Queue, connection and exchange count functions

Connection lookup using tracking tables.
Used in the management only HTTP API with all stats disabled

[#166445368]

Author: dcorbacho

src/rabbit_amqqueue.erl

@@ -30,6 +30,7 @@
 -export([list/0, list/1, info_keys/0, info/1, info/2, info_all/1, info_all/2,
          emit_info_all/5, list_local/1, info_local/1,
          emit_info_local/4, emit_info_down/4]).
+-export([count/0]).
 -export([list_down/1, count/1, list_names/0, list_names/1, list_local_names/0,
          list_with_possible_retry/1]).
 -export([list_by_type/1]).
@@ -794,6 +795,11 @@ list() ->
 do_list() ->
     mnesia:dirty_match_object(rabbit_queue, amqqueue:pattern_match_all()).
 
+-spec count() -> non_neg_integer().
+
+count() ->
+    mnesia:table_info(rabbit_queue, size).
+
 -spec list_names() -> [rabbit_amqqueue:name()].
 
 list_names() -> mnesia:dirty_all_keys(rabbit_queue).

src/rabbit_connection_tracking.erl

@@ -39,7 +39,9 @@
          list/0, list/1, list_on_node/1, list_on_node/2, list_of_user/1,
          tracked_connection_from_connection_created/1,
          tracked_connection_from_connection_state/1,
-         count_connections_in/1]).
+         count_connections_in/1,
+         lookup/1,
+         count/0]).
 
 -include_lib("rabbit.hrl").
 
@@ -287,6 +289,20 @@ unregister_connection(ConnId = {Node, _Name}) when Node =:= node() ->
             mnesia:dirty_delete(TableName, ConnId)
     end.
 
+-spec lookup(rabbit_types:connection_name()) -> rabbit_types:tracked_connection() | 'not_found'.
+
+lookup(Name) ->
+    Nodes = rabbit_mnesia:cluster_nodes(running),
+    lookup(Name, Nodes).
+
+lookup(_, []) ->
+    not_found;
+lookup(Name, [Node | Nodes]) ->
+    TableName = tracked_connection_table_name_for(Node),
+    case mnesia:dirty_read(TableName, {Node, Name}) of
+        [] -> lookup(Name, Nodes);
+        [Row] -> Row
+    end.
 
 -spec list() -> [rabbit_types:tracked_connection()].
 
@@ -297,6 +313,14 @@ list() ->
               Acc ++ mnesia:dirty_match_object(Tab, #tracked_connection{_ = '_'})
       end, [], rabbit_mnesia:cluster_nodes(running)).
 
+-spec count() -> non_neg_integer().
+
+count() ->
+    lists:foldl(
+      fun (Node, Acc) ->
+              Tab = tracked_connection_table_name_for(Node),
+              Acc + mnesia:table_info(Tab, size)
+      end, 0, rabbit_mnesia:cluster_nodes(running)).
 
 -spec list(rabbit_types:vhost()) -> [rabbit_types:tracked_connection()].
 

src/rabbit_exchange.erl

@@ -23,7 +23,7 @@
          lookup/1, lookup_or_die/1, list/0, list/1, lookup_scratch/2,
          update_scratch/3, update_decorators/1, immutable/1,
          info_keys/0, info/1, info/2, info_all/1, info_all/2, info_all/4,
-         route/2, delete/3, validate_binding/2]).
+         route/2, delete/3, validate_binding/2, count/0]).
 -export([list_names/0]).
 %% these must be run inside a mnesia tx
 -export([maybe_auto_delete/2, serial/1, peek_serial/1, update/2]).
@@ -238,6 +238,11 @@ lookup_or_die(Name) ->
 
 list() -> mnesia:dirty_match_object(rabbit_exchange, #exchange{_ = '_'}).
 
+-spec count() -> non_neg_integer().
+
+count() ->
+    mnesia:table_info(rabbit_exchange, size).
+
 -spec list_names() -> [rabbit_exchange:name()].
 
 list_names() -> mnesia:dirty_all_keys(rabbit_exchange).