Class: Diecut::PluginLoader

Inherits:
Object
  • Object
show all
Includes:
TSort
Defined in:
lib/diecut/plugin-loader.rb

Defined Under Namespace

Classes: GemPlugin

Constant Summary collapse

NO_VALUE = 
Object.new.freeze
PLUGIN_FILENAME =

:nocov:

'diecut_plugin.rb'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ PluginLoader

Returns a new instance of PluginLoader.



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# File 'lib/diecut/plugin-loader.rb', line 17

def initialize
  @sources = {}
  @local_sources = []
  @by_gem_name = Hash.new{|h,k| h[k] = []}
  @plugins = []
end

Instance Attribute Details

#local_valise ⇒ Object

Returns the value of attribute local_valise.



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# File 'lib/diecut/plugin-loader.rb', line 24

def local_valise
  @local_valise
end

#plugins ⇒ Object (readonly)

Returns the value of attribute plugins.



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# File 'lib/diecut/plugin-loader.rb', line 23

def plugins
  @plugins
end

Instance Method Details

#add_plugin_desc(desc) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 176

def add_plugin_desc(desc)
  plugins << desc
end

#choose_source(locations) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 166

def choose_source(locations)
  locations.each do |loc|
    path = loc.absolute_path
    if @sources.has_key?(path)
      return path
    end
  end
  raise "Couldn't find source of plugin..."
end

#component_sort ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 93

def component_sort
  unless block_given?
    return enum_for(:component_sort)
  end
  child_idxs = {}
  strongly_connected_components.each_with_index do |component, idx|
    component.sort_by{|node| child_idxs.fetch(node, -1) }.each do |comp|
      yield(comp)
    end

    component.each do |comp|
      tsort_each_child(comp) do |child|
        child_idxs[child] = idx
      end
    end
  end
end

#dep_path?(from_gem, to_gem) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/diecut/plugin-loader.rb', line 145

def dep_path?(from_gem, to_gem)
  # potential to optimize this: build a map of reachablility and test
  # against that.
  closed = {}
  open = [from_gem]
  until open.empty?
    current = open.shift
    return true if current == to_gem
    closed[current] = true
    open += @by_gem_name[current.gem.name].select{|gem| !closed.has_key?(gem)}
  end
  return false
end

#describe_plugin(name) {|desc| ... } ⇒ Object

Yields:

  • (desc) 


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# File 'lib/diecut/plugin-loader.rb', line 180

def describe_plugin(name)
  source_path = choose_source(caller_locations)
  desc = PluginDescription.new(name, source_path)
  yield(desc)
  add_plugin_desc(desc)
  return desc
end

#discover(prerelease) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 46

def discover(prerelease)
  latest_specs(prerelease).map do |spec|
    spec.matches_for_glob(PLUGIN_FILENAME).map do |match|
      from_gem(spec, match)
    end
  end
  local_valise.get(PLUGIN_FILENAME).present.map(&:full_path).each do |path|
    from_local(path)
  end
end

#each_path ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 111

def each_path
  component_sort.reverse_each do |source|
    yield source.path
  end
end

#from_gem(spec, path) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 57

def from_gem(spec, path)
  plugin = GemPlugin.new(spec, path)

  @sources[path] = plugin
  spec.dependencies.map(&:name).each do |depname|
    @by_gem_name[depname] << plugin
  end
end

#from_local(path) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 66

def from_local(path)
  source = GemPlugin.new(NO_VALUE, path)
  @sources[path] = source
  @local_sources << source
end

#latest_specs(prerelease) ⇒ Object

:nocov:



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# File 'lib/diecut/plugin-loader.rb', line 36

def latest_specs(prerelease)
  Gem::Specification.latest_specs(prerelease)
end

#load_plugins(prerelease = false) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 159

def load_plugins(prerelease = false)
  discover(prerelease)
  each_path do |path|
    require_plugin(path)
  end
end

#require_plugin(path) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 40

def require_plugin(path)
  require path
end

#strict_sequence?(to, from) ⇒ Boolean

Can a chain of “is after” arrows be walked from ‘from’ to ‘to’. The rules are: A plugin defined by a gem that depends on another gem “is after” the plugin defined in the latter gem. A plugin defined in a local config file is after “more general” local files (project config is after personal is after system). All local plugins are after all gem plugins

The rationale for these rules is that decisions made later in time have more information and that decisions made closer to the problem know the problem domain better.

Returns:

  • (Boolean) 


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# File 'lib/diecut/plugin-loader.rb', line 129

def strict_sequence?(to, from)
  from_source = @sources[from.source_path]
  to_source = @sources[to.source_path]

  case [from_source.gem?, to_source.gem?]
  when [true, true]
    dep_path?(to_source, from_source)
  when [true, false]
    false
  when [false, true]
    true
  when [false, false]
    @local_sources.index_of(from.source_path) <= @local_sources.index_of(to.source_path)
  end
end

#tsort_each_child(node) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 76

def tsort_each_child(node)
  if node.gem?
    @by_gem_name[node.gem.name].each do |depplugin|
      yield depplugin
    end
    @local_sources.each do |local|
      yield local
    end
  else
    @local_sources.drop_while do |src|
      src != node
    end.drop(1).each do |node|
      yield(node)
    end
  end
end

#tsort_each_node(&block) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 72

def tsort_each_node(&block)
  @sources.each_value(&block)
end