Shared reusable client for RM_Call() (#8516)

A single client pointer is added in the server struct. This is
initialized by the first RM_Call() and reused for every subsequent
RM_Call() except if it's already in use, which means that it's not
used for (recursive) module calls to modules. For these, a new
"fake" client is created each time.

Other changes:
* Avoid allocating a dict iterator in pubsubUnsubscribeAllChannels
  when not needed

1 files changed, 8 insertions, 6 deletions

diff --git a/src/pubsub.c b/src/pubsub.c
index a7b370d5d..5f7335bbe 100644
--- a/src/pubsub.c
+++ b/src/pubsub.c
@@ -250,18 +250,20 @@ int pubsubUnsubscribePattern(client *c, robj *pattern, int notify) {
 /* Unsubscribe from all the channels. Return the number of channels the
  * client was subscribed to. */
 int pubsubUnsubscribeAllChannels(client *c, int notify) {
-    dictIterator *di = dictGetSafeIterator(c->pubsub_channels);
-    dictEntry *de;
     int count = 0;
+    if (dictSize(c->pubsub_channels) > 0) {
+        dictIterator *di = dictGetSafeIterator(c->pubsub_channels);
+        dictEntry *de;
 
-    while((de = dictNext(di)) != NULL) {
-        robj *channel = dictGetKey(de);
+        while((de = dictNext(di)) != NULL) {
+            robj *channel = dictGetKey(de);
 
-        count += pubsubUnsubscribeChannel(c,channel,notify);
+            count += pubsubUnsubscribeChannel(c,channel,notify);
+        }
+        dictReleaseIterator(di);
     }
     /* We were subscribed to nothing? Still reply to the client. */
     if (notify && count == 0) addReplyPubsubUnsubscribed(c,NULL);
-    dictReleaseIterator(di);
     return count;
 }