Class: CompositeReadIO

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

Overview

Concatenate together multiple IO objects into a single, composite IO object for purposes of reading as a single stream.

Examples:

crio = CompositeReadIO.new(StringIO.new('one'),
                           StringIO.new('two'),
                           StringIO.new('three'))
puts crio.read # => "onetwothree"

Instance Method Summary collapse

Constructor Details

#initialize(*ios) ⇒ CompositeReadIO

Create a new composite-read IO from the arguments, all of which should respond to #read in a manner consistent with IO.



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# File 'lib/composite_io.rb', line 18

def initialize(*ios)
  @ios = ios.flatten
  @index = 0
end

Instance Method Details

#read(length = nil, outbuf = nil) ⇒ Object

Read from IOs in order until ‘length` bytes have been received.



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# File 'lib/composite_io.rb', line 24

def read(length = nil, outbuf = nil)
  got_result = false
  outbuf = outbuf ? outbuf.replace("") : ""

  while io = current_io
    if result = io.read(length)
      got_result ||= !result.nil?
      result.force_encoding("BINARY") if result.respond_to?(:force_encoding)
      outbuf << result
      length -= result.length if length
      break if length == 0
    end
    advance_io
  end
  (!got_result && length) ? nil : outbuf
end

#rewind ⇒ Object 



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# File 'lib/composite_io.rb', line 41

def rewind
  @ios.each { |io| io.rewind }
  @index = 0
end