From 8a2045381830c81b7bf09da835c7a68c864bfac2 Mon Sep 17 00:00:00 2001
From: Gustaw Lippa <gustaw.lippa@erlang-solutions.com>
Date: Thu, 22 Apr 2021 17:28:20 +0200
Subject: [PATCH] Move MAM metrics to mod_mam

Now mod_mam is responsible for starting and updating metrics related to MAM.
Thanks to this change MAM metrics will not be reported if Mongoose is started
with MAM disabled.
---
 src/mam/mod_mam.erl                          | 33 +++++++++++++++++---
 src/metrics/mongoose_metrics_definitions.hrl | 12 -------
 src/metrics/mongoose_metrics_hooks.erl       |  3 +-
 3 files changed, 30 insertions(+), 18 deletions(-)

diff --git a/src/mam/mod_mam.erl b/src/mam/mod_mam.erl
index 48519c2b446..a5ba51edd64 100644
--- a/src/mam/mod_mam.erl
+++ b/src/mam/mod_mam.erl
@@ -218,9 +218,7 @@ start(Host, Opts) ->
     ejabberd_hooks:add(amp_determine_strategy, Host, ?MODULE, determine_amp_strategy, 20),
     ejabberd_hooks:add(sm_filter_offline_message, Host, ?MODULE, sm_filter_offline_message, 50),
     ejabberd_hooks:add(get_personal_data, Host, ?MODULE, get_personal_data, 50),
-    mongoose_metrics:ensure_metric(Host, [backends, ?MODULE, lookup], histogram),
-    mongoose_metrics:ensure_metric(Host, [Host, modMamLookups, simple], spiral),
-    mongoose_metrics:ensure_metric(Host, [backends, ?MODULE, archive], histogram),
+    ensure_metrics(Host),
     ok.
 
 
@@ -684,5 +682,32 @@ is_archivable_message(Host, Dir, Packet) ->
     erlang:apply(M, F, [?MODULE, Dir, Packet, ArchiveChatMarkers]).
 
 config_metrics(Host) ->
-    OptsToReport = [{backend, rdbms}], %list of tuples {option, defualt_value}
+    OptsToReport = [{backend, rdbms}], %list of tuples {option, default_value}
     mongoose_module_metrics:opts_for_module(Host, ?MODULE, OptsToReport).
+
+ensure_metrics(Host) ->
+    mongoose_metrics:ensure_metric(Host, [backends, ?MODULE, lookup], histogram),
+    mongoose_metrics:ensure_metric(Host, [Host, modMamLookups, simple], spiral),
+    mongoose_metrics:ensure_metric(Host, [backends, ?MODULE, archive], histogram),
+    lists:foreach(fun(Name) ->
+                      mongoose_metrics:ensure_metric(Host, Name, spiral)
+                  end,
+                  spirals()),
+    lists:foreach(fun(Hook) ->
+                      apply(ejabberd_hooks, add, Hook)
+                  end,
+                  mongoose_metrics_mam_hooks:get_hooks(Host)).
+
+spirals() ->
+    [modMamPrefsSets,
+    modMamPrefsGets,
+    modMamArchiveRemoved,
+    modMamLookups,
+    modMamForwarded,
+    modMamArchived,
+    modMamFlushed,
+    modMamDropped,
+    modMamDropped2,
+    modMamDroppedIQ,
+    modMamSinglePurges,
+    modMamMultiplePurges].
diff --git a/src/metrics/mongoose_metrics_definitions.hrl b/src/metrics/mongoose_metrics_definitions.hrl
index a2ad46335e5..8577b45a4de 100644
--- a/src/metrics/mongoose_metrics_definitions.hrl
+++ b/src/metrics/mongoose_metrics_definitions.hrl
@@ -35,18 +35,6 @@
     modPrivacyStanzaDenied,
     modPrivacyStanzaBlocked,
     modPrivacyStanzaAll,
-    modMamPrefsSets,
-    modMamPrefsGets,
-    modMamArchiveRemoved,
-    modMamLookups,
-    modMamForwarded,
-    modMamArchived,
-    modMamFlushed,
-    modMamDropped,
-    modMamDropped2,
-    modMamDroppedIQ,
-    modMamSinglePurges,
-    modMamMultiplePurges,
     modMucMamPrefsSets,
     modMucMamPrefsGets,
     modMucMamArchiveRemoved,
diff --git a/src/metrics/mongoose_metrics_hooks.erl b/src/metrics/mongoose_metrics_hooks.erl
index 81356ac7aeb..ba1b0a8cad4 100644
--- a/src/metrics/mongoose_metrics_hooks.erl
+++ b/src/metrics/mongoose_metrics_hooks.erl
@@ -66,8 +66,7 @@ get_hooks(Host) ->
       {privacy_iq_get, Host, ?MODULE, privacy_iq_get, 1},
       {privacy_iq_set, Host, ?MODULE, privacy_iq_set, 1},
       {privacy_check_packet, Host, ?MODULE, privacy_check_packet, 55},
-      {sm_broadcast, Host, ?MODULE, privacy_list_push, 1}
-      | mongoose_metrics_mam_hooks:get_hooks(Host)].
+      {sm_broadcast, Host, ?MODULE, privacy_list_push, 1}].
 
 -spec sm_register_connection_hook(map(), tuple(), jid:jid(), term()
                                  ) -> metrics_notify_return().