require 'active_record/connection_adapters/postgresql/cast'
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, oid_type, sql_type[0..sql_type.length - 3], null)
else
@array = false
super(name, default_value, oid_type, sql_type, null)
end
@default_function = default if has_default_function?(default_value, default)
end
# :stopdoc:
class << self
include PostgreSQL::Cast
# Loads pg_array_parser if available. String parsing can be
# performed quicker by a native extension, which will not create
# a large amount of Ruby objects that will need to be garbage
# collected. pg_array_parser has a C and Java extension
begin
require 'pg_array_parser'
include PgArrayParser
rescue LoadError
require 'active_record/connection_adapters/postgresql/array_parser'
include PostgreSQL::ArrayParser
end
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
# Casts a Ruby value to something appropriate for writing to PostgreSQL.
# see ActiveRecord::ConnectionAdapters::Class#type_cast_for_write
# see ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::OID::Type
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 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
end
end
end