Make decorators field in exchange and queue transient, i.e. we recalcualte it on recovery in case plugins have changed. Also document a bit more clearly what the lifecycle is of the different fields in these records since that area is becoming confusing.

1 files changed, 17 insertions, 6 deletions

diff --git a/include/rabbit.hrl b/include/rabbit.hrl
index 5ac3197ed9..a0e96d87e4 100644
--- a/include/rabbit.hrl
+++ b/include/rabbit.hrl
@@ -39,13 +39,24 @@
 
 -record(resource, {virtual_host, kind, name}).
 
--record(exchange, {name, type, durable, auto_delete, internal, arguments,
-                   scratches, policy, decorators}).
--record(exchange_serial, {name, next}).
+%% fields described as 'transient' here are cleared when writing to
+%% rabbit_durable_<thing>
+-record(exchange, {
+          name, type, durable, auto_delete, internal, arguments, %% immutable
+          scratches,    %% durable, explicitly updated via update_scratch/3
+          policy,       %% durable, implicitly updated when policy changes
+          decorators}). %% transient, recalculated in store/1 (i.e. recovery)
+
+-record(amqqueue, {
+          name, durable, auto_delete, exclusive_owner = none, %% immutable
+          arguments,                   %% immutable
+          pid,                         %% durable (just so we know home node)
+          slave_pids, sync_slave_pids, %% transient
+          policy,                      %% durable, implicit update as above
+          gm_pids,                     %% transient
+          decorators}).                %% transient, recalculated as above
 
--record(amqqueue, {name, durable, auto_delete, exclusive_owner = none,
-                   arguments, pid, slave_pids, sync_slave_pids, policy,
-                   gm_pids, decorators}).
+-record(exchange_serial, {name, next}).
 
 %% mnesia doesn't like unary records, so we add a dummy 'value' field
 -record(route, {binding, value = const}).