Class: HTTP2::FrameBuffer

Inherits:
Object
  • Object
show all
Includes:
BufferUtils
Defined in:
lib/http/2/flow_buffer.rb,
sig/frame_buffer.rbs

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from BufferUtils

#append_str, #read_str, #read_uint32, #shift_byte

Constructor Details

#initialize ⇒ FrameBuffer

Returns a new instance of FrameBuffer.



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# File 'lib/http/2/flow_buffer.rb', line 122

def initialize
  @buffer = []
  @bytesize = 0
end

Instance Attribute Details

#bytesize ⇒ Integer (readonly)

Returns the value of attribute bytesize.

Returns:

  • (Integer) 


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# File 'lib/http/2/flow_buffer.rb', line 120

def bytesize
  @bytesize
end

Instance Method Details

#<<(frame) ⇒ void

This method returns an undefined value.

Parameters:

  • frame (data_frame_props) 


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# File 'lib/http/2/flow_buffer.rb', line 127

def <<(frame)
  @buffer << frame
  @bytesize += frame[:payload].bytesize
end

#clear ⇒ void

This method returns an undefined value.



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# File 'lib/http/2/flow_buffer.rb', line 132

def clear
  @buffer.clear
  @bytesize = 0
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/http/2/flow_buffer.rb', line 137

def empty?
  @buffer.empty?
end

#retrieve(window_size) ⇒ data_frame_props?

Parameters:

  • (Integer)

Returns:

  • (data_frame_props, nil) 


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# File 'lib/http/2/flow_buffer.rb', line 141

def retrieve(window_size)
  frame = @buffer.first or return

  frame_size = frame[:payload].bytesize
  end_stream = frame[:flags].anybits?(END_STREAM)

  # Frames with zero length with the END_STREAM flag set (that
  # is, an empty DATA frame) MAY be sent if there is no available space
  # in either flow control window.
  return if window_size <= 0 && !(frame_size.zero? && end_stream)

  if frame_size > window_size
    chunk = frame.dup

    # Split frame so that it fits in the window
    # TODO: consider padding!

    chunk[:payload] = read_str(frame[:payload], window_size) # mutates frame[:payload]
    chunk[:length]  = window_size
    frame[:length] = frame_size - window_size

    # if no longer last frame in sequence...
    chunk[:flags] ^= END_STREAM if end_stream

    @bytesize -= window_size
    chunk
  else
    @bytesize -= frame_size
    @buffer.shift
  end
end