1 files changed, 76 insertions, 0 deletions
diff --git a/lib/gitlab/database/partitioning/single_numeric_list_partition.rb b/lib/gitlab/database/partitioning/single_numeric_list_partition.rb
new file mode 100644
index 00000000000..23ac73a0e53
--- /dev/null
+++ b/lib/gitlab/database/partitioning/single_numeric_list_partition.rb
@@ -0,0 +1,76 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module Partitioning
+      class SingleNumericListPartition
+        include Comparable
+
+        def self.from_sql(table, partition_name, definition)
+          # A list partition can support multiple values, but we only support a single number
+          matches = definition.match(/FOR VALUES IN \('(?<value>\d+)'\)/)
+
+          raise ArgumentError, 'Unknown partition definition' unless matches
+
+          value = Integer(matches[:value])
+
+          new(table, value, partition_name: partition_name)
+        end
+
+        attr_reader :table, :value
+
+        def initialize(table, value, partition_name: nil )
+          @table = table
+          @value = value
+          @partition_name = partition_name
+        end
+
+        def partition_name
+          @partition_name || "#{table}_#{value}"
+        end
+
+        def to_sql
+          <<~SQL
+            CREATE TABLE IF NOT EXISTS #{fully_qualified_partition}
+            PARTITION OF #{conn.quote_table_name(table)}
+            FOR VALUES IN (#{conn.quote(value)})
+          SQL
+        end
+
+        def to_detach_sql
+          <<~SQL
+            ALTER TABLE #{conn.quote_table_name(table)}
+            DETACH PARTITION #{fully_qualified_partition}
+          SQL
+        end
+
+        def ==(other)
+          table == other.table &&
+            partition_name == other.partition_name &&
+            value == other.value
+        end
+        alias_method :eql?, :==
+
+        def hash
+          [table, partition_name, value].hash
+        end
+
+        def <=>(other)
+          return if table != other.table
+
+          value <=> other.value
+        end
+
+        private
+
+        def fully_qualified_partition
+          "%s.%s" % [conn.quote_table_name(Gitlab::Database::DYNAMIC_PARTITIONS_SCHEMA), conn.quote_table_name(partition_name)]
+        end
+
+        def conn
+          @conn ||= Gitlab::Database::SharedModel.connection
+        end
+      end
+    end
+  end
+end