Introduce connection idle timeout.

* NEWS: Updated.
* configure.ac: Version 2.2.90
* doc/vmod-dbrw.3: Document connection idle timeout.
* doc/vmod-dbrw.texi: Likewise.
* src/dbrw.h (dbrw_backend) <sql_idle_timeout>: New method.
(dbrw_config)<idle_timeout>: New member.
(dbrw_connection)<timestamp>: New member.
(sql_idle_timeout): New proto.
* src/mysql.c (vmod_mysql_data) <mysql>: Change storage.
All uses changed.
(s_mysql_idle_timeout): New function.
* src/sql.c (sql_idle_timeout): New function.
(sql_query): Update connection timestamp.
(sql_idle_timeout): New function.
* src/vmod_dbrw.c (dbrw_connection_get): Force disconnect if connection
remained idle for too long. Initialize cfg->idle_timeout.
(vmod_config): New parameter 'timeout='

1 files changed, 40 insertions, 28 deletions

diff --git a/src/mysql.c b/src/mysql.c
index d7406ca..d97200a 100644
--- a/src/mysql.c
+++ b/src/mysql.c
@@ -1,5 +1,5 @@
 /* This file is part of vmod-dbrw
-   Copyright (C) 2013-2014 Sergey Poznyakoff
+   Copyright (C) 2013-2018 Sergey Poznyakoff
 
    Vmod-dbrw is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -21,7 +21,7 @@
 
 struct vmod_mysql_data
 {
-	MYSQL *mysql;
+	MYSQL mysql;
 	MYSQL_RES *result;
 	char *buffer;
 	size_t bufsize;
@@ -33,12 +33,12 @@ check_errno(struct dbrw_connection *conn)
 {
 	struct vmod_mysql_data *mp = conn->data;
 
-	switch (mysql_errno(mp->mysql)) {
+	switch (mysql_errno(&mp->mysql)) {
 	case CR_SERVER_GONE_ERROR:
 	case CR_SERVER_LOST:
 	case ER_SERVER_SHUTDOWN:
 	case ER_ABORTING_CONNECTION:
-		dbrw_error("query failed: %s", mysql_error(mp->mysql));
+		dbrw_error("query failed: %s", mysql_error(&mp->mysql));
 		sql_disconnect(conn);
 		if (conn->state == state_error) {
 			conn->state = state_disabled;
@@ -58,13 +58,13 @@ check_errno(struct dbrw_connection *conn)
 	case ER_FIELD_SPECIFIED_TWICE:
 	case ER_NO_SUCH_TABLE:
 	case ER_NOT_ALLOWED_COMMAND:
-		dbrw_error("query failed: %s", mysql_error(mp->mysql));
+		dbrw_error("query failed: %s", mysql_error(&mp->mysql));
 		dbrw_error("disabling MySQL connection");
 		sql_disconnect(conn);
 		conn->state = state_disabled;
 		break;
 	default:
-		dbrw_error("query failed: %s", mysql_error(mp->mysql));
+		dbrw_error("query failed: %s", mysql_error(&mp->mysql));
 	}
 }
 
@@ -88,7 +88,6 @@ s_mysql_destroy(struct dbrw_connection *conn)
 {
 	struct vmod_mysql_data *mp = conn->data;
 	free(mp->buffer);
-	free(mp->mysql);
 	free(mp);
 	conn->data = NULL;
 }
@@ -102,14 +101,7 @@ s_mysql_connect(struct dbrw_connection *conn)
 	char *s;
 	int port = 0;
 	
-	mp->mysql = malloc(sizeof(MYSQL));
-	if (!mp->mysql) {
-		dbrw_error("not enough memory");
-		conn->state = state_disabled;
-		return -1;
-	}
-	
-	mysql_init(mp->mysql);
+	mysql_init(&mp->mysql);
 
 	host = findparam(conn->conf->param, "server");
 	if (host && host[0] == '/') {
@@ -123,17 +115,17 @@ s_mysql_connect(struct dbrw_connection *conn)
 
 	s = findparam(conn->conf->param, "config");
 	if (s)
-		mysql_options(mp->mysql, MYSQL_READ_DEFAULT_FILE, s);
+		mysql_options(&mp->mysql, MYSQL_READ_DEFAULT_FILE, s);
 
 	s = findparam(conn->conf->param, "group");
 	if (s)
-		mysql_options(mp->mysql, MYSQL_READ_DEFAULT_GROUP, s);
+		mysql_options(&mp->mysql, MYSQL_READ_DEFAULT_GROUP, s);
 
 	s = findparam(conn->conf->param, "cacert");
 	if (s)
-		mysql_ssl_set(mp->mysql, NULL, NULL, s, NULL, NULL);
+		mysql_ssl_set(&mp->mysql, NULL, NULL, s, NULL, NULL);
 	debug(conn->conf, 1, ("connecting to database"));
-	if (!mysql_real_connect(mp->mysql, 
+	if (!mysql_real_connect(&mp->mysql, 
 				host,
 				findparam(conn->conf->param, "user"),
 				findparam(conn->conf->param, "password"),
@@ -141,7 +133,7 @@ s_mysql_connect(struct dbrw_connection *conn)
 				port,
 				socket_name,
 				CLIENT_MULTI_RESULTS)) {
-		dbrw_error("cannot connect: %s", mysql_error(mp->mysql));
+		dbrw_error("cannot connect: %s", mysql_error(&mp->mysql));
 		return -1;
 	}
 	debug(conn->conf, 1, ("connected to database"));
@@ -153,7 +145,7 @@ static int
 s_mysql_disconnect(struct dbrw_connection *conn)
 {
 	struct vmod_mysql_data *mp = conn->data;
-	mysql_close(mp->mysql);
+	mysql_close(&mp->mysql);
 	return 0;
 }
 
@@ -166,8 +158,7 @@ s_mysql_query(struct dbrw_connection *conn, const char *query)
 	MYSQL *mysql;
 	
 	for (i = 0; i < 10; i++) {
-		mysql = mp->mysql;
-		rc = mysql_query(mysql, query);
+		rc = mysql_query(&mp->mysql, query);
 		if (rc) {
 			check_errno(conn);
 			if (conn->state != state_init)
@@ -177,13 +168,13 @@ s_mysql_query(struct dbrw_connection *conn, const char *query)
 				return -1;
 			continue;
 		}
-		mp->result = mysql_store_result(mp->mysql);
+		mp->result = mysql_store_result(&mp->mysql);
 		if (mp->result) {
 			conn->state = state_result;
 		        rc = 0;
-		} else if (mysql_field_count(mp->mysql)) {
+		} else if (mysql_field_count(&mp->mysql)) {
 			dbrw_error("cannot store result: %s",
-				    mysql_error(mp->mysql));
+				    mysql_error(&mp->mysql));
 			conn->state = state_error;
 			rc = 1;
 		} else
@@ -267,7 +258,7 @@ s_mysql_escape (struct dbrw_connection *conn, const char *arg)
 		mp->bufsize = size;
 	}
 			 
-	mysql_real_escape_string(mp->mysql, mp->buffer, arg, len);
+	mysql_real_escape_string(&mp->mysql, mp->buffer, arg, len);
 
 	p = strdup(mp->buffer);
 	if (!p)
@@ -275,6 +266,26 @@ s_mysql_escape (struct dbrw_connection *conn, const char *arg)
 	return p;
 }
 
+static int
+s_mysql_idle_timeout(struct dbrw_connection *conn)
+{
+	const char *res;
+	int n;
+	if (sql_connect(conn) || conn->state != state_connected)
+		return -1;
+	if (sql_query(conn,
+		      "SHOW VARIABLES WHERE Variable_name = 'wait_timeout'"))
+		return -1;
+	res = sql_get_column(conn, 0, 1);
+	if (res)
+		n = atoi(res);
+	else
+		n = -1;
+	sql_free_result(conn);
+	return n;
+}
+
+
 struct dbrw_backend mysql_backend = {
 	"mysql",
 	s_mysql_init,
@@ -286,5 +297,6 @@ struct dbrw_backend mysql_backend = {
 	s_mysql_num_tuples,
 	s_mysql_num_fields,
 	s_mysql_free_result,
-	s_mysql_get_column
+	s_mysql_get_column,
+	s_mysql_idle_timeout
 };