WebSockAdapter v0.5.4

View Source WebSockAdapter (WebSockAdapter v0.5.4)

Defines adapters to allow common Web Servers to serve applications via the WebSock API. Also provides a consistent upgrade facility to upgrade Plug.Conn requests to WebSock connections for supported servers.

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Types

connection_opt()

The type of a supported connection option

Functions

upgrade(conn, websock, state, opts)

Upgrades the provided Plug.Conn connection request to a WebSock connection using the provided WebSock compliant module as a handler.

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connection_opt()

View Source 
@type connection_opt() ::
  {:compress, boolean()}
  | {:timeout, timeout()}
  | {:max_frame_size, non_neg_integer()}
  | {:fullsweep_after, non_neg_integer()}
  | {:validate_utf8, boolean()}
  | {:active_n, integer()}

The type of a supported connection option

Link to this section Functions

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upgrade(conn, websock, state, opts)

View Source 
@spec upgrade(Plug.Conn.t(), WebSock.impl(), WebSock.state(), [connection_opt()]) ::
  Plug.Conn.t()

Upgrades the provided Plug.Conn connection request to a WebSock connection using the provided WebSock compliant module as a handler.

This function returns the passed conn set to an :upgraded state.

The provided state value will be used as the argument for WebSock.init/1 once the WebSocket connection has been successfully negotiated.

The opts keyword list argument allows a number of options to be set on the WebSocket connection. Not all options may be supported by the underlying HTTP server. Possible values are as follows:

  • timeout: The number of milliseconds to wait after no client data is received before closing the connection. Defaults to 60_000
  • compress: Whether or not to accept negotiation of a compression extension with the client. Defaults to false
  • max_frame_size: The maximum frame size to accept, in octets. If a frame size larger than this is received the connection will be closed. Defaults to :infinity
  • fullsweep_after: The maximum number of garbage collections before forcing a fullsweep of the WebSocket connection process. Setting this option requires OTP 24 or newer
  • validate_utf8: Whether Cowboy should verify that the payload of text and close frames is valid UTF-8. This is required by the protocol specification but in some cases it may be more interesting to disable it in order to save resources. Note that binary frames do not have this UTF-8 requirement and are what should be used under normal circumstances if necessary.
  • active_n: The number of packets Cowboy will request from the socket at once. This can be used to tweak the performance of the server. Higher values reduce the number of times Cowboy need to request more packets from the port driver at the expense of potentially higher memory being used. This option does not apply to Websocket over HTTP/2.