refactor, put `PostgreSQLColumn` into `column.rb`.

We have `connection_adapters/column.rb` so it's easier to remember
that the column in in a separate file.

1 files changed, 221 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
new file mode 100644
index 0000000000..823189934d
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -0,0 +1,221 @@
+module ActiveRecord
+  module ConnectionAdapters
+    # PostgreSQL-specific extensions to column definitions in a table.
+    class PostgreSQLColumn < Column #:nodoc:
+      attr_accessor :array
+
+      def initialize(name, default, oid_type, sql_type = nil, null = true)
+        @oid_type = oid_type
+        default_value     = self.class.extract_value_from_default(default)
+
+        if sql_type =~ /\[\]$/
+          @array = true
+          super(name, default_value, sql_type[0..sql_type.length - 3], null)
+        else
+          @array = false
+          super(name, default_value, sql_type, null)
+        end
+
+        @default_function = default if has_default_function?(default_value, default)
+      end
+
+      def number?
+        !array && super
+      end
+
+      def text?
+        !array && super
+      end
+
+      # :stopdoc:
+      class << self
+        include ConnectionAdapters::PostgreSQLColumn::Cast
+        include ConnectionAdapters::PostgreSQLColumn::ArrayParser
+        attr_accessor :money_precision
+      end
+      # :startdoc:
+
+      # Extracts the value from a PostgreSQL column default definition.
+      def self.extract_value_from_default(default)
+        # This is a performance optimization for Ruby 1.9.2 in development.
+        # If the value is nil, we return nil straight away without checking
+        # the regular expressions. If we check each regular expression,
+        # Regexp#=== will call NilClass#to_str, which will trigger
+        # method_missing (defined by whiny nil in ActiveSupport) which
+        # makes this method very very slow.
+        return default unless default
+
+        case default
+          when /\A'(.*)'::(num|date|tstz|ts|int4|int8)range\z/m
+            $1
+          # Numeric types
+          when /\A\(?(-?\d+(\.\d*)?\)?(::bigint)?)\z/
+            $1
+          # Character types
+          when /\A\(?'(.*)'::.*\b(?:character varying|bpchar|text)\z/m
+            $1.gsub(/''/, "'")
+          # Binary data types
+          when /\A'(.*)'::bytea\z/m
+            $1
+          # Date/time types
+          when /\A'(.+)'::(?:time(?:stamp)? with(?:out)? time zone|date)\z/
+            $1
+          when /\A'(.*)'::interval\z/
+            $1
+          # Boolean type
+          when 'true'
+            true
+          when 'false'
+            false
+          # Geometric types
+          when /\A'(.*)'::(?:point|line|lseg|box|"?path"?|polygon|circle)\z/
+            $1
+          # Network address types
+          when /\A'(.*)'::(?:cidr|inet|macaddr)\z/
+            $1
+          # Bit string types
+          when /\AB'(.*)'::"?bit(?: varying)?"?\z/
+            $1
+          # XML type
+          when /\A'(.*)'::xml\z/m
+            $1
+          # Arrays
+          when /\A'(.*)'::"?\D+"?\[\]\z/
+            $1
+          # Hstore
+          when /\A'(.*)'::hstore\z/
+            $1
+          # JSON
+          when /\A'(.*)'::json\z/
+            $1
+          # Object identifier types
+          when /\A-?\d+\z/
+            $1
+          else
+            # Anything else is blank, some user type, or some function
+            # and we can't know the value of that, so return nil.
+            nil
+        end
+      end
+
+      def type_cast_for_write(value)
+        if @oid_type.respond_to?(:type_cast_for_write)
+          @oid_type.type_cast_for_write(value)
+        else
+          super
+        end
+      end
+
+      def type_cast(value)
+        return if value.nil?
+        return super if encoded?
+
+        @oid_type.type_cast value
+      end
+
+      def accessor
+        @oid_type.accessor
+      end
+
+      private
+
+        def has_default_function?(default_value, default)
+          !default_value && (%r{\w+\(.*\)} === default)
+        end
+
+        def extract_limit(sql_type)
+          case sql_type
+          when /^bigint/i;    8
+          when /^smallint/i;  2
+          when /^timestamp/i; nil
+          else super
+          end
+        end
+
+        # Extracts the scale from PostgreSQL-specific data types.
+        def extract_scale(sql_type)
+          # Money type has a fixed scale of 2.
+          sql_type =~ /^money/ ? 2 : super
+        end
+
+        # Extracts the precision from PostgreSQL-specific data types.
+        def extract_precision(sql_type)
+          if sql_type == 'money'
+            self.class.money_precision
+          elsif sql_type =~ /timestamp/i
+            $1.to_i if sql_type =~ /\((\d+)\)/
+          else
+            super
+          end
+        end
+
+        # Maps PostgreSQL-specific data types to logical Rails types.
+        def simplified_type(field_type)
+          case field_type
+          # Numeric and monetary types
+          when /^(?:real|double precision)$/
+            :float
+          # Monetary types
+          when 'money'
+            :decimal
+          when 'hstore'
+            :hstore
+          when 'ltree'
+            :ltree
+          # Network address types
+          when 'inet'
+            :inet
+          when 'cidr'
+            :cidr
+          when 'macaddr'
+            :macaddr
+          # Character types
+          when /^(?:character varying|bpchar)(?:\(\d+\))?$/
+            :string
+          when /^citext(?:\(\d+\))?$/
+            :citext
+          # Binary data types
+          when 'bytea'
+            :binary
+          # Date/time types
+          when /^timestamp with(?:out)? time zone$/
+            :datetime
+          when /^interval(?:|\(\d+\))$/
+            :string
+          # Geometric types
+          when /^(?:point|line|lseg|box|"?path"?|polygon|circle)$/
+            :string
+          # Bit strings
+          when /^bit(?: varying)?(?:\(\d+\))?$/
+            :string
+          # XML type
+          when 'xml'
+            :xml
+          # tsvector type
+          when 'tsvector'
+            :tsvector
+          # Arrays
+          when /^\D+\[\]$/
+            :string
+          # Object identifier types
+          when 'oid'
+            :integer
+          # UUID type
+          when 'uuid'
+            :uuid
+          # JSON type
+          when 'json'
+            :json
+          # Small and big integer types
+          when /^(?:small|big)int$/
+            :integer
+          when /(num|date|tstz|ts|int4|int8)range$/
+            field_type.to_sym
+          # Pass through all types that are not specific to PostgreSQL.
+          else
+            super
+          end
+        end
+    end
+  end
+end