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

#issue_handler ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 35

def issue_handler
  @issue_handler ||= Diecut.issue_handler
end

#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 183

def add_plugin_desc(desc)
  plugins << desc
end

#choose_source(locations) ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 171

def choose_source(locations)
  locations.each do |loc|
    path = loc.absolute_path
    if @sources.has_key?(path)
      return path
    end
  end
  fallback_location = locations.first.absolute_path
  issue_handler.unregistered_plugin_source(fallback_location)
  return fallback_location
end

#component_sort ⇒ Object 



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# File 'lib/diecut/plugin-loader.rb', line 98

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 150

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 187

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 51

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 116

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 62

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 71

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 41

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 164

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 45

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 134

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 81

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 77

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