verdaccio/lib/streams.js

'use strict';

let Stream = require('stream');
let Util = require('util');

module.exports.ReadTarballStream = ReadTarball;
module.exports.UploadTarballStream = UploadTarball;

//
// This stream is used to read tarballs from repository
//
function ReadTarball(options) {
  let self = new Stream.PassThrough(options);
  Object.setPrototypeOf(self, ReadTarball.prototype);

  // called when data is not needed anymore
  add_abstract_method(self, 'abort');

  return self;
}

Util.inherits(ReadTarball, Stream.PassThrough);

//
// This stream is used to upload tarballs to a repository
//
function UploadTarball(options) {
  let self = new Stream.PassThrough(options);
  Object.setPrototypeOf(self, UploadTarball.prototype);

  // called when user closes connection before upload finishes
  add_abstract_method(self, 'abort');

  // called when upload finishes successfully
  add_abstract_method(self, 'done');

  return self;
}

Util.inherits(UploadTarball, Stream.PassThrough);

//
// This function intercepts abstract calls and replays them allowing
// us to attach those functions after we are ready to do so
//
function add_abstract_method(self, name) {
  self._called_methods = self._called_methods || {};
  self.__defineGetter__(name, function() {
    return function() {
      self._called_methods[name] = true;
    };
  });
  self.__defineSetter__(name, function(fn) {
    delete self[name];
    self[name] = fn;
    if (self._called_methods && self._called_methods[name]) {
      delete self._called_methods[name];
      self[name]();
    }
  });
}