besya / awaiter

Awaiter

Using ruby Threads as async/await

Installation

Add this line to your application's Gemfile:

gem 'awaiter'

And then execute:

$ bundle

Or install it yourself as:

$ gem install awaiter

Usage

require 'awaiter'

class MyClass
  include Awaiter
  async :first, :second
  
  def first
    p 'First stared'
    sleep(1)
    p 'First finished'
    'first result'
  end
  
  def second
    p 'Second stared'
    sleep(1)
    first_result = await first
    p 'Second finished'
    'second result with ' + first_result
  end
end
  

my = MyClass.new

p await my.first
# "First stared"
# "First finished"
# "first result"

p await my.second
# "Second stared"
# "First stared"
# "First finished"
# "Second finished"
# "second result with first result"

require 'awaiter'

class MyClass
  include Awaiter
  async :first
  
  def first
    p 'First stared'
    sleep(2)
    p 'First finished'
    'first result'
  end  
end
  

my = MyClass.new
t1 = my.first
sleep(1)
p 'Main thread'
r1 = await t1
p r1

# "First stared"
# "Main thread"
# "First finished"
# "first result"

require 'awaiter'

class MyClass
  include Awaiter
  async :first, :second
  
  def first
    sleep(4)
    'first result'
  end  

  def second
    sleep(2)
    'second result'
  end  
end

my = MyClass.new

r1, r2 = wait(my.first, my.second)

p r1
p r2

# "first result"
# "second result"

Example

Without threads

require 'open-uri'

class Downloader
  def download(name, url)
    open('./files/' + name, 'wb') do |file|
      file << open(url).read
    end
  end
end

file_url = 'http://www.sample-videos.com/audio/mp3/crowd-cheering.mp3'

downloader = Downloader.new

start = Time.now

f1 = downloader.download('1.mp3', file_url)
f2 = downloader.download('2.mp3', file_url)
f3 = downloader.download('3.mp3', file_url)
f4 = downloader.download('4.mp3', file_url)
f5 = downloader.download('5.mp3', file_url)

finish = Time.now

p finish - start
# 17.071239374

Using threads

require 'awaiter'
require 'open-uri'

class Downloader
  include Awaiter
  async :download

  def download(name, url)
    open('./files/' + name, 'wb') do |file|
      file << open(url).read
    end
  end
end

file_url = 'http://www.sample-videos.com/audio/mp3/crowd-cheering.mp3'

downloader = Downloader.new

start = Time.now

f1 = downloader.download('1.mp3', file_url)
f2 = downloader.download('2.mp3', file_url)
f3 = downloader.download('3.mp3', file_url)
f4 = downloader.download('4.mp3', file_url)
f5 = downloader.download('5.mp3', file_url)

wait f1, f2, f3, f4, f5

finish = Time.now

p finish - start
# 3.379413503

How it works

When you use async :method your method will be wrapped in Thread.new. Calling of method returns this thread. Usage of await method is waiting for the thread was done and returns the result of work.
The await method is just equivalent of method.join.value. Usage of wait method1, method2 will wait when both methods were finished and will return array of results. You can use result1, result2 = wait method1, method2 for getting results from async methods. The wait f1, f2, f3 it's just equivalent of [f1.join.value, f2.join.value, f3.join.value]

With Awaiter

require 'awaiter'

class MyClass
  include Awaiter
  async :first, :second

  def first
    'first result'
  end

  def second
    first_result = await first
    'second result with ' + first_result
  end
end

my = MyClass.new

p await my.first
# "first result"

p wait my.first, my.second
# ["first result", "second result with first result"]

Equivalent without using Awaiter

class MyClass
  def first
    Thread.new do
      'first result'
    end
  end

  def second
    Thread.new do
      first_result = first.join.value
      'second result with ' + first_result
    end
  end
end

my = MyClass.new

p my.first.join.value
# "first result"

p [my.first.join.value, my.second.join.value]
# ["first result", "second result with first result"]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/besya/awaiter. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Awaiter project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.