Class: IncrementalBackup::Lock

Inherits:
Object
  • Object
show all
Defined in:
lib/incremental_backup/lock.rb

Constant Summary collapse

LOCK_FILENAME = 
'lock_{task_id}'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(task) ⇒ Lock

Should not be called from other places than Lock.create



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# File 'lib/incremental_backup/lock.rb', line 11

def initialize task
  @task = task

  @lock_file = File.open(path, File::RDWR|File::CREAT, 0644)
  unless @lock_file.flock(File::LOCK_EX|File::LOCK_NB)
    self.failed = true
  end
end

Instance Attribute Details

#failed ⇒ Object

Returns the value of attribute failed.



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# File 'lib/incremental_backup/lock.rb', line 8

def failed
  @failed
end

Class Method Details

.create(task, &block) ⇒ Object

Obtains lock, run block, release lock



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# File 'lib/incremental_backup/lock.rb', line 21

def self.create task, &block
  task.logger.info 'Obtaining lock...'

  lock = Lock.new task

  if lock.failed
    task.logger.info 'Lock can not be obtained. Exiting!'
    return
  end

  task.logger.info 'Obtained lock'

  begin
    yield
  ensure
    task.logger.info 'Releasing lock...'
    lock.release
    task.logger.info 'Released lock'
  end

  true
end

Instance Method Details

#release ⇒ Object

Release lock



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# File 'lib/incremental_backup/lock.rb', line 45

def release
  @lock_file.close if @lock_file
end