in_threads

Easily execute Ruby code in parallel.

urls.in_threads(20).map do |url|
  HTTP.get(url)
end

Installation

Add the gem to your Gemfile...

gem 'in_threads'

...and install it with Bundler.

$ bundle install

Or, if you don't use Bundler, install it globally:

$ gem install in_threads

Usage

Let's say you have a list of web pages to download.

urls = [
  "https://google.com",
  "https://en.wikipedia.org/wiki/Ruby",
  "https://news.ycombinator.com",
  "https://github.com/trending"
]

You can easily download each web page one after the other.

urls.each do |url|
  HTTP.get(url)
end

However, this is slow, especially for a large number of web pages. Instead, download the web pages in parallel with in_threads.

require 'in_threads'

urls.in_threads.each do |url|
  HTTP.get(url)
end

By calling in_threads, the each web page is downloaded in its own thread, reducing the time by almost 4x.

By default, no more than 10 threads run at any one time. However, this can be easily overriden.

# Read all XML files in a directory
Dir['*.xml'].in_threads(100).each do |file|
  File.read(file)
end

Predicate methods (methods that return true or false for each object in a collection) are particularly well suited for use with in_threads.

# Are all URLs valid?
urls.in_threads.all? { |url| HTTP.get(url).status == 200 }

# Are any URLs invalid?
urls.in_threads.any? { |url| HTTP.get(url).status == 404 }

You can call any Enumerable method, but some (#inject, #reduce, #max, #min, #sort, #to_a, and others) cannot run concurrently, and so will simply act as if in_threads wasn't used.

in_threads

Installation

Usage

Copyright