Class: Isolate

Inherits:
Object
  • Object
show all
Defined in:
lib/isolate.rb

Overview

Restricts GEM_PATH and GEM_HOME and provides a DSL for expressing your code’s runtime Gem dependencies. See README.rdoc for rationale, limitations, and examples.

Defined Under Namespace

Classes: Entry

Constant Summary collapse

VERSION =

:nodoc:

"1.4.0"
@@instance = 
nil

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, options = {}, &block) ⇒ Isolate

Create a new Isolate instance. See Isolate.gems for the public API. Don’t use this constructor directly.



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# File 'lib/isolate.rb', line 70

def initialize path, options = {}, &block
  @enabled      = false
  @entries      = []
  @environments = []
  @path         = path

  @install      = options.fetch :install, true
  @verbose      = options.fetch :verbose, true
  @cleanup      = @install && options.fetch(:cleanup, true)

  instance_eval(&block) if block_given?
end

Instance Attribute Details

#entries ⇒ Object (readonly)

:nodoc:



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# File 'lib/isolate.rb', line 26

def entries
  @entries
end

#path ⇒ Object (readonly)

:nodoc:



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# File 'lib/isolate.rb', line 28

def path
  @path
end

Class Method Details

.activate(environment) ⇒ Object

Activate (and possibly install) gems for a specific environment. This allows two-stage isolation, which is necessary for stuff like Rails. See README.rdoc for a detailed example.



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# File 'lib/isolate.rb', line 34

def self.activate environment
  instance.activate environment
  instance.cleanup if instance.cleanup?
end

.gems(path, options = {}, &block) ⇒ Object

Declare an isolated RubyGems environment, installed in path. The block given will be instance_evaled, see Isolate#gem and Isolate#environment for the sort of stuff you can do.

Option defaults:

{ :cleanup => true, :install => true, :verbose => true }



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# File 'lib/isolate.rb', line 47

def self.gems path, options = {}, &block
  @@instance = new path, options, &block
  @@instance.activate
end

.instance ⇒ Object

:nodoc:



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# File 'lib/isolate.rb', line 54

def self.instance # :nodoc:
  @@instance
end

.refresh ⇒ Object

Poke RubyGems, we’ve probably monkeyed with a bunch of paths and suchlike. Clears paths, loaded specs, and source indexes.



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# File 'lib/isolate.rb', line 61

def self.refresh # :nodoc:
  Gem.loaded_specs.clear
  Gem.clear_paths
  Gem.source_index.refresh!
end

Instance Method Details

#activate(environment = nil) ⇒ Object

:nodoc:



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# File 'lib/isolate.rb', line 83

def activate environment = nil # :nodoc:
  enable unless enabled?

  env = environment.to_s if environment
  install environment if install?

  entries.each do |e|
    Gem.activate e.name, *e.requirement.as_list if e.matches? env
  end

  self
end

#cleanup ⇒ Object 



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# File 'lib/isolate.rb', line 96

def cleanup
  activated = Gem.loaded_specs.values.map { |s| s.full_name }
  extra     = Gem.source_index.gems.values.sort.reject { |spec|
    activated.include? spec.full_name or
      entries.any? { |e| e.matches_spec? spec }
  }

  log "Cleaning..." unless extra.empty?

  padding = extra.size.to_s.size # omg... heaven forbid you use math
  format  = "[%0#{padding}d/%s] Nuking %s."
  extra.each_with_index do |e, i|
    log format % [i + 1, extra.size, e.full_name]

    Gem::DefaultUserInteraction.use_ui Gem::SilentUI.new do
      Gem::Uninstaller.new(e.name,
                           :version     => e.version,
                           :ignore      => true,
                           :executables => true,
                           :install_dir => self.path).uninstall
    end
  end
end

#cleanup? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/isolate.rb', line 120

def cleanup? # :nodoc:
  @cleanup
end

#disable ⇒ Object

:nodoc:



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# File 'lib/isolate.rb', line 124

def disable # :nodoc:
  return self unless enabled?

  ENV["GEM_PATH"] = @old_gem_path
  ENV["GEM_HOME"] = @old_gem_home
  ENV["RUBYOPT"]  = @old_ruby_opt

  $LOAD_PATH.replace @old_load_path

  @enabled = false

  self.class.refresh
  self
end

#enable ⇒ Object

:nodoc:



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# File 'lib/isolate.rb', line 139

def enable # :nodoc:
  return self if enabled?

  @old_gem_path  = ENV["GEM_PATH"]
  @old_gem_home  = ENV["GEM_HOME"]
  @old_ruby_opt  = ENV["RUBYOPT"]
  @old_load_path = $LOAD_PATH.dup

  $LOAD_PATH.reject! { |p| Gem.path.any? { |gp| p.include?(gp) } }

  # HACK: Gotta keep isolate explicitly in the LOAD_PATH in
  # subshells, and the only way I can think of to do that is by
  # abusing RUBYOPT.

  ENV["RUBYOPT"]  = "#{ENV['RUBYOPT']} -I#{File.dirname(__FILE__)}"
  ENV["GEM_PATH"] = ENV["GEM_HOME"] = path

  self.class.refresh

  @enabled = true
  self
end

#enabled? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/isolate.rb', line 162

def enabled? # :nodoc:
  @enabled
end

#environment(*environments, &block) ⇒ Object

Restricts gem calls inside block to a set of environments.



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# File 'lib/isolate.rb', line 168

def environment *environments, &block
  old = @environments
  @environments = @environments.dup.concat environments.map { |e| e.to_s }

  instance_eval(&block)
ensure
  @environments = old
end

#gem(name, *requirements) ⇒ Object

Express a gem dependency. Works pretty much like RubyGems’ gem method, but respects environment and doesn’t activate ‘til later.



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# File 'lib/isolate.rb', line 181

def gem name, *requirements
  options = Hash === requirements.last ? requirements.pop : {}

  requirement = if requirements.empty? then
                  Gem::Requirement.default
                else
                  Gem::Requirement.new(requirements)
                end

  entry = Entry.new name, requirement, @environments,  options

  entries << entry
  entry
end

#install(environment = nil) ⇒ Object

:nodoc:



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# File 'lib/isolate.rb', line 200

def install environment = nil # :nodoc:
  env = environment.to_s if environment

  installable = entries.select do |e|
    !Gem.available?(e.name, *e.requirement.as_list) && e.matches?(env)
  end

  log "Isolating #{environment}..." unless installable.empty?

  padding = installable.size.to_s.size # omg... heaven forbid you use math
  format  = "[%0#{padding}d/%s] Isolating %s (%s)."
  installable.each_with_index do |e, i|
    log format % [i + 1, installable.size, e.name, e.requirement]

    old         = Gem.sources.dup
    options     = e.options.merge(:install_dir   => path,
                                  :generate_rdoc => false,
                                  :generate_ri   => false)
    source      = options.delete :source
    args        = options.delete :args
    Gem.sources = Array(source) if source
    installer   = Gem::DependencyInstaller.new options

    Gem::Command.build_args = args if args
    installer.install e.name, e.requirement

    Gem.sources = old
    Gem::Command.build_args = nil if args
  end

  Gem.source_index.refresh!
  self
end

#install? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/isolate.rb', line 234

def install? # :nodoc:
  @install
end

#log(s) ⇒ Object 



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# File 'lib/isolate.rb', line 196

def log s
  $stderr.puts s if verbose?
end

#verbose? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/isolate.rb', line 238

def verbose? # :nodoc:
  @verbose
end