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, #available_size, #consume_local_window, #consume_remote_window, #consume_window, #request_window_update, #send_window_update, #update_local_window, #window_updated

Constructor Details

#initialize(framer, local_stream_id) ⇒ Connection

Returns a new instance of Connection.



31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
 
# File 'lib/protocol/http2/connection.rb', line 31

def initialize(framer, local_stream_id)
	super()
	
	@state = :new
	@streams = {}
	@children = {}
	
	@active = 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

#children ⇒ Object (readonly)

Returns the value of attribute children.



142
143
144
 
# File 'lib/protocol/http2/connection.rb', line 142

def children
  @children
end

#framer ⇒ Object (readonly)

Returns the value of attribute framer.



79
80
81
 
# File 'lib/protocol/http2/connection.rb', line 79

def framer
  @framer
end

#local_settings ⇒ Object

Current settings value for local and peer



85
86
87
 
# File 'lib/protocol/http2/connection.rb', line 85

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.



90
91
92
 
# File 'lib/protocol/http2/connection.rb', line 90

def local_window
  @local_window
end

#remote_settings ⇒ Object

Returns the value of attribute remote_settings.



86
87
88
 
# File 'lib/protocol/http2/connection.rb', line 86

def remote_settings
  @remote_settings
end

#remote_stream_id ⇒ Object (readonly)

The highest stream_id that has been successfully accepted by this connection.



96
97
98
 
# File 'lib/protocol/http2/connection.rb', line 96

def remote_stream_id
  @remote_stream_id
end

#remote_window ⇒ Object (readonly)

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



93
94
95
 
# File 'lib/protocol/http2/connection.rb', line 93

def remote_window
  @remote_window
end

#state ⇒ Object

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



82
83
84
 
# File 'lib/protocol/http2/connection.rb', line 82

def state
  @state
end

#streams ⇒ Object (readonly)

Returns the value of attribute streams.



141
142
143
 
# File 'lib/protocol/http2/connection.rb', line 141

def streams
  @streams
end

Instance Method Details

#[](id) ⇒ Object 



62
63
64
65
66
67
68
 
# File 'lib/protocol/http2/connection.rb', line 62

def [] id
	if id.zero?
		self
	else
		@streams[id]
	end
end

#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.



367
368
369
 
# File 'lib/protocol/http2/connection.rb', line 367

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.



356
357
358
359
360
361
362
 
# File 'lib/protocol/http2/connection.rb', line 356

def accept_stream(stream_id, &block)
	unless valid_remote_stream_id?(stream_id)
		raise ProtocolError, "Invalid stream id: #{stream_id}"
	end
	
	create_stream(stream_id, &block)
end

#activate(stream) ⇒ Object

The stream has become active (i.e. not idle or closed).



103
104
105
 
# File 'lib/protocol/http2/connection.rb', line 103

def activate(stream)
	@active += 1
end

#active_streams ⇒ Object

The number of active streams.



113
114
115
 
# File 'lib/protocol/http2/connection.rb', line 113

def active_streams
	@active
end

#add_child(stream) ⇒ Object 



144
145
146
 
# File 'lib/protocol/http2/connection.rb', line 144

def add_child(stream)
	@children[stream.id] = stream
end

#close(error = nil) ⇒ Object

Close the underlying framer and all streams.



118
119
120
121
122
 
# File 'lib/protocol/http2/connection.rb', line 118

def close(error = nil)
	@framer.close
	
	@streams.each_value{|stream| stream.close(error)}
end

#close! ⇒ Object

Transition the connection into the closed state.



218
219
220
221
222
 
# File 'lib/protocol/http2/connection.rb', line 218

def close!
	@state = :closed
	
	return self
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


98
99
100
 
# File 'lib/protocol/http2/connection.rb', line 98

def closed?
	@state == :closed
end

#create_push_promise_stream(&block) ⇒ Object 



382
383
384
 
# File 'lib/protocol/http2/connection.rb', line 382

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

#create_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.



374
375
376
377
378
379
380
 
# File 'lib/protocol/http2/connection.rb', line 374

def create_stream(id = next_stream_id, &block)
	if block_given?
		return yield(self, id)
	else
		return Stream.create(self, id)
	end
end

#deactivate(stream) ⇒ Object

The stream is no longer active (i.e. has become closed).



108
109
110
 
# File 'lib/protocol/http2/connection.rb', line 108

def deactivate(stream)
	@active -= 1
end

#decode_headers(data) ⇒ Object 



128
129
130
 
# File 'lib/protocol/http2/connection.rb', line 128

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

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



124
125
126
 
# File 'lib/protocol/http2/connection.rb', line 124

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

#exclusive_child(stream) ⇒ Object 



152
153
154
155
156
157
158
159
160
161
162
 
# File 'lib/protocol/http2/connection.rb', line 152

def exclusive_child(stream)
	stream.children = @children
	
	@children.each_value do |child|
		child.dependent_id = stream.id
	end
	
	@children = {stream.id => stream}
	
	stream.dependent_id = 0
end

#id ⇒ Object 



54
55
56
 
# File 'lib/protocol/http2/connection.rb', line 54

def id
	0
end

#ignore_frame?(frame) ⇒ Boolean

6.8. GOAWAY There is an inherent race condition between an endpoint starting new streams and the remote sending a GOAWAY frame. To deal with this case, the GOAWAY contains the stream identifier of the last peer-initiated stream that was or might be processed on the sending endpoint in this connection. For instance, if the server sends a GOAWAY frame, the identified stream is the highest-numbered stream initiated by the client. Once sent, the sender will ignore frames sent on streams initiated by the receiver if the stream has an identifier higher than the included last stream identifier. Receivers of a GOAWAY frame MUST NOT open additional streams on the connection, although a new connection can be established for new streams.

Returns:

  • (Boolean) 


167
168
169
170
171
172
173
174
 
# File 'lib/protocol/http2/connection.rb', line 167

def ignore_frame?(frame)
	if self.closed?
		# puts "ignore_frame? #{frame.stream_id} -> #{valid_remote_stream_id?(frame.stream_id)} > #{@remote_stream_id}"
		if valid_remote_stream_id?(frame.stream_id)
			return frame.stream_id > @remote_stream_id
		end
	end
end

#maximum_concurrent_streams ⇒ Object 



75
76
77
 
# File 'lib/protocol/http2/connection.rb', line 75

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.



71
72
73
 
# File 'lib/protocol/http2/connection.rb', line 71

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.



133
134
135
136
137
138
139
 
# File 'lib/protocol/http2/connection.rb', line 133

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

#open! ⇒ Object 



296
297
298
299
300
 
# File 'lib/protocol/http2/connection.rb', line 296

def open!
	@state = :open
	
	return self
end

#parent ⇒ Object 



58
59
60
 
# File 'lib/protocol/http2/connection.rb', line 58

def parent
	nil
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



273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
 
# File 'lib/protocol/http2/connection.rb', line 273

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

Reads one frame from the network and processes. Processing the frame updates the state of the connection and related streams. If the frame triggers an error, e.g. a protocol error, the connection will typically emit a goaway frame and re-raise the exception. You should continue processing frames until the underlying connection is closed.



177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
 
# File 'lib/protocol/http2/connection.rb', line 177

def read_frame
	frame = @framer.read_frame(@local_settings.maximum_frame_size)
	# puts "#{self.class} #{@state} read_frame: class=#{frame.class} stream_id=#{frame.stream_id} flags=#{frame.flags} length=#{frame.length} (remote_stream_id=#{@remote_stream_id})"
	# puts "Windows: local_window=#{@local_window.inspect}; remote_window=#{@remote_window.inspect}"
	
	return if ignore_frame?(frame)
	
	yield frame if block_given?
	frame.apply(self)
	
	return frame
rescue GoawayError => error
	# Go directly to jail. Do not pass go, do not collect $200.
	raise
rescue ProtocolError => error
	send_goaway(error.code || PROTOCOL_ERROR, error.message)
	
	raise
rescue HPACK::Error => error
	send_goaway(COMPRESSION_ERROR, error.message)
	
	raise
end

#receive_continuation(frame) ⇒ Object

Raises:



459
460
461
 
# File 'lib/protocol/http2/connection.rb', line 459

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

#receive_data(frame) ⇒ Object 



340
341
342
343
344
345
346
347
348
 
# File 'lib/protocol/http2/connection.rb', line 340

def receive_data(frame)
	update_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 



463
464
465
 
# File 'lib/protocol/http2/connection.rb', line 463

def receive_frame(frame)
	# ignore.
end

#receive_goaway(frame) ⇒ Object 



234
235
236
237
238
239
240
241
242
243
244
 
# File 'lib/protocol/http2/connection.rb', line 234

def receive_goaway(frame)
	# We capture the last stream that was processed.
	@remote_stream_id, error_code, message = frame.unpack
	
	self.close!
	
	if error_code != 0
		# Shut down immediately.
		raise GoawayError.new(message, error_code)
	end
end

#receive_headers(frame) ⇒ Object

On the server side, starts a new request.



387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
 
# File 'lib/protocol/http2/connection.rb', line 387

def receive_headers(frame)
	stream_id = frame.stream_id
	
	if stream_id.zero?
		raise ProtocolError, "Cannot receive headers for stream 0!"
	end
	
	if stream = @streams[stream_id]
		stream.receive_headers(frame)
	else
		if stream_id <= @remote_stream_id
			raise ProtocolError, "Invalid stream id: #{stream_id} <= #{@remote_stream_id}!"
		end
		
		if self.active_streams.size < self.maximum_concurrent_streams
			stream = accept_stream(stream_id)
			@remote_stream_id = stream_id
			
			stream.receive_headers(frame)
		else
			raise ProtocolError, "Exceeded maximum concurrent streams"
		end
	end
end

#receive_ping(frame) ⇒ Object 



324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
 
# File 'lib/protocol/http2/connection.rb', line 324

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

Sets the priority for an incoming stream.



420
421
422
423
424
425
426
427
428
 
# File 'lib/protocol/http2/connection.rb', line 420

def receive_priority(frame)
	if stream = @streams[frame.stream_id]
		stream.receive_priority(frame)
	else
		# Stream doesn't exist yet.
		stream = accept_stream(frame.stream_id)
		stream.receive_priority(frame)
	end
end

#receive_push_promise(frame) ⇒ Object

Raises:



430
431
432
 
# File 'lib/protocol/http2/connection.rb', line 430

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

#receive_reset_stream(frame) ⇒ Object 



434
435
436
437
438
439
440
 
# File 'lib/protocol/http2/connection.rb', line 434

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 



302
303
304
305
306
307
308
309
310
311
 
# File 'lib/protocol/http2/connection.rb', line 302

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 



442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
 
# File 'lib/protocol/http2/connection.rb', line 442

def receive_window_update(frame)
	if frame.connection?
		super
		
		self.consume_window
	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

#remove_child(stream) ⇒ Object 



148
149
150
 
# File 'lib/protocol/http2/connection.rb', line 148

def remove_child(stream)
	@children.delete(stream.id)
end

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

Tell the remote end that the connection is being shut down. If the ‘error_code` is 0, this is a graceful shutdown. The other end of the connection should not make any new streams, but existing streams may be completed.



225
226
227
228
229
230
231
232
 
# File 'lib/protocol/http2/connection.rb', line 225

def send_goaway(error_code = 0, message = "")
	frame = GoawayFrame.new
	frame.pack @remote_stream_id, error_code, message
	
	write_frame(frame)
ensure
	self.close!
end

#send_ping(data) ⇒ Object 



313
314
315
316
317
318
319
320
321
322
 
# File 'lib/protocol/http2/connection.rb', line 313

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_priority(stream_id, priority) ⇒ Object 



412
413
414
415
416
417
 
# File 'lib/protocol/http2/connection.rb', line 412

def send_priority(stream_id, priority)
	frame = PriorityFrame.new(stream_id)
	frame.pack(priority)
	
	write_frame(frame)
end

#send_settings(changes) ⇒ Object 



201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
 
# File 'lib/protocol/http2/connection.rb', line 201

def send_settings(changes)
	@local_settings.append(changes)
	
	frame = SettingsFrame.new
	frame.pack(changes)
	
	write_frame(frame)
	
	# If the initial window size is set to something bigger than the default, we want to increase it.
	difference = @local_settings.pending.initial_window_size - @local_window.capacity
	
	if difference > 0
		send_window_update(difference)
	end
end

#update_local_settings(changes) ⇒ Object 



254
255
256
257
258
259
260
 
# File 'lib/protocol/http2/connection.rb', line 254

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 



262
263
264
265
266
267
268
 
# File 'lib/protocol/http2/connection.rb', line 262

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) 


350
351
352
 
# File 'lib/protocol/http2/connection.rb', line 350

def valid_remote_stream_id?
	false
end

#write_frame(frame) ⇒ Object 



246
247
248
 
# File 'lib/protocol/http2/connection.rb', line 246

def write_frame(frame)
	@framer.write_frame(frame)
end

#write_frames {|@framer| ... } ⇒ Object

Yields:



250
251
252
 
# File 'lib/protocol/http2/connection.rb', line 250

def write_frames
	yield @framer
end