1 files changed, 88 insertions, 0 deletions
diff --git a/storage/mroonga/vendor/groonga/plugins/sharding/range_expression_builder.rb b/storage/mroonga/vendor/groonga/plugins/sharding/range_expression_builder.rb
new file mode 100644
index 00000000..cc80735d
--- /dev/null
+++ b/storage/mroonga/vendor/groonga/plugins/sharding/range_expression_builder.rb
@@ -0,0 +1,88 @@
+module Groonga
+  module Sharding
+    class RangeExpressionBuilder
+      attr_reader :match_columns_expression
+
+      attr_writer :match_columns
+      attr_writer :query
+      attr_writer :filter
+
+      def initialize(key, target_range)
+        @key = key
+        @target_range = target_range
+        @match_columns_expression = nil
+        @match_columns = nil
+        @query = nil
+        @filter = nil
+      end
+
+      def build_all(expression)
+        build_condition(expression)
+      end
+
+      def build_partial_min(expression)
+        expression.append_object(@key, Operator::PUSH, 1)
+        expression.append_operator(Operator::GET_VALUE, 1)
+        expression.append_constant(@target_range.min, Operator::PUSH, 1)
+        if @target_range.min_border == :include
+          expression.append_operator(Operator::GREATER_EQUAL, 2)
+        else
+          expression.append_operator(Operator::GREATER, 2)
+        end
+        build_condition(expression)
+      end
+
+      def build_partial_max(expression)
+        expression.append_object(@key, Operator::PUSH, 1)
+        expression.append_operator(Operator::GET_VALUE, 1)
+        expression.append_constant(@target_range.max, Operator::PUSH, 1)
+        if @target_range.max_border == :include
+          expression.append_operator(Operator::LESS_EQUAL, 2)
+        else
+          expression.append_operator(Operator::LESS, 2)
+        end
+        build_condition(expression)
+      end
+
+      def build_partial_min_and_max(expression)
+        between = Groonga::Context.instance["between"]
+        expression.append_object(between, Operator::PUSH, 1)
+        expression.append_object(@key, Operator::PUSH, 1)
+        expression.append_operator(Operator::GET_VALUE, 1)
+        expression.append_constant(@target_range.min, Operator::PUSH, 1)
+        expression.append_constant(@target_range.min_border,
+                                   Operator::PUSH, 1)
+        expression.append_constant(@target_range.max, Operator::PUSH, 1)
+        expression.append_constant(@target_range.max_border,
+                                   Operator::PUSH, 1)
+        expression.append_operator(Operator::CALL, 5)
+        build_condition(expression)
+      end
+
+      private
+      def build_condition(expression)
+        if @query
+          is_empty = expression.empty?
+          if @match_columns
+            table = Context.instance[expression[0].domain]
+            @match_columns_expression = Expression.create(table)
+            @match_columns_expression.parse(@match_columns)
+          end
+          flags = Expression::SYNTAX_QUERY |
+            Expression::ALLOW_PRAGMA |
+            Expression::ALLOW_COLUMN
+          expression.parse(@query,
+                           default_column: @match_columns_expression,
+                           flags: flags)
+          expression.append_operator(Operator::AND, 2) unless is_empty
+        end
+
+        if @filter
+          is_empty = expression.empty?
+          expression.parse(@filter)
+          expression.append_operator(Operator::AND, 2) unless is_empty
+        end
+      end
+    end
+  end
+end