src/utils_match.[ch]: Add a module to automate regular expression matching on a string.

[collectd.git] / src / utils_match.c

diff --git a/src/utils_match.c b/src/utils_match.c
new file mode 100644 (file)
index 0000000..23bedb1
--- /dev/null
+++ b/src/utils_match.c
@@ -0,0 +1,201 @@
+/**
+ * collectd - src/utils_match.c
+ * Copyright (C) 2008  Florian octo 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; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * 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>
+ **/
+
+#include "collectd.h"
+#include "common.h"
+#include "plugin.h"
+
+#include "utils_match.h"
+
+#include <regex.h>
+
+#define UTILS_MATCH_FLAGS_FREE_USER_DATA 0x01
+
+struct cu_match_s
+{
+  regex_t regex;
+  int flags;
+
+  int (*callback) (const char *str, void *user_data);
+  void *user_data;
+};
+
+/*
+ * Private functions
+ */
+static int default_callback (const char *str, void *user_data)
+{
+  cu_match_value_t *data = (cu_match_value_t *) user_data;
+
+  if (data->ds_type == UTILS_MATCH_DS_TYPE_GAUGE)
+  {
+    gauge_t value;
+    char *endptr = NULL;
+
+    value = strtod (str, &endptr);
+    if (str == endptr)
+      return (-1);
+
+    data->value.gauge = value;
+  }
+  else if ((data->ds_type == UTILS_MATCH_DS_TYPE_COUNTER_SET)
+      || (data->ds_type == UTILS_MATCH_DS_TYPE_COUNTER_ADD))
+  {
+    counter_t value;
+    char *endptr = NULL;
+
+    value = strtoll (str, &endptr, 0);
+    if (str == endptr)
+      return (-1);
+
+    if (data->ds_type == UTILS_MATCH_DS_TYPE_COUNTER_SET)
+      data->value.counter = value;
+    else
+      data->value.counter += value;
+  }
+  else if (data->ds_type == UTILS_MATCH_DS_TYPE_COUNTER_INC)
+  {
+    data->value.counter++;
+  }
+  else
+  {
+    return (-1);
+  }
+
+  return (0);
+} /* int default_callback */
+
+/*
+ * Public functions
+ */
+cu_match_t *match_create_callback (const char *regex,
+               int (*callback) (const char *str, void *user_data),
+               void *user_data)
+{
+  cu_match_t *obj;
+  int status;
+
+  obj = (cu_match_t *) malloc (sizeof (cu_match_t));
+  if (obj == NULL)
+    return (NULL);
+  memset (obj, '\0', sizeof (cu_match_t));
+
+  status = regcomp (&obj->regex, regex, REG_EXTENDED);
+  if (status != 0)
+  {
+    ERROR ("Compiling the regular expression \"%s\" failed.", regex);
+    sfree (obj);
+    return (NULL);
+  }
+
+  obj->callback = callback;
+  obj->user_data = user_data;
+
+  return (obj);
+} /* cu_match_t *match_create_callback */
+
+cu_match_t *match_create_default (const char *regex, int match_ds_type)
+{
+  cu_match_value_t *user_data;
+  cu_match_t *obj;
+
+  user_data = (cu_match_value_t *) malloc (sizeof (cu_match_value_t));
+  if (user_data == NULL)
+    return (NULL);
+  memset (user_data, '\0', sizeof (cu_match_value_t));
+
+  obj = match_create_callback (regex, default_callback, user_data);
+  if (obj == NULL)
+  {
+    sfree (user_data);
+    return (NULL);
+  }
+
+  obj->flags |= UTILS_MATCH_FLAGS_FREE_USER_DATA;
+
+  return (obj);
+} /* cu_match_t *match_create_default */
+
+void match_destroy (cu_match_t *obj)
+{
+  if (obj == NULL)
+    return;
+
+  if (obj->flags & UTILS_MATCH_FLAGS_FREE_USER_DATA)
+  {
+    sfree (obj->user_data);
+  }
+
+  sfree (obj);
+} /* void match_destroy */
+
+int match_apply (cu_match_t *obj, const char *str)
+{
+  int status;
+  regmatch_t re_match;
+  char *sub_match;
+  size_t sub_match_len;
+
+  if ((obj == NULL) || (str == NULL))
+    return (-1);
+
+  re_match.rm_so = -1;
+  re_match.rm_eo = -1;
+
+  status = regexec (&obj->regex, str, /* nmatch = */ 1, &re_match,
+      /* eflags = */ 0);
+
+  /* Regex did not match */
+  if (status != 0)
+    return (0);
+
+  if (re_match.rm_so < 0)
+  {
+    status = obj->callback (str, obj->user_data);
+    return (status);
+  }
+
+  assert (re_match.rm_so < re_match.rm_eo);
+  sub_match_len = (size_t) (re_match.rm_eo - re_match.rm_so);
+  sub_match = (char *) malloc (sizeof (char) * (sub_match_len + 1));
+  if (sub_match == NULL)
+  {
+    ERROR ("malloc failed.");
+    return (-1);
+  }
+  sstrncpy (sub_match, str + re_match.rm_so, sub_match_len + 1);
+
+  status = obj->callback (sub_match, obj->user_data);
+
+  sfree (sub_match);
+
+  return (status);
+} /* int match_apply */
+
+void *match_get_user_data (cu_match_t *obj)
+{
+  if (obj == NULL)
+    return (NULL);
+  return (obj->user_data);
+} /* void *match_get_user_data */
+
+/* vim: set sw=2 sts=2 ts=8 : */