lib-sql: cassandra - Keep a persistent cache of used sql databases

diff --git a/src/lib-sql/driver-cassandra.c b/src/lib-sql/driver-cassandra.c
index f1d513a0004212b542dbe7197928754ccd564866..ee1819e7b4c6fc763bb0f9e00b6e89e735283153 100644 (file)
--- a/src/lib-sql/driver-cassandra.c
+++ b/src/lib-sql/driver-cassandra.c
@@ -421,6 +421,7 @@ static struct event_category event_category_cassandra = {
 
 static pthread_t main_thread_id;
 static bool main_thread_id_set;
+static ARRAY(struct cassandra_db *) cassandra_db_cache;
 
 static void driver_cassandra_prepare_pending(struct cassandra_db *db);
 static void
@@ -1272,6 +1273,23 @@ static int driver_cassandra_init_ssl(struct cassandra_db *db, const char **error
        return 0;
 }
 
+static struct cassandra_db *
+driver_cassandra_db_cache_find(const struct cassandra_settings *set,
+                              const struct ssl_settings *ssl_set)
+{
+       struct cassandra_db *db;
+
+       array_foreach_elem(&cassandra_db_cache, db) {
+               if (settings_equal(&cassandra_setting_parser_info,
+                                  set, db->set, NULL) &&
+                   (strcmp(set->ssl, "no") == 0 ||
+                    settings_equal(&ssl_setting_parser_info,
+                                   ssl_set, db->set, NULL)))
+                       return db;
+       }
+       return NULL;
+}
+
 static int
 driver_cassandra_init_common(struct event *event_parent,
                             const struct cassandra_settings *set,
@@ -1368,7 +1386,7 @@ driver_cassandra_init_v(struct event *event, struct sql_db **db_r,
                        const char **error_r)
 {
        const struct cassandra_settings *set;
-       const struct ssl_settings *ssl_set;
+       const struct ssl_settings *ssl_set = NULL;
 
        if (settings_get(event, &cassandra_setting_parser_info, 0,
                         &set, error_r) < 0)
@@ -1382,9 +1400,22 @@ driver_cassandra_init_v(struct event *event, struct sql_db **db_r,
                }
        }
 
-       if (driver_cassandra_init_common(event, set, ssl_set, db_r, error_r) < 0)
-               return -1;
-       sql_init_common(*db_r);
+       struct cassandra_db *db =
+               driver_cassandra_db_cache_find(set, ssl_set);
+       if (db != NULL) {
+               settings_free(set);
+               settings_free(ssl_set);
+       } else {
+               if (driver_cassandra_init_common(event, set, ssl_set,
+                                                &db, error_r) < 0)
+                       return -1;
+               sql_init_common(&db->api);
+               array_push_back(&cassandra_db_cache, &db);
+               /* Add an extra reference to the db, so it won't be freed while
+                  it's still in the cache array. */
+       }
+       db->api.refcount++;
+       *db_r = &db->api;
        return 0;
 }
 
@@ -3209,11 +3240,19 @@ const char *driver_cassandra_version = DOVECOT_ABI_VERSION;
 
 void driver_cassandra_init(void)
 {
+       i_array_init(&cassandra_db_cache, 4);
        sql_driver_register(&driver_cassandra_db);
 }
 
 void driver_cassandra_deinit(void)
 {
+       struct cassandra_db *db;
+
+       array_foreach_elem(&cassandra_db_cache, db) {
+               struct sql_db *_db = &db->api;
+               sql_unref(&_db);
+       }
+       array_free(&cassandra_db_cache);
        sql_driver_unregister(&driver_cassandra_db);
 }