mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-01-16 12:02:42 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions
mariadb/storage/myisam/ha_myisam.cc
Sergey Vojtovich a82cc50958 BUG#51307 - widespread corruption with partitions and 
insert...select

Queries following bulk insert into an empty MyISAM table
may break it. This was pure MyISAM problem.

When bulk insert into an empty table is complete, MyISAM
may want to enable indexes via repair by sort. If repair
by sort fails (e.g. insufficient buffer), MyISAM failover
to repair with key cache, requesting repair of data file.

Repair of data file performs data file substitution. This
means that current table instance will point to new data
file. Other cached table instances are still pointing to
an old, deleted data file.

This is fixed by not requesting repair of data file
during enable indexes.

Explicit REPAIR is not affected, since it flushes all
table instances.

mysql-test/r/myisam.result:
  A test case for BUG#51307.
mysql-test/t/myisam.test:
  A test case for BUG#51307.
storage/myisam/ha_myisam.cc:
  When enabling indexes do not attempt to repair data file.
2010-03-02 13:45:50 +04:00

2227 lines
68 KiB
C++
Raw Blame History

/* Copyright (C) 2000-2006 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 */
#ifdef USE_PRAGMA_IMPLEMENTATION
#pragma implementation // gcc: Class implementation
#endif
#define MYSQL_SERVER 1
#include "mysql_priv.h"
#include <mysql/plugin.h>
#include <m_ctype.h>
#include <my_bit.h>
#include <myisampack.h>
#include "ha_myisam.h"
#include <stdarg.h>
#include "myisamdef.h"
#include "rt_index.h"
ulong myisam_recover_options= HA_RECOVER_NONE;
/* bits in myisam_recover_options */
const char *myisam_recover_names[] =
{ "DEFAULT", "BACKUP", "FORCE", "QUICK", NullS};
TYPELIB myisam_recover_typelib= {array_elements(myisam_recover_names)-1,"",
myisam_recover_names, NULL};
const char *myisam_stats_method_names[] = {"nulls_unequal", "nulls_equal",
"nulls_ignored", NullS};
TYPELIB myisam_stats_method_typelib= {
array_elements(myisam_stats_method_names) - 1, "",
myisam_stats_method_names, NULL};
#ifndef DBUG_OFF
/**
Causes the thread to wait in a spin lock for a query kill signal.
This function is used by the test frame work to identify race conditions.
The signal is caught and ignored and the thread is not killed.
*/
static void debug_wait_for_kill(const char *info)
{
DBUG_ENTER("debug_wait_for_kill");
const char *prev_info;
THD *thd;
thd= current_thd;
prev_info= thd_proc_info(thd, info);
while(!thd->killed)
my_sleep(1000);
DBUG_PRINT("info", ("Exit debug_wait_for_kill"));
thd_proc_info(thd, prev_info);
DBUG_VOID_RETURN;
}
#endif
/*****************************************************************************
** MyISAM tables
*****************************************************************************/
static handler *myisam_create_handler(handlerton *hton,
TABLE_SHARE *table,
MEM_ROOT *mem_root)
{
return new (mem_root) ha_myisam(hton, table);
}
// collect errors printed by mi_check routines
static void mi_check_print_msg(MI_CHECK *param, const char* msg_type,
const char *fmt, va_list args)
{
THD* thd = (THD*)param->thd;
Protocol *protocol= thd->protocol;
size_t length, msg_length;
char msgbuf[MI_MAX_MSG_BUF];
char name[NAME_LEN*2+2];
msg_length= my_vsnprintf(msgbuf, sizeof(msgbuf), fmt, args);
msgbuf[sizeof(msgbuf) - 1] = 0; // healthy paranoia
DBUG_PRINT(msg_type,("message: %s",msgbuf));
if (!thd->vio_ok())
{
sql_print_error("%s", msgbuf);
return;
}
if (param->testflag & (T_CREATE_MISSING_KEYS | T_SAFE_REPAIR |
T_AUTO_REPAIR))
{
my_message(ER_NOT_KEYFILE,msgbuf,MYF(MY_WME));
return;
}
length=(uint) (strxmov(name, param->db_name,".",param->table_name,NullS) -
name);
/*
TODO: switch from protocol to push_warning here. The main reason we didn't
it yet is parallel repair. Due to following trace:
mi_check_print_msg/push_warning/sql_alloc/my_pthread_getspecific_ptr.
Also we likely need to lock mutex here (in both cases with protocol and
push_warning).
*/
#ifdef THREAD
if (param->need_print_msg_lock)
pthread_mutex_lock(&param->print_msg_mutex);
#endif
protocol->prepare_for_resend();
protocol->store(name, length, system_charset_info);
protocol->store(param->op_name, system_charset_info);
protocol->store(msg_type, system_charset_info);
protocol->store(msgbuf, msg_length, system_charset_info);
if (protocol->write())
sql_print_error("Failed on my_net_write, writing to stderr instead: %s\n",
msgbuf);
#ifdef THREAD
if (param->need_print_msg_lock)
pthread_mutex_unlock(&param->print_msg_mutex);
#endif
return;
}
/*
Convert TABLE object to MyISAM key and column definition
SYNOPSIS
table2myisam()
table_arg in TABLE object.
keydef_out out MyISAM key definition.
recinfo_out out MyISAM column definition.
records_out out Number of fields.
DESCRIPTION
This function will allocate and initialize MyISAM key and column
definition for further use in mi_create or for a check for underlying
table conformance in merge engine.
The caller needs to free *recinfo_out after use. Since *recinfo_out
and *keydef_out are allocated with a my_multi_malloc, *keydef_out
is freed automatically when *recinfo_out is freed.
RETURN VALUE
0 OK
!0 error code
*/
int table2myisam(TABLE *table_arg, MI_KEYDEF **keydef_out,
MI_COLUMNDEF **recinfo_out, uint *records_out)
{
uint i, j, recpos, minpos, fieldpos, temp_length, length;
enum ha_base_keytype type= HA_KEYTYPE_BINARY;
uchar *record;
KEY *pos;
MI_KEYDEF *keydef;
MI_COLUMNDEF *recinfo, *recinfo_pos;
HA_KEYSEG *keyseg;
TABLE_SHARE *share= table_arg->s;
uint options= share->db_options_in_use;
DBUG_ENTER("table2myisam");
if (!(my_multi_malloc(MYF(MY_WME),
recinfo_out, (share->fields * 2 + 2) * sizeof(MI_COLUMNDEF),
keydef_out, share->keys * sizeof(MI_KEYDEF),
&keyseg,
(share->key_parts + share->keys) * sizeof(HA_KEYSEG),
NullS)))
DBUG_RETURN(HA_ERR_OUT_OF_MEM); /* purecov: inspected */
keydef= *keydef_out;
recinfo= *recinfo_out;
pos= table_arg->key_info;
for (i= 0; i < share->keys; i++, pos++)
{
keydef[i].flag= ((uint16) pos->flags & (HA_NOSAME | HA_FULLTEXT | HA_SPATIAL));
keydef[i].key_alg= pos->algorithm == HA_KEY_ALG_UNDEF ?
(pos->flags & HA_SPATIAL ? HA_KEY_ALG_RTREE : HA_KEY_ALG_BTREE) :
pos->algorithm;
keydef[i].block_length= pos->block_size;
keydef[i].seg= keyseg;
keydef[i].keysegs= pos->key_parts;
for (j= 0; j < pos->key_parts; j++)
{
Field *field= pos->key_part[j].field;
type= field->key_type();
keydef[i].seg[j].flag= pos->key_part[j].key_part_flag;
if (options & HA_OPTION_PACK_KEYS ||
(pos->flags & (HA_PACK_KEY | HA_BINARY_PACK_KEY |
HA_SPACE_PACK_USED)))
{
if (pos->key_part[j].length > 8 &&
(type == HA_KEYTYPE_TEXT ||
type == HA_KEYTYPE_NUM ||
(type == HA_KEYTYPE_BINARY && !field->zero_pack())))
{
/* No blobs here */
if (j == 0)
keydef[i].flag|= HA_PACK_KEY;
if (!(field->flags & ZEROFILL_FLAG) &&
(field->type() == MYSQL_TYPE_STRING ||
field->type() == MYSQL_TYPE_VAR_STRING ||
((int) (pos->key_part[j].length - field->decimals())) >= 4))
keydef[i].seg[j].flag|= HA_SPACE_PACK;
}
else if (j == 0 && (!(pos->flags & HA_NOSAME) || pos->key_length > 16))
keydef[i].flag|= HA_BINARY_PACK_KEY;
}
keydef[i].seg[j].type= (int) type;
keydef[i].seg[j].start= pos->key_part[j].offset;
keydef[i].seg[j].length= pos->key_part[j].length;
keydef[i].seg[j].bit_start= keydef[i].seg[j].bit_end=
keydef[i].seg[j].bit_length= 0;
keydef[i].seg[j].bit_pos= 0;
keydef[i].seg[j].language= field->charset()->number;
if (field->null_ptr)
{
keydef[i].seg[j].null_bit= field->null_bit;
keydef[i].seg[j].null_pos= (uint) (field->null_ptr-
(uchar*) table_arg->record[0]);
}
else
{
keydef[i].seg[j].null_bit= 0;
keydef[i].seg[j].null_pos= 0;
}
if (field->type() == MYSQL_TYPE_BLOB ||
field->type() == MYSQL_TYPE_GEOMETRY)
{
keydef[i].seg[j].flag|= HA_BLOB_PART;
/* save number of bytes used to pack length */
keydef[i].seg[j].bit_start= (uint) (field->pack_length() -
share->blob_ptr_size);
}
else if (field->type() == MYSQL_TYPE_BIT)
{
keydef[i].seg[j].bit_length= ((Field_bit *) field)->bit_len;
keydef[i].seg[j].bit_start= ((Field_bit *) field)->bit_ofs;
keydef[i].seg[j].bit_pos= (uint) (((Field_bit *) field)->bit_ptr -
(uchar*) table_arg->record[0]);
}
}
keyseg+= pos->key_parts;
}
if (table_arg->found_next_number_field)
keydef[share->next_number_index].flag|= HA_AUTO_KEY;
record= table_arg->record[0];
recpos= 0;
recinfo_pos= recinfo;
while (recpos < (uint) share->reclength)
{
Field **field, *found= 0;
minpos= share->reclength;
length= 0;
for (field= table_arg->field; *field; field++)
{
if ((fieldpos= (*field)->offset(record)) >= recpos &&
fieldpos <= minpos)
{
/* skip null fields */
if (!(temp_length= (*field)->pack_length_in_rec()))
continue; /* Skip null-fields */
if (! found || fieldpos < minpos ||
(fieldpos == minpos && temp_length < length))
{
minpos= fieldpos;
found= *field;
length= temp_length;
}
}
}
DBUG_PRINT("loop", ("found: 0x%lx recpos: %d minpos: %d length: %d",
(long) found, recpos, minpos, length));
if (recpos != minpos)
{ // Reserved space (Null bits?)
bzero((char*) recinfo_pos, sizeof(*recinfo_pos));
recinfo_pos->type= (int) FIELD_NORMAL;
recinfo_pos++->length= (uint16) (minpos - recpos);
}
if (!found)
break;
if (found->flags & BLOB_FLAG)
recinfo_pos->type= (int) FIELD_BLOB;
else if (found->type() == MYSQL_TYPE_VARCHAR)
recinfo_pos->type= FIELD_VARCHAR;
else if (!(options & HA_OPTION_PACK_RECORD))
recinfo_pos->type= (int) FIELD_NORMAL;
else if (found->zero_pack())
recinfo_pos->type= (int) FIELD_SKIP_ZERO;
else
recinfo_pos->type= (int) ((length <= 3 ||
(found->flags & ZEROFILL_FLAG)) ?
FIELD_NORMAL :
found->type() == MYSQL_TYPE_STRING ||
found->type() == MYSQL_TYPE_VAR_STRING ?
FIELD_SKIP_ENDSPACE :
FIELD_SKIP_PRESPACE);
if (found->null_ptr)
{
recinfo_pos->null_bit= found->null_bit;
recinfo_pos->null_pos= (uint) (found->null_ptr -
(uchar*) table_arg->record[0]);
}
else
{
recinfo_pos->null_bit= 0;
recinfo_pos->null_pos= 0;
}
(recinfo_pos++)->length= (uint16) length;
recpos= minpos + length;
DBUG_PRINT("loop", ("length: %d type: %d",
recinfo_pos[-1].length,recinfo_pos[-1].type));
}
*records_out= (uint) (recinfo_pos - recinfo);
DBUG_RETURN(0);
}
/*
Check for underlying table conformance
SYNOPSIS
check_definition()
t1_keyinfo in First table key definition
t1_recinfo in First table record definition
t1_keys in Number of keys in first table
t1_recs in Number of records in first table
t2_keyinfo in Second table key definition
t2_recinfo in Second table record definition
t2_keys in Number of keys in second table
t2_recs in Number of records in second table
strict in Strict check switch
table in handle to the table object
DESCRIPTION
This function compares two MyISAM definitions. By intention it was done
to compare merge table definition against underlying table definition.
It may also be used to compare dot-frm and MYI definitions of MyISAM
table as well to compare different MyISAM table definitions.
For merge table it is not required that number of keys in merge table
must exactly match number of keys in underlying table. When calling this
function for underlying table conformance check, 'strict' flag must be
set to false, and converted merge definition must be passed as t1_*.
Otherwise 'strict' flag must be set to 1 and it is not required to pass
converted dot-frm definition as t1_*.
For compatibility reasons we relax some checks, specifically:
- 4.0 (and earlier versions) always set key_alg to 0.
- 4.0 (and earlier versions) have the same language for all keysegs.
RETURN VALUE
0 - Equal definitions.
1 - Different definitions.
TODO
- compare FULLTEXT keys;
- compare SPATIAL keys;
- compare FIELD_SKIP_ZERO which is converted to FIELD_NORMAL correctly
(should be corretly detected in table2myisam).
*/
int check_definition(MI_KEYDEF *t1_keyinfo, MI_COLUMNDEF *t1_recinfo,
uint t1_keys, uint t1_recs,
MI_KEYDEF *t2_keyinfo, MI_COLUMNDEF *t2_recinfo,
uint t2_keys, uint t2_recs, bool strict, TABLE *table_arg)
{
uint i, j;
DBUG_ENTER("check_definition");
my_bool mysql_40_compat= table_arg && table_arg->s->frm_version < FRM_VER_TRUE_VARCHAR;
if ((strict ? t1_keys != t2_keys : t1_keys > t2_keys))
{
DBUG_PRINT("error", ("Number of keys differs: t1_keys=%u, t2_keys=%u",
t1_keys, t2_keys));
DBUG_RETURN(1);
}
if (t1_recs != t2_recs)
{
DBUG_PRINT("error", ("Number of recs differs: t1_recs=%u, t2_recs=%u",
t1_recs, t2_recs));
DBUG_RETURN(1);
}
for (i= 0; i < t1_keys; i++)
{
HA_KEYSEG *t1_keysegs= t1_keyinfo[i].seg;
HA_KEYSEG *t2_keysegs= t2_keyinfo[i].seg;
if (t1_keyinfo[i].flag & HA_FULLTEXT && t2_keyinfo[i].flag & HA_FULLTEXT)
continue;
else if (t1_keyinfo[i].flag & HA_FULLTEXT ||
t2_keyinfo[i].flag & HA_FULLTEXT)
{
DBUG_PRINT("error", ("Key %d has different definition", i));
DBUG_PRINT("error", ("t1_fulltext= %d, t2_fulltext=%d",
test(t1_keyinfo[i].flag & HA_FULLTEXT),
test(t2_keyinfo[i].flag & HA_FULLTEXT)));
DBUG_RETURN(1);
}
if (t1_keyinfo[i].flag & HA_SPATIAL && t2_keyinfo[i].flag & HA_SPATIAL)
continue;
else if (t1_keyinfo[i].flag & HA_SPATIAL ||
t2_keyinfo[i].flag & HA_SPATIAL)
{
DBUG_PRINT("error", ("Key %d has different definition", i));
DBUG_PRINT("error", ("t1_spatial= %d, t2_spatial=%d",
test(t1_keyinfo[i].flag & HA_SPATIAL),
test(t2_keyinfo[i].flag & HA_SPATIAL)));
DBUG_RETURN(1);
}
if ((!mysql_40_compat &&
t1_keyinfo[i].key_alg != t2_keyinfo[i].key_alg) ||
t1_keyinfo[i].keysegs != t2_keyinfo[i].keysegs)
{
DBUG_PRINT("error", ("Key %d has different definition", i));
DBUG_PRINT("error", ("t1_keysegs=%d, t1_key_alg=%d",
t1_keyinfo[i].keysegs, t1_keyinfo[i].key_alg));
DBUG_PRINT("error", ("t2_keysegs=%d, t2_key_alg=%d",
t2_keyinfo[i].keysegs, t2_keyinfo[i].key_alg));
DBUG_RETURN(1);
}
for (j= t1_keyinfo[i].keysegs; j--;)
{
uint8 t1_keysegs_j__type= t1_keysegs[j].type;
/*
Table migration from 4.1 to 5.1. In 5.1 a *TEXT key part is
always HA_KEYTYPE_VARTEXT2. In 4.1 we had only the equivalent of
HA_KEYTYPE_VARTEXT1. Since we treat both the same on MyISAM
level, we can ignore a mismatch between these types.
*/
if ((t1_keysegs[j].flag & HA_BLOB_PART) &&
(t2_keysegs[j].flag & HA_BLOB_PART))
{
if ((t1_keysegs_j__type == HA_KEYTYPE_VARTEXT2) &&
(t2_keysegs[j].type == HA_KEYTYPE_VARTEXT1))
t1_keysegs_j__type= HA_KEYTYPE_VARTEXT1; /* purecov: tested */
else if ((t1_keysegs_j__type == HA_KEYTYPE_VARBINARY2) &&
(t2_keysegs[j].type == HA_KEYTYPE_VARBINARY1))
t1_keysegs_j__type= HA_KEYTYPE_VARBINARY1; /* purecov: inspected */
}
if ((!mysql_40_compat &&
t1_keysegs[j].language != t2_keysegs[j].language) ||
t1_keysegs_j__type != t2_keysegs[j].type ||
t1_keysegs[j].null_bit != t2_keysegs[j].null_bit ||
t1_keysegs[j].length != t2_keysegs[j].length)
{
DBUG_PRINT("error", ("Key segment %d (key %d) has different "
"definition", j, i));
DBUG_PRINT("error", ("t1_type=%d, t1_language=%d, t1_null_bit=%d, "
"t1_length=%d",
t1_keysegs[j].type, t1_keysegs[j].language,
t1_keysegs[j].null_bit, t1_keysegs[j].length));
DBUG_PRINT("error", ("t2_type=%d, t2_language=%d, t2_null_bit=%d, "
"t2_length=%d",
t2_keysegs[j].type, t2_keysegs[j].language,
t2_keysegs[j].null_bit, t2_keysegs[j].length));
DBUG_RETURN(1);
}
}
}
for (i= 0; i < t1_recs; i++)
{
MI_COLUMNDEF *t1_rec= &t1_recinfo[i];
MI_COLUMNDEF *t2_rec= &t2_recinfo[i];
/*
FIELD_SKIP_ZERO can be changed to FIELD_NORMAL in mi_create,
see NOTE1 in mi_create.c
*/
if ((t1_rec->type != t2_rec->type &&
!(t1_rec->type == (int) FIELD_SKIP_ZERO &&
t1_rec->length == 1 &&
t2_rec->type == (int) FIELD_NORMAL)) ||
t1_rec->length != t2_rec->length ||
t1_rec->null_bit != t2_rec->null_bit)
{
DBUG_PRINT("error", ("Field %d has different definition", i));
DBUG_PRINT("error", ("t1_type=%d, t1_length=%d, t1_null_bit=%d",
t1_rec->type, t1_rec->length, t1_rec->null_bit));
DBUG_PRINT("error", ("t2_type=%d, t2_length=%d, t2_null_bit=%d",
t2_rec->type, t2_rec->length, t2_rec->null_bit));
DBUG_RETURN(1);
}
}
DBUG_RETURN(0);
}
extern "C" {
volatile int *killed_ptr(MI_CHECK *param)
{
/* In theory Unsafe conversion, but should be ok for now */
return (int*) &(((THD *)(param->thd))->killed);
}
void mi_check_print_error(MI_CHECK *param, const char *fmt,...)
{
param->error_printed|=1;
param->out_flag|= O_DATA_LOST;
va_list args;
va_start(args, fmt);
mi_check_print_msg(param, "error", fmt, args);
va_end(args);
}
void mi_check_print_info(MI_CHECK *param, const char *fmt,...)
{
va_list args;
va_start(args, fmt);
mi_check_print_msg(param, "info", fmt, args);
va_end(args);
}
void mi_check_print_warning(MI_CHECK *param, const char *fmt,...)
{
param->warning_printed=1;
param->out_flag|= O_DATA_LOST;
va_list args;
va_start(args, fmt);
mi_check_print_msg(param, "warning", fmt, args);
va_end(args);
}
}
ha_myisam::ha_myisam(handlerton *hton, TABLE_SHARE *table_arg)
:handler(hton, table_arg), file(0),
int_table_flags(HA_NULL_IN_KEY | HA_CAN_FULLTEXT | HA_CAN_SQL_HANDLER |
HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE |
HA_DUPLICATE_POS | HA_CAN_INDEX_BLOBS | HA_AUTO_PART_KEY |
HA_FILE_BASED | HA_CAN_GEOMETRY | HA_NO_TRANSACTIONS |
HA_CAN_INSERT_DELAYED | HA_CAN_BIT_FIELD | HA_CAN_RTREEKEYS |
HA_HAS_RECORDS | HA_STATS_RECORDS_IS_EXACT),
can_enable_indexes(1)
{}
handler *ha_myisam::clone(MEM_ROOT *mem_root)
{
ha_myisam *new_handler= static_cast <ha_myisam *>(handler::clone(mem_root));
if (new_handler)
new_handler->file->state= file->state;
return new_handler;
}
static const char *ha_myisam_exts[] = {
".MYI",
".MYD",
NullS
};
const char **ha_myisam::bas_ext() const
{
return ha_myisam_exts;
}
const char *ha_myisam::index_type(uint key_number)
{
return ((table->key_info[key_number].flags & HA_FULLTEXT) ?
"FULLTEXT" :
(table->key_info[key_number].flags & HA_SPATIAL) ?
"SPATIAL" :
(table->key_info[key_number].algorithm == HA_KEY_ALG_RTREE) ?
"RTREE" :
"BTREE");
}
#ifdef HAVE_REPLICATION
int ha_myisam::net_read_dump(NET* net)
{
int data_fd = file->dfile;
int error = 0;
my_seek(data_fd, 0L, MY_SEEK_SET, MYF(MY_WME));
for (;;)
{
ulong packet_len = my_net_read(net);
if (!packet_len)
break ; // end of file
if (packet_len == packet_error)
{
sql_print_error("ha_myisam::net_read_dump - read error ");
error= -1;
goto err;
}
if (my_write(data_fd, (uchar*)net->read_pos, (uint) packet_len,
MYF(MY_WME|MY_FNABP)))
{
error = errno;
goto err;
}
}
err:
return error;
}
int ha_myisam::dump(THD* thd, int fd)
{
MYISAM_SHARE* share = file->s;
NET* net = &thd->net;
uint blocksize = share->blocksize;
my_off_t bytes_to_read = share->state.state.data_file_length;
int data_fd = file->dfile;
uchar *buf = (uchar*) my_malloc(blocksize, MYF(MY_WME));
if (!buf)
return ENOMEM;
int error = 0;
my_seek(data_fd, 0L, MY_SEEK_SET, MYF(MY_WME));
for (; bytes_to_read > 0;)
{
size_t bytes = my_read(data_fd, buf, blocksize, MYF(MY_WME));
if (bytes == MY_FILE_ERROR)
{
error = errno;
goto err;
}
if (fd >= 0)
{
if (my_write(fd, buf, bytes, MYF(MY_WME | MY_FNABP)))
{
error = errno ? errno : EPIPE;
goto err;
}
}
else
{
if (my_net_write(net, buf, bytes))
{
error = errno ? errno : EPIPE;
goto err;
}
}
bytes_to_read -= bytes;
}
if (fd < 0)
{
if (my_net_write(net, (uchar*) "", 0))
error = errno ? errno : EPIPE;
net_flush(net);
}
err:
my_free((uchar*) buf, MYF(0));
return error;
}
#endif /* HAVE_REPLICATION */
/* Name is here without an extension */
int ha_myisam::open(const char *name, int mode, uint test_if_locked)
{
MI_KEYDEF *keyinfo;
MI_COLUMNDEF *recinfo= 0;
uint recs;
uint i;
/*
If the user wants to have memory mapped data files, add an
open_flag. Do not memory map temporary tables because they are
expected to be inserted and thus extended a lot. Memory mapping is
efficient for files that keep their size, but very inefficient for
growing files. Using an open_flag instead of calling mi_extra(...
HA_EXTRA_MMAP ...) after mi_open() has the advantage that the
mapping is not repeated for every open, but just done on the initial
open, when the MyISAM share is created. Everytime the server
requires to open a new instance of a table it calls this method. We
will always supply HA_OPEN_MMAP for a permanent table. However, the
MyISAM storage engine will ignore this flag if this is a secondary
open of a table that is in use by other threads already (if the
MyISAM share exists already).
*/
if (!(test_if_locked & HA_OPEN_TMP_TABLE) && opt_myisam_use_mmap)
test_if_locked|= HA_OPEN_MMAP;
if (!(file=mi_open(name, mode, test_if_locked | HA_OPEN_FROM_SQL_LAYER)))
return (my_errno ? my_errno : -1);
if (!table->s->tmp_table) /* No need to perform a check for tmp table */
{
if ((my_errno= table2myisam(table, &keyinfo, &recinfo, &recs)))
{
/* purecov: begin inspected */
DBUG_PRINT("error", ("Failed to convert TABLE object to MyISAM "
"key and column definition"));
goto err;
/* purecov: end */
}
if (check_definition(keyinfo, recinfo, table->s->keys, recs,
file->s->keyinfo, file->s->rec,
file->s->base.keys, file->s->base.fields,
true, table))
{
/* purecov: begin inspected */
my_errno= HA_ERR_CRASHED;
goto err;
/* purecov: end */
}
}
if (test_if_locked & (HA_OPEN_IGNORE_IF_LOCKED | HA_OPEN_TMP_TABLE))
VOID(mi_extra(file, HA_EXTRA_NO_WAIT_LOCK, 0));
info(HA_STATUS_NO_LOCK | HA_STATUS_VARIABLE | HA_STATUS_CONST);
if (!(test_if_locked & HA_OPEN_WAIT_IF_LOCKED))
VOID(mi_extra(file, HA_EXTRA_WAIT_LOCK, 0));
if (!table->s->db_record_offset)
int_table_flags|=HA_REC_NOT_IN_SEQ;
if (file->s->options & (HA_OPTION_CHECKSUM | HA_OPTION_COMPRESS_RECORD))
int_table_flags|=HA_HAS_CHECKSUM;
for (i= 0; i < table->s->keys; i++)
{
plugin_ref parser= table->key_info[i].parser;
if (table->key_info[i].flags & HA_USES_PARSER)
file->s->keyinfo[i].parser=
(struct st_mysql_ftparser *)plugin_decl(parser)->info;
table->key_info[i].block_size= file->s->keyinfo[i].block_length;
}
my_errno= 0;
goto end;
err:
this->close();
end:
/*
Both recinfo and keydef are allocated by my_multi_malloc(), thus only
recinfo must be freed.
*/
if (recinfo)
my_free((uchar*) recinfo, MYF(0));
return my_errno;
}
int ha_myisam::close(void)
{
MI_INFO *tmp=file;
file=0;
return mi_close(tmp);
}
int ha_myisam::write_row(uchar *buf)
{
ha_statistic_increment(&SSV::ha_write_count);
/* If we have a timestamp column, update it to the current time */
if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
table->timestamp_field->set_time();
/*
If we have an auto_increment column and we are writing a changed row
or a new row, then update the auto_increment value in the record.
*/
if (table->next_number_field && buf == table->record[0])
{
int error;
if ((error= update_auto_increment()))
return error;
}
return mi_write(file,buf);
}
int ha_myisam::check(THD* thd, HA_CHECK_OPT* check_opt)
{
if (!file) return HA_ADMIN_INTERNAL_ERROR;
int error;
MI_CHECK param;
MYISAM_SHARE* share = file->s;
const char *old_proc_info=thd->proc_info;
thd_proc_info(thd, "Checking table");
myisamchk_init(&param);
param.thd = thd;
param.op_name = "check";
param.db_name= table->s->db.str;
param.table_name= table->alias;
param.testflag = check_opt->flags | T_CHECK | T_SILENT;
param.stats_method= (enum_mi_stats_method)thd->variables.myisam_stats_method;
if (!(table->db_stat & HA_READ_ONLY))
param.testflag|= T_STATISTICS;
param.using_global_keycache = 1;
if (!mi_is_crashed(file) &&
(((param.testflag & T_CHECK_ONLY_CHANGED) &&
!(share->state.changed & (STATE_CHANGED | STATE_CRASHED |
STATE_CRASHED_ON_REPAIR)) &&
share->state.open_count == 0) ||
((param.testflag & T_FAST) && (share->state.open_count ==
(uint) (share->global_changed ? 1 : 0)))))
return HA_ADMIN_ALREADY_DONE;
error = chk_status(&param, file); // Not fatal
error = chk_size(&param, file);
if (!error)
error |= chk_del(&param, file, param.testflag);
if (!error)
error = chk_key(&param, file);
if (!error)
{
if ((!(param.testflag & T_QUICK) &&
((share->options &
(HA_OPTION_PACK_RECORD | HA_OPTION_COMPRESS_RECORD)) ||
(param.testflag & (T_EXTEND | T_MEDIUM)))) ||
mi_is_crashed(file))
{
uint old_testflag=param.testflag;
param.testflag|=T_MEDIUM;
if (!(error= init_io_cache(&param.read_cache, file->dfile,
my_default_record_cache_size, READ_CACHE,
share->pack.header_length, 1, MYF(MY_WME))))
{
error= chk_data_link(&param, file, param.testflag & T_EXTEND);
end_io_cache(&(param.read_cache));
}
param.testflag= old_testflag;
}
}
if (!error)
{
if ((share->state.changed & (STATE_CHANGED |
STATE_CRASHED_ON_REPAIR |
STATE_CRASHED | STATE_NOT_ANALYZED)) ||
(param.testflag & T_STATISTICS) ||
mi_is_crashed(file))
{
file->update|=HA_STATE_CHANGED | HA_STATE_ROW_CHANGED;
pthread_mutex_lock(&share->intern_lock);
share->state.changed&= ~(STATE_CHANGED | STATE_CRASHED |
STATE_CRASHED_ON_REPAIR);
if (!(table->db_stat & HA_READ_ONLY))
error=update_state_info(&param,file,UPDATE_TIME | UPDATE_OPEN_COUNT |
UPDATE_STAT);
pthread_mutex_unlock(&share->intern_lock);
info(HA_STATUS_NO_LOCK | HA_STATUS_TIME | HA_STATUS_VARIABLE |
HA_STATUS_CONST);
}
}
else if (!mi_is_crashed(file) && !thd->killed)
{
mi_mark_crashed(file);
file->update |= HA_STATE_CHANGED | HA_STATE_ROW_CHANGED;
}
thd_proc_info(thd, old_proc_info);
return error ? HA_ADMIN_CORRUPT : HA_ADMIN_OK;
}
/*
analyze the key distribution in the table
As the table may be only locked for read, we have to take into account that
two threads may do an analyze at the same time!
*/
int ha_myisam::analyze(THD *thd, HA_CHECK_OPT* check_opt)
{
int error=0;
MI_CHECK param;
MYISAM_SHARE* share = file->s;
myisamchk_init(&param);
param.thd = thd;
param.op_name= "analyze";
param.db_name= table->s->db.str;
param.table_name= table->alias;
param.testflag= (T_FAST | T_CHECK | T_SILENT | T_STATISTICS |
T_DONT_CHECK_CHECKSUM);
param.using_global_keycache = 1;
param.stats_method= (enum_mi_stats_method)thd->variables.myisam_stats_method;
if (!(share->state.changed & STATE_NOT_ANALYZED))
return HA_ADMIN_ALREADY_DONE;
error = chk_key(&param, file);
if (!error)
{
pthread_mutex_lock(&share->intern_lock);
error=update_state_info(&param,file,UPDATE_STAT);
pthread_mutex_unlock(&share->intern_lock);
}
else if (!mi_is_crashed(file) && !thd->killed)
mi_mark_crashed(file);
return error ? HA_ADMIN_CORRUPT : HA_ADMIN_OK;
}
int ha_myisam::restore(THD* thd, HA_CHECK_OPT *check_opt)
{
HA_CHECK_OPT tmp_check_opt;
char *backup_dir= thd->lex->backup_dir;
char src_path[FN_REFLEN], dst_path[FN_REFLEN];
char table_name[FN_REFLEN];
int error;
const char* errmsg;
DBUG_ENTER("restore");
VOID(tablename_to_filename(table->s->table_name.str, table_name,
sizeof(table_name)));
if (fn_format_relative_to_data_home(src_path, table_name, backup_dir,
MI_NAME_DEXT))
DBUG_RETURN(HA_ADMIN_INVALID);
strxmov(dst_path, table->s->normalized_path.str, MI_NAME_DEXT, NullS);
if (my_copy(src_path, dst_path, MYF(MY_WME)))
{
error= HA_ADMIN_FAILED;
errmsg= "Failed in my_copy (Error %d)";
goto err;
}
tmp_check_opt.init();
tmp_check_opt.flags |= T_VERY_SILENT | T_CALC_CHECKSUM | T_QUICK;
DBUG_RETURN(repair(thd, &tmp_check_opt));
err:
{
MI_CHECK param;
myisamchk_init(&param);
param.thd= thd;
param.op_name= "restore";
param.db_name= table->s->db.str;
param.table_name= table->s->table_name.str;
param.testflag= 0;
mi_check_print_error(&param, errmsg, my_errno);
DBUG_RETURN(error);
}
}
int ha_myisam::backup(THD* thd, HA_CHECK_OPT *check_opt)
{
char *backup_dir= thd->lex->backup_dir;
char src_path[FN_REFLEN], dst_path[FN_REFLEN];
char table_name[FN_REFLEN];
int error;
const char *errmsg;
DBUG_ENTER("ha_myisam::backup");
VOID(tablename_to_filename(table->s->table_name.str, table_name,
sizeof(table_name)));
if (fn_format_relative_to_data_home(dst_path, table_name, backup_dir,
reg_ext))
{
errmsg= "Failed in fn_format() for .frm file (errno: %d)";
error= HA_ADMIN_INVALID;
goto err;
}
strxmov(src_path, table->s->normalized_path.str, reg_ext, NullS);
if (my_copy(src_path, dst_path,
MYF(MY_WME | MY_HOLD_ORIGINAL_MODES | MY_DONT_OVERWRITE_FILE)))
{
error = HA_ADMIN_FAILED;
errmsg = "Failed copying .frm file (errno: %d)";
goto err;
}
/* Change extension */
if (fn_format_relative_to_data_home(dst_path, table_name, backup_dir,
MI_NAME_DEXT))
{
errmsg = "Failed in fn_format() for .MYD file (errno: %d)";
error = HA_ADMIN_INVALID;
goto err;
}
strxmov(src_path, table->s->normalized_path.str, MI_NAME_DEXT, NullS);
if (my_copy(src_path, dst_path,
MYF(MY_WME | MY_HOLD_ORIGINAL_MODES | MY_DONT_OVERWRITE_FILE)))
{
errmsg = "Failed copying .MYD file (errno: %d)";
error= HA_ADMIN_FAILED;
goto err;
}
DBUG_RETURN(HA_ADMIN_OK);
err:
{
MI_CHECK param;
myisamchk_init(&param);
param.thd= thd;
param.op_name= "backup";
param.db_name= table->s->db.str;
param.table_name= table->s->table_name.str;
param.testflag = 0;
mi_check_print_error(&param,errmsg, my_errno);
DBUG_RETURN(error);
}
}
int ha_myisam::repair(THD* thd, HA_CHECK_OPT *check_opt)
{
int error;
MI_CHECK param;
ha_rows start_records;
if (!file) return HA_ADMIN_INTERNAL_ERROR;
myisamchk_init(&param);
param.thd = thd;
param.op_name= "repair";
param.testflag= ((check_opt->flags & ~(T_EXTEND)) |
T_SILENT | T_FORCE_CREATE | T_CALC_CHECKSUM |
(check_opt->flags & T_EXTEND ? T_REP : T_REP_BY_SORT));
param.sort_buffer_length= check_opt->sort_buffer_size;
start_records=file->state->records;
while ((error=repair(thd,param,0)) && param.retry_repair)
{
param.retry_repair=0;
if (test_all_bits(param.testflag,
(uint) (T_RETRY_WITHOUT_QUICK | T_QUICK)))
{
param.testflag&= ~T_RETRY_WITHOUT_QUICK;
sql_print_information("Retrying repair of: '%s' without quick",
table->s->path.str);
continue;
}
param.testflag&= ~T_QUICK;
if ((param.testflag & T_REP_BY_SORT))
{
param.testflag= (param.testflag & ~T_REP_BY_SORT) | T_REP;
sql_print_information("Retrying repair of: '%s' with keycache",
table->s->path.str);
continue;
}
break;
}
if (!error && start_records != file->state->records &&
!(check_opt->flags & T_VERY_SILENT))
{
char llbuff[22],llbuff2[22];
sql_print_information("Found %s of %s rows when repairing '%s'",
llstr(file->state->records, llbuff),
llstr(start_records, llbuff2),
table->s->path.str);
}
return error;
}
int ha_myisam::optimize(THD* thd, HA_CHECK_OPT *check_opt)
{
int error;
if (!file) return HA_ADMIN_INTERNAL_ERROR;
MI_CHECK param;
myisamchk_init(&param);
param.thd = thd;
param.op_name= "optimize";
param.testflag= (check_opt->flags | T_SILENT | T_FORCE_CREATE |
T_REP_BY_SORT | T_STATISTICS | T_SORT_INDEX);
param.sort_buffer_length= check_opt->sort_buffer_size;
if ((error= repair(thd,param,1)) && param.retry_repair)
{
sql_print_warning("Warning: Optimize table got errno %d on %s.%s, retrying",
my_errno, param.db_name, param.table_name);
param.testflag&= ~T_REP_BY_SORT;
error= repair(thd,param,1);
}
return error;
}
int ha_myisam::repair(THD *thd, MI_CHECK &param, bool do_optimize)
{
int error=0;
uint local_testflag=param.testflag;
bool optimize_done= !do_optimize, statistics_done=0;
const char *old_proc_info=thd->proc_info;
char fixed_name[FN_REFLEN];
MYISAM_SHARE* share = file->s;
ha_rows rows= file->state->records;
DBUG_ENTER("ha_myisam::repair");
param.db_name= table->s->db.str;
param.table_name= table->alias;
param.tmpfile_createflag = O_RDWR | O_TRUNC;
param.using_global_keycache = 1;
param.thd= thd;
param.tmpdir= &mysql_tmpdir_list;
param.out_flag= 0;
strmov(fixed_name,file->filename);
// Release latches since this can take a long time
ha_release_temporary_latches(thd);
// Don't lock tables if we have used LOCK TABLE
if (!thd->locked_tables &&
mi_lock_database(file, table->s->tmp_table ? F_EXTRA_LCK : F_WRLCK))
{
mi_check_print_error(&param,ER(ER_CANT_LOCK),my_errno);
DBUG_RETURN(HA_ADMIN_FAILED);
}
if (!do_optimize ||
((file->state->del || share->state.split != file->state->records) &&
(!(param.testflag & T_QUICK) ||
!(share->state.changed & STATE_NOT_OPTIMIZED_KEYS))))
{
ulonglong key_map= ((local_testflag & T_CREATE_MISSING_KEYS) ?
mi_get_mask_all_keys_active(share->base.keys) :
share->state.key_map);
uint testflag=param.testflag;
if (mi_test_if_sort_rep(file,file->state->records,key_map,0) &&
(local_testflag & T_REP_BY_SORT))
{
local_testflag|= T_STATISTICS;
param.testflag|= T_STATISTICS; // We get this for free
statistics_done=1;
if (thd->variables.myisam_repair_threads>1)
{
char buf[40];
/* TODO: respect myisam_repair_threads variable */
my_snprintf(buf, 40, "Repair with %d threads", my_count_bits(key_map));
thd_proc_info(thd, buf);
error = mi_repair_parallel(&param, file, fixed_name,
param.testflag & T_QUICK);
thd_proc_info(thd, "Repair done"); // to reset proc_info, as
// it was pointing to local buffer
}
else
{
thd_proc_info(thd, "Repair by sorting");
error = mi_repair_by_sort(&param, file, fixed_name,
param.testflag & T_QUICK);
}
}
else
{
thd_proc_info(thd, "Repair with keycache");
param.testflag &= ~T_REP_BY_SORT;
error= mi_repair(&param, file, fixed_name,
param.testflag & T_QUICK);
}
param.testflag=testflag;
optimize_done=1;
}
if (!error)
{
if ((local_testflag & T_SORT_INDEX) &&
(share->state.changed & STATE_NOT_SORTED_PAGES))
{
optimize_done=1;
thd_proc_info(thd, "Sorting index");
error=mi_sort_index(&param,file,fixed_name);
}
if (!statistics_done && (local_testflag & T_STATISTICS))
{
if (share->state.changed & STATE_NOT_ANALYZED)
{
optimize_done=1;
thd_proc_info(thd, "Analyzing");
error = chk_key(&param, file);
}
else
local_testflag&= ~T_STATISTICS; // Don't update statistics
}
}
thd_proc_info(thd, "Saving state");
if (!error)
{
if ((share->state.changed & STATE_CHANGED) || mi_is_crashed(file))
{
share->state.changed&= ~(STATE_CHANGED | STATE_CRASHED |
STATE_CRASHED_ON_REPAIR);
file->update|=HA_STATE_CHANGED | HA_STATE_ROW_CHANGED;
}
/*
the following 'if', thought conceptually wrong,
is a useful optimization nevertheless.
*/
if (file->state != &file->s->state.state)
file->s->state.state = *file->state;
if (file->s->base.auto_key)
update_auto_increment_key(&param, file, 1);
if (optimize_done)
error = update_state_info(&param, file,
UPDATE_TIME | UPDATE_OPEN_COUNT |
(local_testflag &
T_STATISTICS ? UPDATE_STAT : 0));
info(HA_STATUS_NO_LOCK | HA_STATUS_TIME | HA_STATUS_VARIABLE |
HA_STATUS_CONST);
if (rows != file->state->records && ! (param.testflag & T_VERY_SILENT))
{
char llbuff[22],llbuff2[22];
mi_check_print_warning(&param,"Number of rows changed from %s to %s",
llstr(rows,llbuff),
llstr(file->state->records,llbuff2));
}
}
else
{
mi_mark_crashed_on_repair(file);
file->update |= HA_STATE_CHANGED | HA_STATE_ROW_CHANGED;
update_state_info(&param, file, 0);
}
thd_proc_info(thd, old_proc_info);
if (!thd->locked_tables)
mi_lock_database(file,F_UNLCK);
DBUG_RETURN(error ? HA_ADMIN_FAILED :
!optimize_done ? HA_ADMIN_ALREADY_DONE : HA_ADMIN_OK);
}
/*
Assign table indexes to a specific key cache.
*/
int ha_myisam::assign_to_keycache(THD* thd, HA_CHECK_OPT *check_opt)
{
KEY_CACHE *new_key_cache= check_opt->key_cache;
const char *errmsg= 0;
int error= HA_ADMIN_OK;
ulonglong map;
TABLE_LIST *table_list= table->pos_in_table_list;
DBUG_ENTER("ha_myisam::assign_to_keycache");
table->keys_in_use_for_query.clear_all();
if (table_list->process_index_hints(table))
DBUG_RETURN(HA_ADMIN_FAILED);
map= ~(ulonglong) 0;
if (!table->keys_in_use_for_query.is_clear_all())
/* use all keys if there's no list specified by the user through hints */
map= table->keys_in_use_for_query.to_ulonglong();
if ((error= mi_assign_to_key_cache(file, map, new_key_cache)))
{
char buf[STRING_BUFFER_USUAL_SIZE];
my_snprintf(buf, sizeof(buf),
"Failed to flush to index file (errno: %d)", error);
errmsg= buf;
error= HA_ADMIN_CORRUPT;
}
if (error != HA_ADMIN_OK)
{
/* Send error to user */
MI_CHECK param;
myisamchk_init(&param);
param.thd= thd;
param.op_name= "assign_to_keycache";
param.db_name= table->s->db.str;
param.table_name= table->s->table_name.str;
param.testflag= 0;
mi_check_print_error(&param, errmsg);
}
DBUG_RETURN(error);
}
/*
Preload pages of the index file for a table into the key cache.
*/
int ha_myisam::preload_keys(THD* thd, HA_CHECK_OPT *check_opt)
{
int error;
const char *errmsg;
ulonglong map;
TABLE_LIST *table_list= table->pos_in_table_list;
my_bool ignore_leaves= table_list->ignore_leaves;
char buf[MYSQL_ERRMSG_SIZE];
DBUG_ENTER("ha_myisam::preload_keys");
table->keys_in_use_for_query.clear_all();
if (table_list->process_index_hints(table))
DBUG_RETURN(HA_ADMIN_FAILED);
map= ~(ulonglong) 0;
/* Check validity of the index references */
if (!table->keys_in_use_for_query.is_clear_all())
/* use all keys if there's no list specified by the user through hints */
map= table->keys_in_use_for_query.to_ulonglong();
mi_extra(file, HA_EXTRA_PRELOAD_BUFFER_SIZE,
(void *) &thd->variables.preload_buff_size);
if ((error= mi_preload(file, map, ignore_leaves)))
{
switch (error) {
case HA_ERR_NON_UNIQUE_BLOCK_SIZE:
errmsg= "Indexes use different block sizes";
break;
case HA_ERR_OUT_OF_MEM:
errmsg= "Failed to allocate buffer";
break;
default:
my_snprintf(buf, sizeof(buf),
"Failed to read from index file (errno: %d)", my_errno);
errmsg= buf;
}
error= HA_ADMIN_FAILED;
goto err;
}
DBUG_RETURN(HA_ADMIN_OK);
err:
{
MI_CHECK param;
myisamchk_init(&param);
param.thd= thd;
param.op_name= "preload_keys";
param.db_name= table->s->db.str;
param.table_name= table->s->table_name.str;
param.testflag= 0;
mi_check_print_error(&param, errmsg);
DBUG_RETURN(error);
}
}
/*
Disable indexes, making it persistent if requested.
SYNOPSIS
disable_indexes()
mode mode of operation:
HA_KEY_SWITCH_NONUNIQ disable all non-unique keys
HA_KEY_SWITCH_ALL disable all keys
HA_KEY_SWITCH_NONUNIQ_SAVE dis. non-uni. and make persistent
HA_KEY_SWITCH_ALL_SAVE dis. all keys and make persistent
IMPLEMENTATION
HA_KEY_SWITCH_NONUNIQ is not implemented.
HA_KEY_SWITCH_ALL_SAVE is not implemented.
RETURN
0 ok
HA_ERR_WRONG_COMMAND mode not implemented.
*/
int ha_myisam::disable_indexes(uint mode)
{
int error;
if (mode == HA_KEY_SWITCH_ALL)
{
/* call a storage engine function to switch the key map */
error= mi_disable_indexes(file);
}
else if (mode == HA_KEY_SWITCH_NONUNIQ_SAVE)
{
mi_extra(file, HA_EXTRA_NO_KEYS, 0);
info(HA_STATUS_CONST); // Read new key info
error= 0;
}
else
{
/* mode not implemented */
error= HA_ERR_WRONG_COMMAND;
}
return error;
}
/*
Enable indexes, making it persistent if requested.
SYNOPSIS
enable_indexes()
mode mode of operation:
HA_KEY_SWITCH_NONUNIQ enable all non-unique keys
HA_KEY_SWITCH_ALL enable all keys
HA_KEY_SWITCH_NONUNIQ_SAVE en. non-uni. and make persistent
HA_KEY_SWITCH_ALL_SAVE en. all keys and make persistent
DESCRIPTION
Enable indexes, which might have been disabled by disable_index() before.
The modes without _SAVE work only if both data and indexes are empty,
since the MyISAM repair would enable them persistently.
To be sure in these cases, call handler::delete_all_rows() before.
IMPLEMENTATION
HA_KEY_SWITCH_NONUNIQ is not implemented.
HA_KEY_SWITCH_ALL_SAVE is not implemented.
RETURN
0 ok
!=0 Error, among others:
HA_ERR_CRASHED data or index is non-empty. Delete all rows and retry.
HA_ERR_WRONG_COMMAND mode not implemented.
*/
int ha_myisam::enable_indexes(uint mode)
{
int error;
DBUG_EXECUTE_IF("wait_in_enable_indexes",
debug_wait_for_kill("wait_in_enable_indexes"); );
if (mi_is_all_keys_active(file->s->state.key_map, file->s->base.keys))
{
/* All indexes are enabled already. */
return 0;
}
if (mode == HA_KEY_SWITCH_ALL)
{
error= mi_enable_indexes(file);
/*
Do not try to repair on error,
as this could make the enabled state persistent,
but mode==HA_KEY_SWITCH_ALL forbids it.
*/
}
else if (mode == HA_KEY_SWITCH_NONUNIQ_SAVE)
{
THD *thd=current_thd;
MI_CHECK param;
const char *save_proc_info=thd->proc_info;
thd_proc_info(thd, "Creating index");
myisamchk_init(&param);
param.op_name= "recreating_index";
param.testflag= (T_SILENT | T_REP_BY_SORT | T_QUICK |
T_CREATE_MISSING_KEYS);
param.myf_rw&= ~MY_WAIT_IF_FULL;
param.sort_buffer_length= thd->variables.myisam_sort_buff_size;
param.stats_method= (enum_mi_stats_method)thd->variables.myisam_stats_method;
param.tmpdir=&mysql_tmpdir_list;
if ((error= (repair(thd,param,0) != HA_ADMIN_OK)) && param.retry_repair)
{
sql_print_warning("Warning: Enabling keys got errno %d on %s.%s, retrying",
my_errno, param.db_name, param.table_name);
/*
Repairing by sort failed. Now try standard repair method.
Still we want to fix only index file. If data file corruption
was detected (T_RETRY_WITHOUT_QUICK), we shouldn't do much here.
Let implicit repair do this job.
*/
if (!(param.testflag & T_RETRY_WITHOUT_QUICK))
{
param.testflag&= ~T_REP_BY_SORT;
error= (repair(thd,param,0) != HA_ADMIN_OK);
}
/*
If the standard repair succeeded, clear all error messages which
might have been set by the first repair. They can still be seen
with SHOW WARNINGS then.
*/
if (! error)
thd->clear_error();
}
info(HA_STATUS_CONST);
thd_proc_info(thd, save_proc_info);
}
else
{
/* mode not implemented */
error= HA_ERR_WRONG_COMMAND;
}
return error;
}
/*
Test if indexes are disabled.
SYNOPSIS
indexes_are_disabled()
no parameters
RETURN
0 indexes are not disabled
1 all indexes are disabled
[2 non-unique indexes are disabled - NOT YET IMPLEMENTED]
*/
int ha_myisam::indexes_are_disabled(void)
{
return mi_indexes_are_disabled(file);
}
/*
prepare for a many-rows insert operation
e.g. - disable indexes (if they can be recreated fast) or
activate special bulk-insert optimizations
SYNOPSIS
start_bulk_insert(rows)
rows Rows to be inserted
0 if we don't know
NOTICE
Do not forget to call end_bulk_insert() later!
*/
void ha_myisam::start_bulk_insert(ha_rows rows)
{
DBUG_ENTER("ha_myisam::start_bulk_insert");
THD *thd= current_thd;
ulong size= min(thd->variables.read_buff_size,
(ulong) (table->s->avg_row_length*rows));
DBUG_PRINT("info",("start_bulk_insert: rows %lu size %lu",
(ulong) rows, size));
/* don't enable row cache if too few rows */
if (! rows || (rows > MI_MIN_ROWS_TO_USE_WRITE_CACHE))
mi_extra(file, HA_EXTRA_WRITE_CACHE, (void*) &size);
can_enable_indexes= mi_is_all_keys_active(file->s->state.key_map,
file->s->base.keys);
if (!(specialflag & SPECIAL_SAFE_MODE))
{
/*
Only disable old index if the table was empty and we are inserting
a lot of rows.
Note that in end_bulk_insert() we may truncate the table if
enable_indexes() failed, thus it's essential that indexes are
disabled ONLY for an empty table.
*/
if (file->state->records == 0 && can_enable_indexes &&
(!rows || rows >= MI_MIN_ROWS_TO_DISABLE_INDEXES))
mi_disable_non_unique_index(file,rows);
else
if (!file->bulk_insert &&
(!rows || rows >= MI_MIN_ROWS_TO_USE_BULK_INSERT))
{
mi_init_bulk_insert(file, thd->variables.bulk_insert_buff_size, rows);
}
}
DBUG_VOID_RETURN;
}
/*
end special bulk-insert optimizations,
which have been activated by start_bulk_insert().
SYNOPSIS
end_bulk_insert()
no arguments
RETURN
0 OK
!= 0 Error
*/
int ha_myisam::end_bulk_insert()
{
mi_end_bulk_insert(file);
int err=mi_extra(file, HA_EXTRA_NO_CACHE, 0);
if (!err)
{
if (can_enable_indexes)
{
/*
Truncate the table when enable index operation is killed.
After truncating the table we don't need to enable the
indexes, because the last repair operation is aborted after
setting the indexes as active and trying to recreate them.
*/
if (((err= enable_indexes(HA_KEY_SWITCH_NONUNIQ_SAVE)) != 0) &&
current_thd->killed)
{
delete_all_rows();
/* not crashed, despite being killed during repair */
file->s->state.changed&= ~(STATE_CRASHED|STATE_CRASHED_ON_REPAIR);
}
}
}
return err;
}
bool ha_myisam::check_and_repair(THD *thd)
{
int error=0;
int marked_crashed;
char *old_query;
uint old_query_length;
HA_CHECK_OPT check_opt;
DBUG_ENTER("ha_myisam::check_and_repair");
check_opt.init();
check_opt.flags= T_MEDIUM | T_AUTO_REPAIR;
// Don't use quick if deleted rows
if (!file->state->del && (myisam_recover_options & HA_RECOVER_QUICK))
check_opt.flags|=T_QUICK;
sql_print_warning("Checking table: '%s'",table->s->path.str);
old_query= thd->query();
old_query_length= thd->query_length();
thd->set_query(table->s->table_name.str,
(uint) table->s->table_name.length);
if ((marked_crashed= mi_is_crashed(file)) || check(thd, &check_opt))
{
sql_print_warning("Recovering table: '%s'",table->s->path.str);
check_opt.flags=
((myisam_recover_options & HA_RECOVER_BACKUP ? T_BACKUP_DATA : 0) |
(marked_crashed ? 0 : T_QUICK) |
(myisam_recover_options & HA_RECOVER_FORCE ? 0 : T_SAFE_REPAIR) |
T_AUTO_REPAIR);
if (repair(thd, &check_opt))
error=1;
}
thd->set_query(old_query, old_query_length);
DBUG_RETURN(error);
}
bool ha_myisam::is_crashed() const
{
return (file->s->state.changed & STATE_CRASHED ||
(my_disable_locking && file->s->state.open_count));
}
int ha_myisam::update_row(const uchar *old_data, uchar *new_data)
{
ha_statistic_increment(&SSV::ha_update_count);
if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
table->timestamp_field->set_time();
return mi_update(file,old_data,new_data);
}
int ha_myisam::delete_row(const uchar *buf)
{
ha_statistic_increment(&SSV::ha_delete_count);
return mi_delete(file,buf);
}
int ha_myisam::index_read_map(uchar *buf, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag)
{
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_key_count);
int error=mi_rkey(file, buf, active_index, key, keypart_map, find_flag);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_read_idx_map(uchar *buf, uint index, const uchar *key,
key_part_map keypart_map,
enum ha_rkey_function find_flag)
{
ha_statistic_increment(&SSV::ha_read_key_count);
int error=mi_rkey(file, buf, index, key, keypart_map, find_flag);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_read_last_map(uchar *buf, const uchar *key,
key_part_map keypart_map)
{
DBUG_ENTER("ha_myisam::index_read_last");
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_key_count);
int error=mi_rkey(file, buf, active_index, key, keypart_map,
HA_READ_PREFIX_LAST);
table->status=error ? STATUS_NOT_FOUND: 0;
DBUG_RETURN(error);
}
int ha_myisam::index_next(uchar *buf)
{
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_next_count);
int error=mi_rnext(file,buf,active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_prev(uchar *buf)
{
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_prev_count);
int error=mi_rprev(file,buf, active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_first(uchar *buf)
{
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_first_count);
int error=mi_rfirst(file, buf, active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_last(uchar *buf)
{
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_last_count);
int error=mi_rlast(file, buf, active_index);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::index_next_same(uchar *buf,
const uchar *key __attribute__((unused)),
uint length __attribute__((unused)))
{
int error;
DBUG_ASSERT(inited==INDEX);
ha_statistic_increment(&SSV::ha_read_next_count);
do
{
error= mi_rnext_same(file,buf);
} while (error == HA_ERR_RECORD_DELETED);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::rnd_init(bool scan)
{
if (scan)
return mi_scan_init(file);
return mi_reset(file); // Free buffers
}
int ha_myisam::rnd_next(uchar *buf)
{
ha_statistic_increment(&SSV::ha_read_rnd_next_count);
int error=mi_scan(file, buf);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
int ha_myisam::restart_rnd_next(uchar *buf, uchar *pos)
{
return rnd_pos(buf,pos);
}
int ha_myisam::rnd_pos(uchar *buf, uchar *pos)
{
ha_statistic_increment(&SSV::ha_read_rnd_count);
int error=mi_rrnd(file, buf, my_get_ptr(pos,ref_length));
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
void ha_myisam::position(const uchar *record)
{
my_off_t row_position= mi_position(file);
my_store_ptr(ref, ref_length, row_position);
}
int ha_myisam::info(uint flag)
{
MI_ISAMINFO misam_info;
char name_buff[FN_REFLEN];
(void) mi_status(file,&misam_info,flag);
if (flag & HA_STATUS_VARIABLE)
{
stats.records= misam_info.records;
stats.deleted= misam_info.deleted;
stats.data_file_length= misam_info.data_file_length;
stats.index_file_length= misam_info.index_file_length;
stats.delete_length= misam_info.delete_length;
stats.check_time= (ulong) misam_info.check_time;
stats.mean_rec_length= misam_info.mean_reclength;
}
if (flag & HA_STATUS_CONST)
{
TABLE_SHARE *share= table->s;
stats.max_data_file_length= misam_info.max_data_file_length;
stats.max_index_file_length= misam_info.max_index_file_length;
stats.create_time= (ulong) misam_info.create_time;
ref_length= misam_info.reflength;
share->db_options_in_use= misam_info.options;
stats.block_size= myisam_block_size; /* record block size */
/* Update share */
if (share->tmp_table == NO_TMP_TABLE)
pthread_mutex_lock(&share->mutex);
share->keys_in_use.set_prefix(share->keys);
share->keys_in_use.intersect_extended(misam_info.key_map);
share->keys_for_keyread.intersect(share->keys_in_use);
share->db_record_offset= misam_info.record_offset;
if (share->key_parts)
memcpy((char*) table->key_info[0].rec_per_key,
(char*) misam_info.rec_per_key,
sizeof(table->key_info[0].rec_per_key[0])*share->key_parts);
if (share->tmp_table == NO_TMP_TABLE)
pthread_mutex_unlock(&share->mutex);
/*
Set data_file_name and index_file_name to point at the symlink value
if table is symlinked (Ie; Real name is not same as generated name)
*/
data_file_name= index_file_name= 0;
fn_format(name_buff, file->filename, "", MI_NAME_DEXT,
MY_APPEND_EXT | MY_UNPACK_FILENAME);
if (strcmp(name_buff, misam_info.data_file_name))
data_file_name=misam_info.data_file_name;
fn_format(name_buff, file->filename, "", MI_NAME_IEXT,
MY_APPEND_EXT | MY_UNPACK_FILENAME);
if (strcmp(name_buff, misam_info.index_file_name))
index_file_name=misam_info.index_file_name;
}
if (flag & HA_STATUS_ERRKEY)
{
errkey = misam_info.errkey;
my_store_ptr(dup_ref, ref_length, misam_info.dupp_key_pos);
}
if (flag & HA_STATUS_TIME)
stats.update_time = (ulong) misam_info.update_time;
if (flag & HA_STATUS_AUTO)
stats.auto_increment_value= misam_info.auto_increment;
return 0;
}
int ha_myisam::extra(enum ha_extra_function operation)
{
if ((specialflag & SPECIAL_SAFE_MODE) && operation == HA_EXTRA_KEYREAD)
return 0;
if (operation == HA_EXTRA_MMAP && !opt_myisam_use_mmap)
return 0;
return mi_extra(file, operation, 0);
}
int ha_myisam::reset(void)
{
return mi_reset(file);
}
/* To be used with WRITE_CACHE and EXTRA_CACHE */
int ha_myisam::extra_opt(enum ha_extra_function operation, ulong cache_size)
{
if ((specialflag & SPECIAL_SAFE_MODE) && operation == HA_EXTRA_WRITE_CACHE)
return 0;
return mi_extra(file, operation, (void*) &cache_size);
}
int ha_myisam::delete_all_rows()
{
return mi_delete_all_rows(file);
}
int ha_myisam::reset_auto_increment(ulonglong value)
{
file->s->state.auto_increment= value;
return 0;
}
int ha_myisam::delete_table(const char *name)
{
return mi_delete_table(name);
}
int ha_myisam::external_lock(THD *thd, int lock_type)
{
return mi_lock_database(file, !table->s->tmp_table ?
lock_type : ((lock_type == F_UNLCK) ?
F_UNLCK : F_EXTRA_LCK));
}
THR_LOCK_DATA **ha_myisam::store_lock(THD *thd,
THR_LOCK_DATA **to,
enum thr_lock_type lock_type)
{
if (lock_type != TL_IGNORE && file->lock.type == TL_UNLOCK)
file->lock.type=lock_type;
*to++= &file->lock;
return to;
}
void ha_myisam::update_create_info(HA_CREATE_INFO *create_info)
{
ha_myisam::info(HA_STATUS_AUTO | HA_STATUS_CONST);
if (!(create_info->used_fields & HA_CREATE_USED_AUTO))
{
create_info->auto_increment_value= stats.auto_increment_value;
}
create_info->data_file_name=data_file_name;
create_info->index_file_name=index_file_name;
}
int ha_myisam::create(const char *name, register TABLE *table_arg,
HA_CREATE_INFO *ha_create_info)
{
int error;
uint create_flags= 0, records, i;
char buff[FN_REFLEN];
MI_KEYDEF *keydef;
MI_COLUMNDEF *recinfo;
MI_CREATE_INFO create_info;
TABLE_SHARE *share= table_arg->s;
uint options= share->db_options_in_use;
DBUG_ENTER("ha_myisam::create");
for (i= 0; i < share->keys; i++)
{
if (table_arg->key_info[i].flags & HA_USES_PARSER)
{
create_flags|= HA_CREATE_RELIES_ON_SQL_LAYER;
break;
}
}
if ((error= table2myisam(table_arg, &keydef, &recinfo, &records)))
DBUG_RETURN(error); /* purecov: inspected */
bzero((char*) &create_info, sizeof(create_info));
create_info.max_rows= share->max_rows;
create_info.reloc_rows= share->min_rows;
create_info.with_auto_increment= share->next_number_key_offset == 0;
create_info.auto_increment= (ha_create_info->auto_increment_value ?
ha_create_info->auto_increment_value -1 :
(ulonglong) 0);
create_info.data_file_length= ((ulonglong) share->max_rows *
share->avg_row_length);
create_info.data_file_name= ha_create_info->data_file_name;
create_info.index_file_name= ha_create_info->index_file_name;
create_info.language= share->table_charset->number;
if (ha_create_info->options & HA_LEX_CREATE_TMP_TABLE)
create_flags|= HA_CREATE_TMP_TABLE;
if (ha_create_info->options & HA_CREATE_KEEP_FILES)
create_flags|= HA_CREATE_KEEP_FILES;
if (options & HA_OPTION_PACK_RECORD)
create_flags|= HA_PACK_RECORD;
if (options & HA_OPTION_CHECKSUM)
create_flags|= HA_CREATE_CHECKSUM;
if (options & HA_OPTION_DELAY_KEY_WRITE)
create_flags|= HA_CREATE_DELAY_KEY_WRITE;
/* TODO: Check that the following fn_format is really needed */
error= mi_create(fn_format(buff, name, "", "",
MY_UNPACK_FILENAME|MY_APPEND_EXT),
share->keys, keydef,
records, recinfo,
0, (MI_UNIQUEDEF*) 0,
&create_info, create_flags);
my_free((uchar*) recinfo, MYF(0));
DBUG_RETURN(error);
}
int ha_myisam::rename_table(const char * from, const char * to)
{
return mi_rename(from,to);
}
void ha_myisam::get_auto_increment(ulonglong offset, ulonglong increment,
ulonglong nb_desired_values,
ulonglong *first_value,
ulonglong *nb_reserved_values)
{
ulonglong nr;
int error;
uchar key[MI_MAX_KEY_LENGTH];
if (!table->s->next_number_key_offset)
{ // Autoincrement at key-start
ha_myisam::info(HA_STATUS_AUTO);
*first_value= stats.auto_increment_value;
/* MyISAM has only table-level lock, so reserves to +inf */
*nb_reserved_values= ULONGLONG_MAX;
return;
}
/* it's safe to call the following if bulk_insert isn't on */
mi_flush_bulk_insert(file, table->s->next_number_index);
(void) extra(HA_EXTRA_KEYREAD);
key_copy(key, table->record[0],
table->key_info + table->s->next_number_index,
table->s->next_number_key_offset);
error= mi_rkey(file, table->record[1], (int) table->s->next_number_index,
key, make_prev_keypart_map(table->s->next_number_keypart),
HA_READ_PREFIX_LAST);
if (error)
nr= 1;
else
{
/* Get data from record[1] */
nr= ((ulonglong) table->next_number_field->
val_int_offset(table->s->rec_buff_length)+1);
}
extra(HA_EXTRA_NO_KEYREAD);
*first_value= nr;
/*
MySQL needs to call us for next row: assume we are inserting ("a",null)
here, we return 3, and next this statement will want to insert ("b",null):
there is no reason why ("b",3+1) would be the good row to insert: maybe it
already exists, maybe 3+1 is too large...
*/
*nb_reserved_values= 1;
}
/*
Find out how many rows there is in the given range
SYNOPSIS
records_in_range()
inx Index to use
min_key Start of range. Null pointer if from first key
max_key End of range. Null pointer if to last key
NOTES
min_key.flag can have one of the following values:
HA_READ_KEY_EXACT Include the key in the range
HA_READ_AFTER_KEY Don't include key in range
max_key.flag can have one of the following values:
HA_READ_BEFORE_KEY Don't include key in range
HA_READ_AFTER_KEY Include all 'end_key' values in the range
RETURN
HA_POS_ERROR Something is wrong with the index tree.
0 There is no matching keys in the given range
number > 0 There is approximately 'number' matching rows in
the range.
*/
ha_rows ha_myisam::records_in_range(uint inx, key_range *min_key,
key_range *max_key)
{
return (ha_rows) mi_records_in_range(file, (int) inx, min_key, max_key);
}
int ha_myisam::ft_read(uchar *buf)
{
int error;
if (!ft_handler)
return -1;
thread_safe_increment(table->in_use->status_var.ha_read_next_count,
&LOCK_status); // why ?
error=ft_handler->please->read_next(ft_handler,(char*) buf);
table->status=error ? STATUS_NOT_FOUND: 0;
return error;
}
uint ha_myisam::checksum() const
{
return (uint)file->state->checksum;
}
bool ha_myisam::check_if_incompatible_data(HA_CREATE_INFO *info,
uint table_changes)
{
uint options= table->s->db_options_in_use;
if (info->auto_increment_value != stats.auto_increment_value ||
info->data_file_name != data_file_name ||
info->index_file_name != index_file_name ||
table_changes == IS_EQUAL_NO ||
table_changes & IS_EQUAL_PACK_LENGTH) // Not implemented yet
return COMPATIBLE_DATA_NO;
if ((options & (HA_OPTION_PACK_RECORD | HA_OPTION_CHECKSUM |
HA_OPTION_DELAY_KEY_WRITE)) !=
(info->table_options & (HA_OPTION_PACK_RECORD | HA_OPTION_CHECKSUM |
HA_OPTION_DELAY_KEY_WRITE)))
return COMPATIBLE_DATA_NO;
return COMPATIBLE_DATA_YES;
}
extern int mi_panic(enum ha_panic_function flag);
int myisam_panic(handlerton *hton, ha_panic_function flag)
{
return mi_panic(flag);
}
static int myisam_init(void *p)
{
handlerton *myisam_hton;
myisam_hton= (handlerton *)p;
myisam_hton->state= SHOW_OPTION_YES;
myisam_hton->db_type= DB_TYPE_MYISAM;
myisam_hton->create= myisam_create_handler;
myisam_hton->panic= myisam_panic;
myisam_hton->flags= HTON_CAN_RECREATE | HTON_SUPPORT_LOG_TABLES;
return 0;
}
struct st_mysql_storage_engine myisam_storage_engine=
{ MYSQL_HANDLERTON_INTERFACE_VERSION };
mysql_declare_plugin(myisam)
{
MYSQL_STORAGE_ENGINE_PLUGIN,
&myisam_storage_engine,
"MyISAM",
"MySQL AB",
"Default engine as of MySQL 3.23 with great performance",
PLUGIN_LICENSE_GPL,
myisam_init, /* Plugin Init */
NULL, /* Plugin Deinit */
0x0100, /* 1.0 */
NULL, /* status variables */
NULL, /* system variables */
NULL /* config options */
}
mysql_declare_plugin_end;
#ifdef HAVE_QUERY_CACHE
/**
@brief Register a named table with a call back function to the query cache.
@param thd The thread handle
@param table_key A pointer to the table name in the table cache
@param key_length The length of the table name
@param[out] engine_callback The pointer to the storage engine call back
function, currently 0
@param[out] engine_data Engine data will be set to 0.
@note Despite the name of this function, it is used to check each statement
before it is cached and not to register a table or callback function.
@see handler::register_query_cache_table
@return The error code. The engine_data and engine_callback will be set to 0.
@retval TRUE Success
@retval FALSE An error occured
*/
my_bool ha_myisam::register_query_cache_table(THD *thd, char *table_name,
uint table_name_len,
qc_engine_callback
*engine_callback,
ulonglong *engine_data)
{
DBUG_ENTER("ha_myisam::register_query_cache_table");
/*
No call back function is needed to determine if a cached statement
is valid or not.
*/
*engine_callback= 0;
/*
No engine data is needed.
*/
*engine_data= 0;
if (file->s->concurrent_insert)
{
/*
If a concurrent INSERT has happened just before the currently
processed SELECT statement, the total size of the table is
unknown.
To determine if the table size is known, the current thread's snap
shot of the table size with the actual table size are compared.
If the table size is unknown the SELECT statement can't be cached.
When concurrent inserts are disabled at table open, mi_open()
does not assign a get_status() function. In this case the local
("current") status is never updated. We would wrongly think that
we cannot cache the statement.
*/
ulonglong actual_data_file_length;
ulonglong current_data_file_length;
/*
POSIX visibility rules specify that "2. Whatever memory values a
thread can see when it unlocks a mutex <...> can also be seen by any
thread that later locks the same mutex". In this particular case,
concurrent insert thread had modified the data_file_length in
MYISAM_SHARE before it has unlocked (or even locked)
structure_guard_mutex. So, here we're guaranteed to see at least that
value after we've locked the same mutex. We can see a later value
(modified by some other thread) though, but it's ok, as we only want
to know if the variable was changed, the actual new value doesn't matter
*/
actual_data_file_length= file->s->state.state.data_file_length;
current_data_file_length= file->save_state.data_file_length;
if (current_data_file_length != actual_data_file_length)
{
/* Don't cache current statement. */
DBUG_RETURN(FALSE);
}
}
/*
This query execution might have started after the query cache was flushed
by a concurrent INSERT. In this case, don't cache this statement as the
data file length difference might not be visible yet if the tables haven't
been unlocked by the concurrent insert thread.
*/
if (file->state->uncacheable)
DBUG_RETURN(FALSE);
/* It is ok to try to cache current statement. */
DBUG_RETURN(TRUE);
}
#endif
Reference in a new issue View git blame Copy permalink