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Kirill Smelkov
mariadb
Commits
52758d86
Commit
52758d86
authored
Sep 28, 2006
by
istruewing@chilla.local
Browse files
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Merge bk-internal.mysql.com:/home/bk/mysql-4.1-engines
into chilla.local:/home/mydev/mysql-4.1-bug20719-m
parents
a324cb89
ac778232
Changes
1
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Showing
1 changed file
with
130 additions
and
29 deletions
+130
-29
myisam/mi_dynrec.c
myisam/mi_dynrec.c
+130
-29
No files found.
myisam/mi_dynrec.c
View file @
52758d86
...
...
@@ -1091,12 +1091,41 @@ void _my_store_blob_length(byte *pos,uint pack_length,uint length)
}
/* Read record from datafile */
/* Returns 0 if ok, -1 if error */
/*
Read record from datafile.
SYNOPSIS
_mi_read_dynamic_record()
info MI_INFO pointer to table.
filepos From where to read the record.
buf Destination for record.
NOTE
If a write buffer is active, it needs to be flushed if its contents
intersects with the record to read. We always check if the position
of the first byte of the write buffer is lower than the position
past the last byte to read. In theory this is also true if the write
buffer is completely below the read segment. That is, if there is no
intersection. But this case is unusual. We flush anyway. Only if the
first byte in the write buffer is above the last byte to read, we do
not flush.
A dynamic record may need several reads. So this check must be done
before every read. Reading a dynamic record starts with reading the
block header. If the record does not fit into the free space of the
header, the block may be longer than the header. In this case a
second read is necessary. These one or two reads repeat for every
part of the record.
RETURN
0 OK
-1 Error
*/
int
_mi_read_dynamic_record
(
MI_INFO
*
info
,
my_off_t
filepos
,
byte
*
buf
)
{
int
flag
;
int
block_of_record
;
uint
b_type
,
left_length
;
byte
*
to
;
MI_BLOCK_INFO
block_info
;
...
...
@@ -1108,20 +1137,19 @@ int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
LINT_INIT
(
to
);
LINT_INIT
(
left_length
);
file
=
info
->
dfile
;
block_
info
.
next_filepos
=
filepos
;
/* for easyer loop
*/
flag
=
block_info
.
second_read
=
0
;
block_
of_record
=
0
;
/* First block of record is numbered as zero.
*/
block_info
.
second_read
=
0
;
do
{
/* A corrupted table can have wrong pointers. (Bug# 19835) */
if
(
filepos
==
HA_OFFSET_ERROR
)
goto
panic
;
if
(
info
->
opt_flag
&
WRITE_CACHE_USED
&&
info
->
rec_cache
.
pos_in_file
<
=
block_info
.
next_filepos
&&
info
->
rec_cache
.
pos_in_file
<
filepos
+
MI_BLOCK_INFO_HEADER_LENGTH
&&
flush_io_cache
(
&
info
->
rec_cache
))
goto
err
;
/* A corrupted table can have wrong pointers. (Bug# 19835) */
if
(
block_info
.
next_filepos
==
HA_OFFSET_ERROR
)
goto
panic
;
info
->
rec_cache
.
seek_not_done
=
1
;
if
((
b_type
=
_mi_get_block_info
(
&
block_info
,
file
,
block_info
.
next_filepos
))
if
((
b_type
=
_mi_get_block_info
(
&
block_info
,
file
,
filepos
))
&
(
BLOCK_DELETED
|
BLOCK_ERROR
|
BLOCK_SYNC_ERROR
|
BLOCK_FATAL_ERROR
))
{
...
...
@@ -1129,9 +1157,8 @@ int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
my_errno
=
HA_ERR_RECORD_DELETED
;
goto
err
;
}
if
(
flag
==
0
)
/* First block */
if
(
block_of_record
++
==
0
)
/* First block */
{
flag
=
1
;
if
(
block_info
.
rec_len
>
(
uint
)
info
->
s
->
base
.
max_pack_length
)
goto
panic
;
if
(
info
->
s
->
base
.
blobs
)
...
...
@@ -1146,11 +1173,35 @@ int _mi_read_dynamic_record(MI_INFO *info, my_off_t filepos, byte *buf)
}
if
(
left_length
<
block_info
.
data_len
||
!
block_info
.
data_len
)
goto
panic
;
/* Wrong linked record */
if
(
my_pread
(
file
,(
byte
*
)
to
,
block_info
.
data_len
,
block_info
.
filepos
,
MYF
(
MY_NABP
)))
goto
panic
;
left_length
-=
block_info
.
data_len
;
to
+=
block_info
.
data_len
;
/* copy information that is already read */
{
uint
offset
=
(
uint
)
(
block_info
.
filepos
-
filepos
);
uint
prefetch_len
=
(
sizeof
(
block_info
.
header
)
-
offset
);
filepos
+=
sizeof
(
block_info
.
header
);
if
(
prefetch_len
>
block_info
.
data_len
)
prefetch_len
=
block_info
.
data_len
;
if
(
prefetch_len
)
{
memcpy
((
byte
*
)
to
,
block_info
.
header
+
offset
,
prefetch_len
);
block_info
.
data_len
-=
prefetch_len
;
left_length
-=
prefetch_len
;
to
+=
prefetch_len
;
}
}
/* read rest of record from file */
if
(
block_info
.
data_len
)
{
if
(
info
->
opt_flag
&
WRITE_CACHE_USED
&&
info
->
rec_cache
.
pos_in_file
<
filepos
+
block_info
.
data_len
&&
flush_io_cache
(
&
info
->
rec_cache
))
goto
err
;
if
(
my_read
(
file
,
(
byte
*
)
to
,
block_info
.
data_len
,
MYF
(
MY_NABP
)))
goto
panic
;
left_length
-=
block_info
.
data_len
;
to
+=
block_info
.
data_len
;
}
filepos
=
block_info
.
next_filepos
;
}
while
(
left_length
);
info
->
update
|=
HA_STATE_AKTIV
;
/* We have a aktive record */
...
...
@@ -1307,11 +1358,45 @@ err:
}
/*
Read record from datafile.
SYNOPSIS
_mi_read_rnd_dynamic_record()
info MI_INFO pointer to table.
buf Destination for record.
filepos From where to read the record.
skip_deleted_blocks If to repeat reading until a non-deleted
record is found.
NOTE
If a write buffer is active, it needs to be flushed if its contents
intersects with the record to read. We always check if the position
of the first byte of the write buffer is lower than the position
past the last byte to read. In theory this is also true if the write
buffer is completely below the read segment. That is, if there is no
intersection. But this case is unusual. We flush anyway. Only if the
first byte in the write buffer is above the last byte to read, we do
not flush.
A dynamic record may need several reads. So this check must be done
before every read. Reading a dynamic record starts with reading the
block header. If the record does not fit into the free space of the
header, the block may be longer than the header. In this case a
second read is necessary. These one or two reads repeat for every
part of the record.
RETURN
0 OK
!= 0 Error
*/
int
_mi_read_rnd_dynamic_record
(
MI_INFO
*
info
,
byte
*
buf
,
register
my_off_t
filepos
,
my_bool
skip_deleted_blocks
)
{
int
flag
,
info_read
,
save_errno
;
int
block_of_record
,
info_read
,
save_errno
;
uint
left_len
,
b_type
;
byte
*
to
;
MI_BLOCK_INFO
block_info
;
...
...
@@ -1337,7 +1422,8 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
else
info_read
=
1
;
/* memory-keyinfoblock is ok */
flag
=
block_info
.
second_read
=
0
;
block_of_record
=
0
;
/* First block of record is numbered as zero. */
block_info
.
second_read
=
0
;
left_len
=
1
;
do
{
...
...
@@ -1360,15 +1446,15 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
{
if
(
_mi_read_cache
(
&
info
->
rec_cache
,(
byte
*
)
block_info
.
header
,
filepos
,
sizeof
(
block_info
.
header
),
(
!
flag
&&
skip_deleted_blocks
?
READING_NEXT
:
0
)
|
READING_HEADER
))
(
!
block_of_record
&&
skip_deleted_blocks
?
READING_NEXT
:
0
)
|
READING_HEADER
))
goto
panic
;
b_type
=
_mi_get_block_info
(
&
block_info
,
-
1
,
filepos
);
}
else
{
if
(
info
->
opt_flag
&
WRITE_CACHE_USED
&&
info
->
rec_cache
.
pos_in_file
<
=
filepos
&&
info
->
rec_cache
.
pos_in_file
<
filepos
+
MI_BLOCK_INFO_HEADER_LENGTH
&&
flush_io_cache
(
&
info
->
rec_cache
))
DBUG_RETURN
(
my_errno
);
info
->
rec_cache
.
seek_not_done
=
1
;
...
...
@@ -1393,7 +1479,7 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
}
goto
err
;
}
if
(
flag
==
0
)
/* First block */
if
(
block_of_record
==
0
)
/* First block */
{
if
(
block_info
.
rec_len
>
(
uint
)
share
->
base
.
max_pack_length
)
goto
panic
;
...
...
@@ -1426,7 +1512,7 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
left_len
-=
tmp_length
;
to
+=
tmp_length
;
filepos
+=
tmp_length
;
}
}
}
/* read rest of record from file */
if
(
block_info
.
data_len
)
...
...
@@ -1435,11 +1521,17 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
{
if
(
_mi_read_cache
(
&
info
->
rec_cache
,(
byte
*
)
to
,
filepos
,
block_info
.
data_len
,
(
!
flag
&&
skip_deleted_blocks
)
?
READING_NEXT
:
0
))
(
!
block_of_record
&&
skip_deleted_blocks
)
?
READING_NEXT
:
0
))
goto
panic
;
}
else
{
if
(
info
->
opt_flag
&
WRITE_CACHE_USED
&&
info
->
rec_cache
.
pos_in_file
<
block_info
.
filepos
+
block_info
.
data_len
&&
flush_io_cache
(
&
info
->
rec_cache
))
goto
err
;
/* VOID(my_seek(info->dfile,filepos,MY_SEEK_SET,MYF(0))); */
if
(
my_read
(
info
->
dfile
,(
byte
*
)
to
,
block_info
.
data_len
,
MYF
(
MY_NABP
)))
{
...
...
@@ -1449,10 +1541,14 @@ int _mi_read_rnd_dynamic_record(MI_INFO *info, byte *buf,
}
}
}
if
(
flag
++
==
0
)
/*
Increment block-of-record counter. If it was the first block,
remember the position behind the block for the next call.
*/
if
(
block_of_record
++
==
0
)
{
info
->
nextpos
=
block_info
.
filepos
+
block_info
.
block_len
;
skip_deleted_blocks
=
0
;
info
->
nextpos
=
block_info
.
filepos
+
block_info
.
block_len
;
skip_deleted_blocks
=
0
;
}
left_len
-=
block_info
.
data_len
;
to
+=
block_info
.
data_len
;
...
...
@@ -1484,6 +1580,11 @@ uint _mi_get_block_info(MI_BLOCK_INFO *info, File file, my_off_t filepos)
if
(
file
>=
0
)
{
/*
We do not use my_pread() here because we want to have the file
pointer set to the end of the header after this function.
my_pread() may leave the file pointer untouched.
*/
VOID
(
my_seek
(
file
,
filepos
,
MY_SEEK_SET
,
MYF
(
0
)));
if
(
my_read
(
file
,(
char
*
)
header
,
sizeof
(
info
->
header
),
MYF
(
0
))
!=
sizeof
(
info
->
header
))
...
...
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