quick-start-read.js

const os = require('os');
const path = require('path');
const ulid = require('ulid').ulid;
const BlobStore = require('scalable-blob-store');
const data = 'The quick brown fox jumps over the lazy dog.';
const line = '='.repeat(80);

const options = {
  blobStoreRoot: os.tmpdir() + '/blobs', // TODO: Change this!
  idFunction: ulid,
  dirDepth: 3,
  dirWidth: 1000,
};

// Creating the blobStore Object
const blobStore = new BlobStore(options);

// Calling the quick start async function
quickStartRead(data);

async function quickStartRead(writeData) {
  console.log(line);
  console.log('Quick Start Read Example');
  console.log(line);

  console.log('We need a blob file to read.');
  const blobPath = await blobStore.write(writeData);
  console.log('Following is the blobPath for the file we will read:');
  console.log(blobPath);

  // blobPath is not a full file system path
  // The full path will be the blobStoreRoot + blobPath
  // blobPath: /01CTZBM6BA090XZNRCWBXFA25R/01CTZBM6BBXXTNWM7YZBMFBC3W/01CTZBM6BBD3F8KZQ14Q79ZNKM/01CTZBM6BCEMJ4FXVZKHQ3FAJZ/01CTZBM6BD74MC5HVQ39PFGP0J

  console.log('Here is the full path for the file:');
  console.log(path.join(options.blobStoreRoot, blobPath));

  // Reading Example
  console.log('Lets read the file using blobStore.createReadStream.');
  console.log('Following this log line we should see the data:');
  const readStream = await blobStore.createReadStream(blobPath);
  readStream.on('error', (err) => {
    console.error(err);
  });

  // Pipe the file to the console.
  readStream.pipe(process.stdout);

  // A small delay...
  await new Promise((resolve) => {
    setTimeout(resolve, 400);
  });
  console.log(); // Adding a new line to the console

  // We can also use the blobStore.read method
  const content = await blobStore.read(blobPath);
  console.log('Following is the data from the blobStore.read method:');
  console.log(content);
  console.log(line);
}