Class: Krypt::IOFilter

Inherits:
Object
  • Object
show all
Defined in:
lib/krypt/codec.rb

Overview

Abstract class that represents filters that can be combined with ordinary IO instances, filtering the output before reading/writing to the underlying IO. IOFilter instances can be stacked on top of each other, forming a “filter chain” that “peels of” multiple layers of encoding for example.

IOFilter supports a basic IO interface that responds to IO#read, IO#write and IO#close.

When reading from the IOFilter, the data will first be read from the IO, processed according to the rules of the filter and only then passed on.

When writing to the IOFilter, the data will first be processed by applying the filter and only then written to the IO instance.

Closing the IOFilter with IOFilter#close guarantees (among possibly additional things) a call to IO#close on the underlying IO.

Instance Method Summary collapse

Constructor Details

#initialize(io) ⇒ IOFilter

call-seq: 

IOFilter.new(io) [{ |filter| block }] -> IOFilter

Constructs a new IOFilter with io as its underlying IO. Takes an optional block which is yielded the IOFilter filter. After execution of the block, it is guaranteed that IOFilter#close gets called on the IOFilter.



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# File 'lib/krypt/codec.rb', line 30

def initialize(io)
  @io = io
  if block_given?
    begin
      yield self
    ensure
      close
    end
  end
end

Instance Method Details

#close ⇒ Object

call-seq:

io.close -> nil

Calls, among possibly additional cleanup, IO#close on the underlying IO.



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# File 'lib/krypt/codec.rb', line 47

def close
  @io.close
end