Forked Repository

This is a forked version of zarr.js, with changes which enable easy S3 connection to zarr datasets using an S3Store and an in-built cache for fast frequent lookups. This version also enables 'reading' Datetime values from zarr files, brute-forced by casting Int64 to Float64 within zarr. For now, accessing the actual values requires some user code to convert back from Float64, such as:

function float64ToInt64Bits(value: number): number {
  const buffer = new ArrayBuffer(8);
  const view = new DataView(buffer);
  view.setFloat64(0, value, false);  // Alias to same memory
  return Number(view.getBigInt64(0, false));  // Return as bigint
}

async function getIndexFromTime(timeArray: ZarrArray, time0: Date, time: Date): Promise<number> {
  return float64ToInt64Bits((await timeArray.get(getHourDiff(time0, time))) as number);
}

Changes include:

• s3store.ts for the S3Store implementation;
• package.json for the aws-sdk dependency;
• rollup.config.ts to fix rollup with json dependency (ln6: import json from '@rollup/plugin-json');
• zarr-core.ts to export S3Store;
• names.ts/types.ts for Int64 'integration';

Typescript implementation of Zarr.

Zarr is a library for chunked, compressed, N-dimensional arrays.

Quick start

npm i zarr

See the Getting Started section in the Documentation.

Type Docs

You can generate the type documentation for this project by running npm run generate-typedocs.

Why a Typescript implementation for Zarr?

For better or for worse the browser environment is slowly becoming the world's operating system. Numerical computing with a lot of data is a poor fit for browsers, but for data visualization, exploration and result-sharing the browser is unparalleled.

With this library a workflow as such becomes possible:

• You run an experiment/workflow in Python or Julia.
• You write results to a Zarr store, perhaps one that lives in some cloud storage.
• In a browser you create a visualization suite which allows for some interactivity.
• You share a link to a colleague or friend.