Class: HTTP::Protocol::HTTP2::Frame

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/http/protocol/http2/frame.rb

Constant Summary collapse

VALID_STREAM_ID =

Stream Identifier cannot be bigger than this: http2.github.io/http2-spec/#rfc.section.4.1

0..0x7fffffff
VALID_LENGTH =

The absolute maximum bounds for the length field:

0..0xffffff
LENGTH_HISHIFT =

Used for generating 24-bit frame length:

16
LENGTH_LOMASK = 
0xFFFF
HEADER_FORMAT = 
'CnCCN'.freeze
STREAM_ID_MASK = 
0x7fffffff

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream_id = 0, flags = 0, type = self.class.const_get(:TYPE), length = nil, payload = nil) ⇒ Frame 



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# File 'lib/http/protocol/http2/frame.rb', line 47

def initialize(stream_id = 0, flags = 0, type = self.class.const_get(:TYPE), length = nil, payload = nil)
  @length = length
  @type = type
  @flags = flags
  @stream_id = stream_id
  @payload = payload
end

Instance Attribute Details

#flags ⇒ Object

Returns the value of attribute flags.



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# File 'lib/http/protocol/http2/frame.rb', line 77

def flags
  @flags
end

#length ⇒ Object

The generic frame header uses the following binary representation:

----------------------------------------------- | Length (24) | ---------------—————--------------- | Type (8) | Flags (8) | -————----------------——————————-+ |R| Stream Identifier (31) | ==============================================================+ | Frame Payload (0…) … ---------------------------------------------------------------



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# File 'lib/http/protocol/http2/frame.rb', line 75

def length
  @length
end

#payload ⇒ Object

Returns the value of attribute payload.



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# File 'lib/http/protocol/http2/frame.rb', line 79

def payload
  @payload
end

#stream_id ⇒ Object

Returns the value of attribute stream_id.



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# File 'lib/http/protocol/http2/frame.rb', line 78

def stream_id
  @stream_id
end

#type ⇒ Object

Returns the value of attribute type.



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# File 'lib/http/protocol/http2/frame.rb', line 76

def type
  @type
end

Class Method Details

.parse_header(buffer) ⇒ Object

Decodes common 9-byte header.



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# File 'lib/http/protocol/http2/frame.rb', line 143

def self.parse_header(buffer)
  length_hi, length_lo, type, flags, stream_id = buffer.unpack(HEADER_FORMAT)
  length = (length_hi << LENGTH_HISHIFT) | length_lo
  stream_id = stream_id & STREAM_ID_MASK
  
  return length, type, flags, stream_id
end

Instance Method Details

#<=>(other) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 55

def <=> other
  to_ary <=> other.to_ary
end

#apply(connection) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 181

def apply(connection)
  connection.receive_frame(self)
end

#clear_flags(mask) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 98

def clear_flags(mask)
  @flags &= ~mask
end

#connection? ⇒ Boolean

Check if frame is a connection frame: SETTINGS, PING, GOAWAY, and any frame addressed to stream ID = 0.



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# File 'lib/http/protocol/http2/frame.rb', line 110

def connection?
  @stream_id.zero?
end

#flag_set?(mask) ⇒ Boolean 



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# File 'lib/http/protocol/http2/frame.rb', line 102

def flag_set?(mask)
  @flags & mask != 0
end

#header ⇒ String

Generates common 9-byte frame header.



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# File 'lib/http/protocol/http2/frame.rb', line 121

def header
  unless VALID_LENGTH.include? @length
    raise ProtocolError, "Invalid frame size: #{@length.inspect}"
  end
  
  unless VALID_STREAM_ID.include? @stream_id
    raise ProtocolError, "Invalid stream identifier: #{@stream_id.inspect}"
  end
  
  [
    # These are guaranteed correct due to the length check above.
    @length >> LENGTH_HISHIFT,
    @length & LENGTH_LOMASK,
    @type,
    @flags,
    @stream_id
  ].pack(HEADER_FORMAT)
end

#pack(payload, maximum_size: nil) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 85

def pack(payload, maximum_size: nil)
  @payload = payload
  @length = payload.bytesize
  
  if maximum_size and @length > maximum_size
    raise ProtocolError, "Frame length #{@length} bigger than maximum allowed: #{maximum_size}"
  end
end

#read(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 159

def read(io)
  read_header(io) unless @length
  read_payload(io)
end

#read_header(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 151

def read_header(io)
  @length, @type, @flags, @stream_id = Frame.parse_header(io.read(9))
end

#read_payload(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 155

def read_payload(io)
  @payload = io.read(@length)
end

#set_flags(mask) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 94

def set_flags(mask)
  @flags |= mask
end

#to_ary ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 59

def to_ary
  [@length, @type, @flags, @stream_id, @payload]
end

#unpack ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 81

def unpack
  @payload
end

#write(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 172

def write(io)
  if @payload and @length != @payload.bytesize
    raise ProtocolError, "Invalid payload size: #{@length} != #{@payload.bytesize}"
  end
  
  self.write_header(io)
  self.write_payload(io)
end

#write_header(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 164

def write_header(io)
  io.write self.header
end

#write_payload(io) ⇒ Object 



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# File 'lib/http/protocol/http2/frame.rb', line 168

def write_payload(io)
  io.write(@payload) if @payload
end