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>
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) /* {{{ */
103 m = calloc (1, sizeof (*m));
106 ERROR ("mh_create: calloc failed.");
110 for (int i = 0; i < ci->children_num; i++)
112 oconfig_item_t *child = ci->children + i;
114 if (strcasecmp ("Match", child->key) == 0)
115 mh_config_match (child, m);
117 ERROR ("hashed match: No such config option: %s", child->key);
120 if (m->matches_num == 0)
124 ERROR ("hashed match: No matches were configured. Not creating match.");
130 } /* }}} int mh_create */
132 static int mh_destroy (void **user_data) /* {{{ */
136 if ((user_data == NULL) || (*user_data == NULL))
144 } /* }}} int mh_destroy */
146 static int mh_match (const data_set_t __attribute__((unused)) *ds, /* {{{ */
147 const value_list_t *vl,
148 notification_meta_t __attribute__((unused)) **meta, void **user_data)
153 if ((user_data == NULL) || (*user_data == NULL))
160 for (const char *host_ptr = vl->host; *host_ptr != 0; host_ptr++)
162 /* 2184401929 is some appropriately sized prime number. */
163 hash_val = (hash_val * UINT32_C (2184401929)) + ((uint32_t) *host_ptr);
165 DEBUG ("hashed match: host = %s; hash_val = %"PRIu32";", vl->host, hash_val);
167 for (size_t i = 0; i < m->matches_num; i++)
168 if ((hash_val % m->matches[i].total) == m->matches[i].match)
169 return (FC_MATCH_MATCHES);
171 return (FC_MATCH_NO_MATCH);
172 } /* }}} int mh_match */
174 void module_register (void)
176 match_proc_t mproc = { 0 };
178 mproc.create = mh_create;
179 mproc.destroy = mh_destroy;
180 mproc.match = mh_match;
181 fc_register_match ("hashed", mproc);
182 } /* module_register */
184 /* vim: set sw=2 sts=2 tw=78 et fdm=marker : */