPC(buffer)
+    return data.toArray().map((entry: Record<string, unknown>) => {
+      const newObject: Record<string, unknown> = {}
+      Object.keys(entry).forEach((key: string) => {
+        if (entry[key] instanceof Vector) {
+          newObject[key] = (entry[key] as Vector).toArray()
+        } else {
+          newObject[key] = entry[key]
+        }
+      })
+      return newObject
+    })
+  }
+
+  /**
+     * Execute the query and return the results as an Array of the generic type provided
+     */
+  async execute_cast<T>(): Promise<T[]> {
+    return await this.execute() as T[]
+  }
+}