Class: HTTP2::Connection
- Inherits:
-
Object
- Object
- HTTP2::Connection
- Includes:
- Emitter, Error, FlowBuffer
- Defined in:
- lib/http/2/connection.rb
Overview
Connection encapsulates all of the connection, stream, flow-control, error management, and other processing logic required for a well-behaved HTTP 2.0 endpoint.
Note that this class should not be used directly. Instead, you want to use either Client or Server class to drive the HTTP 2.0 exchange.
rubocop:disable ClassLength
Instance Attribute Summary collapse
-
#active_stream_count ⇒ Object
readonly
Number of active streams between client and server (reserved streams are not counted towards the stream limit).
-
#local_settings ⇒ Object
readonly
Current settings value for local and peer.
-
#local_window ⇒ Object
(also: #window)
readonly
Size of current connection flow control window (by default, set to infinity, but is automatically updated on receipt of peer settings).
-
#pending_settings ⇒ Object
readonly
Pending settings value Sent but not ack’ed settings.
-
#remote_settings ⇒ Object
readonly
Returns the value of attribute remote_settings.
-
#remote_window ⇒ Object
readonly
Returns the value of attribute remote_window.
-
#state ⇒ Object
readonly
Connection state (:new, :closed).
Instance Method Summary collapse
- #<<(*args) ⇒ Object
- #closed? ⇒ Boolean
-
#goaway(error = :no_error, payload = nil) ⇒ Object
Sends a GOAWAY frame indicating that the peer should stop creating new streams for current connection.
-
#initialize(**settings) ⇒ Connection
constructor
Initializes new connection object.
-
#new_stream(**args) ⇒ Object
Allocates new stream for current connection.
-
#ping(payload, &blk) ⇒ Object
Sends PING frame to the peer.
-
#receive(data) ⇒ Object
Decodes incoming bytes into HTTP 2.0 frames and routes them to appropriate receivers: connection frames are handled directly, and stream frames are passed to appropriate stream objects.
-
#settings(payload) ⇒ Object
Sends a connection SETTINGS frame to the peer.
-
#window_update(increment) ⇒ Object
Sends a WINDOW_UPDATE frame to the peer.
Methods included from Emitter
Methods included from FlowBuffer
Constructor Details
#initialize(**settings) ⇒ Connection
Initializes new connection object.
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# File 'lib/http/2/connection.rb', line 75 def initialize(**settings) @local_settings = DEFAULT_CONNECTION_SETTINGS.merge(settings) @remote_settings = SPEC_DEFAULT_CONNECTION_SETTINGS.dup @compressor = Header::Compressor.new(**settings) @decompressor = Header::Decompressor.new(**settings) @active_stream_count = 0 @streams = {} @streams_recently_closed = {} @pending_settings = [] @framer = Framer.new @local_window_limit = @local_settings[:settings_initial_window_size] @local_window = @local_window_limit @remote_window_limit = @remote_settings[:settings_initial_window_size] @remote_window = @remote_window_limit @recv_buffer = Buffer.new @send_buffer = [] @continuation = [] @error = nil @h2c_upgrade = nil @closed_since = nil end |
Instance Attribute Details
#active_stream_count ⇒ Object (readonly)
Number of active streams between client and server (reserved streams are not counted towards the stream limit).
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# File 'lib/http/2/connection.rb', line 71 def active_stream_count @active_stream_count end |
#local_settings ⇒ Object (readonly)
Current settings value for local and peer
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# File 'lib/http/2/connection.rb', line 62 def local_settings @local_settings end |
#local_window ⇒ Object (readonly) Also known as: window
Size of current connection flow control window (by default, set to infinity, but is automatically updated on receipt of peer settings).
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# File 'lib/http/2/connection.rb', line 57 def local_window @local_window end |
#pending_settings ⇒ Object (readonly)
Pending settings value
Sent but not ack'ed settings
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# File 'lib/http/2/connection.rb', line 67 def pending_settings @pending_settings end |
#remote_settings ⇒ Object (readonly)
Returns the value of attribute remote_settings.
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# File 'lib/http/2/connection.rb', line 63 def remote_settings @remote_settings end |
#remote_window ⇒ Object (readonly)
Returns the value of attribute remote_window.
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# File 'lib/http/2/connection.rb', line 58 def remote_window @remote_window end |
#state ⇒ Object (readonly)
Connection state (:new, :closed).
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# File 'lib/http/2/connection.rb', line 53 def state @state end |
Instance Method Details
#<<(*args) ⇒ Object
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# File 'lib/http/2/connection.rb', line 367 def <<(*args) receive(*args) end |
#closed? ⇒ Boolean
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# File 'lib/http/2/connection.rb', line 103 def closed? @state == :closed end |
#goaway(error = :no_error, payload = nil) ⇒ Object
Sends a GOAWAY frame indicating that the peer should stop creating new streams for current connection.
Endpoints MAY append opaque data to the payload of any GOAWAY frame. Additional debug data is intended for diagnostic purposes only and carries no semantic value. Debug data MUST NOT be persistently stored, since it could contain sensitive information.
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# File 'lib/http/2/connection.rb', line 141 def goaway(error = :no_error, payload = nil) last_stream = if (max = @streams.max) max.first else 0 end send(type: :goaway, last_stream: last_stream, error: error, payload: payload) @state = :closed @closed_since = Time.now end |
#new_stream(**args) ⇒ Object
Allocates new stream for current connection.
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# File 'lib/http/2/connection.rb', line 112 def new_stream(**args) fail ConnectionClosed if @state == :closed fail StreamLimitExceeded if @active_stream_count >= @remote_settings[:settings_max_concurrent_streams] stream = activate_stream(id: @stream_id, **args) @stream_id += 2 stream end |
#ping(payload, &blk) ⇒ Object
Sends PING frame to the peer.
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# File 'lib/http/2/connection.rb', line 126 def ping(payload, &blk) send(type: :ping, stream: 0, payload: payload) once(:ack, &blk) if blk end |
#receive(data) ⇒ Object
Decodes incoming bytes into HTTP 2.0 frames and routes them to appropriate receivers: connection frames are handled directly, and stream frames are passed to appropriate stream objects.
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# File 'lib/http/2/connection.rb', line 179 def receive(data) @recv_buffer << data # Upon establishment of a TCP connection and determination that # HTTP/2.0 will be used by both peers, each endpoint MUST send a # connection header as a final confirmation and to establish the # initial settings for the HTTP/2.0 connection. # # Client connection header is 24 byte connection header followed by # SETTINGS frame. Server connection header is SETTINGS frame only. if @state == :waiting_magic if @recv_buffer.size < 24 if !CONNECTION_PREFACE_MAGIC.start_with? @recv_buffer fail HandshakeError else return # maybe next time end elsif @recv_buffer.read(24) == CONNECTION_PREFACE_MAGIC # MAGIC is OK. Send our settings @state = :waiting_connection_preface payload = @local_settings.reject { |k, v| v == SPEC_DEFAULT_CONNECTION_SETTINGS[k] } settings(payload) else fail HandshakeError end end while (frame = @framer.parse(@recv_buffer)) emit(:frame_received, frame) # Header blocks MUST be transmitted as a contiguous sequence of frames # with no interleaved frames of any other type, or from any other stream. unless @continuation.empty? unless frame[:type] == :continuation && frame[:stream] == @continuation.first[:stream] connection_error end @continuation << frame return unless frame[:flags].include? :end_headers payload = @continuation.map { |f| f[:payload] }.join frame = @continuation.shift @continuation.clear frame.delete(:length) frame[:payload] = Buffer.new(payload) frame[:flags] << :end_headers end # SETTINGS frames always apply to a connection, never a single stream. # The stream identifier for a settings frame MUST be zero. If an # endpoint receives a SETTINGS frame whose stream identifier field is # anything other than 0x0, the endpoint MUST respond with a connection # error (Section 5.4.1) of type PROTOCOL_ERROR. if connection_frame?(frame) connection_management(frame) else case frame[:type] when :headers # When server receives even-numbered stream identifier, # the endpoint MUST respond with a connection error of type PROTOCOL_ERROR. connection_error if frame[:stream].even? && self.is_a?(Server) # The last frame in a sequence of HEADERS/CONTINUATION # frames MUST have the END_HEADERS flag set. unless frame[:flags].include? :end_headers @continuation << frame return end # After sending a GOAWAY frame, the sender can discard frames # for new streams. However, any frames that alter connection # state cannot be completely ignored. For instance, HEADERS, # PUSH_PROMISE and CONTINUATION frames MUST be minimally # processed to ensure a consistent compression state decode_headers(frame) return if @state == :closed stream = @streams[frame[:stream]] if stream.nil? stream = activate_stream( id: frame[:stream], weight: frame[:weight] || DEFAULT_WEIGHT, dependency: frame[:dependency] || 0, exclusive: frame[:exclusive] || false, ) emit(:stream, stream) end stream << frame when :push_promise # The last frame in a sequence of PUSH_PROMISE/CONTINUATION # frames MUST have the END_HEADERS flag set unless frame[:flags].include? :end_headers @continuation << frame return end decode_headers(frame) return if @state == :closed # PUSH_PROMISE frames MUST be associated with an existing, peer- # initiated stream... A receiver MUST treat the receipt of a # PUSH_PROMISE on a stream that is neither "open" nor # "half-closed (local)" as a connection error (Section 5.4.1) of # type PROTOCOL_ERROR. Similarly, a receiver MUST treat the # receipt of a PUSH_PROMISE that promises an illegal stream # identifier (Section 5.1.1) (that is, an identifier for a stream # that is not currently in the "idle" state) as a connection error # (Section 5.4.1) of type PROTOCOL_ERROR, unless the receiver # recently sent a RST_STREAM frame to cancel the associated stream. parent = @streams[frame[:stream]] pid = frame[:promise_stream] # if PUSH parent is recently closed, RST_STREAM the push if @streams_recently_closed[frame[:stream]] send(type: :rst_stream, stream: pid, error: :refused_stream) return end connection_error(msg: 'missing parent ID') if parent.nil? unless parent.state == :open || parent.state == :half_closed_local # An endpoint might receive a PUSH_PROMISE frame after it sends # RST_STREAM. PUSH_PROMISE causes a stream to become "reserved". # The RST_STREAM does not cancel any promised stream. Therefore, if # promised streams are not desired, a RST_STREAM can be used to # close any of those streams. if parent.closed == :local_rst # We can either (a) 'resurrect' the parent, or (b) RST_STREAM # ... sticking with (b), might need to revisit later. send(type: :rst_stream, stream: pid, error: :refused_stream) else connection_error end end stream = activate_stream(id: pid, parent: parent) emit(:promise, stream) stream << frame else if (stream = @streams[frame[:stream]]) stream << frame if frame[:type] == :data update_local_window(frame) calculate_window_update(@local_window_limit) end else case frame[:type] # The PRIORITY frame can be sent for a stream in the "idle" or # "closed" state. This allows for the reprioritization of a # group of dependent streams by altering the priority of an # unused or closed parent stream. when :priority stream = activate_stream( id: frame[:stream], weight: frame[:weight] || DEFAULT_WEIGHT, dependency: frame[:dependency] || 0, exclusive: frame[:exclusive] || false, ) emit(:stream, stream) stream << frame # WINDOW_UPDATE can be sent by a peer that has sent a frame # bearing the END_STREAM flag. This means that a receiver could # receive a WINDOW_UPDATE frame on a "half-closed (remote)" or # "closed" stream. A receiver MUST NOT treat this as an error # (see Section 5.1). when :window_update process_window_update(frame) else # An endpoint that receives an unexpected stream identifier # MUST respond with a connection error of type PROTOCOL_ERROR. connection_error end end end end end rescue StandardError => e raise if e.is_a?(Error::Error) connection_error(e: e) end |
#settings(payload) ⇒ Object
Sends a connection SETTINGS frame to the peer. The values are reflected when the corresponding ACK is received.
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# File 'lib/http/2/connection.rb', line 166 def settings(payload) payload = payload.to_a connection_error if validate_settings(@local_role, payload) @pending_settings << payload send(type: :settings, stream: 0, payload: payload) @pending_settings << payload end |
#window_update(increment) ⇒ Object
Sends a WINDOW_UPDATE frame to the peer.
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# File 'lib/http/2/connection.rb', line 157 def window_update(increment) @local_window += increment send(type: :window_update, stream: 0, increment: increment) end |