Module Netamqp_connection

module Netamqp_connection: sig .. end

Manage AMQP connections

A connection on the AMQP level is a managed version of the transport stream (i.e. the TCP connection). There is a handshake at connection establishment time where protocol details are negotiated and the client is authenticated.

There is another handshake at connection close time where one peer initiates the closure and the other peer has to approve. Either peer can initiate closure. It is possible to transmit error codes at connection close time.

The transport stream is automatically closed when the close handshake has finished.

In this implementation, connection management is separated from endpoint management. The latter is done in Netamqp_endpoint, and describes the AMQP client on a lower level.

exception Not_open

Raised if the connection is not known to be open on the client side

exception Error of string

An error occurred in connection management

type connection

The connection management object

type auth_method

An authentication method, including client identity and credentials

type locale_preference = [ `Pref of string | `Select of string list -> string ]

One can select the locale for error messages coming from the server:

`Pref p: Prefer the locale p if possible, otherwise choose the first locale offered by the server
`Select f: Call the function f with all possibilities to select the locale.

Locales are identified as in Unix, e.g. "en_US".

val create : Netamqp_endpoint.endpoint -> connection

Create the connection management object for the endpoint. The endpoint should be in `Off state. The returned connection object is still closed, and may now be opened.

val open_e : connection ->
       auth_method list ->
       locale_preference -> string -> unit Uq_engines.engine

Opens a connection: The endpoint is instructed to connect on the transport level, to negotiate protocol parameters, and to authenticate the client.

The string argument is the virtual host of the AMQP server to connect to, e.g. "/".

val open_s : connection ->
       auth_method list ->
       locale_preference -> string -> unit

Same as synchronous function

val close_e : connection -> unit Uq_engines.engine

val close_s : connection -> unit

Request client side closure.

val is_open : connection -> bool

The connection is first open after the open handshake has been completed, i.e. when open_e or open_s are done.

Note that the peer can close channels at any time, so there is no guarantee that the channel is still open when is_open returns true.

Checking is_open is mainly useful for recovery after exceptions. Some exceptions close the channel, some do not.

val plain_auth : string -> string -> auth_method

plain_auth username password: use PLAIN authentication.

Note that username and password are not encrypted on the wire!

val endpoint : connection -> Netamqp_endpoint.endpoint

Return the endpoint the connection uses

val event_system : connection -> Unixqueue.event_system

Return the event system the connection uses

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