Class: MaglevRecord::Migrator

Inherits:
Object
  • Object
show all
Defined in:
lib/maglev_record/migration/migrator.rb

Overview

Given a migration list (the desired applied migrations) this class migrates to these state. Therefore, it decides which migrations must be undone, and which must be done and leaves the stone in the desired state.

Constant Summary collapse

MIGRATION_KEY = 
:__migrations__

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(migration_list) ⇒ Migrator

Returns a new instance of Migrator.



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# File 'lib/maglev_record/migration/migrator.rb', line 11

def initialize(migration_list)
  @migration_list = migration_list
  @non_displaying_logger = Logger.new(STDOUT)
  @non_displaying_logger.level = Logger::FATAL
end

Class Method Details

.for_directory(directory) ⇒ Object 



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# File 'lib/maglev_record/migration/migrator.rb', line 52

def self.for_directory(directory)
  loader = MigrationLoader.new
  loader.load_directory(directory)
  new(loader.migration_list)
end

Instance Method Details

#migration_store ⇒ Object

Returns all migrations currently in the stone in the correct order.



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# File 'lib/maglev_record/migration/migrator.rb', line 19

def migration_store
  Maglev::PERSISTENT_ROOT[MIGRATION_KEY] ||= []
end

#migrations_todo ⇒ Object 



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# File 'lib/maglev_record/migration/migrator.rb', line 23

def migrations_todo
  @migration_list.reject do |mig|
    migration_store.include?(mig.id)
  end
end

#up(logger = @non_displaying_logger) ⇒ Object

Applies the desired state of migrations.



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# File 'lib/maglev_record/migration/migrator.rb', line 39

def up(logger = @non_displaying_logger)
  Maglev.abort_transaction
  to_do = migrations_todo
  logger.info("Already applied all migrations.") if to_do.empty?
  to_do.sort.each do |mig|
    mig.logger = logger
    logger.info("Doing '" + mig.name + "' from " + mig.timestamp.to_s)
    mig.do
    migration_store << mig.id
  end
  Maglev.commit_transaction
end

#up?(logger = @non_displaying_logger) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/maglev_record/migration/migrator.rb', line 29

def up?(logger = @non_displaying_logger)
  # todo: test
  migrations_todo.sort.each do |mig|
    logger.info("to do: '" + mig.name + "' from " + mig.timestamp.to_s)
  end
  logger.info("Already applied all migrations.") if migrations_todo.empty?
end