Class: Protocol::HTTP2::Connection

Inherits:
Object
  • Object
show all
Includes:
FlowControl
Defined in:
lib/protocol/http2/connection.rb

Direct Known Subclasses

Client, Server

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from FlowControl

#available_frame_size, #consume_local_window, #consume_remote_window, #send_window_update

Constructor Details

#initialize(framer, local_stream_id) ⇒ Connection 



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# File 'lib/protocol/http2/connection.rb', line 31

def initialize(framer, local_stream_id)
  @state = :new
  @streams = {}
  
  @framer = framer
  @local_stream_id = local_stream_id
  @remote_stream_id = 0
  
  @local_settings = PendingSettings.new
  @remote_settings = Settings.new
  
  @decoder = HPACK::Context.new
  @encoder = HPACK::Context.new
  
  @local_window = Window.new(@local_settings.initial_window_size)
  @remote_window = Window.new(@remote_settings.initial_window_size)
end

Instance Attribute Details

#framer ⇒ Object (readonly)

Returns the value of attribute framer.



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# File 'lib/protocol/http2/connection.rb', line 62

def framer
  @framer
end

#local_settings ⇒ Object

Current settings value for local and peer



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# File 'lib/protocol/http2/connection.rb', line 68

def local_settings
  @local_settings
end

#local_window ⇒ Object (readonly)

Our window for receiving data. When we receive data, it reduces this window. If the window gets too small, we must send a window update.



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# File 'lib/protocol/http2/connection.rb', line 73

def local_window
  @local_window
end

#remote_settings ⇒ Object

Returns the value of attribute remote_settings.



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# File 'lib/protocol/http2/connection.rb', line 69

def remote_settings
  @remote_settings
end

#remote_window ⇒ Object (readonly)

Our window for sending data. When we send data, it reduces this window.



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

def remote_window
  @remote_window
end

#state ⇒ Object

Connection state (:new, :open, :closed).



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# File 'lib/protocol/http2/connection.rb', line 65

def state
  @state
end

#streams ⇒ Object (readonly)

Returns the value of attribute streams.



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# File 'lib/protocol/http2/connection.rb', line 113

def streams
  @streams
end

Instance Method Details

#accept_push_promise_stream(stream_id, &block) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 293

def accept_push_promise_stream(stream_id, &block)
  accept_stream(stream_id, &block)
end

#accept_stream(stream_id, &block) ⇒ Object

Accept an incoming stream from the other side of the connnection. On the server side, we accept requests.



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# File 'lib/protocol/http2/connection.rb', line 279

def accept_stream(stream_id, &block)
  unless valid_remote_stream_id?(stream_id)
    raise ProtocolError, "Invalid remote stream id: #{stream_id}"
  end
  
  if stream_id <= @remote_stream_id
    raise ProtocolError, "Invalid stream id: #{stream_id} <= #{@remote_stream_id}!"
  end
  
  @remote_stream_id = stream_id
  
  create_stream(stream_id, &block)
end

#close ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 90

def close
  @framer.close
end

#closed? ⇒ Boolean 



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

def closed?
  @state == :closed
end

#connection_error!(error, message) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 82

def connection_error!(error, message)
  return if @framer.closed?
  
  send_goaway(error, message)
  
  self.close
end

#create_push_promise_stream(&block) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 314

def create_push_promise_stream(&block)
  create_stream(&block)
end

#create_stream(stream_id = next_stream_id, &block) ⇒ Stream

Create a stream, defaults to an outgoing stream. On the client side, we create requests.



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# File 'lib/protocol/http2/connection.rb', line 300

def create_stream(stream_id = next_stream_id, &block)
  if block_given?
    yield(stream_id)
  else
    return Stream.new(self, stream_id)
  end
  
  if stream = @streams[stream_id]
    return stream
  else
    raise ProtocolError, "Stream creation failed!"
  end
end

#decode_headers(data) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 100

def decode_headers(data)
  HPACK::Decompressor.new(data, @decoder).decode
end

#encode_headers(headers, buffer = String.new.b) ⇒ Object 



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

def encode_headers(headers, buffer = String.new.b)
  HPACK::Compressor.new(buffer, @encoder).encode(headers)
  
  return buffer
end

#id ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 49

def id
  0
end

#maximum_concurrent_streams ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 58

def maximum_concurrent_streams
  [@local_settings.maximum_concurrent_streams, @remote_settings.maximum_concurrent_streams].min
end

#maximum_frame_size ⇒ Object

The size of a frame payload is limited by the maximum size that a receiver advertises in the SETTINGS_MAX_FRAME_SIZE setting.



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# File 'lib/protocol/http2/connection.rb', line 54

def maximum_frame_size
  @remote_settings.maximum_frame_size
end

#next_stream_id ⇒ Object

Streams are identified with an unsigned 31-bit integer. Streams initiated by a client MUST use odd-numbered stream identifiers; those initiated by the server MUST use even-numbered stream identifiers. A stream identifier of zero (0x0) is used for connection control messages; the stream identifier of zero cannot be used to establish a new stream.



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# File 'lib/protocol/http2/connection.rb', line 105

def next_stream_id
  id = @local_stream_id
  
  @local_stream_id += 2
  
  return id
end

#open! ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 230

def open!
  @state = :open
  
  return self
end

#process_settings(frame) ⇒ Boolean

In addition to changing the flow-control window for streams that are not yet active, a SETTINGS frame can alter the initial flow-control window size for streams with active flow-control windows (that is, streams in the “open” or “half-closed (remote)” state). When the value of SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST adjust the size of all stream flow-control windows that it maintains by the difference between the new value and the old value.



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# File 'lib/protocol/http2/connection.rb', line 207

def process_settings(frame)
  if frame.acknowledgement?
    # The remote end has confirmed the settings have been received:
    changes = @local_settings.acknowledge
    
    update_local_settings(changes)
    
    return true
  else
    # The remote end is updating the settings, we reply with acknowledgement:
    reply = frame.acknowledge
    
    write_frame(reply)
    
    changes = frame.unpack
    @remote_settings.update(changes)
    
    update_remote_settings(changes)
    
    return false
  end
end

#read_frame ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 115

def read_frame
  frame = @framer.read_frame(@local_settings.maximum_frame_size)
  # puts "#{self.class} #{@state} read_frame: class=#{frame.class} flags=#{frame.flags} length=#{frame.length}"
  # puts "Windows: local_window=#{@local_window.inspect}; remote_window=#{@remote_window.inspect}"
  
  yield frame if block_given?
  
  frame.apply(self)
  
  return frame
rescue GoawayError
  # This is not a connection error. We are done.
  self.close
  
  raise
rescue ProtocolError => error
  connection_error!(error.code || PROTOCOL_ERROR, error.message)
  
  raise
rescue HPACK::CompressionError => error
  connection_error!(COMPRESSION_ERROR, error.message)
  
  raise
rescue
  connection_error!(PROTOCOL_ERROR, $!.message)
  
  raise
end

#receive_continuation(frame) ⇒ Object

Raises:



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# File 'lib/protocol/http2/connection.rb', line 380

def receive_continuation(frame)
  raise ProtocolError, "Received unexpected continuation: #{frame.class}"
end

#receive_data(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 263

def receive_data(frame)
  consume_local_window(frame)
  
  if stream = @streams[frame.stream_id]
    stream.receive_data(frame)
  else
    raise ProtocolError, "Cannot receive data for idle stream #{frame.stream_id}"
  end
end

#receive_frame(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 384

def receive_frame(frame)
  # ignore.
end

#receive_goaway(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 162

def receive_goaway(frame)
  @state = :closed
  
  last_stream_id, error_code, message = frame.unpack
  
  if error_code != 0
    raise GoawayError.new(message, error_code)
  end
end

#receive_headers(frame) ⇒ Object

On the server side, starts a new request.



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# File 'lib/protocol/http2/connection.rb', line 319

def receive_headers(frame)
  if frame.stream_id == 0
    raise ProtocolError, "Cannot receive headers for stream 0!"
  end
  
  if stream = @streams[frame.stream_id]
    stream.receive_headers(frame)
  else
    if @streams.count < self.maximum_concurrent_streams
      stream = accept_stream(frame.stream_id)
      stream.receive_headers(frame)
    else
      raise ProtocolError, "Exceeded maximum concurrent streams"
    end
  end
end

#receive_ping(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 247

def receive_ping(frame)
  if @state != :closed
    if frame.stream_id != 0
      raise ProtocolError, "Ping received for non-zero stream!"
    end
    
    unless frame.acknowledgement?
      reply = frame.acknowledge
      
      write_frame(reply)
    end
  else
    raise ProtocolError, "Cannot receive ping in state #{@state}"
  end
end

#receive_priority(frame) ⇒ Object

On the client and server side, sets the priority for an incoming stream.



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# File 'lib/protocol/http2/connection.rb', line 337

def receive_priority(frame)
  if stream = @streams[frame.stream_id]
    stream.receive_priority(frame)
  else
    stream = accept_stream(frame.stream_id)
    stream.receive_priority(frame)
  end
end

#receive_push_promise(frame) ⇒ Object

Raises:



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# File 'lib/protocol/http2/connection.rb', line 346

def receive_push_promise(frame)
  raise ProtocolError, "Unable to receive push promise!"
end

#receive_reset_stream(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 350

def receive_reset_stream(frame)
  if stream = @streams[frame.stream_id]
    stream.receive_reset_stream(frame)
  else
    raise StreamClosed, "Cannot reset stream #{frame.stream_id}"
  end
end

#receive_settings(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 236

def receive_settings(frame)
  if @state == :new
    # We transition to :open when we receive acknowledgement of first settings frame:
    open! if process_settings(frame)
  elsif @state != :closed
    process_settings(frame)
  else
    raise ProtocolError, "Cannot receive settings in state #{@state}"
  end
end

#receive_window_update(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 358

def receive_window_update(frame)
  if frame.connection?
    super
  elsif stream = @streams[frame.stream_id]
    begin
      stream.receive_window_update(frame)
    rescue ProtocolError => error
      stream.send_reset_stream(error.code)
    end
  else
    # Receiving any frame other than HEADERS or PRIORITY on a stream in this state MUST be treated as a connection error of type PROTOCOL_ERROR.
    raise ProtocolError, "Cannot update window of idle stream #{frame.stream_id}"
  end
end

#send_goaway(error_code = 0, message = "") ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 153

def send_goaway(error_code = 0, message = "")
  frame = GoawayFrame.new
  frame.pack @remote_stream_id, error_code, message
  
  write_frame(frame)
  
  @state = :closed
end

#send_ping(data) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 177

def send_ping(data)
  if @state != :closed
    frame = PingFrame.new
    frame.pack data
    
    write_frame(frame)
  else
    raise ProtocolError, "Cannot send ping in state #{@state}"
  end
end

#send_settings(changes) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 144

def send_settings(changes)
  @local_settings.append(changes)
  
  frame = SettingsFrame.new
  frame.pack(changes)
  
  write_frame(frame)
end

#update_local_settings(changes) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 188

def update_local_settings(changes)
  capacity = @local_settings.initial_window_size
  
  @streams.each_value do |stream|
    stream.local_window.capacity = capacity
  end
end

#update_remote_settings(changes) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 196

def update_remote_settings(changes)
  capacity = @remote_settings.initial_window_size
  
  @streams.each_value do |stream|
    stream.remote_window.capacity = capacity
  end
end

#valid_remote_stream_id? ⇒ Boolean 



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# File 'lib/protocol/http2/connection.rb', line 273

def valid_remote_stream_id?
  false
end

#window_updated ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 373

def window_updated
  # This is very inefficient, but workable.
  @streams.each_value do |stream|
    stream.window_updated unless stream.closed?
  end
end

#write_frame(frame) ⇒ Object 



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

def write_frame(frame)
  # puts "#{self.class} #{@state} write_frame: class=#{frame.class} flags=#{frame.flags} length=#{frame.length}"
  @framer.write_frame(frame)
end