DO NOT MERGE Remove CQv1

deps/rabbit/src/rabbit_backing_queue.erl

@@ -173,13 +173,6 @@
 %% each message, its ack tag, and an accumulator.
 -callback ackfold(msg_fun(A), A, state(), [ack()]) -> {A, state()}.
 
-%% Fold over all the messages in a queue and return the accumulated
-%% results, leaving the queue undisturbed.
--callback fold(fun((mc:state(),
-                    rabbit_types:message_properties(),
-                    boolean(), A) -> {('stop' | 'cont'), A}),
-               A, state()) -> {A, state()}.
-
 %% How long is my queue?
 -callback len(state()) -> non_neg_integer().
 

deps/rabbit/src/rabbit_classic_queue_store_v2.erl

@@ -147,8 +147,8 @@ info(#qs{ write_buffer = WriteBuffer }) ->
 
 %% @todo I think we can disable the old message store at the same
 %%       place where we create MsgId. If many queues receive the
-%%       message, then we create an MsgId. If not, we don't. But
-%%       we can only do this after removing support for v1.
+%%       message, then we create an MsgId. If not, we don't until
+%%       strictly necessary (large messages).
 write(SeqId, Msg, Props, State0 = #qs{ write_buffer = WriteBuffer0,
                                        write_buffer_size = WriteBufferSize }) ->
     ?DEBUG("~0p ~0p ~0p ~0p", [SeqId, Msg, Props, State0]),

deps/rabbit/src/rabbit_guid.erl

@@ -31,6 +31,7 @@
 
 -spec start_link() -> rabbit_types:ok_pid_or_error().
 
+%% @todo Serial can be in persistent_term instead of process.
 start_link() ->
     gen_server:start_link({local, ?SERVER}, ?MODULE,
                           [update_disk_serial()], []).

deps/rabbit/src/rabbit_priority_queue.erl

@@ -29,7 +29,7 @@
          purge/1, purge_acks/1,
          publish/5, publish_delivered/4, discard/3, drain_confirmed/1,
          dropwhile/2, fetchwhile/4, fetch/2, drop/2, ack/2, requeue/2,
-         ackfold/4, fold/3, len/1, is_empty/1, depth/1,
+         ackfold/4, len/1, is_empty/1, depth/1,
          update_rates/1, needs_timeout/1, timeout/1,
          handle_pre_hibernate/1, resume/1, msg_rates/1,
          info/2, invoke/3, is_duplicate/2, set_queue_mode/2,
@@ -302,11 +302,6 @@ ackfold(MsgFun, Acc, State = #state{bq = BQ}, AckTags) ->
 ackfold(MsgFun, Acc, State = #passthrough{bq = BQ, bqs = BQS}, AckTags) ->
     ?passthrough2(ackfold(MsgFun, Acc, BQS, AckTags)).
 
-fold(Fun, Acc, State = #state{bq = BQ}) ->
-    fold2(fun (_P, BQSN, AccN) -> BQ:fold(Fun, AccN, BQSN) end, Acc, State);
-fold(Fun, Acc, State = #passthrough{bq = BQ, bqs = BQS}) ->
-    ?passthrough2(fold(Fun, Acc, BQS)).
-
 len(#state{bq = BQ, bqss = BQSs}) ->
     add0(fun (_P, BQSN) -> BQ:len(BQSN) end, BQSs);
 len(#passthrough{bq = BQ, bqs = BQS}) ->