/usr/include/mysql/private/hash_filo.h is in libmariadbclient-dev 5.5.36-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 | /* Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
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; version 2 of the License.
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 */
/*
** A class for static sized hash tables where old entries are deleted in
** first-in-last-out to usage.
*/
#ifndef HASH_FILO_H
#define HASH_FILO_H
#ifdef USE_PRAGMA_INTERFACE
#pragma interface /* gcc class interface */
#endif
#include "hash.h" /* my_hash_get_key, my_hash_free_key, HASH */
#include "m_string.h" /* bzero */
#include "mysqld.h" /* key_hash_filo_lock */
class hash_filo_element
{
hash_filo_element *next_used,*prev_used;
public:
hash_filo_element() {}
friend class hash_filo;
};
class hash_filo
{
const uint size, key_offset, key_length;
const my_hash_get_key get_key;
my_hash_free_key free_element;
bool init;
CHARSET_INFO *hash_charset;
hash_filo_element *first_link,*last_link;
public:
mysql_mutex_t lock;
HASH cache;
hash_filo(uint size_arg, uint key_offset_arg , uint key_length_arg,
my_hash_get_key get_key_arg, my_hash_free_key free_element_arg,
CHARSET_INFO *hash_charset_arg)
:size(size_arg), key_offset(key_offset_arg), key_length(key_length_arg),
get_key(get_key_arg), free_element(free_element_arg),init(0),
hash_charset(hash_charset_arg)
{
bzero((char*) &cache,sizeof(cache));
}
~hash_filo()
{
if (init)
{
if (cache.array.buffer) /* Avoid problems with thread library */
(void) my_hash_free(&cache);
mysql_mutex_destroy(&lock);
}
}
void clear(bool locked=0)
{
if (!init)
{
init=1;
mysql_mutex_init(key_hash_filo_lock, &lock, MY_MUTEX_INIT_FAST);
}
if (!locked)
mysql_mutex_lock(&lock);
(void) my_hash_free(&cache);
(void) my_hash_init(&cache,hash_charset,size,key_offset,
key_length, get_key, free_element,0);
if (!locked)
mysql_mutex_unlock(&lock);
first_link=last_link=0;
}
hash_filo_element *search(uchar* key, size_t length)
{
hash_filo_element *entry=(hash_filo_element*)
my_hash_search(&cache,(uchar*) key,length);
if (entry)
{ // Found; link it first
if (entry != first_link)
{ // Relink used-chain
if (entry == last_link)
last_link=entry->prev_used;
else
{
entry->next_used->prev_used = entry->prev_used;
entry->prev_used->next_used = entry->next_used;
}
if ((entry->next_used= first_link))
first_link->prev_used=entry;
first_link=entry;
}
}
return entry;
}
bool add(hash_filo_element *entry)
{
if (cache.records == size)
{
hash_filo_element *tmp=last_link;
last_link=last_link->prev_used;
my_hash_delete(&cache,(uchar*) tmp);
}
if (my_hash_insert(&cache,(uchar*) entry))
{
if (free_element)
(*free_element)(entry); // This should never happen
return 1;
}
if ((entry->next_used=first_link))
first_link->prev_used=entry;
else
last_link=entry;
first_link=entry;
return 0;
}
};
#endif
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