Basically wrapping librabbitmq/rabbitmq-c with some code to make the following pair of daemons that should be reasonably efficient, have low memory usage, and not fall over at the faintest whiff of some new AMQP feature:

graphite-enqueue - provides the graphite TCP line receiver protocol and forwards all received messages on to a given AMQP exchange. Uses libevent2 to handle multiple clients simultaneously. Supports using the metric name as the routing key or using an arbitrary routing key and keeping the metric name in the message payload.

graphite-dequeue - does the opposite, receives messages from a given AMQP queue bound to an exchange (creating both if necessary) with arbitrary bindings and posts them on to a given graphite TCP line receiver. Supports setting various extended queue attributes such as mirroring and message TTL.