Merge branch 'collectd-4.4'

[collectd.git] / src / postgresql.c

diff --git a/src/postgresql.c b/src/postgresql.c
index f326a23..fbc117b 100644 (file)
--- a/src/postgresql.c
+++ b/src/postgresql.c
@@ -103,6 +103,8 @@ typedef struct {
        PGconn      *conn;
        c_complain_t conn_complaint;
 
+       int proto_version;
+
        int max_params_num;
 
        /* user configuration */
@@ -209,6 +211,8 @@ static c_psql_database_t *c_psql_database_new (const char *name)
        db->conn_complaint.last     = 0;
        db->conn_complaint.interval = 0;
 
+       db->proto_version = 0;
+
        db->max_params_num = 0;
 
        db->queries     = NULL;
@@ -323,6 +327,11 @@ static int c_psql_check_connection (c_psql_database_t *db)
                                        db->database, PQerrorMessage (db->conn));
                        return -1;
                }
+
+               db->proto_version = PQprotocolVersion (db->conn);
+               if (3 > db->proto_version)
+                       log_warn ("Protocol version %d does not support parameters.",
+                                       db->proto_version);
        }
 
        c_release (LOG_INFO, &db->conn_complaint,
@@ -330,20 +339,11 @@ static int c_psql_check_connection (c_psql_database_t *db)
        return 0;
 } /* c_psql_check_connection */
 
-static int c_psql_exec_query (c_psql_database_t *db, int idx)
+static PGresult *c_psql_exec_query_params (c_psql_database_t *db,
+               c_psql_query_t *query)
 {
-       c_psql_query_t *query;
-       PGresult       *res;
-
        char *params[db->max_params_num];
-
-       int rows, cols;
-       int i;
-
-       if (idx >= db->queries_num)
-               return -1;
-
-       query = db->queries[idx];
+       int   i;
 
        assert (db->max_params_num >= query->params_num);
 
@@ -364,9 +364,40 @@ static int c_psql_exec_query (c_psql_database_t *db, int idx)
                }
        }
 
-       res = PQexecParams (db->conn, query->query, query->params_num, NULL,
+       return PQexecParams (db->conn, query->query, query->params_num, NULL,
                        (const char *const *)((0 == query->params_num) ? NULL : params),
                        NULL, NULL, /* return text data */ 0);
+} /* c_psql_exec_query_params */
+
+static PGresult *c_psql_exec_query_noparams (c_psql_database_t *db,
+               c_psql_query_t *query)
+{
+       return PQexec (db->conn, query->query);
+} /* c_psql_exec_query_noparams */
+
+static int c_psql_exec_query (c_psql_database_t *db, int idx)
+{
+       c_psql_query_t *query;
+       PGresult       *res;
+
+       int rows, cols;
+       int i;
+
+       if (idx >= db->queries_num)
+               return -1;
+
+       query = db->queries[idx];
+
+       if (3 <= db->proto_version)
+               res = c_psql_exec_query_params (db, query);
+       else if (0 == query->params_num)
+               res = c_psql_exec_query_noparams (db, query);
+       else {
+               log_err ("Connection to database \"%s\" does not support parameters "
+                               "(protocol version %d) - cannot execute query \"%s\".",
+                               db->database, db->proto_version, query->name);
+               return -1;
+       }
 
        if (PGRES_TUPLES_OK != PQresultStatus (res)) {
                log_err ("Failed to execute SQL query: %s",
@@ -522,6 +553,8 @@ static int c_psql_init (void)
                if (0 != c_psql_check_connection (db))
                        continue;
 
+               db->proto_version = PQprotocolVersion (db->conn);
+
                server_host    = PQhost (db->conn);
                server_version = PQserverVersion (db->conn);
                log_info ("Sucessfully connected to database %s (user %s) "
@@ -530,7 +563,11 @@ static int c_psql_init (void)
                                PQdb (db->conn), PQuser (db->conn),
                                C_PSQL_SOCKET3 (server_host, PQport (db->conn)),
                                C_PSQL_SERVER_VERSION3 (server_version),
-                               PQprotocolVersion (db->conn), PQbackendPID (db->conn));
+                               db->proto_version, PQbackendPID (db->conn));
+
+               if (3 > db->proto_version)
+                       log_warn ("Protocol version %d does not support parameters.",
+                                       db->proto_version);
        }
 
        plugin_register_read ("postgresql", c_psql_read);
@@ -621,20 +658,14 @@ static int config_set_column (c_psql_query_t *query, const oconfig_item_t *ci)
        return 0;
 } /* config_set_column */
 
-static int config_set_query (c_psql_database_t *db, const oconfig_item_t *ci)
+static int set_query (c_psql_database_t *db, const char *name)
 {
        c_psql_query_t *query;
 
-       if ((0 != ci->children_num) || (1 != ci->values_num)
-                       || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
-               log_err ("Query expects a single string argument.");
-               return 1;
-       }
-
-       query = c_psql_query_get (ci->values[0].value.string);
+       query = c_psql_query_get (name);
        if (NULL == query) {
                log_err ("Query \"%s\" not found - please check your configuration.",
-                               ci->values[0].value.string);
+                               name);
                return 1;
        }
 
@@ -650,6 +681,16 @@ static int config_set_query (c_psql_database_t *db, const oconfig_item_t *ci)
 
        db->queries[db->queries_num - 1] = query;
        return 0;
+} /* set_query */
+
+static int config_set_query (c_psql_database_t *db, const oconfig_item_t *ci)
+{
+       if ((0 != ci->children_num) || (1 != ci->values_num)
+                       || (OCONFIG_TYPE_STRING != ci->values[0].type)) {
+               log_err ("Query expects a single string argument.");
+               return 1;
+       }
+       return set_query (db, ci->values[0].value.string);
 } /* config_set_query */
 
 static int c_psql_config_query (oconfig_item_t *ci)
@@ -719,18 +760,8 @@ static int c_psql_config_database (oconfig_item_t *ci)
        }
 
        if (NULL == db->queries) {
-               db->queries = (c_psql_query_t **)malloc (def_queries_num
-                               * sizeof (*db->queries));
-
-               for (i = 0; i < def_queries_num; ++i) {
-                       db->queries[i] = c_psql_query_get (def_queries[i]);
-                       if (NULL == db->queries[i])
-                               log_err ("Query \"%s\" not found - "
-                                               "please check your installation.",
-                                               def_queries[i]);
-                       else
-                               ++db->queries_num;
-               }
+               for (i = 0; i < def_queries_num; ++i)
+                       set_query (db, def_queries[i]);
        }
        return 0;
 }