Re: [amqp] Request to add filters to public registry

[Gordon Sim <gsim@redhat.com>]

On 04/11/2012 04:00 PM, Godfrey, Robert X wrote:
> I would like to propose add the following three filter types to the registries, along with an associated connection capability
>
>
> 	<type class="composite" name="amqp-direct-filter" source="string" provides="filter">
> 		<descriptor name="apache.org:amqp-direct-filter:string" code="0x0000468C:0x00000000"/>
> 	</type>
> 	<type class="restricted" name="amqp-topic-filter" source="string" provides="filter">
> 		<descriptor name="apache.org:amqp-topic-filter:string" code="0x0000468C:0x00000001"/>
> 	</type>
> 	<type class="restricted" name="amqp-headers-filter" source="map" provides="filter">
> 		<descriptor name="apache.org:amqp-headers-filter:map" code="0x0000468C:0x00000002"/>
> 	</type>
>
> The amqp-direct-filter string is used as an exact character match on the "subject" field of the properties section of a message.
> The amqp-topic-filter string is used as a pattern match against the "subject" field using the syntax defined in AMQP v0-8, v0-9, v0-9-1 and v0-10
> The amqp-headers-filter contains a map which matches against the application-properties map in the manner defined for arguments in binding to a headers exchange in AMQP v0-8, v0-9, v0-9-1 and v0-10
>
> I would propose a connection capability of
>
> APACHE.ORG:AMQP_EXCHANGE_BINDING_FILTERS
>
> to denote the support of these filter types.
>
> Obviously the intent here is to support legacy v0-x AMQP binding models behind an AMQP 1.0 front end where the consumer creates a receiving link from a node which represents an "exchange" in a legacy AMQP v0-x broker.

I agree with the intent. However I'm not so sure its a good idea (a) to 
use 'amqp' in 'vendor' extensions and (b) to use 'amqp' unqualified for 
legacy support for pre 1.0 concepts.

What about simply: subject-filter-exact, subject-filter-hierarchical and 
properties-match-filter? They would potentially be applicable even in 
implementations that were not based on the old pre-1.0 concepts.