From: Sebastian Harl <sh@tokkee.org>
Date: Thu, 25 Mar 2010 17:49:48 +0000 (+0100)
Subject: postgresql plugin: Connect to the database in the read function.
X-Git-Tag: collectd-4.10.0~41
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=8c8ad69c937a0dfdf328896c217c91499bf3e219;p=collectd.git

postgresql plugin: Connect to the database in the read function.

… rather than the init function. This way, we don't need access to some global
list of databases in the init function and it's done in preparation to using
the "complex read" system.
---

diff --git a/src/postgresql.c b/src/postgresql.c
index e6527b95..6a54fc0a 100644
--- a/src/postgresql.c
+++ b/src/postgresql.c
@@ -196,8 +196,49 @@ static void c_psql_database_delete (c_psql_database_t *db)
 	return;
 } /* c_psql_database_delete */
 
+static int c_psql_connect (c_psql_database_t *db)
+{
+	char  conninfo[4096];
+	char *buf     = conninfo;
+	int   buf_len = sizeof (conninfo);
+	int   status;
+
+	if (! db)
+		return -1;
+
+	status = ssnprintf (buf, buf_len, "dbname = '%s'", db->database);
+	if (0 < status) {
+		buf     += status;
+		buf_len -= status;
+	}
+
+	C_PSQL_PAR_APPEND (buf, buf_len, "host",       db->host);
+	C_PSQL_PAR_APPEND (buf, buf_len, "port",       db->port);
+	C_PSQL_PAR_APPEND (buf, buf_len, "user",       db->user);
+	C_PSQL_PAR_APPEND (buf, buf_len, "password",   db->password);
+	C_PSQL_PAR_APPEND (buf, buf_len, "sslmode",    db->sslmode);
+	C_PSQL_PAR_APPEND (buf, buf_len, "krbsrvname", db->krbsrvname);
+	C_PSQL_PAR_APPEND (buf, buf_len, "service",    db->service);
+
+	db->conn = PQconnectdb (conninfo);
+	db->proto_version = PQprotocolVersion (db->conn);
+	return 0;
+} /* c_psql_connect */
+
 static int c_psql_check_connection (c_psql_database_t *db)
 {
+	_Bool init = 0;
+
+	if (! db->conn) {
+		init = 1;
+
+		/* trigger c_release() */
+		if (0 == db->conn_complaint.interval)
+			db->conn_complaint.interval = 1;
+
+		c_psql_connect (db);
+	}
+
 	/* "ping" */
 	PQclear (PQexec (db->conn, "SELECT 42;"));
 
@@ -216,15 +257,30 @@ static int c_psql_check_connection (c_psql_database_t *db)
 		}
 
 		db->proto_version = PQprotocolVersion (db->conn);
-		if (3 > db->proto_version)
-			log_warn ("Protocol version %d does not support parameters.",
-					db->proto_version);
 	}
 
 	db->server_version = PQserverVersion (db->conn);
 
-	c_release (LOG_INFO, &db->conn_complaint,
-			"Successfully reconnected to database %s", PQdb (db->conn));
+	if (c_would_release (&db->conn_complaint)) {
+		char *server_host;
+		int   server_version;
+
+		server_host    = PQhost (db->conn);
+		server_version = PQserverVersion (db->conn);
+
+		c_do_release (LOG_INFO, &db->conn_complaint,
+				"Successfully %sconnected to database %s (user %s) "
+				"at server %s%s%s (server version: %d.%d.%d, "
+				"protocol version: %d, pid: %d)", init ? "" : "re",
+				PQdb (db->conn), PQuser (db->conn),
+				C_PSQL_SOCKET3 (server_host, PQport (db->conn)),
+				C_PSQL_SERVER_VERSION3 (server_version),
+				db->proto_version, PQbackendPID (db->conn));
+
+		if (3 > db->proto_version)
+			log_warn ("Protocol version %d does not support parameters.",
+					db->proto_version);
+	}
 	return 0;
 } /* c_psql_check_connection */
 
@@ -452,63 +508,9 @@ static int c_psql_shutdown (void)
 
 static int c_psql_init (void)
 {
-	int i;
-
 	if ((NULL == databases) || (0 == databases_num))
 		return 0;
 
-	for (i = 0; i < databases_num; ++i) {
-		c_psql_database_t *db = databases + i;
-
-		char  conninfo[4096];
-		char *buf     = conninfo;
-		int   buf_len = sizeof (conninfo);
-		int   status;
-
-		char *server_host;
-		int   server_version;
-
-		/* this will happen during reinitialization */
-		if (NULL != db->conn) {
-			c_psql_check_connection (db);
-			continue;
-		}
-
-		status = ssnprintf (buf, buf_len, "dbname = '%s'", db->database);
-		if (0 < status) {
-			buf     += status;
-			buf_len -= status;
-		}
-
-		C_PSQL_PAR_APPEND (buf, buf_len, "host",       db->host);
-		C_PSQL_PAR_APPEND (buf, buf_len, "port",       db->port);
-		C_PSQL_PAR_APPEND (buf, buf_len, "user",       db->user);
-		C_PSQL_PAR_APPEND (buf, buf_len, "password",   db->password);
-		C_PSQL_PAR_APPEND (buf, buf_len, "sslmode",    db->sslmode);
-		C_PSQL_PAR_APPEND (buf, buf_len, "krbsrvname", db->krbsrvname);
-		C_PSQL_PAR_APPEND (buf, buf_len, "service",    db->service);
-
-		db->conn = PQconnectdb (conninfo);
-		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 ("Successfully connected to database %s (user %s) "
-				"at server %s%s%s (server version: %d.%d.%d, "
-				"protocol version: %d, pid: %d)",
-				PQdb (db->conn), PQuser (db->conn),
-				C_PSQL_SOCKET3 (server_host, PQport (db->conn)),
-				C_PSQL_SERVER_VERSION3 (server_version),
-				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);
 	plugin_register_shutdown ("postgresql", c_psql_shutdown);
 	return 0;