- Quickly build virtual proxies.
- Messages sent to these proxies are forwarded to custom lazily-evaluated subjects.
- Based on the GoF proxy pattern.
- Uses Ruby's Delegator library to avoid
method_missinggotchas.
Add this line to your application's Gemfile:
gem'virtual_proxy'And then execute:
$ bundle
Or install it yourself as:
$ gem install virtual_proxy
# Create a proxy to some subjectproxy=VirtualProxy.to{ExpensiveObject.new}# => VirtualProxy::Proxyproxy.expensive_object_method# Get the subject directlyproxy.__getobj__# => ExpensiveObject instance# Dynamically set a new subjectproxy.__setobj__{OtherExpensiveObject.new}proxy.other_expensive_object_method# Extend any class with proxy construction capabilitiesclassExpensiveObjectextendVirtualProxyattr_reader:namedefinitialize(name:)@name=nameendendproxy=ExpensiveObject.build_lazy(name: 'fubar')proxy.foo# => 'fubar'# Use it for any expensive codeproxy=VirtualProxy.to{perform_intensive_task}proxy.generate_report# Avoid method_missing gotchasproxy=VirtualProxy.to{[1,2,3]}proxy == [1,2,3]# => trueproxy.methods# => [..., :push, :append, :pop, :shift, ...]proxy.respond_to?(:sort)# => true# NOTE: introspective methods such as :respond_to? require the subject to be evaluatedNote that the Ruby Delegator class uses method_missing under the hood.
This benchmark suggests that the Delegator approach taken in this gem, when compared against a simpler but more limited approach, incurs a %1.28 performance penalty:
user system total real
virtual_proxy 6.834716 0.000324 6.835040 ( 6.849857)
simple_proxy 6.754349 0.000008 6.754357 ( 6.763423)
To run this benchmark,
chmod +x ./bin/benchmark
./bin/benchmarkAfter checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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.
Bug reports and pull requests are welcome on GitHub at https://github.com/johnc219/virtual_proxy.
The gem is available as open source under the terms of the MIT License.