Cancel activedefrag in case we empty db

src/db.c

@@ -559,6 +559,10 @@ long long emptyData(int dbnum, int flags, void(callback)(dict *)) {
         return -1;
     }
 
+    /* In case we are in the process of activedefrag, the db keys and expire might be in the stage of defrag.
+     * we thus cancel the active defrag so that it will be restarted from the beginning. */
+    cancelActiveDefrag();
+
     /* Fire the flushdb modules event. */
     moduleFireServerEvent(VALKEYMODULE_EVENT_FLUSHDB, VALKEYMODULE_SUBEVENT_FLUSHDB_START, &fi);
 

src/defrag.c

@@ -1367,6 +1367,12 @@ static void updateDefragCpuPercent(void) {
     }
 }
 
+void cancelActiveDefrag(void) {
+    if (defragIsRunning()) {
+        // Defrag is requested to stop while running
+        endDefragCycle(false);
+    }
+}
 
 void monitorActiveDefrag(void) {
     if (!server.active_defrag_enabled) return;
@@ -1382,6 +1388,10 @@ void monitorActiveDefrag(void) {
 
 #else /* HAVE_DEFRAG */
 
+void cancelActiveDefrag(void) {
+    /* Not implemented yet. */
+}
+
 void monitorActiveDefrag(void) {
     /* Not implemented yet. */
 }

src/server.h

@@ -3354,6 +3354,7 @@ void enterExecutionUnit(int update_cached_time, long long us);
 void exitExecutionUnit(void);
 void resetServerStats(void);
 void monitorActiveDefrag(void);
+void cancelActiveDefrag(void);
 void defragWhileBlocked(void);
 unsigned int getLRUClock(void);
 unsigned int LRU_CLOCK(void);