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mariadb/storage/maria/ma_blockrec.c
unknown e10fe77b0a Merge desktop.sanja.is.com.ua:/home/bell/mysql/bk/work-maria.bak 
into  desktop.sanja.is.com.ua:/home/bell/mysql/bk/work-test


include/maria.h:
  Auto merged
mysys/Makefile.am:
  Auto merged
mysys/mf_keycaches.c:
  Auto merged
sql/handler.h:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/set_var.cc:
  Auto merged
sql/set_var.h:
  Auto merged
storage/maria/Makefile.am:
  Auto merged
storage/maria/ha_maria.cc:
  Auto merged
storage/maria/ma_bitmap.c:
  Auto merged
storage/maria/ma_check.c:
  Auto merged
storage/maria/ma_close.c:
  Auto merged
storage/maria/ma_dynrec.c:
  Auto merged
storage/maria/ma_extra.c:
  Auto merged
storage/maria/ma_info.c:
  Auto merged
storage/maria/ma_keycache.c:
  Auto merged
storage/maria/ma_locking.c:
  Auto merged
storage/maria/ma_loghandler.c:
  Auto merged
storage/maria/ma_open.c:
  Auto merged
storage/maria/ma_packrec.c:
  Auto merged
storage/maria/ma_page.c:
  Auto merged
storage/maria/ma_pagecache.c:
  Auto merged
storage/maria/ma_panic.c:
  Auto merged
storage/maria/ma_preload.c:
  Auto merged
storage/maria/ma_static.c:
  Auto merged
storage/maria/ma_test1.c:
  Auto merged
storage/maria/ma_test2.c:
  Auto merged
storage/maria/ma_test3.c:
  Auto merged
storage/maria/ma_write.c:
  Auto merged
storage/maria/maria_chk.c:
  Auto merged
storage/maria/maria_def.h:
  Auto merged
storage/maria/maria_ftdump.c:
  Auto merged
storage/maria/maria_pack.c:
  Auto merged
sql/handler.cc:
  merge
storage/maria/ma_blockrec.c:
  merge
storage/maria/ma_delete_all.c:
  merge
2007-04-16 13:19:43 +03:00

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/* Copyright (C) 2007 Michael Widenius
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 */
/*
Storage of records in block
Maria will have a LSN at start of each page (including the bitmap page)
Maria will for each row have the additional information:
TRANSID Transaction ID that last updated row (6 bytes)
VER_PTR Version pointer that points on the UNDO entry that
contains last version of the row versions (7 bytes)
The different page types that are in a data file are:
Bitmap pages Map of free pages in the next extent (8129 page size
gives us 256M of mapped pages / bitmap)
Head page Start of rows are stored on this page.
A rowid always points to a head page
Blob page This page is totally filled with data from one blob or by
a set of long VARCHAR/CHAR fields
Tail page This contains the last part from different rows, blobs
or varchar fields.
The data file starts with a bitmap page, followed by as many data
pages as the bitmap can cover. After this there is a new bitmap page
and more data pages etc.
For information about the bitmap page, see ma_bitmap.c
Structure of data and tail page:
The page has a row directory at end of page to allow us to do deletes
without having to reorganize the page. It also allows us to store some
extra bytes after each row to allow them to grow without having to move
around other rows
Page header:
LSN 7 bytes Log position for last page change
PAGE_TYPE 1 byte 1 for head / 2 for tail / 3 for blob
NO 1 byte Number of row/tail entries on page
empty space 2 bytes Empty space on page
The upmost bit in PAGE_TYPE is set to 1 if the data on the page
can be compacted to get more space. (PAGE_CAN_BE_COMPACTED)
Row data
Row directory of NO entires, that consist of the following for each row
(in reverse order; ie, first record is stored last):
Position 2 bytes Position of row on page
Length 2 bytes Length of entry
For Position and Length, the 1 upmost bit of the position and the 1
upmost bit of the length could be used for some states of the row (in
other words, we should try to keep these reserved)
eof flag 1 byte Reserved for full page read testing
----------------
Structure of blob pages:
LSN 7 bytes Log position for last page change
PAGE_TYPE 1 byte 3
data
-----------------
Row data structure:
Flag 1 byte Marker of which header field exists
TRANSID 6 bytes TRANSID of changing transaction
(optional, added on insert and first
update/delete)
VER_PTR 7 bytes Pointer to older version in log
(undo record)
(optional, added after first
update/delete)
DELETE_TRANSID 6 bytes (optional). TRANSID of original row.
Added on delete.
Nulls_extended 1 byte To allow us to add new DEFAULT NULL
fields (optional, added after first
change of row after alter table)
Number of ROW_EXTENT's 1-3 byte Length encoded, optional
This is the number of extents the
row is split into
First row_extent 7 byte Pointer to first row extent (optional)
Total length of length array 1-3 byte Only used if we have
char/varchar/blob fields.
Row checksum 1 byte Only if table created with checksums
Null_bits .. One bit for each NULL field
Empty_bits .. One bit for each NOT NULL field. This bit is
0 if the value is 0 or empty string.
field_offsets 2 byte/offset
For each 32 field, there is one offset that
points to where the field information starts
in the block. This is to provide fast access
to later field in the row when we only need
to return a small set of fields.
Things marked above as 'optional' will only be present if the corresponding
bit is set in 'Flag' field.
Data in the following order:
(Field order is precalculated when table is created)
Critical fixed length, not null, fields. (Note, these can't be dropped)
Fixed length, null fields
Length array, 1-4 byte per field for all CHAR/VARCHAR/BLOB fields.
Number of bytes used in length array per entry is depending on max length
for field.
ROW_EXTENT's
CHAR data (space stripped)
VARCHAR data
BLOB data
Fields marked in null_bits or empty_bits are not stored in data part or
length array.
If row doesn't fit into the given block, then the first EXTENT will be
stored last on the row. This is done so that we don't break any field
data in the middle.
We first try to store the full row into one block. If that's not possible
we move out each big blob into their own extents. If this is not enough we
move out a concatenation of all varchars to their own extent.
Each blob and the concatenated char/varchar fields are stored the following
way:
- Store the parts in as many full-contiguous pages as possible.
- The last part, that doesn't fill a full page, is stored in tail page.
When doing an insert of a new row, we don't have to have
VER_PTR in the row. This will make rows that are not changed stored
efficiently. On update and delete we would add TRANSID (if it was an old
committed row) and VER_PTR to
the row. On row page compaction we can easily detect rows where
TRANSID was committed before the the longest running transaction
started and we can then delete TRANSID and VER_PTR from the row to
gain more space.
If a row is deleted in Maria, we change TRANSID to current transid and
change VER_PTR to point to the undo record for the delete. The undo
record must contain the original TRANSID, so that another transaction
can use this to check if they should use the found row or go to the
previous row pointed to by the VER_PTR in the undo row.
Description of the different parts:
Flag is coded as:
Description bit
TRANS_ID_exists 0
VER_PTR_exists 1
Row is deleted 2 (Means that DELETE_TRANSID exists)
Nulls_extended_exists 3
Row is split 7 This means that 'Number_of_row_extents' exists
This would be a way to get more space on a page when doing page
compaction as we don't need to store TRANSID that have committed
before the smallest running transaction we have in memory.
Nulls_extended is the number of new DEFAULT NULL fields in the row
compared to the number of DEFAULT NULL fields when the first version
of the table was created. If Nulls_extended doesn't exist in the row,
we know it's 0 as this must be one of the original rows from when the
table was created first time. This coding allows us to add 255*8 =
2048 new fields without requiring a full alter table.
Empty_bits is used to allow us to store 0, 0.0, empty string, empty
varstring and empty blob efficiently. (This is very good for data
warehousing where NULL's are often regarded as evil). Having this
bitmap also allows us to drop information of a field during a future
delete if field was deleted with ALTER TABLE DROP COLUMN. To be able
to handle DROP COLUMN, we must store in the index header the fields
that has been dropped. When unpacking a row we will ignore dropped
fields. When storing a row, we will mark a dropped field either with a
null in the null bit map or in the empty_bits and not store any data
for it.
One ROW_EXTENT is coded as:
START_PAGE 5 bytes
PAGE_COUNT 2 bytes. High bit is used to indicate tail page/
end of blob
With 8K pages, we can cover 256M in one extent. This coding gives us a
maximum file size of 2^40*8192 = 8192 tera
As an example of ROW_EXTENT handling, assume a row with one integer
field (value 5), two big VARCHAR fields (size 250 and 8192*3), and 2
big BLOB fields that we have updated.
The record format for storing this into an empty file would be:
Page 1:
00 00 00 00 00 00 00 LSN
01 Only one row in page
xx xx Empty space on page
10 Flag: row split, VER_PTR exists
01 00 00 00 00 00 TRANSID 1
00 00 00 00 00 01 00 VER_PTR to first block in LOG file 1
5 Number of row extents
02 00 00 00 00 03 00 VARCHAR's are stored in full pages 2,3,4
0 No null fields
0 No empty fields
05 00 00 00 00 00 80 Tail page for VARCHAR, rowid 0
06 00 00 00 00 80 00 First blob, stored at page 6-133
05 00 00 00 00 01 80 Tail of first blob (896 bytes) at page 5
86 00 00 00 00 80 00 Second blob, stored at page 134-262
05 00 00 00 00 02 80 Tail of second blob (896 bytes) at page 5
05 00 5 integer
FA Length of first varchar field (size 250)
00 60 Length of second varchar field (size 8192*3)
00 60 10 First medium BLOB, 1M
01 00 10 00 Second BLOB, 1M
xx xx xx xx xx xx Varchars are stored here until end of page
..... until end of page
09 00 F4 1F 00 (Start position 9, length 8180, end byte)
*/
#define SANITY_CHECKS
#include "maria_def.h"
#include "ma_blockrec.h"
typedef struct st_maria_extent_cursor
{
byte *extent;
byte *data_start; /* For error checking */
MARIA_RECORD_POS *tail_positions;
my_off_t page;
uint extent_count, page_count;
uint tail; /* <> 0 if current extent is a tail page */
my_bool first_extent;
} MARIA_EXTENT_CURSOR;
static my_bool delete_tails(MARIA_HA *info, MARIA_RECORD_POS *tails);
static my_bool delete_head_or_tail(MARIA_HA *info,
ulonglong page, uint record_number,
my_bool head);
static void _ma_print_directory(byte *buff, uint block_size);
static void compact_page(byte *buff, uint block_size, uint rownr,
my_bool extend_block);
/****************************************************************************
Initialization
****************************************************************************/
/*
Initialize data needed for block structures
*/
/* Size of the different header elements for a row */
static uchar header_sizes[]=
{
TRANSID_SIZE,
VERPTR_SIZE,
TRANSID_SIZE, /* Delete transid */
1 /* Null extends */
};
/*
Calculate array of all used headers
Used to speed up:
size= 1;
if (flag & 1)
size+= TRANSID_SIZE;
if (flag & 2)
size+= VERPTR_SIZE;
if (flag & 4)
size+= TRANSID_SIZE
if (flag & 8)
size+= 1;
NOTES
This is called only once at startup of Maria
*/
static uchar total_header_size[1 << array_elements(header_sizes)];
#define PRECALC_HEADER_BITMASK (array_elements(total_header_size) -1)
void _ma_init_block_record_data(void)
{
uint i;
bzero(total_header_size, sizeof(total_header_size));
total_header_size[0]= FLAG_SIZE; /* Flag byte */
for (i= 1; i < array_elements(total_header_size); i++)
{
uint size= FLAG_SIZE, j, bit;
for (j= 0; (bit= (1 << j)) <= i; j++)
{
if (i & bit)
size+= header_sizes[j];
}
total_header_size[i]= size;
}
}
my_bool _ma_once_init_block_row(MARIA_SHARE *share, File data_file)
{
share->base.max_data_file_length=
(((ulonglong) 1 << ((share->base.rec_reflength-1)*8))-1) *
share->block_size;
#if SIZEOF_OFF_T == 4
set_if_smaller(max_data_file_length, INT_MAX32);
#endif
return _ma_bitmap_init(share, data_file);
}
my_bool _ma_once_end_block_row(MARIA_SHARE *share)
{
int res= _ma_bitmap_end(share);
if (flush_pagecache_blocks(share->pagecache, (PAGECACHE_FILE*)&share->bitmap,
share->temporary ? FLUSH_IGNORE_CHANGED :
FLUSH_RELEASE))
res= 1;
if (share->bitmap.file >= 0 && my_close(share->bitmap.file, MYF(MY_WME)))
res= 1;
return res;
}
/* Init info->cur_row structure */
my_bool _ma_init_block_row(MARIA_HA *info)
{
MARIA_ROW *row= &info->cur_row, *new_row= &info->new_row;
DBUG_ENTER("_ma_init_block_row");
if (!my_multi_malloc(MY_WME,
&row->empty_bits_buffer, info->s->base.pack_bytes,
&row->field_lengths, info->s->base.max_field_lengths,
&row->blob_lengths, sizeof(ulong) * info->s->base.blobs,
&row->null_field_lengths, (sizeof(uint) *
(info->s->base.fields -
info->s->base.blobs +
EXTRA_LENGTH_FIELDS)),
&row->tail_positions, (sizeof(MARIA_RECORD_POS) *
(info->s->base.blobs + 2)),
&new_row->empty_bits_buffer, info->s->base.pack_bytes,
&new_row->field_lengths,
info->s->base.max_field_lengths,
&new_row->blob_lengths,
sizeof(ulong) * info->s->base.blobs,
&new_row->null_field_lengths, (sizeof(uint) *
(info->s->base.fields -
info->s->base.blobs +
EXTRA_LENGTH_FIELDS)),
NullS, 0))
DBUG_RETURN(1);
if (my_init_dynamic_array(&info->bitmap_blocks,
sizeof(MARIA_BITMAP_BLOCK),
ELEMENTS_RESERVED_FOR_MAIN_PART, 16))
my_free((char*) &info->bitmap_blocks, MYF(0));
row->base_length= new_row->base_length= info->s->base_length;
/*
We need to reserve 'EXTRA_LENGTH_FIELDS' number of parts in
null_field_lengths to allow splitting of rows in 'find_where_to_split_row'
*/
row->null_field_lengths+= EXTRA_LENGTH_FIELDS;
new_row->null_field_lengths+= EXTRA_LENGTH_FIELDS;
DBUG_RETURN(0);
}
void _ma_end_block_row(MARIA_HA *info)
{
DBUG_ENTER("_ma_end_block_row");
my_free((gptr) info->cur_row.empty_bits_buffer, MYF(MY_ALLOW_ZERO_PTR));
delete_dynamic(&info->bitmap_blocks);
my_free((gptr) info->cur_row.extents, MYF(MY_ALLOW_ZERO_PTR));
DBUG_VOID_RETURN;
}
/****************************************************************************
Helper functions
****************************************************************************/
static inline uint empty_pos_after_row(byte *dir)
{
byte *prev;
/*
Find previous used entry. (There is always a previous entry as
the directory never starts with a deleted entry)
*/
for (prev= dir - DIR_ENTRY_SIZE ;
prev[0] == 0 && prev[1] == 0 ;
prev-= DIR_ENTRY_SIZE)
{}
return (uint) uint2korr(prev);
}
static my_bool check_if_zero(byte *pos, uint length)
{
byte *end;
for (end= pos+ length; pos != end ; pos++)
if (pos[0] != 0)
return 1;
return 0;
}
/*
Find free postion in directory
SYNOPSIS
find_free_position()
buff Page
block_size Size of page
res_rownr Store index to free position here
res_length Store length of found segment here
empty_space Store length of empty space on disk here. This is
all empty space, including the found block.
NOTES
If there is a free directory entry (entry with postion == 0),
then use it and change it to be the size of the empty block
after the previous entry. This guarantees that all row entries
are stored on disk in inverse directory order, which makes life easier for
'compact_page()' and to know if there is free space after any block.
If there is no free entry (entry with position == 0), then we create
a new one. If there is not space for the directory entry (because
the last block overlapps with the directory), we compact the page.
We will update the offset and the length of the found dir entry to
match the position and empty space found.
buff[EMPTY_SPACE_OFFSET] is NOT updated but left up to the caller
RETURN
0 Error (directory full or last block goes over directory)
# Pointer to directory entry on page
*/
static byte *find_free_position(byte *buff, uint block_size, uint *res_rownr,
uint *res_length, uint *empty_space)
{
uint max_entry= (uint) ((uchar*) buff)[DIR_ENTRY_OFFSET];
uint entry, length, first_pos;
byte *dir, *end;
DBUG_ENTER("find_free_position");
DBUG_PRINT("info", ("max_entry: %u", max_entry));
dir= (buff + block_size - DIR_ENTRY_SIZE * max_entry - PAGE_SUFFIX_SIZE);
end= buff + block_size - PAGE_SUFFIX_SIZE - DIR_ENTRY_SIZE;
first_pos= PAGE_HEADER_SIZE;
*empty_space= uint2korr(buff + EMPTY_SPACE_OFFSET);
/* Search after first empty position */
for (entry= 0 ; dir <= end ; end-= DIR_ENTRY_SIZE, entry++)
{
if (end[0] == 0 && end[1] == 0) /* Found not used entry */
{
length= empty_pos_after_row(end) - first_pos;
int2store(end, first_pos); /* Update dir entry */
int2store(end + 2, length);
*res_rownr= entry;
*res_length= length;
DBUG_RETURN(end);
}
first_pos= uint2korr(end) + uint2korr(end + 2);
}
/* No empty places in dir; create a new one */
dir= end;
/* Check if there is place for the directory entry */
if (max_entry == MAX_ROWS_PER_PAGE)
DBUG_RETURN(0);
/* Check if there is place for the directory entry */
if ((dir - buff) < first_pos)
{
/* Create place for directory */
compact_page(buff, block_size, max_entry-1, 0);
first_pos= (uint2korr(end + DIR_ENTRY_SIZE) +
uint2korr(end + DIR_ENTRY_SIZE+ 2));
*empty_space= uint2korr(buff + EMPTY_SPACE_OFFSET);
}
buff[DIR_ENTRY_OFFSET]= (byte) (uchar) max_entry+1;
length= (uint) (dir - buff - first_pos);
DBUG_ASSERT(length <= *empty_space - DIR_ENTRY_SIZE);
int2store(dir, first_pos);
int2store(dir+2, length); /* Current max length */
*res_rownr= max_entry;
*res_length= length;
/* Reduce directory entry size from free space size */
(*empty_space)-= DIR_ENTRY_SIZE;
DBUG_RETURN(dir);
}
/****************************************************************************
Updating records
****************************************************************************/
/*
Calculate length of all the different field parts
SYNOPSIS
calc_record_size()
info Maria handler
record Row to store
row Store statistics about row here
NOTES
The statistics is used to find out how much space a row will need
and also where we can split a row when we need to split it into several
extents.
*/
static void calc_record_size(MARIA_HA *info, const byte *record,
MARIA_ROW *row)
{
MARIA_SHARE *share= info->s;
byte *field_length_data;
MARIA_COLUMNDEF *rec, *end_field;
uint *null_field_lengths= row->null_field_lengths;
ulong *blob_lengths= row->blob_lengths;
row->normal_length= row->char_length= row->varchar_length=
row->blob_length= row->extents_count= 0;
/* Create empty bitmap and calculate length of each varlength/char field */
bzero(row->empty_bits_buffer, share->base.pack_bytes);
row->empty_bits= row->empty_bits_buffer;
field_length_data= row->field_lengths;
for (rec= share->rec + share->base.fixed_not_null_fields,
end_field= share->rec + share->base.fields;
rec < end_field; rec++, null_field_lengths++)
{
if ((record[rec->null_pos] & rec->null_bit))
{
if (rec->type != FIELD_BLOB)
*null_field_lengths= 0;
else
*blob_lengths++= 0;
continue;
}
switch ((enum en_fieldtype) rec->type) {
case FIELD_CHECK:
case FIELD_NORMAL: /* Fixed length field */
case FIELD_ZERO:
DBUG_ASSERT(rec->empty_bit == 0);
/* fall through */
case FIELD_SKIP_PRESPACE: /* Not packed */
row->normal_length+= rec->length;
*null_field_lengths= rec->length;
break;
case FIELD_SKIP_ZERO: /* Fixed length field */
if (memcmp(record+ rec->offset, maria_zero_string,
rec->length) == 0)
{
row->empty_bits[rec->empty_pos] |= rec->empty_bit;
*null_field_lengths= 0;
}
else
{
row->normal_length+= rec->length;
*null_field_lengths= rec->length;
}
break;
case FIELD_SKIP_ENDSPACE: /* CHAR */
{
const char *pos, *end;
for (pos= record + rec->offset, end= pos + rec->length;
end > pos && end[-1] == ' '; end--)
;
if (pos == end) /* If empty string */
{
row->empty_bits[rec->empty_pos]|= rec->empty_bit;
*null_field_lengths= 0;
}
else
{
uint length= (end - pos);
if (rec->length <= 255)
*field_length_data++= (byte) (uchar) length;
else
{
int2store(field_length_data, length);
field_length_data+= 2;
}
row->char_length+= length;
*null_field_lengths= length;
}
break;
}
case FIELD_VARCHAR:
{
uint length, field_length_data_length;
const byte *field_pos= record + rec->offset;
/* 256 is correct as this includes the length byte */
field_length_data[0]= field_pos[0];
if (rec->length <= 256)
{
length= (uint) (uchar) *field_pos;
field_length_data_length= 1;
}
else
{
length= uint2korr(field_pos);
field_length_data[1]= field_pos[1];
field_length_data_length= 2;
}
*null_field_lengths= length;
if (!length)
{
row->empty_bits[rec->empty_pos]|= rec->empty_bit;
break;
}
row->varchar_length+= length;
*null_field_lengths= length;
field_length_data+= field_length_data_length;
break;
}
case FIELD_BLOB:
{
const byte *field_pos= record + rec->offset;
uint size_length= rec->length - maria_portable_sizeof_char_ptr;
ulong blob_length= _ma_calc_blob_length(size_length, field_pos);
*blob_lengths++= blob_length;
if (!blob_length)
row->empty_bits[rec->empty_pos]|= rec->empty_bit;
else
{
row->blob_length+= blob_length;
memcpy(field_length_data, field_pos, size_length);
field_length_data+= size_length;
}
break;
}
default:
DBUG_ASSERT(0);
}
}
row->field_lengths_length= (uint) (field_length_data - row->field_lengths);
row->head_length= (row->base_length +
share->base.fixed_not_null_fields_length +
row->field_lengths_length +
size_to_store_key_length(row->field_lengths_length) +
row->normal_length +
row->char_length + row->varchar_length);
row->total_length= (row->head_length + row->blob_length);
if (row->total_length < share->base.min_row_length)
row->total_length= share->base.min_row_length;
}
/*
Compact page by removing all space between rows
IMPLEMENTATION
Move up all rows to start of page.
Move blocks that are directly after each other with one memmove.
TODO LATER
Remove TRANSID from rows that are visible to all transactions
SYNOPSIS
compact_page()
buff Page to compact
block_size Size of page
recnr Put empty data after this row
extend_block If 1, extend the block at 'rownr' to cover the
whole block.
*/
static void compact_page(byte *buff, uint block_size, uint rownr,
my_bool extend_block)
{
uint max_entry= (uint) ((uchar *) buff)[DIR_ENTRY_OFFSET];
uint page_pos, next_free_pos, start_of_found_block, diff, end_of_found_block;
byte *dir, *end;
DBUG_ENTER("compact_page");
DBUG_PRINT("enter", ("rownr: %u", rownr));
DBUG_ASSERT(max_entry > 0 &&
max_entry < (block_size - PAGE_HEADER_SIZE -
PAGE_SUFFIX_SIZE) / DIR_ENTRY_SIZE);
/* Move all entries before and including rownr up to start of page */
dir= buff + block_size - DIR_ENTRY_SIZE * (rownr+1) - PAGE_SUFFIX_SIZE;
end= buff + block_size - DIR_ENTRY_SIZE - PAGE_SUFFIX_SIZE;
page_pos= next_free_pos= start_of_found_block= PAGE_HEADER_SIZE;
diff= 0;
for (; dir <= end ; end-= DIR_ENTRY_SIZE)
{
uint offset= uint2korr(end);
if (offset)
{
uint row_length= uint2korr(end + 2);
DBUG_ASSERT(offset >= page_pos);
DBUG_ASSERT(buff + offset + row_length <= dir);
if (offset != next_free_pos)
{
uint length= (next_free_pos - start_of_found_block);
/*
There was empty space before this and prev block
Check if we have to move prevous block up to page start
*/
if (page_pos != start_of_found_block)
{
/* move up previous block */
memmove(buff + page_pos, buff + start_of_found_block, length);
}
page_pos+= length;
/* next continous block starts here */
start_of_found_block= offset;
diff= offset - page_pos;
}
int2store(end, offset - diff); /* correct current pos */
next_free_pos= offset + row_length;
}
}
if (page_pos != start_of_found_block)
{
uint length= (next_free_pos - start_of_found_block);
memmove(buff + page_pos, buff + start_of_found_block, length);
}
start_of_found_block= uint2korr(dir);
if (rownr != max_entry - 1)
{
/* Move all entries after rownr to end of page */
uint rownr_length;
next_free_pos= end_of_found_block= page_pos=
block_size - DIR_ENTRY_SIZE * max_entry - PAGE_SUFFIX_SIZE;
diff= 0;
/* End points to entry before 'rownr' */
for (dir= buff + end_of_found_block ; dir <= end ; dir+= DIR_ENTRY_SIZE)
{
uint offset= uint2korr(dir);
uint row_length= uint2korr(dir + 2);
uint row_end= offset + row_length;
if (!offset)
continue;
DBUG_ASSERT(offset >= start_of_found_block && row_end <= next_free_pos);
if (row_end != next_free_pos)
{
uint length= (end_of_found_block - next_free_pos);
if (page_pos != end_of_found_block)
{
/* move next block down */
memmove(buff + page_pos - length, buff + next_free_pos, length);
}
page_pos-= length;
/* next continous block starts here */
end_of_found_block= row_end;
diff= page_pos - row_end;
}
int2store(dir, offset + diff); /* correct current pos */
next_free_pos= offset;
}
if (page_pos != end_of_found_block)
{
uint length= (end_of_found_block - next_free_pos);
memmove(buff + page_pos - length, buff + next_free_pos, length);
next_free_pos= page_pos- length;
}
/* Extend rownr block to cover hole */
rownr_length= next_free_pos - start_of_found_block;
int2store(dir+2, rownr_length);
}
else
{
if (extend_block)
{
/* Extend last block cover whole page */
uint length= (uint) (dir - buff) - start_of_found_block;
int2store(dir+2, length);
}
buff[PAGE_TYPE_OFFSET]&= ~(byte) PAGE_CAN_BE_COMPACTED;
}
DBUG_EXECUTE("directory", _ma_print_directory(buff, block_size););
DBUG_VOID_RETURN;
}
/*
Read or initialize new head or tail page
SYNOPSIS
get_head_or_tail_page()
info Maria handler
block Block to read
buff Suggest this buffer to key cache
length Minimum space needed
page_type HEAD_PAGE || TAIL_PAGE
res Store result position here
NOTES
We don't decremented buff[EMPTY_SPACE_OFFSET] with the allocated data
as we don't know how much data the caller will actually use.
RETURN
0 ok All slots in 'res' are updated
1 error my_errno is set
*/
struct st_row_pos_info
{
byte *buff; /* page buffer */
byte *data; /* Place for data */
byte *dir; /* Directory */
uint length; /* Length for data */
uint offset; /* Offset to directory */
uint empty_space; /* Space left on page */
};
static my_bool get_head_or_tail_page(MARIA_HA *info,
MARIA_BITMAP_BLOCK *block,
byte *buff, uint length, uint page_type,
struct st_row_pos_info *res)
{
uint block_size;
DBUG_ENTER("get_head_or_tail_page");
DBUG_PRINT("enter", ("length: %u", length));
block_size= info->s->block_size;
if (block->org_bitmap_value == 0) /* Empty block */
{
/* New page */
bzero(buff, PAGE_HEADER_SIZE);
/*
We zero the rest of the block to avoid getting old memory information
to disk and to allow the file to be compressed better if archived.
The rest of the code does not assume the block is zeroed above
PAGE_OVERHEAD_SIZE
*/
bzero(buff+ PAGE_HEADER_SIZE, block_size - PAGE_HEADER_SIZE);
buff[PAGE_TYPE_OFFSET]= (byte) page_type;
buff[DIR_ENTRY_OFFSET]= 1;
res->buff= buff;
res->empty_space= res->length= (block_size - PAGE_OVERHEAD_SIZE);
res->data= (buff + PAGE_HEADER_SIZE);
res->dir= res->data + res->length;
res->offset= 0;
/* Store poistion to the first row */
int2store(res->dir, PAGE_HEADER_SIZE);
DBUG_ASSERT(length <= res->length);
}
else
{
byte *dir;
/* TODO: lock the page */
/* Read old page */
DBUG_ASSERT(info->s->pagecache->block_size == block_size);
if (!(res->buff= pagecache_read(info->s->pagecache,
&info->dfile,
(my_off_t) block->page, 0,
buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(1);
DBUG_ASSERT((res->buff[PAGE_TYPE_OFFSET] & PAGE_TYPE_MASK) == page_type);
if (!(dir= find_free_position(res->buff, block_size, &res->offset,
&res->length, &res->empty_space)))
goto crashed;
if (res->length < length)
{
if (res->empty_space + res->length < length)
{
compact_page(res->buff, block_size, res->offset, 1);
/* All empty space are now after current position */
dir= (res->buff + block_size - DIR_ENTRY_SIZE * res->offset -
PAGE_SUFFIX_SIZE);
res->length= res->empty_space= uint2korr(dir+2);
}
if (res->length < length)
goto crashed; /* Wrong bitmap information */
}
res->dir= dir;
res->data= res->buff + uint2korr(dir);
}
DBUG_RETURN(0);
crashed:
my_errno= HA_ERR_WRONG_IN_RECORD; /* File crashed */
DBUG_RETURN(1);
}
/*
Write tail of non-blob-data or blob
SYNOPSIS
write_tail()
info Maria handler
block Block to tail page
row_part Data to write to page
length Length of data
NOTES
block->page_count is updated to the directory offset for the tail
so that we can store the position in the row extent information
RETURN
0 ok
block->page_count is set to point (dir entry + TAIL_BIT)
1 error; In this case my_errno is set to the error
*/
static my_bool write_tail(MARIA_HA *info,
MARIA_BITMAP_BLOCK *block,
byte *row_part, uint length)
{
MARIA_SHARE *share= share= info->s;
uint block_size= share->block_size, empty_space;
struct st_row_pos_info row_pos;
my_off_t position;
DBUG_ENTER("write_tail");
DBUG_PRINT("enter", ("page: %lu length: %u",
(ulong) block->page, length));
info->keybuff_used= 1;
/* page will be pinned & locked by get_head_or_tail_page */
if (get_head_or_tail_page(info, block, info->keyread_buff, length,
TAIL_PAGE, &row_pos))
DBUG_RETURN(1);
memcpy(row_pos.data, row_part, length);
int2store(row_pos.dir + 2, length);
empty_space= row_pos.empty_space - length;
int2store(row_pos.buff + EMPTY_SPACE_OFFSET, empty_space);
block->page_count= row_pos.offset + TAIL_BIT;
/*
If there is less directory entries free than number of possible tails
we can write for a row, we mark the page full to ensure that we don't
during _ma_bitmap_find_place() allocate more entires on the tail page
than it can hold
*/
block->empty_space= ((uint) ((uchar*) row_pos.buff)[DIR_ENTRY_OFFSET] <=
MAX_ROWS_PER_PAGE - 1 - info->s->base.blobs ?
empty_space : 0);
block->used= BLOCKUSED_USED | BLOCKUSED_TAIL;
/* Increase data file size, if extended */
position= (my_off_t) block->page * block_size;
if (info->state->data_file_length <= position)
info->state->data_file_length= position + block_size;
/* TODO: left the page pinned (or pin it if it is new) and unlock\
the page (do not lock if it is new */
DBUG_ASSERT(share->pagecache->block_size == block_size);
DBUG_RETURN(pagecache_write(share->pagecache,
&info->dfile, block->page, 0,
row_pos.buff,PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_PINNED,
PAGECACHE_WRITE_DELAY, 0));
}
/*
Write full pages
SYNOPSIS
write_full_pages()
info Maria handler
block Where to write data
data Data to write
length Length of data
*/
static my_bool write_full_pages(MARIA_HA *info,
MARIA_BITMAP_BLOCK *block,
byte *data, ulong length)
{
my_off_t page;
MARIA_SHARE *share= share= info->s;
uint block_size= share->block_size;
uint data_size= FULL_PAGE_SIZE(block_size);
byte *buff= info->keyread_buff;
uint page_count;
my_off_t position;
DBUG_ENTER("write_full_pages");
DBUG_PRINT("enter", ("length: %lu page: %lu page_count: %lu",
(ulong) length, (ulong) block->page,
(ulong) block->page_count));
info->keybuff_used= 1;
page= block->page;
page_count= block->page_count;
position= (my_off_t) (page + page_count) * block_size;
if (info->state->data_file_length < position)
info->state->data_file_length= position;
/* Increase data file size, if extended */
for (; length; data+= data_size)
{
uint copy_length;
if (!page_count--)
{
block++;
page= block->page;
page_count= block->page_count - 1;
DBUG_PRINT("info", ("page: %lu page_count: %lu",
(ulong) block->page, (ulong) block->page_count));
position= (page + page_count + 1) * block_size;
if (info->state->data_file_length < position)
info->state->data_file_length= position;
}
bzero(buff, LSN_SIZE);
buff[PAGE_TYPE_OFFSET]= (byte) BLOB_PAGE;
copy_length= min(data_size, length);
memcpy(buff + LSN_SIZE + PAGE_TYPE_SIZE, data, copy_length);
length-= copy_length;
/*
TODO: replace PAGECACHE_PLAIN_PAGE with PAGECACHE_LSN_PAGE when
LSN on the pages will be implemented
*/
DBUG_ASSERT(share->pagecache->block_size == block_size);
if (pagecache_write(share->pagecache,
&info->dfile, page, 0,
buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_PINNED,
PAGECACHE_WRITE_DELAY,
0))
DBUG_RETURN(1);
page++;
block->used= BLOCKUSED_USED;
}
DBUG_RETURN(0);
}
/*
Store packed extent data
SYNOPSIS
store_extent_info()
to Store first packed data here
row_extents_second_part Store rest here
first_block First block to store
count Number of blocks
NOTES
We don't have to store the position for the head block
*/
static void store_extent_info(byte *to,
byte *row_extents_second_part,
MARIA_BITMAP_BLOCK *first_block,
uint count)
{
MARIA_BITMAP_BLOCK *block, *end_block;
uint copy_length;
my_bool first_found= 0;
for (block= first_block, end_block= first_block+count ;
block < end_block; block++)
{
/* The following is only false for marker blocks */
if (likely(block->used & BLOCKUSED_USED))
{
DBUG_ASSERT(block->page_count != 0);
int5store(to, block->page);
int2store(to + 5, block->page_count);
to+= ROW_EXTENT_SIZE;
if (!first_found)
{
first_found= 1;
to= row_extents_second_part;
}
}
}
copy_length= (count - 1) * ROW_EXTENT_SIZE;
/*
In some unlikely cases we have allocated to many blocks. Clear this
data.
*/
bzero(to, (my_size_t) (row_extents_second_part + copy_length - to));
}
/*
Write a record to a (set of) pages
SYNOPSIS
write_block_record()
info Maria handler
record Record we should write
row Statistics about record (calculated by calc_record_size())
map_blocks On which pages the record should be stored
row_pos Position on head page where to put head part of record
RETURN
0 ok
1 error
*/
static my_bool write_block_record(MARIA_HA *info, const byte *record,
MARIA_ROW *row,
MARIA_BITMAP_BLOCKS *bitmap_blocks,
struct st_row_pos_info *row_pos)
{
byte *data, *end_of_data, *tmp_data_used, *tmp_data;
byte *row_extents_first_part, *row_extents_second_part;
byte *field_length_data;
byte *page_buff;
MARIA_BITMAP_BLOCK *block, *head_block;
MARIA_SHARE *share;
MARIA_COLUMNDEF *rec, *end_field;
uint block_size, flag;
ulong *blob_lengths;
my_off_t position;
my_bool row_extents_in_use;
DBUG_ENTER("write_block_record");
LINT_INIT(row_extents_first_part);
LINT_INIT(row_extents_second_part);
share= info->s;
head_block= bitmap_blocks->block;
block_size= share->block_size;
page_buff= row_pos->buff;
/* Position on head page where we should store the head part */
data= row_pos->data;
end_of_data= data + row_pos->length;
/* Write header */
flag= share->base.default_row_flag;
row_extents_in_use= 0;
if (unlikely(row->total_length > row_pos->length))
{
/* Need extent */
if (bitmap_blocks->count <= 1)
goto crashed; /* Wrong in bitmap */
flag|= ROW_FLAG_EXTENTS;
row_extents_in_use= 1;
}
/* For now we have only a minimum header */
*data++= (uchar) flag;
if (unlikely(flag & ROW_FLAG_NULLS_EXTENDED))
*data++= (uchar) (share->base.null_bytes -
share->base.original_null_bytes);
if (row_extents_in_use)
{
/* Store first extent in header */
store_key_length_inc(data, bitmap_blocks->count - 1);
row_extents_first_part= data;
data+= ROW_EXTENT_SIZE;
}
if (share->base.pack_fields)
store_key_length_inc(data, row->field_lengths_length);
if (share->calc_checksum)
*(data++)= (byte) info->cur_row.checksum;
memcpy(data, record, share->base.null_bytes);
data+= share->base.null_bytes;
memcpy(data, row->empty_bits, share->base.pack_bytes);
data+= share->base.pack_bytes;
/*
Allocate a buffer of rest of data (except blobs)
To avoid double copying of data, we copy as many columns that fits into
the page. The rest goes into info->packed_row.
Using an extra buffer, instead of doing continuous writes to different
pages, uses less code and we don't need to have to do a complex call
for every data segment we want to store.
*/
if (_ma_alloc_buffer(&info->rec_buff, &info->rec_buff_size,
row->head_length))
DBUG_RETURN(1);
tmp_data_used= 0; /* Either 0 or last used byte in 'data' */
tmp_data= data;
if (row_extents_in_use)
{
uint copy_length= (bitmap_blocks->count - 2) * ROW_EXTENT_SIZE;
if (!tmp_data_used && tmp_data + copy_length > end_of_data)
{
tmp_data_used= tmp_data;
tmp_data= info->rec_buff;
}
row_extents_second_part= tmp_data;
/*
We will copy the extents here when we have figured out the tail
positions.
*/
tmp_data+= copy_length;
}
/* Copy fields that has fixed lengths (primary key etc) */
for (rec= share->rec, end_field= rec + share->base.fixed_not_null_fields;
rec < end_field; rec++)
{
if (!tmp_data_used && tmp_data + rec->length > end_of_data)
{
tmp_data_used= tmp_data;
tmp_data= info->rec_buff;
}
memcpy(tmp_data, record + rec->offset, rec->length);
tmp_data+= rec->length;
}
/* Copy length of data for variable length fields */
if (!tmp_data_used && tmp_data + row->field_lengths_length > end_of_data)
{
tmp_data_used= tmp_data;
tmp_data= info->rec_buff;
}
field_length_data= row->field_lengths;
memcpy(tmp_data, field_length_data, row->field_lengths_length);
tmp_data+= row->field_lengths_length;
/* Copy variable length fields and fields with null/zero */
for (end_field= share->rec + share->base.fields - share->base.blobs;
rec < end_field ;
rec++)
{
const byte *field_pos;
ulong length;
if ((record[rec->null_pos] & rec->null_bit) ||
(row->empty_bits[rec->empty_pos] & rec->empty_bit))
continue;
field_pos= record + rec->offset;
switch ((enum en_fieldtype) rec->type) {
case FIELD_NORMAL: /* Fixed length field */
case FIELD_SKIP_PRESPACE:
case FIELD_SKIP_ZERO: /* Fixed length field */
length= rec->length;
break;
case FIELD_SKIP_ENDSPACE: /* CHAR */
/* Char that is space filled */
if (rec->length <= 255)
length= (uint) (uchar) *field_length_data++;
else
{
length= uint2korr(field_length_data);
field_length_data+= 2;
}
break;
case FIELD_VARCHAR:
if (rec->length <= 256)
{
length= (uint) (uchar) *field_length_data++;
field_pos++; /* Skip length byte */
}
else
{
length= uint2korr(field_length_data);
field_length_data+= 2;
field_pos+= 2;
}
break;
default: /* Wrong data */
DBUG_ASSERT(0);
break;
}
if (!tmp_data_used && tmp_data + length > end_of_data)
{
/* Data didn't fit in page; Change to use tmp buffer */
tmp_data_used= tmp_data;
tmp_data= info->rec_buff;
}
memcpy((char*) tmp_data, (char*) field_pos, length);
tmp_data+= length;
}
block= head_block + head_block->sub_blocks; /* Point to first blob data */
end_field= rec + share->base.blobs;
blob_lengths= row->blob_lengths;
if (!tmp_data_used)
{
/* Still room on page; Copy as many blobs we can into this page */
data= tmp_data;
for (; rec < end_field && *blob_lengths < (ulong) (end_of_data - data);
rec++, blob_lengths++)
{
byte *tmp_pos;
uint length;
if (!*blob_lengths) /* Null or "" */
continue;
length= rec->length - maria_portable_sizeof_char_ptr;
memcpy_fixed((byte*) &tmp_pos, record + rec->offset + length,
sizeof(char*));
memcpy(data, tmp_pos, *blob_lengths);
data+= *blob_lengths;
/* Skip over tail page that was to be used to store blob */
block++;
bitmap_blocks->tail_page_skipped= 1;
}
if (head_block->sub_blocks > 1)
{
/* We have allocated pages that where not used */
bitmap_blocks->page_skipped= 1;
}
}
else
data= tmp_data_used; /* Get last used on page */
{
/* Update page directory */
uint length= (uint) (data - row_pos->data);
DBUG_PRINT("info", ("head length: %u", length));
if (length < info->s->base.min_row_length)
length= info->s->base.min_row_length;
int2store(row_pos->dir + 2, length);
/* update empty space at start of block */
row_pos->empty_space-= length;
int2store(page_buff + EMPTY_SPACE_OFFSET, row_pos->empty_space);
/* Mark in bitmaps how the current page was actually used */
head_block->empty_space= row_pos->empty_space;
if (page_buff[DIR_ENTRY_OFFSET] == (char) MAX_ROWS_PER_PAGE)
head_block->empty_space= 0; /* Page is full */
head_block->used= BLOCKUSED_USED;
}
/*
Now we have to write tail pages, as we need to store the position
to them in the row extent header.
We first write out all blob tails, to be able to store them in
the current page or 'tmp_data'.
Then we write the tail of the non-blob fields (The position to the
tail page is stored either in row header, the extents in the head
page or in the first full page of the non-blob data. It's never in
the tail page of the non-blob data)
*/
if (row_extents_in_use)
{
if (rec != end_field) /* If blob fields */
{
MARIA_COLUMNDEF *save_rec= rec;
MARIA_BITMAP_BLOCK *save_block= block;
MARIA_BITMAP_BLOCK *end_block;
ulong *save_blob_lengths= blob_lengths;
for (; rec < end_field; rec++, blob_lengths++)
{
byte *blob_pos;
if (!*blob_lengths) /* Null or "" */
continue;
if (block[block->sub_blocks - 1].used & BLOCKUSED_TAIL)
{
uint length;
length= rec->length - maria_portable_sizeof_char_ptr;
memcpy_fixed((byte *) &blob_pos, record + rec->offset + length,
sizeof(char*));
length= *blob_lengths % FULL_PAGE_SIZE(block_size); /* tail size */
if (write_tail(info, block + block->sub_blocks-1,
blob_pos + *blob_lengths - length,
length))
goto disk_err;
}
for (end_block= block + block->sub_blocks; block < end_block; block++)
{
/*
Set only a bit, to not cause bitmap code to belive a block is full
when there is still a lot of entries in it
*/
block->used|= BLOCKUSED_USED;
}
}
rec= save_rec;
block= save_block;
blob_lengths= save_blob_lengths;
}
if (tmp_data_used) /* non blob data overflows */
{
MARIA_BITMAP_BLOCK *cur_block, *end_block, *last_head_block;
MARIA_BITMAP_BLOCK *head_tail_block= 0;
ulong length;
ulong data_length= (tmp_data - info->rec_buff);
#ifdef SANITY_CHECK
if (cur_block->sub_blocks == 1)
goto crashed; /* no reserved full or tails */
#endif
/*
Find out where to write tail for non-blob fields.
Problem here is that the bitmap code may have allocated more
space than we need. We have to handle the following cases:
- Bitmap code allocated a tail page we don't need.
- The last full page allocated needs to be changed to a tail page
(Because we where able to put more data on the head page than
the bitmap allocation assumed)
The reserved pages in bitmap_blocks for the main page has one of
the following allocations:
- Full pages, with following blocks:
# * full pages
empty page ; To be used if we change last full to tail page. This
has 'count' = 0.
tail page (optional, if last full page was part full)
- One tail page
*/
cur_block= head_block + 1;
end_block= head_block + head_block->sub_blocks;
/*
Loop until we have find a block bigger than we need or
we find the the empty page block.
*/
while (data_length >= (length= (cur_block->page_count *
FULL_PAGE_SIZE(block_size))) &&
cur_block->page_count)
{
#ifdef SANITY_CHECK
if ((cur_block == end_block) || (cur_block->used & BLOCKUSED_BIT))
goto crashed;
#endif
data_length-= length;
(cur_block++)->used= BLOCKUSED_USED;
}
last_head_block= cur_block;
if (data_length)
{
if (cur_block->page_count == 0)
{
/* Skip empty filler block */
cur_block++;
}
#ifdef SANITY_CHECK
if ((cur_block >= end_block))
goto crashed;
#endif
if (cur_block->used & BLOCKUSED_TAIL)
{
DBUG_ASSERT(data_length < MAX_TAIL_SIZE(block_size));
/* tail written to full tail page */
cur_block->used= BLOCKUSED_USED;
head_tail_block= cur_block;
}
else if (data_length > length - MAX_TAIL_SIZE(block_size))
{
/* tail written to full page */
cur_block->used= BLOCKUSED_USED;
if ((cur_block != end_block - 1) &&
(end_block[-1].used & BLOCKUSED_TAIL))
bitmap_blocks->tail_page_skipped= 1;
}
else
{
/*
cur_block is a full block, followed by an empty and optional
tail block. Change cur_block to a tail block or split it
into full blocks and tail blocks.
TODO:
If there is enough space on the following tail block, use
this instead of creating a new tail block.
*/
DBUG_ASSERT(cur_block[1].page_count == 0);
if (cur_block->page_count == 1)
{
/* convert full block to tail block */
cur_block->used= BLOCKUSED_USED | BLOCKUSED_TAIL;
head_tail_block= cur_block;
}
else
{
DBUG_ASSERT(data_length < length - FULL_PAGE_SIZE(block_size));
DBUG_PRINT("info", ("Splitting blocks into full and tail"));
cur_block[1].page= (cur_block->page + cur_block->page_count - 1);
cur_block[1].page_count= 1; /* Avoid DBUG_ASSERT */
cur_block[1].used= BLOCKUSED_USED | BLOCKUSED_TAIL;
cur_block->page_count--;
cur_block->used= BLOCKUSED_USED;
last_head_block= head_tail_block= cur_block+1;
}
if (end_block[-1].used & BLOCKUSED_TAIL)
bitmap_blocks->tail_page_skipped= 1;
}
}
else
{
/* Must be an empty or tail page */
DBUG_ASSERT(cur_block->page_count == 0 ||
cur_block->used & BLOCKUSED_TAIL);
if (end_block[-1].used & BLOCKUSED_TAIL)
bitmap_blocks->tail_page_skipped= 1;
}
/*
Write all extents into page or tmp_data
Note that we still don't have a correct position for the tail
of the non-blob fields.
*/
store_extent_info(row_extents_first_part,
row_extents_second_part,
head_block+1, bitmap_blocks->count - 1);
if (head_tail_block)
{
ulong data_length= (tmp_data - info->rec_buff);
uint length;
byte *extent_data;
length= (uint) (data_length % FULL_PAGE_SIZE(block_size));
if (write_tail(info, head_tail_block,
info->rec_buff + data_length - length,
length))
goto disk_err;
tmp_data-= length; /* Remove the tail */
/* Store the tail position for the non-blob fields */
if (head_tail_block == head_block + 1)
{
/*
We had a head block + tail block, which means that the
tail block is the first extent
*/
extent_data= row_extents_first_part;
}
else
{
/*
We have a head block + some full blocks + tail block
last_head_block is pointing after the last used extent
for the head block.
*/
extent_data= row_extents_second_part +
((last_head_block - head_block) - 2) * ROW_EXTENT_SIZE;
}
DBUG_ASSERT(uint2korr(extent_data+5) & TAIL_BIT);
int5store(extent_data, head_tail_block->page);
int2store(extent_data + 5, head_tail_block->page_count);
}
}
else
store_extent_info(row_extents_first_part,
row_extents_second_part,
head_block+1, bitmap_blocks->count - 1);
}
/* Increase data file size, if extended */
position= (my_off_t) head_block->page * block_size;
if (info->state->data_file_length <= position)
info->state->data_file_length= position + block_size;
DBUG_ASSERT(share->pagecache->block_size == block_size);
if (pagecache_write(share->pagecache,
&info->dfile, head_block->page, 0,
page_buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_PINNED,
PAGECACHE_WRITE_DELAY, 0))
goto disk_err;
if (tmp_data_used)
{
/*
Write data stored in info->rec_buff to pages
This is the char/varchar data that didn't fit into the head page.
*/
DBUG_ASSERT(bitmap_blocks->count != 0);
if (write_full_pages(info, head_block + 1, info->rec_buff,
(ulong) (tmp_data - info->rec_buff)))
goto disk_err;
}
/* Write rest of blobs (data, but no tails as they are already written) */
for (; rec < end_field; rec++, blob_lengths++)
{
byte *blob_pos;
uint length;
ulong blob_length;
if (!*blob_lengths) /* Null or "" */
continue;
length= rec->length - maria_portable_sizeof_char_ptr;
memcpy_fixed((byte*) &blob_pos, record + rec->offset + length,
sizeof(char*));
/* remove tail part */
blob_length= *blob_lengths;
if (block[block->sub_blocks - 1].used & BLOCKUSED_TAIL)
blob_length-= (blob_length % FULL_PAGE_SIZE(block_size));
if (write_full_pages(info, block, blob_pos, blob_length))
goto disk_err;
block+= block->sub_blocks;
}
/* Release not used space in used pages */
if (_ma_bitmap_release_unused(info, bitmap_blocks))
goto disk_err;
DBUG_RETURN(0);
crashed:
my_errno= HA_ERR_WRONG_IN_RECORD; /* File crashed */
disk_err:
/* Something was wrong with data on record */
DBUG_RETURN(1);
}
/*
Write a record (to get the row id for it)
SYNOPSIS
_ma_write_init_block_record()
info Maria handler
record Record to write
NOTES
This is done BEFORE we write the keys to the row!
RETURN
HA_OFFSET_ERROR Something went wrong
# Rowid for row
*/
MARIA_RECORD_POS _ma_write_init_block_record(MARIA_HA *info,
const byte *record)
{
MARIA_BITMAP_BLOCKS *blocks= &info->cur_row.insert_blocks;
struct st_row_pos_info row_pos;
DBUG_ENTER("_ma_write_init_block_record");
calc_record_size(info, record, &info->cur_row);
if (_ma_bitmap_find_place(info, &info->cur_row, blocks))
DBUG_RETURN(HA_OFFSET_ERROR); /* Error reading bitmap */
/* page will be pinned & locked by get_head_or_tail_page */
if (get_head_or_tail_page(info, blocks->block, info->buff,
info->s->base.min_row_length, HEAD_PAGE, &row_pos))
DBUG_RETURN(HA_OFFSET_ERROR);
info->cur_row.lastpos= ma_recordpos(blocks->block->page, row_pos.offset);
if (info->s->calc_checksum)
info->cur_row.checksum= (info->s->calc_checksum)(info,record);
if (write_block_record(info, record, &info->cur_row, blocks, &row_pos))
DBUG_RETURN(HA_OFFSET_ERROR); /* Error reading bitmap */
DBUG_PRINT("exit", ("Rowid: %lu", (ulong) info->cur_row.lastpos));
info->s->state.split++;
DBUG_RETURN(info->cur_row.lastpos);
}
/*
Dummy function for (*info->s->write_record)()
Nothing to do here, as we already wrote the record in
_ma_write_init_block_record()
*/
my_bool _ma_write_block_record(MARIA_HA *info __attribute__ ((unused)),
const byte *record __attribute__ ((unused))
)
{
return 0; /* Row already written */
}
/*
Remove row written by _ma_write_block_record
SYNOPSIS
_ma_abort_write_block_record()
info Maria handler
INFORMATION
This is called in case we got a duplicate unique key while
writing keys.
RETURN
0 ok
1 error
*/
my_bool _ma_write_abort_block_record(MARIA_HA *info)
{
my_bool res= 0;
MARIA_BITMAP_BLOCKS *blocks= &info->cur_row.insert_blocks;
MARIA_BITMAP_BLOCK *block, *end;
DBUG_ENTER("_ma_abort_write_block_record");
if (delete_head_or_tail(info,
ma_recordpos_to_page(info->cur_row.lastpos),
ma_recordpos_to_offset(info->cur_row.lastpos), 1))
res= 1;
for (block= blocks->block + 1, end= block + blocks->count - 1; block < end;
block++)
{
if (block->used & BLOCKUSED_TAIL)
{
/*
block->page_count is set to the tail directory entry number in
write_block_record()
*/
if (delete_head_or_tail(info, block->page, block->page_count & ~TAIL_BIT,
0))
res= 1;
}
else
{
pthread_mutex_lock(&info->s->bitmap.bitmap_lock);
if (_ma_reset_full_page_bits(info, &info->s->bitmap, block->page,
block->page_count))
res= 1;
pthread_mutex_unlock(&info->s->bitmap.bitmap_lock);
}
}
DBUG_RETURN(res);
}
/*
Update a record
NOTES
For the moment, we assume that info->curr_row.extents is always updated
when a row is read. In the future we may decide to read this on demand
for rows split into many extents.
*/
my_bool _ma_update_block_record(MARIA_HA *info, MARIA_RECORD_POS record_pos,
const byte *record)
{
MARIA_BITMAP_BLOCKS *blocks= &info->cur_row.insert_blocks;
byte *buff;
MARIA_ROW *cur_row= &info->cur_row, *new_row= &info->new_row;
uint rownr, org_empty_size, head_length;
uint block_size= info->s->block_size;
byte *dir;
ulonglong page;
struct st_row_pos_info row_pos;
DBUG_ENTER("_ma_update_block_record");
DBUG_PRINT("enter", ("rowid: %lu", (long) record_pos));
calc_record_size(info, record, new_row);
page= ma_recordpos_to_page(record_pos);
DBUG_ASSERT(info->s->pagecache->block_size == block_size);
if (!(buff= pagecache_read(info->s->pagecache,
&info->dfile, (my_off_t) page, 0,
info->buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(1);
org_empty_size= uint2korr(buff + EMPTY_SPACE_OFFSET);
rownr= ma_recordpos_to_offset(record_pos);
dir= (buff + block_size - DIR_ENTRY_SIZE * rownr -
DIR_ENTRY_SIZE - PAGE_SUFFIX_SIZE);
if ((org_empty_size + cur_row->head_length) >= new_row->total_length)
{
uint empty, offset, length;
MARIA_BITMAP_BLOCK block;
/*
We can fit the new row in the same page as the original head part
of the row
*/
block.org_bitmap_value= _ma_free_size_to_head_pattern(&info->s->bitmap,
org_empty_size);
offset= uint2korr(dir);
length= uint2korr(dir + 2);
empty= 0;
if (new_row->total_length > length)
{
/* See if there is empty space after */
if (rownr != (uint) ((uchar *) buff)[DIR_ENTRY_OFFSET] - 1)
empty= empty_pos_after_row(dir) - (offset + length);
if (new_row->total_length > length + empty)
{
compact_page(buff, info->s->block_size, rownr, 1);
org_empty_size= 0;
length= uint2korr(dir + 2);
}
}
row_pos.buff= buff;
row_pos.offset= rownr;
row_pos.empty_space= org_empty_size + length;
row_pos.dir= dir;
row_pos.data= buff + uint2korr(dir);
row_pos.length= length + empty;
blocks->block= &block;
blocks->count= 1;
block.page= page;
block.sub_blocks= 1;
block.used= BLOCKUSED_USED | BLOCKUSED_USE_ORG_BITMAP;
block.empty_space= row_pos.empty_space;
/* Update cur_row, if someone calls update at once again */
cur_row->head_length= new_row->total_length;
if (_ma_bitmap_free_full_pages(info, cur_row->extents,
cur_row->extents_count))
DBUG_RETURN(1);
DBUG_RETURN(write_block_record(info, record, new_row, blocks, &row_pos));
}
/*
Allocate all size in block for record
QQ: Need to improve this to do compact if we can fit one more blob into
the head page
*/
head_length= uint2korr(dir + 2);
if (buff[PAGE_TYPE_OFFSET] & PAGE_CAN_BE_COMPACTED && org_empty_size &&
(head_length < new_row->head_length ||
(new_row->total_length <= head_length &&
org_empty_size + head_length >= new_row->total_length)))
{
compact_page(buff, info->s->block_size, rownr, 1);
org_empty_size= 0;
head_length= uint2korr(dir + 2);
}
/* Delete old row */
if (delete_tails(info, cur_row->tail_positions))
DBUG_RETURN(1);
if (_ma_bitmap_free_full_pages(info, cur_row->extents,
cur_row->extents_count))
DBUG_RETURN(1);
if (_ma_bitmap_find_new_place(info, new_row, page, head_length, blocks))
DBUG_RETURN(1);
row_pos.buff= buff;
row_pos.offset= rownr;
row_pos.empty_space= org_empty_size + head_length;
row_pos.dir= dir;
row_pos.data= buff + uint2korr(dir);
row_pos.length= head_length;
DBUG_RETURN(write_block_record(info, record, new_row, blocks, &row_pos));
}
/*
Delete a head a tail part
SYNOPSIS
delete_head_or_tail()
info Maria handler
page Page (not file offset!) on which the row is
head 1 if this is a head page
NOTES
Uses info->keyread_buff
RETURN
0 ok
1 error
*/
static my_bool delete_head_or_tail(MARIA_HA *info,
ulonglong page, uint record_number,
my_bool head)
{
MARIA_SHARE *share= info->s;
uint number_of_records, empty_space, length;
uint block_size= share->block_size;
byte *buff, *dir;
DBUG_ENTER("delete_head_or_tail");
info->keybuff_used= 1;
DBUG_ASSERT(info->s->pagecache->block_size == block_size);
if (!(buff= pagecache_read(share->pagecache,
&info->dfile, page, 0,
info->keyread_buff,
PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(1);
number_of_records= (uint) ((uchar *) buff)[DIR_ENTRY_OFFSET];
#ifdef SANITY_CHECKS
if (record_number >= number_of_records ||
record_number > ((block_size - LSN_SIZE - PAGE_TYPE_SIZE - 1 -
PAGE_SUFFIX_SIZE) / DIR_ENTRY_SIZE))
{
DBUG_PRINT("error", ("record_number: %u number_of_records: %u",
record_number, number_of_records));
DBUG_RETURN(1);
}
#endif
dir= (buff + block_size - DIR_ENTRY_SIZE * record_number -
DIR_ENTRY_SIZE - PAGE_SUFFIX_SIZE);
dir[0]= dir[1]= 0; /* Delete entry */
length= uint2korr(dir + 2);
empty_space= uint2korr(buff + EMPTY_SPACE_OFFSET);
if (record_number == number_of_records - 1)
{
/* Delete this entry and all following empty directory entries */
byte *end= buff + block_size - PAGE_SUFFIX_SIZE;
do
{
number_of_records--;
dir+= DIR_ENTRY_SIZE;
empty_space+= DIR_ENTRY_SIZE;
} while (dir < end && dir[0] == 0 && dir[1] == 0);
buff[DIR_ENTRY_OFFSET]= (byte) (uchar) number_of_records;
}
empty_space+= length;
if (number_of_records != 0)
{
int2store(buff + EMPTY_SPACE_OFFSET, empty_space);
buff[PAGE_TYPE_OFFSET]|= (byte) PAGE_CAN_BE_COMPACTED;
DBUG_ASSERT(share->pagecache->block_size == block_size);
if (pagecache_write(share->pagecache,
&info->dfile, page, 0,
buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_PINNED,
PAGECACHE_WRITE_DELAY, 0))
DBUG_RETURN(1);
}
else
{
DBUG_ASSERT(empty_space >= info->s->bitmap.sizes[0]);
}
DBUG_PRINT("info", ("empty_space: %u", empty_space));
DBUG_RETURN(_ma_bitmap_set(info, page, head, empty_space));
}
/*
delete all tails
SYNOPSIS
delete_tails()
info Handler
tails Pointer to vector of tail positions, ending with 0
NOTES
Uses info->keyread_buff
RETURN
0 ok
1 error
*/
static my_bool delete_tails(MARIA_HA *info, MARIA_RECORD_POS *tails)
{
my_bool res= 0;
DBUG_ENTER("delete_tails");
for (; *tails; tails++)
{
if (delete_head_or_tail(info,
ma_recordpos_to_page(*tails),
ma_recordpos_to_offset(*tails), 0))
res= 1;
}
DBUG_RETURN(res);
}
/*
Delete a record
NOTES
For the moment, we assume that info->cur_row.extents is always updated
when a row is read. In the future we may decide to read this on demand
for rows with many splits.
*/
my_bool _ma_delete_block_record(MARIA_HA *info)
{
DBUG_ENTER("_ma_delete_block_record");
if (delete_head_or_tail(info,
ma_recordpos_to_page(info->cur_row.lastpos),
ma_recordpos_to_offset(info->cur_row.lastpos),
1) ||
delete_tails(info, info->cur_row.tail_positions))
DBUG_RETURN(1);
info->s->state.split--;
DBUG_RETURN(_ma_bitmap_free_full_pages(info, info->cur_row.extents,
info->cur_row.extents_count));
}
/****************************************************************************
Reading of records
****************************************************************************/
/*
Read position to record from record directory at end of page
SYNOPSIS
get_record_position()
buff page buffer
block_size block size for page
record_number Record number in index
end_of_data pointer to end of data for record
RETURN
0 Error in data
# Pointer to start of record.
In this case *end_of_data is set.
*/
static byte *get_record_position(byte *buff, uint block_size,
uint record_number, byte **end_of_data)
{
uint number_of_records= (uint) ((uchar *) buff)[DIR_ENTRY_OFFSET];
byte *dir;
byte *data;
uint offset, length;
#ifdef SANITY_CHECKS
if (record_number >= number_of_records ||
record_number > ((block_size - PAGE_HEADER_SIZE - PAGE_SUFFIX_SIZE) /
DIR_ENTRY_SIZE))
{
DBUG_PRINT("error",
("Wrong row number: record_number: %u number_of_records: %u",
record_number, number_of_records));
return 0;
}
#endif
dir= (buff + block_size - DIR_ENTRY_SIZE * record_number -
DIR_ENTRY_SIZE - PAGE_SUFFIX_SIZE);
offset= uint2korr(dir);
length= uint2korr(dir + 2);
#ifdef SANITY_CHECKS
if (offset < PAGE_HEADER_SIZE ||
offset + length > (block_size -
number_of_records * DIR_ENTRY_SIZE -
PAGE_SUFFIX_SIZE))
{
DBUG_PRINT("error",
("Wrong row position: record_number: %u offset: %u "
"length: %u number_of_records: %u",
record_number, offset, length, number_of_records));
return 0;
}
#endif
data= buff + offset;
*end_of_data= data + length;
return data;
}
/*
Init extent
NOTES
extent is a cursor over which pages to read
*/
static void init_extent(MARIA_EXTENT_CURSOR *extent, byte *extent_info,
uint extents, MARIA_RECORD_POS *tail_positions)
{
uint page_count;
extent->extent= extent_info;
extent->extent_count= extents;
extent->page= uint5korr(extent_info); /* First extent */
page_count= uint2korr(extent_info+5);
extent->page_count= page_count & ~TAIL_BIT;
extent->tail= page_count & TAIL_BIT;
extent->tail_positions= tail_positions;
}
/*
Read next extent
SYNOPSIS
read_next_extent()
info Maria handler
extent Pointer to current extent (this is updated to point
to next)
end_of_data Pointer to end of data in read block (out)
NOTES
New block is read into info->buff
RETURN
0 Error; my_errno is set
# Pointer to start of data in read block
In this case end_of_data is updated to point to end of data.
*/
static byte *read_next_extent(MARIA_HA *info, MARIA_EXTENT_CURSOR *extent,
byte **end_of_data)
{
MARIA_SHARE *share= info->s;
byte *buff, *data;
DBUG_ENTER("read_next_extent");
if (!extent->page_count)
{
uint page_count;
if (!--extent->extent_count)
goto crashed;
extent->extent+= ROW_EXTENT_SIZE;
extent->page= uint5korr(extent->extent);
page_count= uint2korr(extent->extent+ROW_EXTENT_PAGE_SIZE);
DBUG_ASSERT(page_count != 0);
extent->tail= page_count & TAIL_BIT;
extent->page_count= (page_count & ~TAIL_BIT);
extent->first_extent= 0;
DBUG_PRINT("info",("New extent. Page: %lu page_count: %u tail_flag: %d",
(ulong) extent->page, extent->page_count,
extent->tail != 0));
}
if (info->cur_row.empty_bits != info->cur_row.empty_bits_buffer)
{
/*
First read of extents: Move data from info->buff to
internals buffers.
*/
memcpy(info->cur_row.empty_bits_buffer, info->cur_row.empty_bits,
share->base.pack_bytes);
info->cur_row.empty_bits= info->cur_row.empty_bits_buffer;
}
DBUG_ASSERT(share->pagecache->block_size == share->block_size);
if (!(buff= pagecache_read(share->pagecache,
&info->dfile, extent->page, 0,
info->buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
{
/* check if we tried to read over end of file (ie: bad data in record) */
if ((extent->page + 1) * share->block_size > info->state->data_file_length)
goto crashed;
DBUG_RETURN(0);
}
if (!extent->tail)
{
/* Full data page */
DBUG_ASSERT((buff[PAGE_TYPE_OFFSET] & PAGE_TYPE_MASK) == BLOB_PAGE);
extent->page++; /* point to next page */
extent->page_count--;
*end_of_data= buff + share->block_size;
info->cur_row.full_page_count++; /* For maria_chk */
DBUG_RETURN(extent->data_start= buff + LSN_SIZE + PAGE_TYPE_SIZE);
}
/* Found tail. page_count is in this case the position in the tail page */
DBUG_ASSERT((buff[PAGE_TYPE_OFFSET] & PAGE_TYPE_MASK) == TAIL_PAGE);
*(extent->tail_positions++)= ma_recordpos(extent->page,
extent->page_count);
info->cur_row.tail_count++; /* For maria_chk */
if (!(data= get_record_position(buff, share->block_size,
extent->page_count,
end_of_data)))
goto crashed;
extent->data_start= data;
extent->page_count= 0; /* No more data in extent */
DBUG_RETURN(data);
crashed:
my_errno= HA_ERR_WRONG_IN_RECORD; /* File crashed */
DBUG_PRINT("error", ("wrong extent information"));
DBUG_RETURN(0);
}
/*
Read data that may be split over many blocks
SYNOPSIS
read_long_data()
info Maria handler
to Store result string here (this is allocated)
extent Pointer to current extent position
data Current position in buffer
end_of_data End of data in buffer
NOTES
When we have to read a new buffer, it's read into info->buff
This loop is implemented by goto's instead of a for() loop as
the code is notable smaller and faster this way (and it's not nice
to jump into a for loop() or into a 'then' clause)
RETURN
0 ok
1 error
*/
static my_bool read_long_data(MARIA_HA *info, byte *to, ulong length,
MARIA_EXTENT_CURSOR *extent,
byte **data, byte **end_of_data)
{
DBUG_ENTER("read_long_data");
DBUG_PRINT("enter", ("length: %lu", length));
DBUG_ASSERT(*data <= *end_of_data);
for(;;)
{
uint left_length;
left_length= (uint) (*end_of_data - *data);
if (likely(left_length >= length))
{
memcpy(to, *data, length);
(*data)+= length;
DBUG_RETURN(0);
}
memcpy(to, *data, left_length);
to+= left_length;
length-= left_length;
if (!(*data= read_next_extent(info, extent, end_of_data)))
break;
}
DBUG_RETURN(1);
}
/*
Read a record from page (helper function for _ma_read_block_record())
SYNOPSIS
_ma_read_block_record2()
info Maria handler
record Store record here
data Start of head data for row
end_of_data End of data for row
NOTES
The head page is already read by caller
Following data is update in info->cur_row:
cur_row.head_length is set to size of entry in head block
cur_row.tail_positions is set to point to all tail blocks
cur_row.extents points to extents data
cur_row.extents_counts contains number of extents
cur_row.empty_bits points to empty bits part in read record
cur_row.field_lengths contains packed length of all fields
RETURN
0 ok
# Error code
*/
int _ma_read_block_record2(MARIA_HA *info, byte *record,
byte *data, byte *end_of_data)
{
MARIA_SHARE *share= info->s;
byte *field_length_data, *blob_buffer, *start_of_data;
uint flag, null_bytes, cur_null_bytes, row_extents, field_lengths;
my_bool found_blob= 0;
MARIA_EXTENT_CURSOR extent;
MARIA_COLUMNDEF *rec, *end_field;
DBUG_ENTER("_ma_read_block_record2");
LINT_INIT(field_lengths);
LINT_INIT(field_length_data);
LINT_INIT(blob_buffer);
start_of_data= data;
flag= (uint) (uchar) data[0];
cur_null_bytes= share->base.original_null_bytes;
null_bytes= share->base.null_bytes;
info->cur_row.head_length= (uint) (end_of_data - data);
info->cur_row.full_page_count= info->cur_row.tail_count= 0;
/* Skip trans header (for now, until we have MVCC csupport) */
data+= total_header_size[(flag & PRECALC_HEADER_BITMASK)];
if (flag & ROW_FLAG_NULLS_EXTENDED)
cur_null_bytes+= data[-1];
row_extents= 0;
if (flag & ROW_FLAG_EXTENTS)
{
uint row_extent_size;
/*
Record is split over many data pages.
Get number of extents and first extent
*/
get_key_length(row_extents, data);
info->cur_row.extents_count= row_extents;
row_extent_size= row_extents * ROW_EXTENT_SIZE;
if (info->cur_row.extents_buffer_length < row_extent_size &&
_ma_alloc_buffer(&info->cur_row.extents,
&info->cur_row.extents_buffer_length,
row_extent_size))
DBUG_RETURN(my_errno);
memcpy(info->cur_row.extents, data, ROW_EXTENT_SIZE);
data+= ROW_EXTENT_SIZE;
init_extent(&extent, info->cur_row.extents, row_extents,
info->cur_row.tail_positions);
}
else
{
info->cur_row.extents_count= 0;
(*info->cur_row.tail_positions)= 0;
extent.page_count= 0;
extent.extent_count= 1;
}
extent.first_extent= 1;
if (share->base.max_field_lengths)
{
get_key_length(field_lengths, data);
#ifdef SANITY_CHECKS
if (field_lengths > share->base.max_field_lengths)
goto err;
#endif
}
if (share->calc_checksum)
info->cur_row.checksum= (uint) (uchar) *data++;
/* data now points on null bits */
memcpy(record, data, cur_null_bytes);
if (unlikely(cur_null_bytes != null_bytes))
{
/*
This only happens if we have added more NULL columns with
ALTER TABLE and are fetching an old, not yet modified old row
*/
bzero(record + cur_null_bytes, (uint) (null_bytes - cur_null_bytes));
}
data+= null_bytes;
info->cur_row.empty_bits= (byte*) data; /* Pointer to empty bitmask */
data+= share->base.pack_bytes;
/* TODO: Use field offsets, instead of just skipping them */
data+= share->base.field_offsets * FIELD_OFFSET_SIZE;
/*
Read row extents (note that first extent was already read into
info->cur_row.extents above)
*/
if (row_extents)
{
if (read_long_data(info, info->cur_row.extents + ROW_EXTENT_SIZE,
(row_extents - 1) * ROW_EXTENT_SIZE,
&extent, &data, &end_of_data))
DBUG_RETURN(my_errno);
}
/*
Data now points to start of fixed length field data that can't be null
or 'empty'. Note that these fields can't be split over blocks
*/
for (rec= share->rec, end_field= rec + share->base.fixed_not_null_fields;
rec < end_field; rec++)
{
uint rec_length= rec->length;
if (data >= end_of_data &&
!(data= read_next_extent(info, &extent, &end_of_data)))
goto err;
memcpy(record + rec->offset, data, rec_length);
data+= rec_length;
}
/* Read array of field lengths. This may be stored in several extents */
if (share->base.max_field_lengths)
{
field_length_data= info->cur_row.field_lengths;
if (read_long_data(info, field_length_data, field_lengths, &extent,
&data, &end_of_data))
DBUG_RETURN(my_errno);
}
/* Read variable length data. Each of these may be split over many extents */
for (end_field= share->rec + share->base.fields; rec < end_field; rec++)
{
enum en_fieldtype type= (enum en_fieldtype) rec->type;
byte *field_pos= record + rec->offset;
/* First check if field is present in record */
if ((record[rec->null_pos] & rec->null_bit) ||
(info->cur_row.empty_bits[rec->empty_pos] & rec->empty_bit))
{
if (type == FIELD_SKIP_ENDSPACE)
bfill(record + rec->offset, rec->length, ' ');
else
bzero(record + rec->offset, rec->fill_length);
continue;
}
switch (type) {
case FIELD_NORMAL: /* Fixed length field */
case FIELD_SKIP_PRESPACE:
case FIELD_SKIP_ZERO: /* Fixed length field */
if (data >= end_of_data &&
!(data= read_next_extent(info, &extent, &end_of_data)))
goto err;
memcpy(field_pos, data, rec->length);
data+= rec->length;
break;
case FIELD_SKIP_ENDSPACE: /* CHAR */
{
/* Char that is space filled */
uint length;
if (rec->length <= 255)
length= (uint) (uchar) *field_length_data++;
else
{
length= uint2korr(field_length_data);
field_length_data+= 2;
}
#ifdef SANITY_CHECKS
if (length > rec->length)
goto err;
#endif
if (read_long_data(info, field_pos, length, &extent, &data,
&end_of_data))
DBUG_RETURN(my_errno);
bfill(field_pos + length, rec->length - length, ' ');
break;
}
case FIELD_VARCHAR:
{
ulong length;
if (rec->length <= 256)
{
length= (uint) (uchar) (*field_pos++= *field_length_data++);
}
else
{
length= uint2korr(field_length_data);
field_pos[0]= field_length_data[0];
field_pos[1]= field_length_data[1];
field_pos+= 2;
field_length_data+= 2;
}
if (read_long_data(info, field_pos, length, &extent, &data,
&end_of_data))
DBUG_RETURN(my_errno);
break;
}
case FIELD_BLOB:
{
uint size_length= rec->length - maria_portable_sizeof_char_ptr;
ulong blob_length= _ma_calc_blob_length(size_length, field_length_data);
if (!found_blob)
{
/* Calculate total length for all blobs */
ulong blob_lengths= 0;
byte *length_data= field_length_data;
MARIA_COLUMNDEF *blob_field= rec;
found_blob= 1;
for (; blob_field < end_field; blob_field++)
{
uint size_length;
if ((record[blob_field->null_pos] & blob_field->null_bit) ||
(info->cur_row.empty_bits[blob_field->empty_pos] &
blob_field->empty_bit))
continue;
size_length= blob_field->length - maria_portable_sizeof_char_ptr;
blob_lengths+= _ma_calc_blob_length(size_length, length_data);
length_data+= size_length;
}
DBUG_PRINT("info", ("Total blob length: %lu", blob_lengths));
if (_ma_alloc_buffer(&info->rec_buff, &info->rec_buff_size,
blob_lengths))
DBUG_RETURN(my_errno);
blob_buffer= info->rec_buff;
}
memcpy(field_pos, field_length_data, size_length);
memcpy_fixed(field_pos + size_length, (byte *) & blob_buffer,
sizeof(char*));
field_length_data+= size_length;
/*
After we have read one extent, then each blob is in it's own extent
*/
if (extent.first_extent && (ulong) (end_of_data - data) < blob_length)
end_of_data= data; /* Force read of next extent */
if (read_long_data(info, blob_buffer, blob_length, &extent, &data,
&end_of_data))
DBUG_RETURN(my_errno);
blob_buffer+= blob_length;
break;
}
default:
#ifdef EXTRA_DEBUG
DBUG_ASSERT(0); /* purecov: deadcode */
#endif
goto err;
}
continue;
}
if (row_extents)
{
DBUG_PRINT("info", ("Row read: page_count: %u extent_count: %u",
extent.page_count, extent.extent_count));
*extent.tail_positions= 0; /* End marker */
if (extent.page_count)
goto err;
if (extent.extent_count > 1)
if (check_if_zero(extent.extent + ROW_EXTENT_SIZE,
(extent.extent_count-1) * ROW_EXTENT_SIZE))
goto err;
}
else
{
DBUG_PRINT("info", ("Row read"));
/*
data should normally point to end_of_date. The only exception is if
the row is very short in which case we allocated 'min_row_length' data
for allowing the row to expand.
*/
if (data != end_of_data && (uint) (end_of_data - start_of_data) >
info->s->base.min_row_length)
goto err;
}
info->update|= HA_STATE_AKTIV; /* We have an active record */
DBUG_RETURN(0);
err:
/* Something was wrong with data on record */
DBUG_PRINT("error", ("Found record with wrong data"));
DBUG_RETURN((my_errno= HA_ERR_WRONG_IN_RECORD));
}
/*
Read a record based on record position
SYNOPSIS
_ma_read_block_record()
info Maria handler
record Store record here
record_pos Record position
*/
int _ma_read_block_record(MARIA_HA *info, byte *record,
MARIA_RECORD_POS record_pos)
{
byte *data, *end_of_data, *buff;
uint offset;
uint block_size= info->s->block_size;
DBUG_ENTER("_ma_read_block_record");
DBUG_PRINT("enter", ("rowid: %lu", (long) record_pos));
info->cur_row.lastpos= record_pos;
offset= ma_recordpos_to_offset(record_pos);
DBUG_ASSERT(info->s->pagecache->block_size == block_size);
if (!(buff= pagecache_read(info->s->pagecache,
&info->dfile, ma_recordpos_to_page(record_pos), 0,
info->buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(1);
DBUG_ASSERT((buff[PAGE_TYPE_OFFSET] & PAGE_TYPE_MASK) == HEAD_PAGE);
if (!(data= get_record_position(buff, block_size, offset, &end_of_data)))
{
my_errno= HA_ERR_WRONG_IN_RECORD; /* File crashed */
DBUG_PRINT("error", ("Wrong directory entry in data block"));
DBUG_RETURN(1);
}
DBUG_RETURN(_ma_read_block_record2(info, record, data, end_of_data));
}
/* compare unique constraint between stored rows */
my_bool _ma_cmp_block_unique(MARIA_HA *info, MARIA_UNIQUEDEF *def,
const byte *record, MARIA_RECORD_POS pos)
{
byte *org_rec_buff, *old_record;
my_size_t org_rec_buff_size;
int error;
DBUG_ENTER("_ma_cmp_block_unique");
if (!(old_record= my_alloca(info->s->base.reclength)))
DBUG_RETURN(1);
/* Don't let the compare destroy blobs that may be in use */
org_rec_buff= info->rec_buff;
org_rec_buff_size= info->rec_buff_size;
if (info->s->base.blobs)
{
/* Force realloc of record buffer*/
info->rec_buff= 0;
info->rec_buff_size= 0;
}
error= _ma_read_block_record(info, old_record, pos);
if (!error)
error= _ma_unique_comp(def, record, old_record, def->null_are_equal);
if (info->s->base.blobs)
{
my_free(info->rec_buff, MYF(MY_ALLOW_ZERO_PTR));
info->rec_buff= org_rec_buff;
info->rec_buff_size= org_rec_buff_size;
}
DBUG_PRINT("exit", ("result: %d", error));
my_afree(old_record);
DBUG_RETURN(error != 0);
}
/****************************************************************************
Table scan
****************************************************************************/
/*
Allocate buffers for table scan
SYNOPSIS
_ma_scan_init_block_record(MARIA_HA *info)
IMPLEMENTATION
We allocate one buffer for the current bitmap and one buffer for the
current page
RETURN
0 ok
1 error (couldn't allocate memory or disk error)
*/
my_bool _ma_scan_init_block_record(MARIA_HA *info)
{
byte *ptr;
DBUG_ENTER("_ma_scan_init_block_record");
if (!(ptr= (byte *) my_malloc(info->s->block_size * 2, MYF(MY_WME))))
DBUG_RETURN(1);
info->scan.bitmap_buff= ptr;
info->scan.page_buff= ptr + info->s->block_size;
info->scan.bitmap_end= info->scan.bitmap_buff + info->s->bitmap.total_size;
/* Set scan variables to get _ma_scan_block() to start with reading bitmap */
info->scan.number_of_rows= 0;
info->scan.bitmap_pos= info->scan.bitmap_end;
info->scan.bitmap_page= (ulong) - (long) info->s->bitmap.pages_covered;
/*
We have to flush bitmap as we will read the bitmap from the page cache
while scanning rows
*/
DBUG_RETURN(_ma_flush_bitmap(info->s));
}
/* Free buffers allocated by _ma_scan_block_init() */
void _ma_scan_end_block_record(MARIA_HA *info)
{
DBUG_ENTER("_ma_scan_end_block_record");
my_free(info->scan.bitmap_buff, MYF(MY_ALLOW_ZERO_PTR));
info->scan.bitmap_buff= 0;
DBUG_VOID_RETURN;
}
/*
Read next record while scanning table
SYNOPSIS
_ma_scan_block_record()
info Maria handler
record Store found here
record_pos Value stored in info->cur_row.next_pos after last call
skip_deleted
NOTES
- One must have called mi_scan() before this
- In this version, we don't actually need record_pos, we as easily
use a variable in info->scan
IMPLEMENTATION
Current code uses a lot of goto's to separate the different kind of
states we may be in. This gives us a minimum of executed if's for
the normal cases. I tried several different ways to code this, but
the current one was in the end the most readable and fastest.
RETURN
0 ok
# Error code
*/
int _ma_scan_block_record(MARIA_HA *info, byte *record,
MARIA_RECORD_POS record_pos,
my_bool skip_deleted __attribute__ ((unused)))
{
uint block_size;
my_off_t filepos;
DBUG_ENTER("_ma_scan_block_record");
restart_record_read:
/* Find next row in current page */
if (likely(record_pos < info->scan.number_of_rows))
{
uint length, offset;
byte *data, *end_of_data;
while (!(offset= uint2korr(info->scan.dir)))
{
info->scan.dir-= DIR_ENTRY_SIZE;
record_pos++;
#ifdef SANITY_CHECKS
if (info->scan.dir < info->scan.dir_end)
goto err;
#endif
}
/* found row */
info->cur_row.lastpos= info->scan.row_base_page + record_pos;
info->cur_row.nextpos= record_pos + 1;
data= info->scan.page_buff + offset;
length= uint2korr(info->scan.dir + 2);
end_of_data= data + length;
info->scan.dir-= DIR_ENTRY_SIZE; /* Point to previous row */
#ifdef SANITY_CHECKS
if (end_of_data > info->scan.dir_end ||
offset < PAGE_HEADER_SIZE || length < info->s->base.min_block_length)
goto err;
#endif
DBUG_PRINT("info", ("rowid: %lu", (ulong) info->cur_row.lastpos));
DBUG_RETURN(_ma_read_block_record2(info, record, data, end_of_data));
}
/* Find next head page in current bitmap */
restart_bitmap_scan:
block_size= info->s->block_size;
if (likely(info->scan.bitmap_pos < info->scan.bitmap_end))
{
byte *data= info->scan.bitmap_pos;
longlong bits= info->scan.bits;
uint bit_pos= info->scan.bit_pos;
do
{
while (likely(bits))
{
uint pattern= bits & 7;
bits >>= 3;
bit_pos++;
if (pattern > 0 && pattern <= 4)
{
/* Found head page; Read it */
ulong page;
info->scan.bitmap_pos= data;
info->scan.bits= bits;
info->scan.bit_pos= bit_pos;
page= (info->scan.bitmap_page + 1 +
(data - info->scan.bitmap_buff) / 6 * 16 + bit_pos - 1);
info->scan.row_base_page= ma_recordpos(page, 0);
if (!(pagecache_read(info->s->pagecache,
&info->dfile,
page, 0, info->scan.page_buff,
PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(my_errno);
if (((info->scan.page_buff[PAGE_TYPE_OFFSET] & PAGE_TYPE_MASK) !=
HEAD_PAGE) ||
(info->scan.number_of_rows=
(uint) (uchar) info->scan.page_buff[DIR_ENTRY_OFFSET]) == 0)
{
DBUG_PRINT("error", ("Wrong page header"));
DBUG_RETURN((my_errno= HA_ERR_WRONG_IN_RECORD));
}
info->scan.dir= (info->scan.page_buff + block_size -
PAGE_SUFFIX_SIZE - DIR_ENTRY_SIZE);
info->scan.dir_end= (info->scan.dir -
(info->scan.number_of_rows - 1) *
DIR_ENTRY_SIZE);
record_pos= 0;
goto restart_record_read;
}
}
for (data+= 6; data < info->scan.bitmap_end; data+= 6)
{
bits= uint6korr(data);
if (bits && ((bits & LL(04444444444444444)) != LL(04444444444444444)))
break;
}
bit_pos= 0;
} while (data < info->scan.bitmap_end);
}
/* Read next bitmap */
info->scan.bitmap_page+= info->s->bitmap.pages_covered;
filepos= (my_off_t) info->scan.bitmap_page * block_size;
if (unlikely(filepos >= info->state->data_file_length))
{
DBUG_RETURN((my_errno= HA_ERR_END_OF_FILE));
}
if (!(pagecache_read(info->s->pagecache, &info->dfile,
info->scan.bitmap_page,
0, info->scan.bitmap_buff, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0)))
DBUG_RETURN(my_errno);
/* Skip scanning 'bits' in bitmap scan code */
info->scan.bitmap_pos= info->scan.bitmap_buff - 6;
info->scan.bits= 0;
goto restart_bitmap_scan;
err:
DBUG_PRINT("error", ("Wrong data on page"));
DBUG_RETURN((my_errno= HA_ERR_WRONG_IN_RECORD));
}
/*
Compare a row against a stored one
NOTES
Not implemented, as block record is not supposed to be used in a shared
global environment
*/
my_bool _ma_compare_block_record(MARIA_HA *info __attribute__ ((unused)),
const byte *record __attribute__ ((unused)))
{
return 0;
}
#ifndef DBUG_OFF
static void _ma_print_directory(byte *buff, uint block_size)
{
uint max_entry= (uint) ((uchar *) buff)[DIR_ENTRY_OFFSET], row= 0;
uint end_of_prev_row= PAGE_HEADER_SIZE;
byte *dir, *end;
dir= buff + block_size - DIR_ENTRY_SIZE * max_entry - PAGE_SUFFIX_SIZE;
end= buff + block_size - DIR_ENTRY_SIZE - PAGE_SUFFIX_SIZE;
DBUG_LOCK_FILE;
fprintf(DBUG_FILE,"Directory dump (pos:length):\n");
for (row= 1; dir <= end ; end-= DIR_ENTRY_SIZE, row++)
{
uint offset= uint2korr(end);
uint length= uint2korr(end+2);
fprintf(DBUG_FILE, " %4u:%4u", offset, offset ? length : 0);
if (!(row % (80/12)))
fputc('\n', DBUG_FILE);
if (offset)
{
DBUG_ASSERT(offset >= end_of_prev_row);
end_of_prev_row= offset + length;
}
}
fputc('\n', DBUG_FILE);
fflush(DBUG_FILE);
DBUG_UNLOCK_FILE;
}
#endif /* DBUG_OFF */
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