postgresql plugin: Use the "complex read" mechanism.

This way, multiple databases are queried in parallel (depending on the number
of read threads).

diff --git a/src/postgresql.c b/src/postgresql.c
index 6a54fc0..4f140b6 100644 (file)
--- a/src/postgresql.c
+++ b/src/postgresql.c
@@ -132,22 +132,16 @@ static int def_queries_num = STATIC_ARRAY_SIZE (def_queries);
 static udb_query_t      **queries       = NULL;
 static size_t             queries_num   = 0;
 
-static c_psql_database_t *databases     = NULL;
-static int                databases_num = 0;
-
 static c_psql_database_t *c_psql_database_new (const char *name)
 {
        c_psql_database_t *db;
 
-       ++databases_num;
-       if (NULL == (databases = (c_psql_database_t *)realloc (databases,
-                               databases_num * sizeof (*databases)))) {
+       db = (c_psql_database_t *)malloc (sizeof (*db));
+       if (NULL == db) {
                log_err ("Out of memory.");
                exit (5);
        }
 
-       db = databases + (databases_num - 1);
-
        db->conn = NULL;
 
        C_COMPLAIN_INIT (&db->conn_complaint);
@@ -174,8 +168,10 @@ static c_psql_database_t *c_psql_database_new (const char *name)
        return db;
 } /* c_psql_database_new */
 
-static void c_psql_database_delete (c_psql_database_t *db)
+static void c_psql_database_delete (void *data)
 {
+       c_psql_database_t *db = data;
+
        PQfinish (db->conn);
        db->conn = NULL;
 
@@ -447,57 +443,41 @@ static int c_psql_exec_query (c_psql_database_t *db, udb_query_t *q)
 #undef BAIL_OUT
 } /* c_psql_exec_query */
 
-static int c_psql_read (void)
+static int c_psql_read (user_data_t *ud)
 {
-       int success = 0;
+       c_psql_database_t *db;
        int i;
 
-       for (i = 0; i < databases_num; ++i) {
-               c_psql_database_t *db = databases + i;
-
-               int j;
+       if ((ud == NULL) || (ud->data == NULL)) {
+               log_err ("c_psql_read: Invalid user data.");
+               return -1;
+       }
 
-               assert (NULL != db->database);
+       db = ud->data;
 
-               if (0 != c_psql_check_connection (db))
-                       continue;
+       assert (NULL != db->database);
 
-               for (j = 0; j < db->queries_num; ++j)
-               {
-                       udb_query_t *q;
+       if (0 != c_psql_check_connection (db))
+               return -1;
 
-                       q = db->queries[j];
+       for (i = 0; i < db->queries_num; ++i)
+       {
+               udb_query_t *q;
 
-                       if ((0 != db->server_version)
-                               && (udb_query_check_version (q, db->server_version) <= 0))
-                               continue;
+               q = db->queries[i];
 
-                       c_psql_exec_query (db, q);
-               }
+               if ((0 != db->server_version)
+                       && (udb_query_check_version (q, db->server_version) <= 0))
+                       return -1;
 
-               ++success;
+               c_psql_exec_query (db, q);
        }
-
-       if (! success)
-               return -1;
        return 0;
 } /* c_psql_read */
 
 static int c_psql_shutdown (void)
 {
-       int i;
-
-       if ((NULL == databases) || (0 == databases_num))
-               return 0;
-
-       plugin_unregister_read ("postgresql");
-       plugin_unregister_shutdown ("postgresql");
-
-       for (i = 0; i < databases_num; ++i)
-               c_psql_database_delete (databases + i);
-
-       sfree (databases);
-       databases_num = 0;
+       plugin_unregister_read_group ("postgresql");
 
        udb_query_free (queries, queries_num);
        queries = NULL;
@@ -506,16 +486,6 @@ static int c_psql_shutdown (void)
        return 0;
 } /* c_psql_shutdown */
 
-static int c_psql_init (void)
-{
-       if ((NULL == databases) || (0 == databases_num))
-               return 0;
-
-       plugin_register_read ("postgresql", c_psql_read);
-       plugin_register_shutdown ("postgresql", c_psql_shutdown);
-       return 0;
-} /* c_psql_init */
-
 static int config_set_s (char *name, char **var, const oconfig_item_t *ci)
 {
        if ((0 != ci->children_num) || (1 != ci->values_num)
@@ -589,6 +559,9 @@ static int c_psql_config_database (oconfig_item_t *ci)
 {
        c_psql_database_t *db;
 
+       char cb_name[DATA_MAX_NAME_LEN];
+       user_data_t ud;
+
        int i;
 
        if ((1 != ci->values_num)
@@ -597,6 +570,8 @@ static int c_psql_config_database (oconfig_item_t *ci)
                return 1;
        }
 
+       memset (&ud, 0, sizeof (ud));
+
        db = c_psql_database_new (ci->values[0].value.string);
 
        for (i = 0; i < ci->children_num; ++i) {
@@ -638,6 +613,14 @@ static int c_psql_config_database (oconfig_item_t *ci)
                if ((data != NULL) && (data->params_num > db->max_params_num))
                        db->max_params_num = data->params_num;
        }
+
+       ud.data = db;
+       ud.free_func = c_psql_database_delete;
+
+       ssnprintf (cb_name, sizeof (cb_name), "postgresql-%s", db->database);
+
+       plugin_register_complex_read ("postgresql", cb_name, c_psql_read,
+                       /* interval = */ NULL, &ud);
        return 0;
 } /* c_psql_config_database */
 
@@ -681,7 +664,7 @@ static int c_psql_config (oconfig_item_t *ci)
 void module_register (void)
 {
        plugin_register_complex_config ("postgresql", c_psql_config);
-       plugin_register_init ("postgresql", c_psql_init);
+       plugin_register_shutdown ("postgresql", c_psql_shutdown);
 } /* module_register */
 
 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */