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module ActiveRecord
module ConnectionHandling
RAILS_ENV = -> { (Rails.env if defined?(Rails.env)) || ENV["RAILS_ENV"] || ENV["RACK_ENV"] }
DEFAULT_ENV = -> { RAILS_ENV.call || "default_env" }
# Establishes the connection to the database. Accepts a hash as input where
# the <tt>:adapter</tt> key must be specified with the name of a database adapter (in lower-case)
# example for regular databases (MySQL, PostgreSQL, etc):
#
# ActiveRecord::Base.establish_connection(
# adapter: "mysql2",
# host: "localhost",
# username: "myuser",
# password: "mypass",
# database: "somedatabase"
# )
#
# Example for SQLite database:
#
# ActiveRecord::Base.establish_connection(
# adapter: "sqlite3",
# database: "path/to/dbfile"
# )
#
# Also accepts keys as strings (for parsing from YAML for example):
#
# ActiveRecord::Base.establish_connection(
# "adapter" => "sqlite3",
# "database" => "path/to/dbfile"
# )
#
# Or a URL:
#
# ActiveRecord::Base.establish_connection(
# "postgres://myuser:mypass@localhost/somedatabase"
# )
#
# In case {ActiveRecord::Base.configurations}[rdoc-ref:Core.configurations]
# is set (Rails automatically loads the contents of config/database.yml into it),
# a symbol can also be given as argument, representing a key in the
# configuration hash:
#
# ActiveRecord::Base.establish_connection(:production)
#
# The exceptions AdapterNotSpecified, AdapterNotFound and +ArgumentError+
# may be returned on an error.
def establish_connection(config = nil)
raise "Anonymous class is not allowed." unless name
config ||= DEFAULT_ENV.call.to_sym
spec_name = self == Base ? "primary" : name
self.connection_specification_name = spec_name
resolver = ConnectionAdapters::ConnectionSpecification::Resolver.new(Base.configurations)
spec = resolver.resolve(config).symbolize_keys
spec[:name] = spec_name
connection_handler.establish_connection(spec)
end
class MergeAndResolveDefaultUrlConfig # :nodoc:
def initialize(raw_configurations)
@raw_config = raw_configurations.dup
@env = DEFAULT_ENV.call.to_s
end
# Returns fully resolved connection hashes.
# Merges connection information from `ENV['DATABASE_URL']` if available.
def resolve
ConnectionAdapters::ConnectionSpecification::Resolver.new(config).resolve_all
end
private
def config
@raw_config.dup.tap do |cfg|
if url = ENV["DATABASE_URL"]
cfg[@env] ||= {}
cfg[@env]["url"] ||= url
end
end
end
end
# Returns the connection currently associated with the class. This can
# also be used to "borrow" the connection to do database work unrelated
# to any of the specific Active Records.
def connection
retrieve_connection
end
attr_writer :connection_specification_name
# Return the specification name from the current class or its parent.
def connection_specification_name
if !defined?(@connection_specification_name) || @connection_specification_name.nil?
return self == Base ? "primary" : superclass.connection_specification_name
end
@connection_specification_name
end
# Returns the configuration of the associated connection as a hash:
#
# ActiveRecord::Base.connection_config
# # => {pool: 5, timeout: 5000, database: "db/development.sqlite3", adapter: "sqlite3"}
#
# Please use only for reading.
def connection_config
connection_pool.spec.config
end
def connection_pool
connection_handler.retrieve_connection_pool(connection_specification_name) || raise(ConnectionNotEstablished)
end
def retrieve_connection
connection_handler.retrieve_connection(connection_specification_name)
end
# Returns +true+ if Active Record is connected.
def connected?
connection_handler.connected?(connection_specification_name)
end
def remove_connection(name = nil)
name ||= @connection_specification_name if defined?(@connection_specification_name)
# if removing a connection that has a pool, we reset the
# connection_specification_name so it will use the parent
# pool.
if connection_handler.retrieve_connection_pool(name)
self.connection_specification_name = nil
end
connection_handler.remove_connection(name)
end
def clear_cache! # :nodoc:
connection.schema_cache.clear!
end
delegate :clear_active_connections!, :clear_reloadable_connections!,
:clear_all_connections!, to: :connection_handler
end
end