value match: Add a match to check the actual value(s) of data-sources.

[collectd.git] / src / match_value.c

diff --git a/src/match_value.c b/src/match_value.c
new file mode 100644 (file)
index 0000000..b850b77
--- /dev/null
+++ b/src/match_value.c
@@ -0,0 +1,219 @@
+/**
+ * collectd - src/match_value.c
+ * Copyright (C) 2008  Florian Forster
+ *
+ * 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 Forster <octo at verplant.org>
+ **/
+
+/*
+ * This module allows to filter and rewrite value lists based on
+ * Perl-compatible regular expressions.
+ */
+
+#include "collectd.h"
+#include "utils_cache.h"
+#include "filter_chain.h"
+
+/*
+ * private data types
+ */
+struct mv_match_s;
+typedef struct mv_match_s mv_match_t;
+struct mv_match_s
+{
+  gauge_t min;
+  gauge_t max;
+  int invert;
+};
+
+/*
+ * internal helper functions
+ */
+static void mv_free_match (mv_match_t *m) /* {{{ */
+{
+  if (m == NULL)
+    return;
+
+  free (m);
+} /* }}} void mv_free_match */
+
+static int mv_config_add_gauge (gauge_t *ret_value, /* {{{ */
+    oconfig_item_t *ci)
+{
+
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_NUMBER))
+  {
+    ERROR ("`value' match: `%s' needs exactly one numeric argument.",
+        ci->key);
+    return (-1);
+  }
+
+  *ret_value = ci->values[0].value.number;
+
+  return (0);
+} /* }}} int mv_config_add_gauge */
+
+static int mv_config_add_boolean (int *ret_value, /* {{{ */
+    oconfig_item_t *ci)
+{
+
+  if ((ci->values_num != 1) || (ci->values[0].type != OCONFIG_TYPE_BOOLEAN))
+  {
+    ERROR ("`value' match: `%s' needs exactly one boolean argument.",
+        ci->key);
+    return (-1);
+  }
+
+  if (ci->values[0].value.boolean)
+    *ret_value = 1;
+  else
+    *ret_value = 0;
+
+  return (0);
+} /* }}} int mv_config_add_boolean */
+
+static int mv_create (const oconfig_item_t *ci, void **user_data) /* {{{ */
+{
+  mv_match_t *m;
+  int status;
+  int i;
+
+  m = (mv_match_t *) malloc (sizeof (*m));
+  if (m == NULL)
+  {
+    ERROR ("mv_create: malloc failed.");
+    return (-ENOMEM);
+  }
+  memset (m, 0, sizeof (*m));
+
+  m->min = NAN;
+  m->max = NAN;
+  m->invert = 0;
+
+  status = 0;
+  for (i = 0; i < ci->children_num; i++)
+  {
+    oconfig_item_t *child = ci->children + i;
+
+    if (strcasecmp ("Min", child->key) == 0)
+      status = mv_config_add_gauge (&m->min, child);
+    else if (strcasecmp ("Max", child->key) == 0)
+      status = mv_config_add_gauge (&m->max, child);
+    else if (strcasecmp ("Invert", child->key) == 0)
+      status = mv_config_add_boolean (&m->invert, child);
+    else
+    {
+      ERROR ("`value' match: The `%s' configuration option is not "
+          "understood and will be ignored.", child->key);
+      status = 0;
+    }
+
+    if (status != 0)
+      break;
+  }
+
+  /* Additional sanity-checking */
+  while (status == 0)
+  {
+    if (isnan (m->min) && isnan (m->max))
+    {
+      ERROR ("`value' match: Neither minimum nor maximum are defined. "
+          "This match will be ignored.");
+      status = -1;
+    }
+
+    break;
+  }
+
+  if (status != 0)
+  {
+    mv_free_match (m);
+    return (status);
+  }
+
+  *user_data = m;
+  return (0);
+} /* }}} int mv_create */
+
+static int mv_destroy (void **user_data) /* {{{ */
+{
+  if ((user_data != NULL) && (*user_data != NULL))
+    mv_free_match (*user_data);
+  return (0);
+} /* }}} int mv_destroy */
+
+static int mv_match (const data_set_t *ds, const value_list_t *vl, /* {{{ */
+    notification_meta_t **meta, void **user_data)
+{
+  mv_match_t *m;
+  gauge_t *values;
+  int status;
+  int i;
+
+  if ((user_data == NULL) || (*user_data == NULL))
+    return (-1);
+
+  m = *user_data;
+
+  values = uc_get_rate (ds, vl);
+  if (values == NULL)
+  {
+    ERROR ("`value' match: Retrieving the current rate from the cache "
+        "failed.");
+    return (-1);
+  }
+
+  status = FC_MATCH_MATCHES;
+  for (i = 0; i < ds->ds_num; i++)
+  {
+    DEBUG ("`value' match: current = %g; min = %g; max = %g; invert = %s;",
+        values[i], m->min, m->max,
+        m->invert ? "true" : "false");
+
+    if ((!isnan (m->min) && (values[i] < m->min))
+        || (!isnan (m->max) && (values[i] > m->max)))
+    {
+      status = FC_MATCH_NO_MATCH;
+      break;
+    }
+  }
+
+  if (m->invert)
+  {
+    if (status == FC_MATCH_MATCHES)
+      status = FC_MATCH_NO_MATCH;
+    else
+      status = FC_MATCH_MATCHES;
+  }
+
+  free (values);
+  return (status);
+} /* }}} int mv_match */
+
+void module_register (void)
+{
+  match_proc_t mproc;
+
+  memset (&mproc, 0, sizeof (mproc));
+  mproc.create  = mv_create;
+  mproc.destroy = mv_destroy;
+  mproc.match   = mv_match;
+  fc_register_match ("value", mproc);
+} /* module_register */
+
+/* vim: set sw=2 sts=2 tw=78 et fdm=marker : */
+