2 * collectd - src/match_hashed.c
3 * Copyright (C) 2009 Florian Forster
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
12 * The above copyright notice and this permission notice shall be included in
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15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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21 * DEALINGS IN THE SOFTWARE.
24 * Florian Forster <octo at collectd.org>
29 #include "utils_cache.h"
30 #include "filter_chain.h"
35 struct mh_hash_match_s
40 typedef struct mh_hash_match_s mh_hash_match_t;
43 typedef struct mh_match_s mh_match_t;
46 mh_hash_match_t *matches;
51 * internal helper functions
53 static int mh_config_match (const oconfig_item_t *ci, /* {{{ */
58 if ((ci->values_num != 2)
59 || (ci->values[0].type != OCONFIG_TYPE_NUMBER)
60 || (ci->values[1].type != OCONFIG_TYPE_NUMBER))
62 ERROR ("hashed match: The `Match' option requires "
63 "exactly two numeric arguments.");
67 if ((ci->values[0].value.number < 0)
68 || (ci->values[1].value.number < 0))
70 ERROR ("hashed match: The arguments of the `Match' "
71 "option must be positive.");
75 tmp = realloc (m->matches, sizeof (*tmp) * (m->matches_num + 1));
78 ERROR ("hashed match: realloc failed.");
82 tmp = m->matches + m->matches_num;
84 tmp->match = (uint32_t) (ci->values[0].value.number + .5);
85 tmp->total = (uint32_t) (ci->values[1].value.number + .5);
87 if (tmp->match >= tmp->total)
89 ERROR ("hashed match: The first argument of the `Match' option "
90 "must be smaller than the second argument.");
93 assert (tmp->total != 0);
97 } /* }}} int mh_config_match */
99 static int mh_create (const oconfig_item_t *ci, void **user_data) /* {{{ */
104 m = calloc (1, sizeof (*m));
107 ERROR ("mh_create: calloc failed.");
111 for (i = 0; i < ci->children_num; i++)
113 oconfig_item_t *child = ci->children + i;
115 if (strcasecmp ("Match", child->key) == 0)
116 mh_config_match (child, m);
118 ERROR ("hashed match: No such config option: %s", child->key);
121 if (m->matches_num == 0)
125 ERROR ("hashed match: No matches were configured. Not creating match.");
131 } /* }}} int mh_create */
133 static int mh_destroy (void **user_data) /* {{{ */
137 if ((user_data == NULL) || (*user_data == NULL))
145 } /* }}} int mh_destroy */
147 static int mh_match (const data_set_t __attribute__((unused)) *ds, /* {{{ */
148 const value_list_t *vl,
149 notification_meta_t __attribute__((unused)) **meta, void **user_data)
153 const char *host_ptr;
156 if ((user_data == NULL) || (*user_data == NULL))
163 for (host_ptr = vl->host; *host_ptr != 0; host_ptr++)
165 /* 2184401929 is some appropriately sized prime number. */
166 hash_val = (hash_val * UINT32_C (2184401929)) + ((uint32_t) *host_ptr);
168 DEBUG ("hashed match: host = %s; hash_val = %"PRIu32";", vl->host, hash_val);
170 for (i = 0; i < m->matches_num; i++)
171 if ((hash_val % m->matches[i].total) == m->matches[i].match)
172 return (FC_MATCH_MATCHES);
174 return (FC_MATCH_NO_MATCH);
175 } /* }}} int mh_match */
177 void module_register (void)
181 memset (&mproc, 0, sizeof (mproc));
182 mproc.create = mh_create;
183 mproc.destroy = mh_destroy;
184 mproc.match = mh_match;
185 fc_register_match ("hashed", mproc);
186 } /* module_register */
188 /* vim: set sw=2 sts=2 tw=78 et fdm=marker : */