pluggable queue backends

- behaviour and specs for pluggable queue backends
- reworking of the queue code to support pluggability, including
  hookups to memory monitoring and file handle management
- interface to existing persister via the new API

All these changes were cherry-picked from the bug21673 branch.

1 files changed, 63 insertions, 0 deletions

diff --git a/include/rabbit_backing_queue_spec.hrl b/include/rabbit_backing_queue_spec.hrl
new file mode 100644
index 0000000000..1b536dfad1
--- /dev/null
+++ b/include/rabbit_backing_queue_spec.hrl
@@ -0,0 +1,63 @@
+%%   The contents of this file are subject to the Mozilla Public License
+%%   Version 1.1 (the "License"); you may not use this file except in
+%%   compliance with the License. You may obtain a copy of the License at
+%%   http://www.mozilla.org/MPL/
+%%
+%%   Software distributed under the License is distributed on an "AS IS"
+%%   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
+%%   License for the specific language governing rights and limitations
+%%   under the License.
+%%
+%%   The Original Code is RabbitMQ.
+%%
+%%   The Initial Developers of the Original Code are LShift Ltd,
+%%   Cohesive Financial Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created before 22-Nov-2008 00:00:00 GMT by LShift Ltd,
+%%   Cohesive Financial Technologies LLC, or Rabbit Technologies Ltd
+%%   are Copyright (C) 2007-2008 LShift Ltd, Cohesive Financial
+%%   Technologies LLC, and Rabbit Technologies Ltd.
+%%
+%%   Portions created by LShift Ltd are Copyright (C) 2007-2009 LShift
+%%   Ltd. Portions created by Cohesive Financial Technologies LLC are
+%%   Copyright (C) 2007-2009 Cohesive Financial Technologies
+%%   LLC. Portions created by Rabbit Technologies Ltd are Copyright
+%%   (C) 2007-2009 Rabbit Technologies Ltd.
+%%
+%%   All Rights Reserved.
+%%
+%%   Contributor(s): ______________________________________.
+%%
+
+-type(fetch_result() ::
+                 %% Message,  IsDelivered,  AckTag,  Remaining_Len
+        ('empty'|{basic_message(), boolean(), ack(), non_neg_integer()})).
+-type(is_durable() :: boolean()).
+-type(attempt_recovery() :: boolean()).
+-type(purged_msg_count() :: non_neg_integer()).
+-type(ack_required() :: boolean()).
+
+-spec(start/1 :: ([queue_name()]) -> 'ok').
+-spec(init/3 :: (queue_name(), is_durable(), attempt_recovery()) -> state()).
+-spec(terminate/1 :: (state()) -> state()).
+-spec(delete_and_terminate/1 :: (state()) -> state()).
+-spec(purge/1 :: (state()) -> {purged_msg_count(), state()}).
+-spec(publish/2 :: (basic_message(), state()) -> state()).
+-spec(publish_delivered/3 ::
+        (ack_required(), basic_message(), state()) -> {ack(), state()}).
+-spec(fetch/2 :: (ack_required(), state()) -> {fetch_result(), state()}).
+-spec(ack/2 :: ([ack()], state()) -> state()).
+-spec(tx_publish/3 :: (txn(), basic_message(), state()) -> state()).
+-spec(tx_ack/3 :: (txn(), [ack()], state()) -> state()).
+-spec(tx_rollback/2 :: (txn(), state()) -> {[ack()], state()}).
+-spec(tx_commit/3 :: (txn(), fun (() -> any()), state()) -> {[ack()], state()}).
+-spec(requeue/2 :: ([ack()], state()) -> state()).
+-spec(len/1 :: (state()) -> non_neg_integer()).
+-spec(is_empty/1 :: (state()) -> boolean()).
+-spec(set_ram_duration_target/2 ::
+      (('undefined' | 'infinity' | number()), state()) -> state()).
+-spec(ram_duration/1 :: (state()) -> {number(), state()}).
+-spec(needs_sync/1 :: (state()) -> boolean()).
+-spec(sync/1 :: (state()) -> state()).
+-spec(handle_pre_hibernate/1 :: (state()) -> state()).
+-spec(status/1 :: (state()) -> [{atom(), any()}]).