revise internals for loading plugins

3 files changed, 96 insertions, 105 deletions

diff --git a/lib/ohai/dsl/plugin.rb b/lib/ohai/dsl/plugin.rb
index 508c5d6c..092ad4e2 100644
--- a/lib/ohai/dsl/plugin.rb
+++ b/lib/ohai/dsl/plugin.rb
@@ -11,77 +11,101 @@
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
 
 require 'ohai/os'
-
 require 'ohai/mixin/command'
-require 'ohai/mixin/seconds_to_human'
 
 module Ohai
-  #=========================================================
-  # define new plugin class
-  #=========================================================
   def self.plugin(&block)
-    plugin_class = Class.new(DSL::Plugin, &block)
+    Class.new(DSL::Plugin::VersionVII, &block)
+  end
+
+  def self.v6plugin(&block)
+    Class.new(DSL::Plugin::VersionVI, &block)
   end
 
   module DSL
     class Plugin
-
       include Ohai::OS
       include Ohai::Mixin::Command
-      include Ohai::Mixin::SecondsToHuman
+
+      def initialize(controller)
+        @controller = controller
+        @data = controller.data
+      end
 
       #=====================================================
-      # plugin loading phase
+      # version 7 plugin class
       #=====================================================
-      def self.provides_attrs
-        @provides_attrs ||= []
-      end
+      class VersionVII < Plugin
+        def initialize(controller)
+          super(controller)
+        end
 
-      def self.depends_attrs
-        @depends_attrs ||= []
-      end
+        def self.version
+          :version7
+        end
 
-      def self.provides(*args)
-        args.each do |attr|
-          provides_attrs << attr
+        def self.provides_attrs
+          @provides_attrs ||= []
         end
-      end
 
-      def self.depends(*args)
-        args.each do |attr|
-          depends_attrs << attr
+        def self.depends_attrs
+          @depends_attrs ||= []
         end
-      end
 
-      def self.depends_os(*args)
-        args.each do |attr|
-          depends_attrs << "#{Ohai::OS.collect_os}/#{attr}"
+        def self.provides(*attrs)
+          attrs.each do |attr|
+            provides_attrs << attr
+          end
         end
-      end
 
-      def self.collect_data(&block)
-        define_method(:run, &block)
+        def self.depends(*attrs)
+          attrs.each do |attr|
+            depends_attrs << attr
+          end
+        end
+
+        def self.depends_os(*attrs)
+          attrs.each do |attr|
+            depends_attrs << "#{Ohai::OS.collect_os}/#{attr}"
+          end
+        end
+
+        def self.collect_data(&block)
+          define_method(:run, &block)
+        end
       end
 
       #=====================================================
-      # plugin run phase
+      # version 6 plugin class
       #=====================================================
-      attr_reader :data
+      class VersionVI < Plugin
+        def initialize(controller)
+          super(controller)
+        end
 
-      def initialize(controller)
-        @controller = controller
-        @data = controller.data
+        def self.version
+          :version6
+        end
+
+        def self.collect_contents(contents)
+          define_method(:run) { self.instance_eval(contents) }
+        end
       end
-      
+
+      #=====================================================
+      # plugin DSL methods
+      #=====================================================
+      # @note: v6 plugins only
       def require_plugin(*args)
-        # @todo: backwards compat
-        # @controller.require_plugin(*args)
+        # @todo: log deprecation message
+        @controller.require_plugin(*args)
       end
 
       def hints
@@ -116,7 +140,9 @@ module Ohai
         stdout.strip
       end
 
-      # Set the value equal to the stdout of the command, plus run through a regex - the first piece of match data is the value.
+      # Set the value equal to the stdout of the command, plus
+      # run through a regex - the first piece of match data is\
+      # the value.
       def from_with_regex(cmd, *regex_list)
         regex_list.flatten.each do |regex|
           status, stdout, stderr = run_command(:command => cmd)
@@ -146,7 +172,9 @@ module Ohai
           if File.exist?(filename)
             begin
               hash = @json_parser.parse(File.read(filename))
-              hints[name] = hash || Hash.new # hint should exist because the file did, even if it didn't contain anything
+              hints[name] = hash || Hash.new # hint
+              # should exist because the file did, even if it didn't
+              # contain anything
             rescue Yajl::ParseError => e
               Ohai::Log.error("Could not parse hint file at #{filename}: #{e.message}")
             end
diff --git a/lib/ohai/loader.rb b/lib/ohai/loader.rb
index 54d22620..6c2339f2 100644
--- a/lib/ohai/loader.rb
+++ b/lib/ohai/loader.rb
@@ -27,81 +27,48 @@ module Ohai
 
     def initialize(controller)
       @attributes = controller.attributes
-      @plugins = controller.plugins
-      @v6plugins = controller.v6plugins
-      @sources = controller.sources
+      @v6_dependency_solver = controller.v6_dependency_solver
     end
 
     def load_plugin(plugin_path, plugin_name=nil)
-      if version6?(plugin_path)
-        save_plugin(plugin_path)
-      else
-        clean_up(plugin_path) if @sources.has_key?(plugin_path)
-        
-        plugin = nil
+      plugin = nil
+
+      contents = ""
+      begin
+        contents = IO.read(plugin_path)
+      rescue SystemExit, Interrupt
+        raise
+      rescue IOError, Errno::ENOENT
+        Ohai::Log.debug("Unable to open or read #{plugin_path}")
+        return plugin
+      end
 
+      if contents.include?("Ohai.plugin")
         begin
-          plugin = from_file(plugin_path)
+          plugin = self.instance_eval(contents, plugin_path, 1)
         rescue SystemExit, Interrupt
           raise
         rescue Exception, Errno::ENOENT => e
-          Ohai::Log.debug("Plugin #{plugin_name} threw exception #{e.inspect} #{e.backtrace.join("\n")}")
-          return
+          Ohai::Log.debug("Plugin at #{plugin_path} threw exception #{e.inspect} #{e.backtrace.join("\n")}")
         end
 
-        if plugin.nil?
-          Ohai::Log.debug("Unable to load plugin at #{plugin_path}")
-          return
-        end
-
-        plugin_key = plugin_name || plugin.to_s 
-        register_plugin(plugin, plugin_path, plugin_key)
-        collect_provides(plugin, plugin_key)
-      end
-    end
-
-    private
-
-    def version6?(plugin_path)
-      File.open(plugin_path) { |f| f.grep(/Ohai\.plugin/).empty? }
-    end
-
-    def save_plugin(plugin_path)
-      unless @sources.has_key?(plugin_path)
-        Ohai::Config[:plugin_path].each do |path|
-          file_regex = Regexp.new("#{File.expand_path(path)}#{File::SEPARATOR}(.+).rb$")
-          md = file_regex.match(plugin_path)
-          if md
-            plugin_name = md[1].gsub(File::SEPARATOR, "::")
-            @v6plugins[plugin_name] = plugin_path
-            @sources[plugin_path] = plugin_name
-          end
-        end
+        collect_provides(plugin) unless plugin.nil?
+      else
+        plugin = Ohai.v6plugin do collect_contents contents end
       end
-    end
 
-    def clean_up(file)
-      key = @sources[file]
-      @plugins[key][:provides].each do |attr|
-        @attributes[attr][:providers].delete(key)
+      if plugin.nil?
+        Ohai::Log.debug("Unable to load plugin at #{plugin_path}")
+      else
+        @v6_dependency_solver[plugin_path] = plugin
       end
 
-      @plugins.delete(key)
-      @sources.delete(file)
+      plugin
     end
 
-    def register_plugin(plugin, file, plugin_key)
-      @plugins[plugin_key] ||= Mash.new
-      @sources[file] = plugin_key
-
-      p = @plugins[plugin_key]
-      p[:plugin] = plugin
-      p[:provides] = plugin.provides_attrs
-      p[:depends] = plugin.depends_attrs
-    end
-    
+    private
 
-    def collect_provides(plugin, plugin_key)
+    def collect_provides(plugin)
       plugin_provides = plugin.provides_attrs
       
       plugin_provides.each do |attr|
@@ -116,7 +83,7 @@ module Ohai
         end
 
         a[:providers] ||= []
-        a[:providers] << plugin_key
+        a[:providers] << plugin
       end
     end
 
diff --git a/lib/ohai/system.rb b/lib/ohai/system.rb
index f68b8073..b743893e 100644
--- a/lib/ohai/system.rb
+++ b/lib/ohai/system.rb
@@ -32,18 +32,14 @@ module Ohai
   class System
     attr_accessor :data
     attr_reader :attributes
-    attr_reader :plugins
-    attr_reader :v6plugins
-    attr_reader :sources
     attr_reader :hints
+    attr_reader :v6_dependency_solver
 
     def initialize
       @data = Mash.new
       @attributes = Hash.new
-      @plugins = Mash.new
-      @v6plugins = Hash.new
-      @sources = Hash.new
       @hints = Hash.new
+      @v6_dependency_solver = Hash.new
       @plugin_path = ""
     end