require 'thread'
require 'active_support/core_ext/hash/indifferent_access'
require 'active_support/core_ext/object/duplicable'
require 'active_support/core_ext/string/filters'
module ActiveRecord
module Core
extend ActiveSupport::Concern
included do
##
# :singleton-method:
#
# Accepts a logger conforming to the interface of Log4r which is then
# passed on to any new database connections made and which can be
# retrieved on both a class and instance level by calling +logger+.
mattr_accessor :logger, instance_writer: false
##
# Contains the database configuration - as is typically stored in config/database.yml -
# as a Hash.
#
# For example, the following database.yml...
#
# development:
# adapter: sqlite3
# database: db/development.sqlite3
#
# production:
# adapter: sqlite3
# database: db/production.sqlite3
#
# ...would result in ActiveRecord::Base.configurations to look like this:
#
# {
# 'development' => {
# 'adapter' => 'sqlite3',
# 'database' => 'db/development.sqlite3'
# },
# 'production' => {
# 'adapter' => 'sqlite3',
# 'database' => 'db/production.sqlite3'
# }
# }
def self.configurations=(config)
@@configurations = ActiveRecord::ConnectionHandling::MergeAndResolveDefaultUrlConfig.new(config).resolve
end
self.configurations = {}
# Returns fully resolved configurations hash
def self.configurations
@@configurations
end
##
# :singleton-method:
# Determines whether to use Time.utc (using :utc) or Time.local (using :local) when pulling
# dates and times from the database. This is set to :utc by default.
mattr_accessor :default_timezone, instance_writer: false
self.default_timezone = :utc
##
# :singleton-method:
# Specifies the format to use when dumping the database schema with Rails'
# Rakefile. If :sql, the schema is dumped as (potentially database-
# specific) SQL statements. If :ruby, the schema is dumped as an
# ActiveRecord::Schema file which can be loaded into any database that
# supports migrations. Use :ruby if you want to have different database
# adapters for, e.g., your development and test environments.
mattr_accessor :schema_format, instance_writer: false
self.schema_format = :ruby
##
# :singleton-method:
# Specify whether or not to use timestamps for migration versions
mattr_accessor :timestamped_migrations, instance_writer: false
self.timestamped_migrations = true
##
# :singleton-method:
# Specify whether schema dump should happen at the end of the
# db:migrate rake task. This is true by default, which is useful for the
# development environment. This should ideally be false in the production
# environment where dumping schema is rarely needed.
mattr_accessor :dump_schema_after_migration, instance_writer: false
self.dump_schema_after_migration = true
##
# :singleton-method:
# Specifies which database schemas to dump when calling db:structure:dump.
# If the value is :schema_search_path (the default), any schemas listed in
# schema_search_path are dumped. Use :all to dump all schemas regardless
# of schema_search_path, or a string of comma separated schemas for a
# custom list.
mattr_accessor :dump_schemas, instance_writer: false
self.dump_schemas = :schema_search_path
##
# :singleton-method:
# Specify a threshold for the size of query result sets. If the number of
# records in the set exceeds the threshold, a warning is logged. This can
# be used to identify queries which load thousands of records and
# potentially cause memory bloat.
mattr_accessor :warn_on_records_fetched_greater_than, instance_writer: false
self.warn_on_records_fetched_greater_than = nil
mattr_accessor :maintain_test_schema, instance_accessor: false
mattr_accessor :belongs_to_required_by_default, instance_accessor: false
class_attribute :default_connection_handler, instance_writer: false
def self.connection_handler
ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler
end
def self.connection_handler=(handler)
ActiveRecord::RuntimeRegistry.connection_handler = handler
end
self.default_connection_handler = ConnectionAdapters::ConnectionHandler.new
end
module ClassMethods
def allocate
define_attribute_methods
super
end
def initialize_find_by_cache # :nodoc:
@find_by_statement_cache = {}.extend(Mutex_m)
end
def inherited(child_class) # :nodoc:
# initialize cache at class definition for thread safety
child_class.initialize_find_by_cache
super
end
def find(*ids) # :nodoc:
# We don't have cache keys for this stuff yet
return super unless ids.length == 1
return super if block_given? ||
primary_key.nil? ||
scope_attributes? ||
columns_hash.include?(inheritance_column) ||
ids.first.kind_of?(Array)
id = ids.first
if ActiveRecord::Base === id
id = id.id
ActiveSupport::Deprecation.warn(<<-MSG.squish)
You are passing an instance of ActiveRecord::Base to `find`.
Please pass the id of the object by calling `.id`
MSG
end
key = primary_key
statement = cached_find_by_statement(key) { |params|
where(key => params.bind).limit(1)
}
record = statement.execute([id], self, connection).first
unless record
raise RecordNotFound.new("Couldn't find #{name} with '#{primary_key}'=#{id}",
name, primary_key, id)
end
record
rescue RangeError
raise RecordNotFound.new("Couldn't find #{name} with an out of range value for '#{primary_key}'",
name, primary_key)
end
def find_by(*args) # :nodoc:
return super if scope_attributes? || !(Hash === args.first) || reflect_on_all_aggregations.any?
hash = args.first
return super if hash.values.any? { |v|
v.nil? || Array === v || Hash === v || Relation === v
}
# We can't cache Post.find_by(author: david) ...yet
return super unless hash.keys.all? { |k| columns_hash.has_key?(k.to_s) }
keys = hash.keys
statement = cached_find_by_statement(keys) { |params|
wheres = keys.each_with_object({}) { |param, o|
o[param] = params.bind
}
where(wheres).limit(1)
}
begin
statement.execute(hash.values, self, connection).first
rescue TypeError => e
raise ActiveRecord::StatementInvalid.new(e.message, e)
rescue RangeError
nil
end
end
def find_by!(*args) # :nodoc:
find_by(*args) or raise RecordNotFound.new("Couldn't find #{name}", name)
end
def initialize_generated_modules # :nodoc:
generated_association_methods
end
def generated_association_methods
@generated_association_methods ||= begin
mod = const_set(:GeneratedAssociationMethods, Module.new)
include mod
mod
end
end
# Returns a string like 'Post(id:integer, title:string, body:text)'
def inspect
if self == Base
super
elsif abstract_class?
"#{super}(abstract)"
elsif !connected?
"#{super} (call '#{super}.connection' to establish a connection)"
elsif table_exists?
attr_list = attribute_types.map { |name, type| "#{name}: #{type.type}" } * ', '
"#{super}(#{attr_list})"
else
"#{super}(Table doesn't exist)"
end
end
# Overwrite the default class equality method to provide support for association proxies.
def ===(object)
object.is_a?(self)
end
# Returns an instance of Arel::Table loaded with the current table name.
#
# class Post < ActiveRecord::Base
# scope :published_and_commented, -> { published.and(self.arel_table[:comments_count].gt(0)) }
# end
def arel_table # :nodoc:
@arel_table ||= Arel::Table.new(table_name, type_caster: type_caster)
end
# Returns the Arel engine.
def arel_engine # :nodoc:
@arel_engine ||=
if Base == self || connection_handler.retrieve_connection_pool(self)
self
else
superclass.arel_engine
end
end
def predicate_builder # :nodoc:
@predicate_builder ||= PredicateBuilder.new(table_metadata)
end
def type_caster # :nodoc:
TypeCaster::Map.new(self)
end
private
def cached_find_by_statement(key, &block) # :nodoc:
@find_by_statement_cache[key] || @find_by_statement_cache.synchronize {
@find_by_statement_cache[key] ||= StatementCache.create(connection, &block)
}
end
def relation # :nodoc:
relation = Relation.create(self, arel_table, predicate_builder)
if finder_needs_type_condition?
relation.where(type_condition).create_with(inheritance_column.to_sym => sti_name)
else
relation
end
end
def table_metadata # :nodoc:
TableMetadata.new(self, arel_table)
end
end
# New objects can be instantiated as either empty (pass no construction parameter) or pre-set with
# attributes but not yet saved (pass a hash with key names matching the associated table column names).
# In both instances, valid attribute keys are determined by the column names of the associated table --
# hence you can't have attributes that aren't part of the table columns.
#
# ==== Example:
# # Instantiates a single new object
# User.new(first_name: 'Jamie')
def initialize(attributes = nil)
@attributes = self.class._default_attributes.deep_dup
self.class.define_attribute_methods
init_internals
initialize_internals_callback
assign_attributes(attributes) if attributes
yield self if block_given?
_run_initialize_callbacks
end
# Initialize an empty model object from +coder+. +coder+ should be
# the result of previously encoding an Active Record model, using
# #encode_with.
#
# class Post < ActiveRecord::Base
# end
#
# old_post = Post.new(title: "hello world")
# coder = {}
# old_post.encode_with(coder)
#
# post = Post.allocate
# post.init_with(coder)
# post.title # => 'hello world'
def init_with(coder)
coder = LegacyYamlAdapter.convert(self.class, coder)
@attributes = coder['attributes']
init_internals
@new_record = coder['new_record']
self.class.define_attribute_methods
_run_find_callbacks
_run_initialize_callbacks
self
end
##
# :method: clone
# Identical to Ruby's clone method. This is a "shallow" copy. Be warned that your attributes are not copied.
# That means that modifying attributes of the clone will modify the original, since they will both point to the
# same attributes hash. If you need a copy of your attributes hash, please use the #dup method.
#
# user = User.first
# new_user = user.clone
# user.name # => "Bob"
# new_user.name = "Joe"
# user.name # => "Joe"
#
# user.object_id == new_user.object_id # => false
# user.name.object_id == new_user.name.object_id # => true
#
# user.name.object_id == user.dup.name.object_id # => false
##
# :method: dup
# Duped objects have no id assigned and are treated as new records. Note
# that this is a "shallow" copy as it copies the object's attributes
# only, not its associations. The extent of a "deep" copy is application
# specific and is therefore left to the application to implement according
# to its need.
# The dup method does not preserve the timestamps (created|updated)_(at|on).
##
def initialize_dup(other) # :nodoc:
@attributes = @attributes.deep_dup
@attributes.reset(self.class.primary_key)
_run_initialize_callbacks
@new_record = true
@destroyed = false
super
end
# Populate +coder+ with attributes about this record that should be
# serialized. The structure of +coder+ defined in this method is
# guaranteed to match the structure of +coder+ passed to the #init_with
# method.
#
# Example:
#
# class Post < ActiveRecord::Base
# end
# coder = {}
# Post.new.encode_with(coder)
# coder # => {"attributes" => {"id" => nil, ... }}
def encode_with(coder)
# FIXME: Remove this when we better serialize attributes
coder['raw_attributes'] = attributes_before_type_cast
coder['attributes'] = @attributes
coder['new_record'] = new_record?
coder['active_record_yaml_version'] = 1
end
# Returns true if +comparison_object+ is the same exact object, or +comparison_object+
# is of the same type and +self+ has an ID and it is equal to +comparison_object.id+.
#
# Note that new records are different from any other record by definition, unless the
# other record is the receiver itself. Besides, if you fetch existing records with
# +select+ and leave the ID out, you're on your own, this predicate will return false.
#
# Note also that destroying a record preserves its ID in the model instance, so deleted
# models are still comparable.
def ==(comparison_object)
super ||
comparison_object.instance_of?(self.class) &&
!id.nil? &&
comparison_object.id == id
end
alias :eql? :==
# Delegates to id in order to allow two records of the same type and id to work with something like:
# [ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]
def hash
if id
id.hash
else
super
end
end
# Clone and freeze the attributes hash such that associations are still
# accessible, even on destroyed records, but cloned models will not be
# frozen.
def freeze
@attributes = @attributes.clone.freeze
self
end
# Returns +true+ if the attributes hash has been frozen.
def frozen?
@attributes.frozen?
end
# Allows sort on objects
def <=>(other_object)
if other_object.is_a?(self.class)
self.to_key <=> other_object.to_key
else
super
end
end
# Returns +true+ if the record is read only. Records loaded through joins with piggy-back
# attributes will be marked as read only since they cannot be saved.
def readonly?
@readonly
end
# Marks this record as read only.
def readonly!
@readonly = true
end
def connection_handler
self.class.connection_handler
end
# Returns the contents of the record as a nicely formatted string.
def inspect
# We check defined?(@attributes) not to issue warnings if the object is
# allocated but not initialized.
inspection = if defined?(@attributes) && @attributes
self.class.column_names.collect { |name|
if has_attribute?(name)
"#{name}: #{attribute_for_inspect(name)}"
end
}.compact.join(", ")
else
"not initialized"
end
"#<#{self.class} #{inspection}>"
end
# Takes a PP and prettily prints this record to it, allowing you to get a nice result from pp record
# when pp is required.
def pretty_print(pp)
return super if custom_inspect_method_defined?
pp.object_address_group(self) do
if defined?(@attributes) && @attributes
column_names = self.class.column_names.select { |name| has_attribute?(name) || new_record? }
pp.seplist(column_names, proc { pp.text ',' }) do |column_name|
column_value = read_attribute(column_name)
pp.breakable ' '
pp.group(1) do
pp.text column_name
pp.text ':'
pp.breakable
pp.pp column_value
end
end
else
pp.breakable ' '
pp.text 'not initialized'
end
end
end
# Returns a hash of the given methods with their names as keys and returned values as values.
def slice(*methods)
Hash[methods.map! { |method| [method, public_send(method)] }].with_indifferent_access
end
private
# Under Ruby 1.9, Array#flatten will call #to_ary (recursively) on each of the elements
# of the array, and then rescues from the possible NoMethodError. If those elements are
# ActiveRecord::Base's, then this triggers the various method_missing's that we have,
# which significantly impacts upon performance.
#
# So we can avoid the method_missing hit by explicitly defining #to_ary as nil here.
#
# See also http://tenderlovemaking.com/2011/06/28/til-its-ok-to-return-nil-from-to_ary.html
def to_ary # :nodoc:
nil
end
def init_internals
@readonly = false
@destroyed = false
@marked_for_destruction = false
@destroyed_by_association = nil
@new_record = true
@txn = nil
@_start_transaction_state = {}
@transaction_state = nil
end
def initialize_internals_callback
end
def thaw
if frozen?
@attributes = @attributes.dup
end
end
def custom_inspect_method_defined?
self.class.instance_method(:inspect).owner != ActiveRecord::Base.instance_method(:inspect).owner
end
end
end