Class: Amp::DelayedOpener

Inherits:
Object show all
Defined in:
lib/amp/revlogs/changelog.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(realopener, owner) ⇒ DelayedOpener

Initializes the delayed opener, needing the real deal, and the owner of the delayed opener.

Parameters:

  • realopener (Opener) —

    the actual opener. Since the DelayedOpener doesn’t know how to open files, we’ll need this!

  • owner (ChangeLog) —

    the owner of the delayed opener. This reference is needed because we need to check on the state of the delayed_buffer and what not.



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# File 'lib/amp/revlogs/changelog.rb', line 116

def initialize(realopener, owner)
  @real_opener, @owner = realopener, owner
end

Instance Attribute Details

#default ⇒ Object

Returns the value of attribute default.



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# File 'lib/amp/revlogs/changelog.rb', line 105

def default
  @default
end

Instance Method Details

#open(name, mode = "r") ⇒ Object

Specialized opener that will fake writing when asked to. We need to know who our owner is and we need a real opener so we can actually open files. The DelayedOpener doesn’t know how to do real IO.



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# File 'lib/amp/revlogs/changelog.rb', line 124

def open(name, mode="r")
  fp = @real_opener.open(name, mode)
  return fp if name != @owner.index_file
  
  # Are we holding off on writing? if so, set up the file where we
  # writing pending data.
  
  if @owner.delay_count == 0
    @owner.delay_name = File.amp_name(fp)
    mode.gsub!(/a/, 'w') if @owner.empty?
    return @real_opener.open(name+".a", mode) # See what I did there?
  end
  
  # FakeFileAppender = fake file so we don't do any real writing yet
  size = File.stat(@real_opener.join(name)).size
  ffa = FakeFileAppender.new(fp, @owner.delay_buffer, size)
  
  return ffa
end