Server-only via WebSocketServer()
and Node.js
For exceptionally large datasets, a Client
can be bound to a
perspective.table()
instance running in Node.js/Python/Rust remotely, rather
than creating one in a Web Worker and downloading the entire data set. This
trades off network bandwidth and server resource requirements for a smaller
browser memory and CPU footprint.
An example in Node.js:
const { WebSocketServer, table } = require("@finos/perspective");
const fs = require("fs");
// Start a WS/HTTP host on port 8080. The `assets` property allows
// the `WebSocketServer()` to also serves the file structure rooted in this
// module's directory.
const host = new WebSocketServer({ assets: [__dirname], port: 8080 });
// Read an arrow file from the file system and host it as a named table.
const arr = fs.readFileSync(__dirname + "/superstore.lz4.arrow");
await table(arr, { name: "table_one" });
... and the [Client
] implementation in the browser:
const elem = document.getElementsByTagName("perspective-viewer")[0];
// Bind to the server's worker instead of instantiating a Web Worker.
const websocket = await perspective.websocket(
window.location.origin.replace("http", "ws")
);
// Create a virtual `Table` to the preloaded data source. `table` and `view`
// objects live on the server.
const server_table = await websocket.open_table("table_one");