Class: Ddr::Managers::DerivativesManager

Inherits:
Manager
  • Object
show all
Defined in:
lib/ddr/managers/derivatives_manager.rb

Defined Under Namespace

Classes: DerivativeJob

Constant Summary collapse

SCHEDULE_LATER = 
:later
SCHEDULE_NOW = 
:now
SCHEDULES = 
[ SCHEDULE_LATER, SCHEDULE_NOW ]
ACTION_DELETE = 
"delete"
ACTION_GENERATE = 
"generate"

Instance Attribute Summary

Attributes inherited from Manager

#object

Instance Method Summary collapse

Methods inherited from Manager

#initialize

Constructor Details

This class inherits a constructor from Ddr::Managers::Manager

Instance Method Details

#delete_derivative(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 77

def delete_derivative(derivative)
  ActiveSupport::Notifications.instrument(Ddr::Notifications::UPDATE,
                                          pid: object.pid,
                                          summary: "Delete derivative #{derivative.name.to_s}"
                                          ) do |payload|
    delete_derivative! derivative
  end
end

#delete_derivative!(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 86

def delete_derivative!(derivative)
  File.unlink *object.datastreams[derivative.datastream].file_paths if
                                                object.datastreams[derivative.datastream].external?
  object.datastreams[derivative.datastream].delete
  object.save!
end

#generate_derivative(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 44

def generate_derivative(derivative)
  ActiveSupport::Notifications.instrument(Ddr::Notifications::UPDATE,
                                          pid: object.pid,
                                          summary: "Generate #{derivative.name.to_s} derivative"
                                          ) do |payload|
    generate_derivative! derivative
  end
end

#generate_derivative!(derivative) ⇒ Object 



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# File 'lib/ddr/managers/derivatives_manager.rb', line 53

def generate_derivative!(derivative)
  tempdir_path = File.join(Dir.tmpdir, Dir::Tmpname.make_tmpname('',nil))
  begin
    tempdir = FileUtils.mkdir(tempdir_path).first
    generator_source = create_source_file(tempdir)
    generator_output = File.new(File.join(tempdir, "output.out"), 'wb')
    results = derivative.generator.new(generator_source.path, generator_output.path, derivative.options).generate
    generator_source.close unless generator_source.closed?
    if results.status.success?
      generator_output = File.open(generator_output, 'rb')
      object.reload if object.persisted?
      object.add_file generator_output, derivative.datastream, mime_type: derivative.generator.output_mime_type
      object.save!
    else
      Rails.logger.error results.stderr
      raise Ddr::Models::DerivativeGenerationFailure,
              "Failure generating #{derivative.name} for #{object.pid}: #{results.stderr}"
    end
    generator_output.close unless generator_output.closed?
  ensure
    FileUtils.remove_dir(tempdir_path) if File.exist?(tempdir_path)
  end
end

#update_derivative(derivative) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/ddr/managers/derivatives_manager.rb', line 30

def update_derivative(derivative)
  raise ArgumentError, "This object does not have a datastream for #{derivative.name} derivatives" unless
                            object.datastreams.include?(derivative.datastream)
  if generatable? derivative
    generate_derivative derivative
  else
    # Delete existing derivative (if there is one) if that type of derivative is no longer
    # applicable to the object
    if object.datastreams[derivative.datastream].has_content?
      delete_derivative derivative
    end
  end
end

#update_derivatives(schedule = SCHEDULE_LATER) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/ddr/managers/derivatives_manager.rb', line 14

def update_derivatives(schedule=SCHEDULE_LATER)
  raise ArgumentError, "Must be one of #{SCHEDULES}" unless SCHEDULES.include?(schedule)
  Ddr::Derivatives::DERIVATIVES.values.each do |derivative|
    if Ddr::Derivatives.update_derivatives.include?(derivative.name)
      # Need to update derivative if object has a datastream for this type of derivative and
      # either (or both) of the following conditions are true:
      # - object already has content in the derivative's datastream (need to delete or replace it)
      # - the derivative can be generated for this object
      if object.datastreams.include?(derivative.datastream) &&
            (object.datastreams[derivative.datastream].has_content? || generatable?(derivative))
        schedule == SCHEDULE_NOW ? update_derivative(derivative) : Resque.enqueue(DerivativeJob, object.pid, derivative.name)
      end
    end
  end
end