modern-netcdf/src/node-worker.js

Modern NetCDF file reader and utilities

const { parentPort, workerData } = require('worker_threads');
const path = require('path');
const { NetCDFReader } = require('..');

let reader = null;

async function handleMessage(msg) {
  const { id, cmd, payload } = msg;
  try {
    switch (cmd) {
      case 'open': {
        const { source, options } = payload;
        reader = await NetCDFReader.open(source, options);
        parentPort.postMessage({ id, result: 'ok' });
        break;
      }
      case 'getData': {
        const { variable, slice } = payload;
        if (!reader) throw new Error('Reader not open');
        const data = await reader.getData(variable, slice);
        parentPort.postMessage({ id, result: data }, [
          ArrayBuffer.isView(data) ? data.buffer : undefined
        ].filter(Boolean));
        break;
      }
      case 'close': {
        if (reader) reader.close();
        reader = null;
        parentPort.postMessage({ id, result: 'closed' });
        break;
      }
      default:
        throw new Error('Unknown command');
    }
  } catch (err) {
    parentPort.postMessage({ id, error: err.message });
  }
}

parentPort.on('message', handleMessage);