Module: MyStuff::MultiDB

Defined in:
lib/my_stuff/multidb.rb,
lib/my_stuff/multidb/sharded.rb,
lib/my_stuff/multidb/mangling.rb,
lib/my_stuff/multidb/unsharded.rb,
lib/my_stuff/multidb/connection.rb,
lib/my_stuff/multidb/core_ext/base.rb

Overview

Example

module Foo
  class SomeTable < ActiveRecord::Base
  end
  include MyStuff::MultiDB::Unsharded
end
module Bar
  class SomeTable < ActiveRecord::Base
  end
  include MyStuff::MultiDB::Sharded
end

Foo.with_master do |db|
  p db::SomeTable.where(:some_column = 'bar')
end
Foo.with_slave do |db|
  p db::SomeTable.where(:some_column = 'bar')
end

Bar.with_master_for(id) do |db|
  p db::SomeTable.where(:some_column = 'bar')
end
Bar.with_master_for_new do |db|
  db::SomeTable.new do
     ...
  end
end
Bar.with_slave_for(id) do |db|
  p db::SomeTable.where(:some_column = 'bar')
end

See MyStuff::MultiDB::Unsharded and MyStuff::MultiDB::Sharded

Details

When you call with_*, it:

  • Looks for a class called MyStuff::MultiDB::MANGLED_DATABASE_NAME

  • If it doesn’t exist, it creates a new ActiveRecord::Base subclass

  • It then looks for a module within that class with the same name as your module

  • If it’s not there:

    • It creates the module

    • It creates a subclass of each of your ActiveRecord definitions within this module

    • It delegates connection handling to the database class

  • It then returns the database class

So, you end up with an ActiveRecord class like: MyStuff::MultiDB::MANGLED_DATABASE_NAME::YourModule::YourClass

Defined Under Namespace

Modules: Connections, CoreExt, Mangling, Sharded, Unsharded Classes: Connection

Class Method Summary collapse

Class Method Details

.included(othermod) ⇒ Object

:nodoc:



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# File 'lib/my_stuff/multidb.rb', line 63

def self.included othermod # :nodoc:
  class <<othermod
    def with_spec spec, &block
      MyStuff::MultiDB.with_spec(self, spec, &block)
    end
  end
end

.with_spec(original_module, spec, &block) ⇒ Object

:nodoc:



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# File 'lib/my_stuff/multidb.rb', line 71

def self.with_spec original_module, spec, &block # :nodoc:
  ar_base = Connection.base_class_for_spec(spec)
  rebased_module = ar_base.rebased_module(original_module)

  ar_base.connection_pool.with_connection do
    if block.arity == 1
      block.call rebased_module
    else
      block.call rebased_module, spec
    end
  end
end