1 files changed, 180 insertions, 0 deletions
diff --git a/storage/mroonga/vendor/groonga/plugins/sharding/logical_enumerator.rb b/storage/mroonga/vendor/groonga/plugins/sharding/logical_enumerator.rb
new file mode 100644
index 00000000000..1aeafef5438
--- /dev/null
+++ b/storage/mroonga/vendor/groonga/plugins/sharding/logical_enumerator.rb
@@ -0,0 +1,180 @@
+module Groonga
+  module Sharding
+    class LogicalEnumerator
+      attr_reader :target_range
+      attr_reader :logical_table
+      attr_reader :shard_key_name
+      def initialize(command_name, input)
+        @command_name = command_name
+        @input = input
+        initialize_parameters
+      end
+
+      def each(&block)
+        each_internal(:ascending, &block)
+      end
+
+      def reverse_each(&block)
+        each_internal(:descending, &block)
+      end
+
+      private
+      def each_internal(order)
+        prefix = "#{@logical_table}_"
+        context = Context.instance
+        context.database.each_table(:prefix => prefix,
+                                    :order_by => :key,
+                                    :order => order) do |table|
+          shard_range_raw = table.name[prefix.size..-1]
+
+          next unless /\A(\d{4})(\d{2})(\d{2})\z/ =~ shard_range_raw
+          shard_range = ShardRange.new($1.to_i, $2.to_i, $3.to_i)
+
+          physical_shard_key_name = "#{table.name}.#{@shard_key_name}"
+          shard_key = context[physical_shard_key_name]
+          if shard_key.nil?
+            message =
+              "[#{@command_name}] shard_key doesn't exist: " +
+              "<#{physical_shard_key_name}>"
+            raise InvalidArgument, message
+          end
+
+          yield(table, shard_key, shard_range)
+        end
+      end
+
+      private
+      def initialize_parameters
+        @logical_table = @input[:logical_table]
+        if @logical_table.nil?
+          raise InvalidArgument, "[#{@command_name}] logical_table is missing"
+        end
+
+        @shard_key_name = @input[:shard_key]
+        if @shard_key_name.nil?
+          raise InvalidArgument, "[#{@command_name}] shard_key is missing"
+        end
+
+        @target_range = TargetRange.new(@command_name, @input)
+      end
+
+      class ShardRange
+        attr_reader :year, :month, :day
+        def initialize(year, month, day)
+          @year = year
+          @month = month
+          @day = day
+        end
+      end
+
+      class TargetRange
+        attr_reader :min, :min_border
+        attr_reader :max, :max_border
+        def initialize(command_name, input)
+          @command_name = command_name
+          @input = input
+          @min = parse_value(:min)
+          @min_border = parse_border(:min_border)
+          @max = parse_value(:max)
+          @max_border = parse_border(:max_border)
+        end
+
+        def cover_type(shard_range)
+          return :all if @min.nil? and @max.nil?
+
+          if @min and @max
+            return :none unless in_min?(shard_range)
+            return :none unless in_max?(shard_range)
+            min_partial_p = in_min_partial?(shard_range)
+            max_partial_p = in_max_partial?(shard_range)
+            if min_partial_p and max_partial_p
+              :partial_min_and_max
+            elsif min_partial_p
+              :partial_min
+            elsif max_partial_p
+              :partial_max
+            else
+              :all
+            end
+          elsif @min
+            return :none unless in_min?(shard_range)
+            if in_min_partial?(shard_range)
+              :partial_min
+            else
+              :all
+            end
+          else
+            return :none unless in_max?(shard_range)
+            if in_max_partial?(shard_range)
+              :partial_max
+            else
+              :all
+            end
+          end
+        end
+
+        private
+        def parse_value(name)
+          value = @input[name]
+          return nil if value.nil?
+
+          Converter.convert(value, Time)
+        end
+
+        def parse_border(name)
+          border = @input[name]
+          return :include if border.nil?
+
+          case border
+          when "include"
+            :include
+          when "exclude"
+            :exclude
+          else
+            message =
+              "[#{@command_name}] #{name} must be \"include\" or \"exclude\": " +
+              "<#{border}>"
+            raise InvalidArgument, message
+          end
+        end
+
+        def in_min?(shard_range)
+          base_time = Time.local(shard_range.year,
+                                 shard_range.month,
+                                 shard_range.day + 1)
+          @min < base_time
+        end
+
+        def in_min_partial?(shard_range)
+          return false unless @min.year == shard_range.year
+          return false unless @min.month == shard_range.month
+          return false unless @min.day == shard_range.day
+
+          return true if @min_border == :exclude
+
+          not (@min.hour == 0 and
+               @min.min  == 0 and
+               @min.sec  == 0 and
+               @min.usec == 0)
+        end
+
+        def in_max?(shard_range)
+          max_base_time = Time.local(shard_range.year,
+                                     shard_range.month,
+                                     shard_range.day)
+          if @max_border == :include
+            @max >= max_base_time
+          else
+            @max > max_base_time
+          end
+        end
+
+        def in_max_partial?(shard_range)
+          @max.year == shard_range.year and
+            @max.month == shard_range.month and
+            @max.day == shard_range.day
+        end
+      end
+    end
+  end
+end