#cloud storage #cloud functions #google #word-count-read

cloud-storage-index.js

const Storage = require('@google-cloud/storage');
const readline = require('readline');

// Instantiates a client
const storage = Storage();
// [END functions_word_count_setup]

function getFileStream (file) {
  if (!file.bucket) {
    throw new Error('Bucket not provided. Make sure you have a "bucket" property in your request');
  }
  if (!file.name) {
    throw new Error('Filename not provided. Make sure you have a "name" property in your request');
  }

  return storage.bucket(file.bucket).file(file.name).createReadStream();
}

// [START functions_word_count_read]
/**
 * Reads file and responds with the number of words in the file.
 *
 * @example
 * gcloud alpha functions call wordCount --data '{"bucket":"YOUR_BUCKET_NAME","name":"sample.txt"}'
 *
 * @param {object} event The Cloud Functions event.
 * @param {object} event.data A Google Cloud Storage File object.
 * @param {string} event.data.bucket Name of a Cloud Storage bucket.
 * @param {string} event.data.name Name of a file in the Cloud Storage bucket.
 * @param {function} callback The callback function.
 */
exports.wordCount = (event, callback) => {
  const file = event.data;

  if (file.resourceState === 'not_exists') {
    // This is a file deletion event, so skip it
    callback();
    return;
  }

  let count = 0;
  const options = {
    input: getFileStream(file)
  };

  // Use the readline module to read the stream line by line.
  readline.createInterface(options)
    .on('line', (line) => {
      count += line.trim().split(/\s+/).length;
    })
    .on('close', () => {
      callback(null, `File ${file.name} has ${count} words`);
    });
};
// [END functions_word_count_read