Merge pull request #15218 from sgrif/sg-move-oid-types

Move PG OID types to their own files

23 files changed, 532 insertions, 353 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
index 1d0384c3df..e54c092bf6 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid.rb
@@ -1,360 +1,32 @@
+require 'active_record/connection_adapters/postgresql/oid/infinity'
+
+require 'active_record/connection_adapters/postgresql/oid/array'
+require 'active_record/connection_adapters/postgresql/oid/bit'
+require 'active_record/connection_adapters/postgresql/oid/bytea'
+require 'active_record/connection_adapters/postgresql/oid/cidr'
+require 'active_record/connection_adapters/postgresql/oid/date'
+require 'active_record/connection_adapters/postgresql/oid/date_time'
+require 'active_record/connection_adapters/postgresql/oid/decimal'
+require 'active_record/connection_adapters/postgresql/oid/enum'
+require 'active_record/connection_adapters/postgresql/oid/float'
+require 'active_record/connection_adapters/postgresql/oid/hstore'
+require 'active_record/connection_adapters/postgresql/oid/inet'
+require 'active_record/connection_adapters/postgresql/oid/integer'
+require 'active_record/connection_adapters/postgresql/oid/json'
+require 'active_record/connection_adapters/postgresql/oid/money'
+require 'active_record/connection_adapters/postgresql/oid/point'
+require 'active_record/connection_adapters/postgresql/oid/range'
+require 'active_record/connection_adapters/postgresql/oid/specialized_string'
+require 'active_record/connection_adapters/postgresql/oid/time'
+require 'active_record/connection_adapters/postgresql/oid/uuid'
+require 'active_record/connection_adapters/postgresql/oid/vector'
+
+require 'active_record/connection_adapters/postgresql/oid/type_map_initializer'
+
 module ActiveRecord
   module ConnectionAdapters
     module PostgreSQL
       module OID # :nodoc:
-        module Infinity
-          def infinity(options = {})
-            options[:negative] ? -::Float::INFINITY : ::Float::INFINITY
-          end
-        end
-
-        class SpecializedString < Type::String
-          attr_reader :type
-
-          def initialize(type)
-            @type = type
-          end
-
-          def text?
-            false
-          end
-        end
-
-        class Bit < Type::String
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_bit value
-            else
-              value
-            end
-          end
-        end
-
-        class Bytea < Type::Binary
-          def cast_value(value)
-            PGconn.unescape_bytea value
-          end
-        end
-
-        class Money < Type::Decimal
-          include Infinity
-
-          def extract_scale(sql_type)
-            2
-          end
-
-          def cast_value(value)
-            return value unless ::String === value
-
-            # Because money output is formatted according to the locale, there are two
-            # cases to consider (note the decimal separators):
-            #  (1) $12,345,678.12
-            #  (2) $12.345.678,12
-            # Negative values are represented as follows:
-            #  (3) -$2.55
-            #  (4) ($2.55)
-
-            value.sub!(/^\((.+)\)$/, '-\1') # (4)
-            case value
-            when /^-?\D+[\d,]+\.\d{2}$/  # (1)
-              value.gsub!(/[^-\d.]/, '')
-            when /^-?\D+[\d.]+,\d{2}$/  # (2)
-              value.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
-            end
-
-            super(value)
-          end
-        end
-
-        class Vector < Type::Value
-          attr_reader :delim, :subtype
-
-          # +delim+ corresponds to the `typdelim` column in the pg_types
-          # table.  +subtype+ is derived from the `typelem` column in the
-          # pg_types table.
-          def initialize(delim, subtype)
-            @delim   = delim
-            @subtype = subtype
-          end
-
-          # FIXME: this should probably split on +delim+ and use +subtype+
-          # to cast the values.  Unfortunately, the current Rails behavior
-          # is to just return the string.
-          def type_cast(value)
-            value
-          end
-        end
-
-        class Point < Type::String
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_point value
-            else
-              value
-            end
-          end
-        end
-
-        class Array < Type::Value
-          attr_reader :subtype
-          delegate :type, to: :subtype
-
-          def initialize(subtype)
-            @subtype = subtype
-          end
-
-          def type_cast(value)
-            if ::String === value
-              ConnectionAdapters::PostgreSQLColumn.string_to_array value, @subtype
-            else
-              value
-            end
-          end
-        end
-
-        class Range < Type::Value
-          attr_reader :subtype, :type
-
-          def initialize(subtype, type)
-            @subtype = subtype
-            @type = type
-          end
-
-          def extract_bounds(value)
-            from, to = value[1..-2].split(',')
-            {
-              from:          (value[1] == ',' || from == '-infinity') ? @subtype.infinity(negative: true) : from,
-              to:            (value[-2] == ',' || to == 'infinity') ? @subtype.infinity : to,
-              exclude_start: (value[0] == '('),
-              exclude_end:   (value[-1] == ')')
-            }
-          end
-
-          def infinity?(value)
-            value.respond_to?(:infinite?) && value.infinite?
-          end
-
-          def type_cast_single(value)
-            infinity?(value) ? value : @subtype.type_cast(value)
-          end
-
-          def cast_value(value)
-            return if value == 'empty'
-            return value if value.is_a?(::Range)
-
-            extracted = extract_bounds(value)
-            from = type_cast_single extracted[:from]
-            to = type_cast_single extracted[:to]
-
-            if !infinity?(from) && extracted[:exclude_start]
-              if from.respond_to?(:succ)
-                from = from.succ
-                ActiveSupport::Deprecation.warn <<-MESSAGE
-Excluding the beginning of a Range is only partialy supported through `#succ`.
-This is not reliable and will be removed in the future.
-                MESSAGE
-              else
-                raise ArgumentError, "The Ruby Range object does not support excluding the beginning of a Range. (unsupported value: '#{value}')"
-              end
-            end
-            ::Range.new(from, to, extracted[:exclude_end])
-          end
-        end
-
-        class Integer < Type::Integer
-          include Infinity
-        end
-
-        class DateTime < Type::DateTime
-          include Infinity
-
-          def cast_value(value)
-            if value.is_a?(::String)
-              case value
-              when 'infinity' then ::Float::INFINITY
-              when '-infinity' then -::Float::INFINITY
-              when / BC$/
-                super("-" + value.sub(/ BC$/, ""))
-              else
-                super
-              end
-            else
-              value
-            end
-          end
-        end
-
-        class Date < Type::Date
-          include Infinity
-        end
-
-        class Time < Type::Time
-          include Infinity
-        end
-
-        class Float < Type::Float
-          include Infinity
-
-          def type_cast(value)
-            case value
-            when nil then         nil
-            when 'Infinity' then  ::Float::INFINITY
-            when '-Infinity' then -::Float::INFINITY
-            when 'NaN' then       ::Float::NAN
-            else                  value.to_f
-            end
-          end
-        end
-
-        class Decimal < Type::Decimal
-          def infinity(options = {})
-            BigDecimal.new("Infinity") * (options[:negative] ? -1 : 1)
-          end
-        end
-
-        class Enum < Type::Value
-          def type
-            :enum
-          end
-
-          def type_cast(value)
-            value.to_s
-          end
-        end
-
-        class Hstore < Type::Value
-          def type
-            :hstore
-          end
-
-          def type_cast_for_write(value)
-            ConnectionAdapters::PostgreSQLColumn.hstore_to_string value
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_hstore value
-          end
-
-          def accessor
-            ActiveRecord::Store::StringKeyedHashAccessor
-          end
-        end
-
-        class Cidr < Type::Value
-          def type
-            :cidr
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_cidr value
-          end
-        end
-
-        class Inet < Cidr
-          def type
-            :inet
-          end
-        end
-
-        class Json < Type::Value
-          def type
-            :json
-          end
-
-          def type_cast_for_write(value)
-            ConnectionAdapters::PostgreSQLColumn.json_to_string value
-          end
-
-          def cast_value(value)
-            ConnectionAdapters::PostgreSQLColumn.string_to_json value
-          end
-
-          def accessor
-            ActiveRecord::Store::StringKeyedHashAccessor
-          end
-        end
-
-        class Uuid < Type::Value
-          def type
-            :uuid
-          end
-
-          def type_cast(value)
-            value.presence
-          end
-        end
-
-        # This class uses the data from PostgreSQL pg_type table to build
-        # the OID -> Type mapping.
-        #   - OID is and integer representing the type.
-        #   - Type is an OID::Type object.
-        # This class has side effects on the +store+ passed during initialization.
-        class TypeMapInitializer # :nodoc:
-          def initialize(store)
-            @store = store
-          end
-
-          def run(records)
-            mapped, nodes = records.partition { |row| OID.registered_type? row['typname'] }
-            ranges, nodes = nodes.partition { |row| row['typtype'] == 'r' }
-            enums, nodes = nodes.partition { |row| row['typtype'] == 'e' }
-            domains, nodes = nodes.partition { |row| row['typtype'] == 'd' }
-            arrays, nodes = nodes.partition { |row| row['typinput'] == 'array_in' }
-            composites, nodes = nodes.partition { |row| row['typelem'] != '0' }
-
-            mapped.each     { |row| register_mapped_type(row)    }
-            enums.each      { |row| register_enum_type(row)      }
-            domains.each    { |row| register_domain_type(row)    }
-            arrays.each     { |row| register_array_type(row)     }
-            ranges.each     { |row| register_range_type(row)     }
-            composites.each { |row| register_composite_type(row) }
-          end
-
-          private
-          def register_mapped_type(row)
-            register row['oid'], OID::NAMES[row['typname']]
-          end
-
-          def register_enum_type(row)
-            register row['oid'], OID::Enum.new
-          end
-
-          def register_array_type(row)
-            if subtype = @store.lookup(row['typelem'].to_i)
-              register row['oid'], OID::Array.new(subtype)
-            end
-          end
-
-          def register_range_type(row)
-            if subtype = @store.lookup(row['rngsubtype'].to_i)
-              register row['oid'], OID::Range.new(subtype, row['typname'].to_sym)
-            end
-          end
-
-          def register_domain_type(row)
-            if base_type = @store.lookup(row["typbasetype"].to_i)
-              register row['oid'], base_type
-            else
-              warn "unknown base type (OID: #{row["typbasetype"]}) for domain #{row["typname"]}."
-            end
-          end
-
-          def register_composite_type(row)
-            if subtype = @store.lookup(row['typelem'].to_i)
-              register row['oid'], OID::Vector.new(row['typdelim'], subtype)
-            end
-          end
-
-          def register(oid, oid_type)
-            oid = oid.to_i
-
-            raise ArgumentError, "can't register nil type for OID #{oid}" if oid_type.nil?
-            return if @store.key?(oid)
-
-            @store.register_type(oid, oid_type)
-          end
-        end
-
         # When the PG adapter connects, the pg_type table is queried. The
         # key of this hash maps to the `typname` column from the table.
         # type_map is then dynamically built with oids as the key and type
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
new file mode 100644
index 0000000000..0e9dcd8c0c
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
@@ -0,0 +1,24 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Array < Type::Value
+          attr_reader :subtype
+          delegate :type, to: :subtype
+
+          def initialize(subtype)
+            @subtype = subtype
+          end
+
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_array value, @subtype
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
new file mode 100644
index 0000000000..9b2d887d07
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Bit < Type::String
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_bit value
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
new file mode 100644
index 0000000000..36c53d8732
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/bytea.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Bytea < Type::Binary
+          def cast_value(value)
+            PGconn.unescape_bytea value
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
new file mode 100644
index 0000000000..507c3a62b0
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/cidr.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Cidr < Type::Value
+          def type
+            :cidr
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_cidr value
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb
new file mode 100644
index 0000000000..3c30ad5fec
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Date < Type::Date
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
new file mode 100644
index 0000000000..9ccbf71159
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/date_time.rb
@@ -0,0 +1,26 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class DateTime < Type::DateTime
+          include Infinity
+
+          def cast_value(value)
+            if value.is_a?(::String)
+              case value
+              when 'infinity' then ::Float::INFINITY
+              when '-infinity' then -::Float::INFINITY
+              when / BC$/
+                super("-" + value.sub(/ BC$/, ""))
+              else
+                super
+              end
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
new file mode 100644
index 0000000000..ed4b8911d9
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/decimal.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Decimal < Type::Decimal
+          def infinity(options = {})
+            BigDecimal.new("Infinity") * (options[:negative] ? -1 : 1)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
new file mode 100644
index 0000000000..5fed8b0f89
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/enum.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Enum < Type::Value
+          def type
+            :enum
+          end
+
+          def type_cast(value)
+            value.to_s
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb
new file mode 100644
index 0000000000..9753d71461
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/float.rb
@@ -0,0 +1,21 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Float < Type::Float
+          include Infinity
+
+          def type_cast(value)
+            case value
+            when nil then         nil
+            when 'Infinity' then  ::Float::INFINITY
+            when '-Infinity' then -::Float::INFINITY
+            when 'NaN' then       ::Float::NAN
+            else                  value.to_f
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
new file mode 100644
index 0000000000..98f369a7f8
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/hstore.rb
@@ -0,0 +1,25 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Hstore < Type::Value
+          def type
+            :hstore
+          end
+
+          def type_cast_for_write(value)
+            ConnectionAdapters::PostgreSQLColumn.hstore_to_string value
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_hstore value
+          end
+
+          def accessor
+            ActiveRecord::Store::StringKeyedHashAccessor
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
new file mode 100644
index 0000000000..7ed8f5f031
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/inet.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Inet < Cidr
+          def type
+            :inet
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb
new file mode 100644
index 0000000000..d438ffa140
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/infinity.rb
@@ -0,0 +1,13 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        module Infinity
+          def infinity(options = {})
+            options[:negative] ? -::Float::INFINITY : ::Float::INFINITY
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb
new file mode 100644
index 0000000000..388d3dd9ed
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/integer.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Integer < Type::Integer
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb
new file mode 100644
index 0000000000..42bf5656f4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/json.rb
@@ -0,0 +1,25 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Json < Type::Value
+          def type
+            :json
+          end
+
+          def type_cast_for_write(value)
+            ConnectionAdapters::PostgreSQLColumn.json_to_string value
+          end
+
+          def cast_value(value)
+            ConnectionAdapters::PostgreSQLColumn.string_to_json value
+          end
+
+          def accessor
+            ActiveRecord::Store::StringKeyedHashAccessor
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
new file mode 100644
index 0000000000..1e34c09c88
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/money.rb
@@ -0,0 +1,37 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Money < Type::Decimal
+          include Infinity
+
+          def extract_scale(sql_type)
+            2
+          end
+
+          def cast_value(value)
+            return value unless ::String === value
+
+            # Because money output is formatted according to the locale, there are two
+            # cases to consider (note the decimal separators):
+            #  (1) $12,345,678.12
+            #  (2) $12.345.678,12
+            # Negative values are represented as follows:
+            #  (3) -$2.55
+            #  (4) ($2.55)
+
+            value.sub!(/^\((.+)\)$/, '-\1') # (4)
+            case value
+            when /^-?\D+[\d,]+\.\d{2}$/  # (1)
+              value.gsub!(/[^-\d.]/, '')
+            when /^-?\D+[\d.]+,\d{2}$/  # (2)
+              value.gsub!(/[^-\d,]/, '').sub!(/,/, '.')
+            end
+
+            super(value)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
new file mode 100644
index 0000000000..2769a8d3b4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/point.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Point < Type::String
+          def type_cast(value)
+            if ::String === value
+              ConnectionAdapters::PostgreSQLColumn.string_to_point value
+            else
+              value
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
new file mode 100644
index 0000000000..c2262c1599
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/range.rb
@@ -0,0 +1,56 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Range < Type::Value
+          attr_reader :subtype, :type
+
+          def initialize(subtype, type)
+            @subtype = subtype
+            @type = type
+          end
+
+          def extract_bounds(value)
+            from, to = value[1..-2].split(',')
+            {
+              from:          (value[1] == ',' || from == '-infinity') ? @subtype.infinity(negative: true) : from,
+              to:            (value[-2] == ',' || to == 'infinity') ? @subtype.infinity : to,
+              exclude_start: (value[0] == '('),
+              exclude_end:   (value[-1] == ')')
+            }
+          end
+
+          def infinity?(value)
+            value.respond_to?(:infinite?) && value.infinite?
+          end
+
+          def type_cast_single(value)
+            infinity?(value) ? value : @subtype.type_cast(value)
+          end
+
+          def cast_value(value)
+            return if value == 'empty'
+            return value if value.is_a?(::Range)
+
+            extracted = extract_bounds(value)
+            from = type_cast_single extracted[:from]
+            to = type_cast_single extracted[:to]
+
+            if !infinity?(from) && extracted[:exclude_start]
+              if from.respond_to?(:succ)
+                from = from.succ
+                ActiveSupport::Deprecation.warn <<-MESSAGE
+Excluding the beginning of a Range is only partialy supported through `#succ`.
+This is not reliable and will be removed in the future.
+                MESSAGE
+              else
+                raise ArgumentError, "The Ruby Range object does not support excluding the beginning of a Range. (unsupported value: '#{value}')"
+              end
+            end
+            ::Range.new(from, to, extracted[:exclude_end])
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
new file mode 100644
index 0000000000..7b1ca16bc4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/specialized_string.rb
@@ -0,0 +1,19 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class SpecializedString < Type::String
+          attr_reader :type
+
+          def initialize(type)
+            @type = type
+          end
+
+          def text?
+            false
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb
new file mode 100644
index 0000000000..ea1f599b0f
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/time.rb
@@ -0,0 +1,11 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Time < Type::Time
+          include Infinity
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
new file mode 100644
index 0000000000..27829ae1a3
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/type_map_initializer.rb
@@ -0,0 +1,78 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        # This class uses the data from PostgreSQL pg_type table to build
+        # the OID -> Type mapping.
+        #   - OID is and integer representing the type.
+        #   - Type is an OID::Type object.
+        # This class has side effects on the +store+ passed during initialization.
+        class TypeMapInitializer # :nodoc:
+          def initialize(store)
+            @store = store
+          end
+
+          def run(records)
+            mapped, nodes = records.partition { |row| OID.registered_type? row['typname'] }
+            ranges, nodes = nodes.partition { |row| row['typtype'] == 'r' }
+            enums, nodes = nodes.partition { |row| row['typtype'] == 'e' }
+            domains, nodes = nodes.partition { |row| row['typtype'] == 'd' }
+            arrays, nodes = nodes.partition { |row| row['typinput'] == 'array_in' }
+            composites, nodes = nodes.partition { |row| row['typelem'] != '0' }
+
+            mapped.each     { |row| register_mapped_type(row)    }
+            enums.each      { |row| register_enum_type(row)      }
+            domains.each    { |row| register_domain_type(row)    }
+            arrays.each     { |row| register_array_type(row)     }
+            ranges.each     { |row| register_range_type(row)     }
+            composites.each { |row| register_composite_type(row) }
+          end
+
+          private
+          def register_mapped_type(row)
+            register row['oid'], OID::NAMES[row['typname']]
+          end
+
+          def register_enum_type(row)
+            register row['oid'], OID::Enum.new
+          end
+
+          def register_array_type(row)
+            if subtype = @store.lookup(row['typelem'].to_i)
+              register row['oid'], OID::Array.new(subtype)
+            end
+          end
+
+          def register_range_type(row)
+            if subtype = @store.lookup(row['rngsubtype'].to_i)
+              register row['oid'], OID::Range.new(subtype, row['typname'].to_sym)
+            end
+          end
+
+          def register_domain_type(row)
+            if base_type = @store.lookup(row["typbasetype"].to_i)
+              register row['oid'], base_type
+            else
+              warn "unknown base type (OID: #{row["typbasetype"]}) for domain #{row["typname"]}."
+            end
+          end
+
+          def register_composite_type(row)
+            if subtype = @store.lookup(row['typelem'].to_i)
+              register row['oid'], OID::Vector.new(row['typdelim'], subtype)
+            end
+          end
+
+          def register(oid, oid_type)
+            oid = oid.to_i
+
+            raise ArgumentError, "can't register nil type for OID #{oid}" if oid_type.nil?
+            return if @store.key?(oid)
+
+            @store.register_type(oid, oid_type)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
new file mode 100644
index 0000000000..0ed5491887
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/uuid.rb
@@ -0,0 +1,17 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Uuid < Type::Value
+          def type
+            :uuid
+          end
+
+          def type_cast(value)
+            value.presence
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
new file mode 100644
index 0000000000..2f7d1be197
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/vector.rb
@@ -0,0 +1,26 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module PostgreSQL
+      module OID # :nodoc:
+        class Vector < Type::Value
+          attr_reader :delim, :subtype
+
+          # +delim+ corresponds to the `typdelim` column in the pg_types
+          # table.  +subtype+ is derived from the `typelem` column in the
+          # pg_types table.
+          def initialize(delim, subtype)
+            @delim   = delim
+            @subtype = subtype
+          end
+
+          # FIXME: this should probably split on +delim+ and use +subtype+
+          # to cast the values.  Unfortunately, the current Rails behavior
+          # is to just return the string.
+          def type_cast(value)
+            value
+          end
+        end
+      end
+    end
+  end
+end