index.rb in mir-0.1.3

- old
+ new

@@ -1,24 +1,32 @@
 require 'active_record'
 require "active_support/inflector"
 
-# Manages database operations for application
+# The index class is responsible for maintaining knowledge of files uploaded
+# onto the remote file system. The index does this by scanning the directory to
+# be synchronized and evaluating whether a file needs to be uploaded or has changed
+# since the last indexing date
+
 module Mir
   class Index
     
     MIGRATIONS_PATH = File.join(File.dirname(__FILE__), "..", "..", "db", "migrate")
     
     # Returns a databse object used to connect to the indexing database
+    #
+    # @param [String] the absolute path of the directory to be synchronized
     # @param [Hash] database configuration settings. See ActiveRecord#Base::establish_connection
     def initialize(sync_path, connection_params)
       @sync_path = sync_path
       @connection_params = connection_params
     end
     
     attr_reader :sync_path
     
+    #
     # Creates necessary database and tables if this is the first time connecting
+    #
     # @option opts [Boolean] :verbose Enable on ActiveRecord reporting
     # @option opts [Boolean] :force_flush Rebuild index no matter what
     def setup(options = {})
       options[:force_flush] ||= false
       options[:verbose] ||= false
@@ -32,28 +40,54 @@
       
       load_tables
       rebuild if !tables_created? or options[:force_flush]
     end
     
-    # Scans the filesystem and flags any resources which need updating
+    ##
+    # Scans the synchronization path and evaluates whether a resource has changed
+    # since the last index or is new and needs to be added to the index.
     def update
       Mir.logger.info "Updating backup index for '#{sync_path}'"
+      Models::AppSetting.last_indexed_at = @last_indexed_at = DateTime.now
+      
       Dir.glob(File.join(sync_path, "**", "*")) do |f|
         fname = relative_path(f)
         file = File.new(f)
         resource = Models::Resource.find_by_filename(fname)
 
         if resource.nil?
-          Mir.logger.info "Adding file to index #{fname}"
+          Mir.logger.debug "Adding file to index #{fname}"
           resource = Models::Resource.create_from_file_and_name(file, fname)
-        else
-          resource.flag_for_update unless resource.synchronized?(file)
-        end                
+        elsif !resource.synchronized?(file)
+          resource.flag_for_update
+        end
+        resource.update_attribute(:last_indexed_at, last_indexed_at)
       end
+      
       Mir.logger.info "Index updated"
     end
     
+    ##
+    # Returns any files not present since the last re-indexing. This is useful
+    # for finding files that have been deleted post-index.
+    # 
+    # @return [Mir::Models::Resource]
+    def orphans
+      Models::Resource.not_indexed_on(last_indexed_at)
+    end
+    
+    def last_indexed_at
+      @last_indexed_at ||= Models::AppSetting.last_indexed_at
+    end
+    
+    
+    ##
+    # Removes any files from the index that are no longer present locally
+    def clean!
+      Models::Resource.delete_all_except(last_indexed_at)
+    end
+    
     private
       # Returns the path of a file relative to the backup directory
       def relative_path(file)
         File.absolute_path(file).gsub(sync_path,'')
       end
@@ -61,13 +95,15 @@
       # Regenerates the file system index for the backup directory
       def rebuild
         tables.each { |t| ActiveRecord::Migration.drop_table(t.table_name) if t.table_exists? }
         ActiveRecord::Migration.drop_table(:schema_migrations) if @connection.table_exists? :schema_migrations
         ActiveRecord::Migrator.migrate MIGRATIONS_PATH
-        Models::AppSetting.create(:name => Models::AppSetting::SYNC_PATH, :value => sync_path)
-        Models::AppSetting.create(:name => Models::AppSetting::INSTALL_DATE, :value => DateTime.now.to_s)
+        Models::AppSetting.initialize_table(sync_path)
       end
       
+      
+      ##
+      # TODO: no reason to lazy load these activemodels
       def load_tables
         @tables = []
         models = File.join(File.dirname(__FILE__), "models", "*.rb")
         
         # load the AR models for the application
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