Module: Minestrone::Configuration::Execution

Included in:
Minestrone::Configuration
Defined in:
lib/minestrone/configuration/execution.rb

Defined Under Namespace

Classes: TaskCallFrame

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#rollback_requests ⇒ Object

The stack of tasks that have registered rollback handlers within the current transaction. If this is nil, then there is no transaction that is currently active.



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# File 'lib/minestrone/configuration/execution.rb', line 31

def rollback_requests
  @rollback_requests
end

Instance Method Details

#current_task ⇒ Object

Returns the TaskDefinition object for the currently executing task. It returns nil if there is no task being executed.



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# File 'lib/minestrone/configuration/execution.rb', line 73

def current_task
  return nil if task_call_frames.empty?
  task_call_frames.last.task
end

#execute_task(task) ⇒ Object

Executes the task with the given name, without invoking any associated callbacks.



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# File 'lib/minestrone/configuration/execution.rb', line 80

def execute_task(task)
  logger.debug "executing `#{task.fully_qualified_name}'"
  push_task_call_frame(task)
  invoke_task_directly(task)
ensure
  pop_task_call_frame
end

#find_and_execute_task(path, hooks = {}) ⇒ Object

Attempts to locate the task at the given fully-qualified path, and execute it. If no such task exists, a Minestrone::NoSuchTaskError will be raised.



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# File 'lib/minestrone/configuration/execution.rb', line 92

def find_and_execute_task(path, hooks = {})
  task = find_task(path) or raise NoSuchTaskError, "the task `#{path}' does not exist"

  trigger(hooks[:before], task) if hooks[:before]
  result = execute_task(task)
  trigger(hooks[:after], task) if hooks[:after]

  result
end

#initialize_execution ⇒ Object

:nodoc:



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# File 'lib/minestrone/configuration/execution.rb', line 11

def initialize_execution #:nodoc:
  @task_call_frames = []
  @rollback_requests = nil
end

#on_rollback(&block) ⇒ Object

Specifies an on_rollback hook for the currently executing task. If this or any subsequent task then fails, and a transaction is active, this hook will be executed.



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# File 'lib/minestrone/configuration/execution.rb', line 62

def on_rollback(&block)
  if transaction?
    # don't note a new rollback request if one has already been set
    rollback_requests << task_call_frames.last unless task_call_frames.last.rollback
    task_call_frames.last.rollback = block
  end
end

#task_call_frames ⇒ Object

The call stack of the tasks. The currently executing task may inspect this to see who its caller was. The current task is always the last element of this stack.



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# File 'lib/minestrone/configuration/execution.rb', line 24

def task_call_frames
  @task_call_frames
end

#transaction ⇒ Object

Invoke a set of tasks in a transaction. If any task fails (raises an exception), all tasks executed within the transaction are inspected to see if they have an associated on_rollback hook, and if so, that hook is called.

Raises:

  • (ArgumentError) 


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# File 'lib/minestrone/configuration/execution.rb', line 38

def transaction
  raise ArgumentError, "expected a block" unless block_given?
  raise ScriptError, "transaction must be called from within a task" if task_call_frames.empty?

  return yield if transaction?

  logger.info "transaction: start"

  begin
    self.rollback_requests = []
    yield
    logger.info "transaction: commit"
  rescue Object
    rollback!
    raise
  ensure
    self.rollback_requests = nil
  end
end

#transaction? ⇒ Boolean

Returns true if there is a transaction currently active.

Returns:

  • (Boolean) 


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# File 'lib/minestrone/configuration/execution.rb', line 17

def transaction?
  !rollback_requests.nil?
end