/usr/include/mysql/private/hash_filo.h is in libmariadbclient-dev 1:10.1.29-6.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 | /* Copyright (c) 2000, 2011, 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
{
private:
hash_filo_element *next_used,*prev_used;
public:
hash_filo_element() {}
hash_filo_element *next()
{ return next_used; }
hash_filo_element *prev()
{ return prev_used; }
friend class hash_filo;
};
class hash_filo
{
private:
const uint key_offset, key_length;
const my_hash_get_key get_key;
/** Size of this hash table. */
uint m_size;
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)
:key_offset(key_offset_arg), key_length(key_length_arg),
get_key(get_key_arg), m_size(size_arg),
free_element(free_element_arg),init(0),
hash_charset(hash_charset_arg),
first_link(NULL),
last_link(NULL)
{
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);
first_link= NULL;
last_link= NULL;
(void) my_hash_free(&cache);
(void) my_hash_init(&cache,hash_charset,m_size,key_offset,
key_length, get_key, free_element,0);
if (!locked)
mysql_mutex_unlock(&lock);
}
hash_filo_element *first()
{
mysql_mutex_assert_owner(&lock);
return first_link;
}
hash_filo_element *last()
{
mysql_mutex_assert_owner(&lock);
return last_link;
}
hash_filo_element *search(uchar* key, size_t length)
{
mysql_mutex_assert_owner(&lock);
hash_filo_element *entry=(hash_filo_element*)
my_hash_search(&cache,(uchar*) key,length);
if (entry)
{ // Found; link it first
DBUG_ASSERT(first_link != NULL);
DBUG_ASSERT(last_link != NULL);
if (entry != first_link)
{ // Relink used-chain
if (entry == last_link)
{
last_link= last_link->prev_used;
/*
The list must have at least 2 elements,
otherwise entry would be equal to first_link.
*/
DBUG_ASSERT(last_link != NULL);
last_link->next_used= NULL;
}
else
{
DBUG_ASSERT(entry->next_used != NULL);
DBUG_ASSERT(entry->prev_used != NULL);
entry->next_used->prev_used = entry->prev_used;
entry->prev_used->next_used = entry->next_used;
}
entry->prev_used= NULL;
entry->next_used= first_link;
first_link->prev_used= entry;
first_link=entry;
}
}
return entry;
}
bool add(hash_filo_element *entry)
{
if (!m_size) return 1;
if (cache.records == m_size)
{
hash_filo_element *tmp=last_link;
last_link= last_link->prev_used;
if (last_link != NULL)
{
last_link->next_used= NULL;
}
else
{
/* Pathological case, m_size == 1 */
first_link= NULL;
}
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;
}
entry->prev_used= NULL;
entry->next_used= first_link;
if (first_link != NULL)
first_link->prev_used= entry;
else
last_link= entry;
first_link= entry;
return 0;
}
uint size()
{ return m_size; }
void resize(uint new_size)
{
mysql_mutex_lock(&lock);
m_size= new_size;
clear(true);
mysql_mutex_unlock(&lock);
}
};
template <class T> class Hash_filo: public hash_filo
{
public:
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) :
hash_filo(size_arg, key_offset_arg, key_length_arg,
get_key_arg, free_element_arg, hash_charset_arg) {}
T* first() { return (T*)hash_filo::first(); }
T* last() { return (T*)hash_filo::last(); }
T* search(uchar* key, size_t len) { return (T*)hash_filo::search(key, len); }
};
#endif
|