text: /**
   * 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
  #define UTILS_MATCH_FLAGS_EXCLUDE_REGEX 0x02
  
  struct cu_match_s
  {
    regex_t regex;
    regex_t excluderegex;
    int flags;
  
    int (*callback) (const char *str, char * const *matches, size_t matches_num,
        void *user_data);
    void *user_data;
  };
  
  /*
   * Private functions
   */
  static char *match_substr (const char *str, int begin, int end)
  {
    char *ret;
    size_t ret_len;
  
    if ((begin < 0) || (end < 0) || (begin >= end))
      return (NULL);
    if ((size_t) end > (strlen (str) + 1))
    {
      ERROR ("utils_match: match_substr: `end' points after end of string.");
      return (NULL);
    }
  
    ret_len = end - begin;
    ret = (char *) malloc (sizeof (char) * (ret_len + 1));
    if (ret == NULL)
    {
      ERROR ("utils_match: match_substr: malloc failed.");
      return (NULL);
    }
  
    sstrncpy (ret, str + begin, ret_len + 1);
    return (ret);
  } /* char *match_substr */
  
  static int default_callback (const char __attribute__((unused)) *str,
      char * const *matches, size_t matches_num, 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;
  
      if (matches_num < 2)
        return (-1);
  
      value = (gauge_t) strtod (matches[1], &endptr);
      if (matches[1] == endptr)
        return (-1);
  
      if ((data->values_num == 0)
  	|| (data->ds_type & UTILS_MATCH_CF_GAUGE_LAST))
      {
        data->value.gauge = value;
      }
      else if (data->ds_type & UTILS_MATCH_CF_GAUGE_AVERAGE)
      {
        double f = ((double) data->values_num)
  	/ ((double) (data->values_num + 1));
        data->value.gauge = (data->value.gauge * f) + (value * (1.0 - f));
      }
      else if (data->ds_type & UTILS_MATCH_CF_GAUGE_MIN)
      {
        if (data->value.gauge > value)
  	data->value.gauge = value;
      }
      else if (data->ds_type & UTILS_MATCH_CF_GAUGE_MAX)
      {
        if (data->value.gauge < value)
  	data->value.gauge = value;
      }
      else
      {
        ERROR ("utils_match: default_callback: obj->ds_type is invalid!");
        return (-1);
      }
  
      data->values_num++;
    }
    else if (data->ds_type & UTILS_MATCH_DS_TYPE_COUNTER)
    {
      counter_t value;
      char *endptr = NULL;
  
      if (data->ds_type & UTILS_MATCH_CF_COUNTER_INC)
      {
        data->value.counter++;
        data->values_num++;
        return (0);
      }
  
      if (matches_num < 2)
        return (-1);
  
      value = (counter_t) strtoull (matches[1], &endptr, 0);
      if (matches[1] == endptr)
        return (-1);
  
      if (data->ds_type & UTILS_MATCH_CF_COUNTER_SET)
        data->value.counter = value;
      else if (data->ds_type & UTILS_MATCH_CF_COUNTER_ADD)
        data->value.counter += value;
      else
      {
        ERROR ("utils_match: default_callback: obj->ds_type is invalid!");
        return (-1);
      }
  
      data->values_num++;
    }
    else if (data->ds_type & UTILS_MATCH_DS_TYPE_DERIVE)
    {
      derive_t value;
      char *endptr = NULL;
  
      if (data->ds_type & UTILS_MATCH_CF_DERIVE_INC)
      {
        data->value.counter++;
        data->values_num++;
        return (0);
      }
  
      if (matches_num < 2)
        return (-1);
  
      value = (derive_t) strtoll (matches[1], &endptr, 0);
      if (matches[1] == endptr)
        return (-1);
  
      if (data->ds_type & UTILS_MATCH_CF_DERIVE_SET)
        data->value.derive = value;
      else if (data->ds_type & UTILS_MATCH_CF_DERIVE_ADD)
        data->value.derive += value;
      else
      {
        ERROR ("utils_match: default_callback: obj->ds_type is invalid!");
        return (-1);
      }
  
      data->values_num++;
    }
    else if (data->ds_type & UTILS_MATCH_DS_TYPE_ABSOLUTE)
    {
      absolute_t value;
      char *endptr = NULL;
  
      if (matches_num < 2)
        return (-1);
  
      value = (absolute_t) strtoull (matches[1], &endptr, 0);
      if (matches[1] == endptr)
        return (-1);
  
      if (data->ds_type & UTILS_MATCH_CF_ABSOLUTE_SET)
        data->value.absolute = value;
      else
      {
        ERROR ("utils_match: default_callback: obj->ds_type is invalid!");
        return (-1);
      }
  
      data->values_num++;
    }
    else
    {
      ERROR ("utils_match: default_callback: obj->ds_type is invalid!");
      return (-1);
    }
  
    return (0);
  } /* int default_callback */
  
  /*
   * Public functions
   */
  cu_match_t *match_create_callback (const char *regex, const char *excluderegex,
  		int (*callback) (const char *str,
  		  char * const *matches, size_t matches_num, void *user_data),
  		void *user_data)
  {
    cu_match_t *obj;
    int status;
  
    DEBUG ("utils_match: match_create_callback: regex = %s, excluderegex = %s",
  	 regex, excluderegex);
  
    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 | REG_NEWLINE);
    if (status != 0)
    {
      ERROR ("Compiling the regular expression \"%s\" failed.", regex);
      sfree (obj);
      return (NULL);
    }
  
    if (excluderegex && strcmp(excluderegex, "") != 0) {
      status = regcomp (&obj->excluderegex, excluderegex, REG_EXTENDED);
      if (status != 0)
      {
  	ERROR ("Compiling the excluding regular expression \"%s\" failed.",
  	       excluderegex);
  	sfree (obj);
  	return (NULL);
      }
      obj->flags |= UTILS_MATCH_FLAGS_EXCLUDE_REGEX;
    }
  
    obj->callback = callback;
    obj->user_data = user_data;
  
    return (obj);
  } /* cu_match_t *match_create_callback */
  
  cu_match_t *match_create_simple (const char *regex,
  				 const char *excluderegex, 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));
    user_data->ds_type = match_ds_type;
  
    obj = match_create_callback (regex, excluderegex,
  			       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_simple */
  
  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[32];
    char *matches[32];
    size_t matches_num;
    size_t i;
  
    if ((obj == NULL) || (str == NULL))
      return (-1);
  
    if (obj->flags & UTILS_MATCH_FLAGS_EXCLUDE_REGEX) {
      status = regexec (&obj->excluderegex, str,
  		      STATIC_ARRAY_SIZE (re_match), re_match,
  		      /* eflags = */ 0);
      /* Regex did match, so exclude this line */
      if (status == 0) {
        DEBUG("ExludeRegex matched, don't count that line\n");
        return (0);
      }
    }
  
    status = regexec (&obj->regex, str,
        STATIC_ARRAY_SIZE (re_match), re_match,
        /* eflags = */ 0);
  
    /* Regex did not match */
    if (status != 0)
      return (0);
  
    memset (matches, '\0', sizeof (matches));
    for (matches_num = 0; matches_num < STATIC_ARRAY_SIZE (matches); matches_num++)
    {
      if ((re_match[matches_num].rm_so < 0)
  	|| (re_match[matches_num].rm_eo < 0))
        break;
  
      matches[matches_num] = match_substr (str,
  	re_match[matches_num].rm_so, re_match[matches_num].rm_eo);
      if (matches[matches_num] == NULL)
      {
        status = -1;
        break;
      }
    }
  
    if (status != 0)
    {
      ERROR ("utils_match: match_apply: match_substr failed.");
    }
    else
    {
      status = obj->callback (str, matches, matches_num, obj->user_data);
      if (status != 0)
      {
        ERROR ("utils_match: match_apply: callback failed.");
      }
    }
  
    for (i = 0; i < matches_num; i++)
    {
      sfree (matches[i]);
    }
  
    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 : */
  