Modules hooks: implement the FLUSHDB event.

src/db.c

@@ -350,6 +350,12 @@ long long emptyDbGeneric(redisDb *dbarray, int dbnum, int flags, void(callback)(
         return -1;
     }
 
+    /* Fire the flushdb modules event. */
+    RedisModuleFlushInfoV1 fi = {REDISMODULE_FLUSHINFO_VERSION,!async,dbnum};
+    moduleFireServerEvent(REDISMODULE_EVENT_FLUSHDB,
+                          REDISMODULE_SUBEVENT_FLUSHDB_START,
+                          &fi);
+
     /* Make sure the WATCHed keys are affected by the FLUSH* commands.
      * Note that we need to call the function while the keys are still
      * there. */
@@ -380,6 +386,13 @@ long long emptyDbGeneric(redisDb *dbarray, int dbnum, int flags, void(callback)(
         }
     }
     if (dbnum == -1) flushSlaveKeysWithExpireList();
+
+    /* Also fire the end event. Note that this event will fire almost
+     * immediately after the start event if the flush is asynchronous. */
+    moduleFireServerEvent(REDISMODULE_EVENT_FLUSHDB,
+                          REDISMODULE_SUBEVENT_FLUSHDB_END,
+                          &fi);
+
     return removed;
 }
 

src/module.c

@@ -5721,8 +5721,8 @@ void ModuleForkDoneHandler(int exitcode, int bysignal) {
  *          because of replication, after the replica synchronization)
  *          happened. The following sub events are available:
  *
- *              REDISMODULE_EVENT_FLUSHALL_START
- *              REDISMODULE_EVENT_FLUSHALL_END
+ *              REDISMODULE_EVENT_FLUSHDB_START
+ *              REDISMODULE_EVENT_FLUSHDB_END
  *
  *          The data pointer can be casted to a RedisModuleFlushInfo
  *          structure with the following fields:

src/redismodule.h

@@ -239,6 +239,9 @@ static RedisModuleEvent
 #define REDISMODULE_SUBEVENT_REPLICA_CHANGE_CONNECTED 0
 #define REDISMODULE_SUBEVENT_REPLICA_CHANGE_DISCONNECTED 1
 
+#define REDISMODULE_SUBEVENT_FLUSHDB_START 0
+#define REDISMODULE_SUBEVENT_FLUSHDB_END 1
+
 /* RedisModuleClientInfo flags. */
 #define REDISMODULE_CLIENTINFO_FLAG_SSL (1<<0)
 #define REDISMODULE_CLIENTINFO_FLAG_PUBSUB (1<<1)