src/utils_complain.[ch]: Reintroduced an improved version of the complain mechanism.

This has been asked for a couple of times and since I need it now, here it
goes... ;-) I've done the following modifications to Florian's original
version:

 * Renamed "plugin_complain" to "c_complain".
 * Renamed "plugin_relief" to "c_release", thus using two verbs which is
   more consistent imho.
 * Added "c_complain_once" to report a complaint only once.
 * Use timestamps instead of counting multiples of "interval_g" to
   determine when to report again. Thus, multiple calls to the complain-
   functions in one interval are allowed.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>

diff --git a/src/Makefile.am b/src/Makefile.am
index 194c1a7b28d36fe226e4b5f9b575dd03a1e44ee6..42a1124a16fb9c6690afd3cba9040efbb2d24358 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -31,6 +31,7 @@ collectd_SOURCES = collectd.c collectd.h \
                   plugin.c plugin.h \
                   utils_avltree.c utils_avltree.h \
                   utils_cache.c utils_cache.h \
+                  utils_complain.c utils_complain.h \
                   utils_ignorelist.c utils_ignorelist.h \
                   utils_llist.c utils_llist.h \
                   utils_tail_match.c utils_tail_match.h \

diff --git a/src/utils_complain.c b/src/utils_complain.c
new file mode 100644 (file)
index 0000000..9d0f466
--- /dev/null
+++ b/src/utils_complain.c
@@ -0,0 +1,101 @@
+/**
+ * collectd - src/utils_complain.c
+ * Copyright (C) 2006-2007  Florian octo Forster
+ * Copyright (C) 2008  Sebastian tokkee Harl
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ *   Sebastian tokkee Harl <sh at tokkee.org>
+ **/
+
+#include "utils_complain.h"
+#include "plugin.h"
+
+/* vcomplain returns 0 if it did not report, 1 else */
+static int vcomplain (int level, c_complain_t *c,
+               const char *format, va_list ap)
+{
+       time_t now;
+       char   message[512];
+
+       now = time (NULL);
+
+       if (c->last + c->interval > now)
+               return 0;
+
+       c->last = now;
+
+       if (c->interval < interval_g)
+               c->interval = interval_g;
+       else
+               c->interval *= 2;
+
+       if (c->interval > 86400)
+               c->interval = 86400;
+
+       vsnprintf (message, sizeof (message), format, ap);
+       message[sizeof (message) - 1] = '\0';
+
+       plugin_log (level, message);
+       return 1;
+} /* vcomplain */
+
+void c_complain (int level, c_complain_t *c, const char *format, ...)
+{
+       va_list ap;
+
+       /* reset the old interval */
+       if (c->interval < 0)
+               c->interval *= -1;
+
+       va_start (ap, format);
+       vcomplain (level, c, format, ap);
+       va_end (ap);
+} /* c_complain */
+
+void c_complain_once (int level, c_complain_t *c, const char *format, ...)
+{
+       va_list ap;
+
+       if (c->interval < 0)
+               return;
+
+       va_start (ap, format);
+       if (vcomplain (level, c, format, ap))
+               c->interval *= -1;
+       va_end (ap);
+} /* c_complain_once */
+
+void c_release (int level, c_complain_t *c, const char *format, ...)
+{
+       char message[512];
+       va_list ap;
+
+       if (c->interval == 0)
+               return;
+
+       c->interval = 0;
+
+       va_start (ap, format);
+       vsnprintf (message, sizeof (message), format, ap);
+       message[sizeof (message) - 1] = '\0';
+       va_end (ap);
+
+       plugin_log (level, message);
+} /* c_release */
+
+/* vim: set sw=4 ts=4 tw=78 noexpandtab : */
+

diff --git a/src/utils_complain.h b/src/utils_complain.h
new file mode 100644 (file)
index 0000000..56e74ea
--- /dev/null
+++ b/src/utils_complain.h
@@ -0,0 +1,91 @@
+/**
+ * collectd - src/utils_complain.h
+ * Copyright (C) 2006-2007  Florian octo Forster
+ * Copyright (C) 2008  Sebastian tokkee Harl
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; only version 2 of the License is applicable.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ *   Sebastian tokkee Harl <sh at tokkee.org>
+ **/
+
+#ifndef UTILS_COMPLAIN_H
+#define UTILS_COMPLAIN_H 1
+
+#include <time.h>
+
+typedef struct
+{
+       /* time of the last report */
+       time_t last;
+
+       /* how long to wait until reporting again
+        *   0 indicates that the complaint is no longer valid
+        * < 0 indicates that the complaint has been reported once
+        *     => c_complain_once will not report again
+        *     => c_complain uses the absolute value to reset the old value */
+       int interval;
+} c_complain_t;
+
+#define C_COMPLAIN_INIT { 0, 0 }
+
+/*
+ * NAME
+ *   c_complain
+ *
+ * DESCRIPTION
+ *   Complain about something. This function will report a message (usually
+ *   indicating some error condition) using the collectd logging mechanism.
+ *   When this function is called again, reporting the message again will be
+ *   deferred by an increasing interval (up to one day) to prevent flooding
+ *   the logs. A call to `c_release' resets the counter.
+ *
+ * PARAMETERS
+ *   `level'  The log level passed to `plugin_log'.
+ *   `c'      Identifier for the complaint.
+ *   `format' Message format - see the documentation of printf(3).
+ */
+void c_complain (int level, c_complain_t *c, const char *format, ...);
+
+/*
+ * NAME
+ *   c_complain_once
+ *
+ * DESCRIPTION
+ *   Complain about something once. This function will not report anything
+ *   again, unless `c_release' has been called in between. If used after some
+ *   calls to `c_complain', it will report again on the next interval and stop
+ *   after that.
+ *
+ *   See `c_complain' for further details and a description of the parameters.
+ */
+void c_complain_once (int level, c_complain_t *c, const char *format, ...);
+
+/*
+ * NAME
+ *   c_release
+ *
+ * DESCRIPTION
+ *   Release a complaint. This will report a message once, marking the
+ *   complaint as released.
+ *
+ *   See `c_complain' for a description of the parameters.
+ */
+void c_release (int level, c_complain_t *c, const char *format, ...);
+
+#endif /* UTILS_COMPLAIN_H */
+
+/* vim: set sw=4 ts=4 tw=78 noexpandtab : */
+