overleaf/services/project-history/app/js/HashManager.js

/* eslint-disable
    no-undef,
    no-unused-vars,
*/
// TODO: This file was created by bulk-decaffeinate.
// Fix any style issues and re-enable lint.
/*
 * decaffeinate suggestions:
 * DS102: Remove unnecessary code created because of implicit returns
 * DS207: Consider shorter variations of null checks
 * Full docs: https://github.com/decaffeinate/decaffeinate/blob/master/docs/suggestions.md
 */
import fs from 'fs'
import crypto from 'crypto'
import _ from 'lodash'
import logger from '@overleaf/logger'
import OError from '@overleaf/o-error'

export function _getBlobHashFromString(string) {
  const byteLength = Buffer.byteLength(string)
  const hash = crypto.createHash('sha1')
  hash.setEncoding('hex')
  hash.update('blob ' + byteLength + '\x00')
  hash.update(string, 'utf8')
  hash.end()
  return hash.read()
}

export function _getBlobHash(fsPath, _callback) {
  if (_callback == null) {
    _callback = function () {}
  }
  const callback = _.once(_callback)

  return fs.stat(fsPath, function (err, stats) {
    if (err != null) {
      OError.tag(err, 'failed to stat file in _getBlobHash', { fsPath })
      return callback(err)
    }
    const byteLength = stats.size
    const hash = crypto.createHash('sha1')
    hash.setEncoding('hex')
    hash.update('blob ' + byteLength + '\x00')

    const stream = fs.createReadStream(fsPath)

    stream.on('error', function (err) {
      return callback(
        OError.tag(err, 'error streaming file from disk', {
          fsPath,
          byteLength,
        })
      )
    })

    stream.on('end', function () {
      hash.end()
      return callback(null, hash.read(), byteLength)
    })

    return stream.pipe(hash)
  })
}