CosEventChannelAdmin_ProxyPullSupplier

MODULE

CosEventChannelAdmin_ProxyPullSupplier

MODULE SUMMARY

This module implements a ProxyPullSupplier interface which acts as a middleman between pull consumer and the event channel.

DESCRIPTION

The ProxyPullSupplier interface defines the second step for connecting pull consumers to the event channel. A proxy supplier is similar to a normal supplier, but includes an additional method for connecting a consumer to the proxy supplier.

There are a number of exceptions that can be returned from functions in this interface.

• AlreadyConnected is defined as -record('AlreadyConnected', {}).
• Disconnected is defined as -record('Disconnected', {}).

These exceptions are defined in the file event_service.hrl.

Any object that possesses an object reference that supports the ProxyPullSupplier interface can perform the following operations:

EXPORTS

connect_pull_consumer(Object, PullConsumer) -> Return

Types:
Object = #objref
PullConsumer = #objref of PullConsumer type
Return = void

This operation connects PullConsumer object to the ProxyPullSupplier object. A nil object reference can be passed to this operation. If so a channel cannot invoke the disconnect_pull_consumer operation on the consumer; the consumer may be disconnected from the channel without being informed. If the ProxyPullSupplier is already connected to a PullConsumer, then the AlreadyConnected exception is raised.

disconnect_pull_supplier(Object) -> Return

Types:
Object = #objref
Return = void

This operation disconnects proxy pull supplier from the event channel. It sends a notification about the loss of the connection to the pull consumer attached to it, unless nil object reference was passed at the connection time.

pull(Object) -> Return

Types:
Object = #objref
Return = any

This operation blocks until the event data is available or the Disconnected exception is raised. It returns the event data to the consumer.

try_pull(Object) -> Return

Types:
Object = #objref
Return = {any, bool()}

This operation does not block: if the event data is available, it returns the event data and sets the data availability flag to true; otherwise it returns a long with a value of 0 and sets the data availability to false. If the event communication has already been disconnected, the Disconnected exception is raised.

AUTHORS

Helen Airiyan - support@erlang.se