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

Returns a new instance of Connection.



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

def initialize(framer, local_stream_id)
	@state = :new
	@streams = {}
	@closed = 0
	
	@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 63

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 69

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 74

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 70

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 77

def remote_window
  @remote_window
end

#state ⇒ Object

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



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# File 'lib/protocol/http2/connection.rb', line 66

def state
  @state
end

#streams ⇒ Object (readonly)

Returns the value of attribute streams.



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# File 'lib/protocol/http2/connection.rb', line 122

def streams
  @streams
end

Instance Method Details

#accept_push_promise_stream(stream_id, &block) ⇒ Object

Accept an incoming push promise from the other side of the connection. On the client side, we accept push promise streams. On the server side, existing streams create push promise streams.



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# File 'lib/protocol/http2/connection.rb', line 305

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 288

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

#active_stream_count ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 87

def active_stream_count
	@streams.size - @closed
end

#close ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 99

def close
	@framer.close
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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

def closed?
	@state == :closed
end

#connection_error!(error, message) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 91

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 326

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.

Returns:

  • (Stream) —

    the created stream.



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# File 'lib/protocol/http2/connection.rb', line 312

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 109

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 103

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 50

def id
	0
end

#maximum_concurrent_streams ⇒ Object 



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

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 55

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 114

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 239

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.

Returns:

  • (Boolean) —

    whether the frame was an acknowledgement



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# File 'lib/protocol/http2/connection.rb', line 216

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 124

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 392

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 272

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 396

def receive_frame(frame)
	# ignore.
end

#receive_goaway(frame) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 171

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 331

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 self.active_stream_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 256

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 349

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 358

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 362

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 245

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 370

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 162

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 186

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 153

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

#stream_closed(stream) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 83

def stream_closed(stream)
	@closed += 1
end

#update_local_settings(changes) ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 197

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 205

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

Returns:

  • (Boolean) 


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# File 'lib/protocol/http2/connection.rb', line 282

def valid_remote_stream_id?
	false
end

#window_updated ⇒ Object 



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# File 'lib/protocol/http2/connection.rb', line 385

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 181

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