rrdtool: Read last update timestamp from database on startup

[rrdd] / rrdtool.c

diff --git a/rrdtool.c b/rrdtool.c
index 658513be69b309a1e4e017ccacb42cfa7dc396bf..d286963c66ea6c04616ad9b5151a9bd2c530eede 100644 (file)
--- a/rrdtool.c
+++ b/rrdtool.c
@@ -388,6 +388,35 @@ static int database_exists(struct rrd_database *db)
        return 0;
 }
 
+static int get_last_update(struct rrd_database *db)
+{
+       char cmd[] = RRDTOOL_CMD;
+       char *args[10], argstr[ARGSTR_LEN];
+       char buf[16];
+       int idx = 0, argcnt = 0;
+       int ofd, efd, child;
+       int ret;
+
+       add_arg(args, argcnt, argstr, idx, RRDTOOL_CMD);
+       add_arg(args, argcnt, argstr, idx, "last");
+       add_arg(args, argcnt, argstr, idx, db->filename);
+
+       child = run_piped(cmd, args, NULL, &ofd, &efd);
+       ret = read(ofd, buf, sizeof(buf) - 1);
+       if (ret < 0) {
+               pr_err("Error reading: %m\n");
+               buf[0] = 0;
+       } else {
+               buf[ret] = 0;
+       }
+
+       db->last_update = atoi(buf);
+
+       clear_zombie(child);
+
+       return 0;
+}
+
 static int create_database(struct rrd_database *db)
 {
        char cmd[] = RRDTOOL_CMD;
@@ -443,6 +472,7 @@ int rrdtool_create_missing_databases(struct rrd_database *dbs[])
        for (i = 0, db = dbs[i]; db; i++, db = dbs[i]) {
                if (database_exists(db)) {
                        pr_info("database %s found\n", db->filename);
+                       get_last_update(db);
                        continue;
                }
                pr_info("Database %s missing, creating\n", db->filename);