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/* Copyright (C) 2005 MySQL AB
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysql_priv.h"
#ifdef HAVE_REPLICATION
#include "rpl_tblmap.h"
#define MAYBE_TABLE_NAME(T) ((T) ? (T)->s->table_name.str : "<>")
#define TABLE_ID_HASH_SIZE 32
#define TABLE_ID_CHUNK 256
table_mapping::table_mapping()
: m_free(0)
{
/*
No "free_element" function for entries passed here, as the entries are
allocated in a MEM_ROOT (freed as a whole in the destructor), they cannot
be freed one by one.
Note that below we don't test if hash_init() succeeded. This constructor
is called at startup only.
*/
(void) hash_init(&m_table_ids,&my_charset_bin,TABLE_ID_HASH_SIZE,
offsetof(entry,table_id),sizeof(ulong),
0,0,0);
/* We don't preallocate any block, this is consistent with m_free=0 above */
init_alloc_root(&m_mem_root, TABLE_ID_HASH_SIZE*sizeof(entry), 0);
}
table_mapping::~table_mapping()
{
hash_free(&m_table_ids);
free_root(&m_mem_root, MYF(0));
}
st_table* table_mapping::get_table(ulong table_id)
{
entry *e= find_entry(table_id);
if (e)
{
return(e->table);
}
return(NULL);
}
/*
Called when we are out of table id entries. Creates TABLE_ID_CHUNK
new entries, chain them and attach them at the head of the list of free
(free for use) entries.
*/
int table_mapping::expand()
{
/*
If we wanted to use "tmp= new (&m_mem_root) entry[TABLE_ID_CHUNK]",
we would have to make "entry" derive from Sql_alloc but then it would not
be a POD anymore and we want it to be (see rpl_tblmap.h). So we allocate
in C.
*/
entry *tmp= (entry *)alloc_root(&m_mem_root, TABLE_ID_CHUNK*sizeof(entry));
if (tmp == NULL)
return ERR_MEMORY_ALLOCATION; // Memory allocation failed
/* Find the end of this fresh new array of free entries */
entry *e_end= tmp+TABLE_ID_CHUNK-1;
for (entry *e= tmp; e < e_end; e++)
e->next= e+1;
e_end->next= m_free;
m_free= tmp;
return 0;
}
int table_mapping::set_table(ulong table_id, TABLE* table)
{
entry *e= find_entry(table_id);
if (e == 0)
{
if (m_free == 0 && expand())
return(ERR_MEMORY_ALLOCATION); // Memory allocation failed
e= m_free;
m_free= m_free->next;
}
else
hash_delete(&m_table_ids,(uchar *)e);
e->table_id= table_id;
e->table= table;
my_hash_insert(&m_table_ids,(uchar *)e);
return(0); // All OK
}
int table_mapping::remove_table(ulong table_id)
{
entry *e= find_entry(table_id);
if (e)
{
hash_delete(&m_table_ids,(uchar *)e);
/* we add this entry to the chain of free (free for use) entries */
e->next= m_free;
m_free= e;
return 0; // All OK
}
return 1; // No table to remove
}
/*
Puts all entries into the list of free-for-use entries (does not free any
memory), and empties the hash.
*/
void table_mapping::clear_tables()
{
for (uint i= 0; i < m_table_ids.records; i++)
{
entry *e= (entry *)hash_element(&m_table_ids, i);
e->next= m_free;
m_free= e;
}
my_hash_reset(&m_table_ids);
return;
}
#endif
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