Class: Protocol::HTTP2::Stream
- Inherits:
-
Object
- Object
- Protocol::HTTP2::Stream
show all
- Includes:
- FlowControlled
- Defined in:
- lib/protocol/http2/stream.rb
Overview
A single HTTP 2.0 connection can multiplex multiple streams in parallel: multiple requests and responses can be in flight simultaneously and stream data can be interleaved and prioritized.
This class encapsulates all of the state, transition, flow-control, and error management as defined by the HTTP 2.0 specification. All you have to do is subscribe to appropriate events (marked with “:” prefix in diagram below) and provide your application logic to handle request and response processing.
+--------+
send PP | | recv PP
,--------| idle |--------.
/ | | \
v +--------+ v
+----------+ | +----------+
| | | send H / | |
,——| reserved | | recv H | reserved |——. | | (local) | | | (remote) | | | ----------
v ----------
| | | --------
| | | | recv ES | | send ES | | | send H | ,——-| open |——-. | recv H | | | / | | \ | | | v v --------
v v | | ----------
| ----------
| | | half | | | half | | | | closed | | send R / | closed | | | | (remote) | | recv R | (local) | | | ----------
| ----------
| | | | | | | | send ES / | recv ES / | | | | send R / v send R / | | | | recv R --------
recv R | | | send R / ‘———–>| |<———–’ send R / | | recv R | closed | recv R | ‘———————–>| |<———————-’
+--------+
send: endpoint sends this frame
recv: endpoint receives this frame
H: HEADERS frame (with implied CONTINUATIONs)
PP: PUSH_PROMISE frame (with implied CONTINUATIONs)
ES: END_STREAM flag
R: RST_STREAM frame
State transition methods use a trailing “!”.
Instance Attribute Summary collapse
Class Method Summary
collapse
Instance Method Summary
collapse
#available_frame_size, #available_size, #consume_local_window, #receive_window_update, #request_window_update, #send_window_update, #update_local_window, #window_updated
Constructor Details
#initialize(connection, id, state = :idle) ⇒ Stream
Returns a new instance of Stream.
85
86
87
88
89
90
91
92
93
94
95
|
# File 'lib/protocol/http2/stream.rb', line 85
def initialize(connection, id, state = :idle)
@connection = connection
@id = id
@state = state
@local_window = Window.new(@connection.local_settings.initial_window_size)
@remote_window = Window.new(@connection.remote_settings.initial_window_size)
@dependency = Dependency.create(@connection, @id)
end
|
Instance Attribute Details
#connection ⇒ Object
The connection this stream belongs to.
98
99
100
|
# File 'lib/protocol/http2/stream.rb', line 98
def connection
@connection
end
|
#dependency ⇒ Object
Returns the value of attribute dependency.
106
107
108
|
# File 'lib/protocol/http2/stream.rb', line 106
def dependency
@dependency
end
|
#id ⇒ Object
Stream ID (odd for client initiated streams, even otherwise).
101
102
103
|
# File 'lib/protocol/http2/stream.rb', line 101
def id
@id
end
|
#local_window ⇒ Object
Returns the value of attribute local_window.
108
109
110
|
# File 'lib/protocol/http2/stream.rb', line 108
def local_window
@local_window
end
|
#remote_window ⇒ Object
Returns the value of attribute remote_window.
109
110
111
|
# File 'lib/protocol/http2/stream.rb', line 109
def remote_window
@remote_window
end
|
#state ⇒ Object
Stream state, e.g. ‘idle`, `closed`.
104
105
106
|
# File 'lib/protocol/http2/stream.rb', line 104
def state
@state
end
|
Class Method Details
.create(connection, id) ⇒ Object
77
78
79
80
81
82
83
|
# File 'lib/protocol/http2/stream.rb', line 77
def self.create(connection, id)
stream = self.new(connection, id)
connection.streams[id] = stream
return stream
end
|
Instance Method Details
#accept_push_promise_stream(stream_id, headers) ⇒ Object
Override this function to implement your own push promise logic.
433
434
435
|
# File 'lib/protocol/http2/stream.rb', line 433
def accept_push_promise_stream(stream_id, )
@connection.accept_push_promise_stream(stream_id)
end
|
#active? ⇒ Boolean
135
136
137
|
# File 'lib/protocol/http2/stream.rb', line 135
def active?
@state != :closed && @state != :idle
end
|
#close(error = nil) ⇒ Object
Transition directly to closed state. Do not pass go, do not collect $200. This method should only be used by ‘Connection#close`.
145
146
147
148
149
150
|
# File 'lib/protocol/http2/stream.rb', line 145
def close(error = nil)
unless closed?
@state = :closed
self.closed(error)
end
end
|
#close!(error_code = nil) ⇒ Object
Transition the stream into the closed state.
258
259
260
261
262
263
264
265
266
267
268
269
|
# File 'lib/protocol/http2/stream.rb', line 258
def close!(error_code = nil)
@state = :closed
@connection.delete(@id)
if error_code
error = StreamError.new("Stream closed!", error_code)
end
self.closed(error)
return self
end
|
#closed(error = nil) ⇒ Object
The stream has been closed. If closed due to a stream reset, the error will be set.
253
254
|
# File 'lib/protocol/http2/stream.rb', line 253
def closed(error = nil)
end
|
#closed? ⇒ Boolean
139
140
141
|
# File 'lib/protocol/http2/stream.rb', line 139
def closed?
@state == :closed
end
|
#consume_remote_window(frame) ⇒ Object
201
202
203
204
205
|
# File 'lib/protocol/http2/stream.rb', line 201
def consume_remote_window(frame)
super
@connection.consume_remote_window(frame)
end
|
#create_push_promise_stream(headers) ⇒ Object
Override this function to implement your own push promise logic.
413
414
415
|
# File 'lib/protocol/http2/stream.rb', line 413
def create_push_promise_stream()
@connection.create_push_promise_stream
end
|
#ignore_data(frame) ⇒ Object
336
337
338
|
# File 'lib/protocol/http2/stream.rb', line 336
def ignore_data(frame)
end
|
#inspect ⇒ Object
448
449
450
|
# File 'lib/protocol/http2/stream.rb', line 448
def inspect
"\#<#{self.class} id=#{@id} state=#{@state}>"
end
|
#maximum_frame_size ⇒ Object
127
128
129
|
# File 'lib/protocol/http2/stream.rb', line 127
def maximum_frame_size
@connection.available_frame_size
end
|
#open! ⇒ Object
240
241
242
243
244
245
246
247
248
249
250
|
# File 'lib/protocol/http2/stream.rb', line 240
def open!
if @state == :idle
@state = :open
else
raise ProtocolError, "Cannot open stream in state: #{@state}"
end
self.opened
return self
end
|
#opened(error = nil) ⇒ Object
The stream has been opened.
237
238
|
# File 'lib/protocol/http2/stream.rb', line 237
def opened(error = nil)
end
|
#parent=(stream) ⇒ Object
123
124
125
|
# File 'lib/protocol/http2/stream.rb', line 123
def parent=(stream)
@dependency.parent = stream.dependency
end
|
#priority ⇒ Object
115
116
117
|
# File 'lib/protocol/http2/stream.rb', line 115
def priority
@dependency.priority
end
|
#priority=(priority) ⇒ Object
119
120
121
|
# File 'lib/protocol/http2/stream.rb', line 119
def priority= priority
@dependency.priority = priority
end
|
#process_data(frame) ⇒ String
Returns the data that was received.
332
333
334
|
# File 'lib/protocol/http2/stream.rb', line 332
def process_data(frame)
frame.unpack
end
|
284
285
286
287
288
289
290
291
292
293
|
# File 'lib/protocol/http2/stream.rb', line 284
def (frame)
priority, data = frame.unpack
if priority
@dependency.process_priority(priority)
end
@connection.(data)
end
|
#receive_data(frame) ⇒ Object
DATA frames are subject to flow control and can only be sent when a stream is in the “open” or “half-closed (remote)” state. The entire DATA frame payload is included in flow control, including the Pad Length and Padding fields if present. If a DATA frame is received whose stream is not in “open” or “half-closed (local)” state, the recipient MUST respond with a stream error of type STREAM_CLOSED.
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
|
# File 'lib/protocol/http2/stream.rb', line 341
def receive_data(frame)
if @state == :open
update_local_window(frame)
if frame.end_stream?
@state = :half_closed_remote
end
process_data(frame)
elsif @state == :half_closed_local
update_local_window(frame)
process_data(frame)
if frame.end_stream?
close!
end
elsif self.closed?
ignore_data(frame)
else
self.send_reset_stream(Error::STREAM_CLOSED)
end
end
|
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
|
# File 'lib/protocol/http2/stream.rb', line 299
def (frame)
if @state == :idle
if frame.end_stream?
@state = :half_closed_remote
else
open!
end
(frame)
elsif @state == :reserved_remote
(frame)
@state = :half_closed_local
elsif @state == :open
(frame)
if frame.end_stream?
@state = :half_closed_remote
end
elsif @state == :half_closed_local
(frame)
if frame.end_stream?
close!
end
elsif self.closed?
(frame)
else
self.send_reset_stream(Error::STREAM_CLOSED)
end
end
|
#receive_push_promise(frame) ⇒ Object
437
438
439
440
441
442
443
444
445
446
|
# File 'lib/protocol/http2/stream.rb', line 437
def receive_push_promise(frame)
promised_stream_id, data = frame.unpack
= @connection.(data)
stream = self.accept_push_promise_stream(promised_stream_id, )
stream.parent = self
stream.reserved_remote!
return stream,
end
|
#receive_reset_stream(frame) ⇒ Object
366
367
368
369
370
371
372
373
374
375
376
377
|
# File 'lib/protocol/http2/stream.rb', line 366
def receive_reset_stream(frame)
if @state == :idle
raise ProtocolError, "Cannot receive reset stream in state: #{@state}!"
else
error_code = frame.unpack
close!(error_code)
return error_code
end
end
|
#reserved_local! ⇒ Object
396
397
398
399
400
401
402
|
# File 'lib/protocol/http2/stream.rb', line 396
def reserved_local!
if @state == :idle
@state = :reserved_local
else
raise ProtocolError, "Cannot reserve stream in state: #{@state}"
end
end
|
#reserved_remote! ⇒ Object
404
405
406
407
408
409
410
|
# File 'lib/protocol/http2/stream.rb', line 404
def reserved_remote!
if @state == :idle
@state = :reserved_remote
else
raise ProtocolError, "Cannot reserve stream in state: #{@state}"
end
end
|
#send_data(*arguments, **options) ⇒ Object
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
# File 'lib/protocol/http2/stream.rb', line 218
def send_data(*arguments, **options)
if @state == :open
frame = write_data(*arguments, **options)
if frame.end_stream?
@state = :half_closed_local
end
elsif @state == :half_closed_remote
frame = write_data(*arguments, **options)
if frame.end_stream?
close!
end
else
raise ProtocolError, "Cannot send data in state: #{@state}"
end
end
|
The HEADERS frame is used to open a stream, and additionally carries a header block fragment. HEADERS frames can be sent on a stream in the “idle”, “reserved (local)”, “open”, or “half-closed (remote)” state.
171
172
173
174
175
176
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/stream.rb', line 171
def (*arguments)
if @state == :idle
frame = (*arguments)
if frame.end_stream?
@state = :half_closed_local
else
open!
end
elsif @state == :reserved_local
frame = (*arguments)
@state = :half_closed_remote
elsif @state == :open
frame = (*arguments)
if frame.end_stream?
@state = :half_closed_local
end
elsif @state == :half_closed_remote
frame = (*arguments)
if frame.end_stream?
close!
end
else
raise ProtocolError, "Cannot send headers in state: #{@state}"
end
end
|
152
153
154
|
# File 'lib/protocol/http2/stream.rb', line 152
def
@state == :idle or @state == :reserved_local or @state == :open or @state == :half_closed_remote
end
|
#send_push_promise(headers) ⇒ Object
Server push is semantically equivalent to a server responding to a request; however, in this case, that request is also sent by the server, as a PUSH_PROMISE frame.
419
420
421
422
423
424
425
426
427
428
429
430
|
# File 'lib/protocol/http2/stream.rb', line 419
def send_push_promise()
if @state == :open or @state == :half_closed_remote
promised_stream = self.create_push_promise_stream()
promised_stream.reserved_local!
write_push_promise(promised_stream.id, )
return promised_stream
else
raise ProtocolError, "Cannot send push promise in state: #{@state}"
end
end
|
#send_reset_stream(error_code = 0) ⇒ Object
271
272
273
274
275
276
277
278
279
280
281
282
|
# File 'lib/protocol/http2/stream.rb', line 271
def send_reset_stream(error_code = 0)
if @state != :idle and @state != :closed
frame = ResetStreamFrame.new(@id)
frame.pack(error_code)
write_frame(frame)
close!
else
raise ProtocolError, "Cannot send reset stream (#{error_code}) in state: #{@state}"
end
end
|
#to_s ⇒ Object
452
453
454
|
# File 'lib/protocol/http2/stream.rb', line 452
def to_s
inspect
end
|
#weight ⇒ Object
111
112
113
|
# File 'lib/protocol/http2/stream.rb', line 111
def weight
@dependency.weight
end
|
#write_frame(frame) ⇒ Object
131
132
133
|
# File 'lib/protocol/http2/stream.rb', line 131
def write_frame(frame)
@connection.write_frame(frame)
end
|