Fiber::Collector

An easy way to schedule and aggregate the results from multiple concurrent tasks inspired by JavaScript's Promise.all(), Promise.any() and Promise.race() methods.

Installation

Install the gem and add to the application's Gemfile by executing:

$ bundle add fiber-collector

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install fiber-collector

Usage

Here are some examples where sleep is the non-blocking operation, but it could just as well be replaced with calls to Net::HTTP.get() or other I/O.

# needs a fiber scheduler
require 'async'

# Sets the fiber scheduler and executes inside a non-blocking fiber
Async do
  # Collect all results
  Fiber::Collector.schedule { sleep 0.001; 'a' }
      .and { sleep 0.002; 'b' }
      .and { sleep 0.003; 'c' }
      .all(timeout: 0.02)
end.wait
# => ['a', 'b', 'c']

Async do
  Fiber::Collector.schedule { sleep 0.001; 'a' }
      .and { sleep 0.002; raise 'boom' }
      .and { sleep 0.003; 'c' }
      .all
end.wait
# RuntimeError raised

Async do
  Fiber::Collector.schedule { sleep 0.010; 'a' }
      .and { sleep 0.001; raise 'e' }
      .and { sleep 0.005; 'b' } 
      .and { sleep 0.007; 'c' }
      .any(timeout: 0.02)    
end.wait
# => 'b'

Async do
  Fiber::Collector.schedule { sleep 0.010; 'a' }
      .and { sleep 0.001; raise XError }
      .and { sleep 0.005; 'b' } 
      .and { sleep 0.007; raise YError }
      .race(timeout: 0.02)    
end.wait
# XError raised

Async do
  Fiber::Collector.schedule { sleep 0.010; raise XError }
      .and { sleep 0.001; 'a' }
      .and { sleep 0.005; 'b' } 
      .and { sleep 0.007; raise YError }
      .race(timeout: 0.02)    
end.wait
# => "a"

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 the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/beatmadsen/fiber-collector.

License

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