Xirsys.Sockets.Engine (xturn_sockets v2.2.1)

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Drain loop: pop every whole packet from a tier, dispatch the handler, repeat.

Connection and DatagramServer call push_and_drain/9 after each read. drain/8 is used for timer ticks (reorder timeouts) without a new chunk.

Internal API. Used by Xirsys.Sockets.Connection, DatagramServer, and TierSession; not part of the public application surface for host apps.

What problem this solves

Socket reads can carry partial frames, multiple frames, or nested protocol layers. The engine pushes bytes into accumulators, drains every complete packet, runs handlers, sends replies, and follows {:descend, tier, ...} into other tiers (inline or async) until the accumulator needs more data.

RFCs

No STUN/TURN RFC; framing/dispatch infrastructure for XTurn listeners.

Summary

Types

drain_result()

Result of a drain pass: updated accumulators, handler states, async tier pids, and :ok or :close.

Functions

drain(pipeline, tier_key, conn, accs, states, tier_sessions, transport_mod, owner_pid)

Pops whole packets from tier_key until the accumulator returns {:more, _}.

push_and_drain(pipeline, chunk, meta, conn, accs, states, tier_sessions, transport_mod, owner_pid)

Pushes chunk into :root, then drains from :root.

Types

drain_result()

@type drain_result() :: {map(), map(), map(), :ok | :close}

Result of a drain pass: updated accumulators, handler states, async tier pids, and :ok or :close.

Functions

drain(pipeline, tier_key, conn, accs, states, tier_sessions, transport_mod, owner_pid)

@spec drain(
  Xirsys.Sockets.Pipeline.t(),
  atom(),
  Xirsys.Sockets.Conn.t(),
  map(),
  map(),
  map(),
  module(),
  pid()
) :: drain_result()

Pops whole packets from tier_key until the accumulator returns {:more, _}.

Handler {:reply, _, _} is sent on conn.socket. {:descend, next, payload, _} pushes payload into next. {:close, _} stops the connection after this pass. Framing errors emit :frame_error and continue.

Parameters

  • pipeline - compiled pipeline
  • tier_key - tier to drain (:root, ...)
  • conn - connection context used for replies
  • accs - map of tier name to accumulator state
  • states - map of tier name to handler state
  • tier_sessions - map of async tier name to session pid
  • transport_mod - Xirsys.Sockets.Transport implementation
  • owner_pid - connection or datagram-server process

push_and_drain(pipeline, chunk, meta, conn, accs, states, tier_sessions, transport_mod, owner_pid)

@spec push_and_drain(
  Xirsys.Sockets.Pipeline.t(),
  binary(),
  map(),
  Xirsys.Sockets.Conn.t(),
  map(),
  map(),
  map(),
  module(),
  pid()
) :: drain_result()

Pushes chunk into :root, then drains from :root.

Unthrottled: this path carries media as well as control traffic. Apply Config.check_rate_limit/1 in the handler for the message classes that need a budget.

Parameters

  • pipeline - compiled pipeline
  • chunk - inbound bytes from handle_message/2
  • meta - packet metadata (:from, :received_at, ...)
  • conn - connection context
  • accs / states / tier_sessions - session maps
  • transport_mod - transport used for {:reply, _, _}
  • owner_pid - owning process