/* Copyright (C) 2007 Michael Widenius
Copyright (c) 2010, 2013, Monty Program 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., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA */
/*
Bitmap handling (for records in block)
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.
The bitmap code assumes there is always an active bitmap page and thus
that there is at least one bitmap page in the file
Structure of bitmap page:
Fixed size records (to be implemented later):
2 bits are used to indicate:
0 Empty
1 0-75 % full (at least room for 2 records)
2 75-100 % full (at least room for one record)
3 100 % full (no more room for records)
Assuming 8K pages, this will allow us to map:
8192 (bytes per page) * 4 (pages mapped per byte) * 8192 (page size)= 256M
(For Maria this will be 7*4 * 8192 = 224K smaller because of LSN)
Note that for fixed size rows, we can't add more columns without doing
a full reorganization of the table. The user can always force a dynamic
size row format by specifying ROW_FORMAT=dynamic.
Dynamic size records:
3 bits are used to indicate Bytes free in 8K page
0 Empty page 8176 (head or tail)
1 0-30 % full (at least room for 3 records) 5724
2 30-60 % full (at least room for 2 records) 3271
3 60-90 % full (at least room for one record) 818
4 100 % full (no more room for records) 0
5 Tail page, 0-40 % full 4906
6 Tail page, 40-80 % full 1636
7 Full tail page or full blob page 0
Assuming 8K pages, this will allow us to map:
8192 (bytes per page) * 8 bits/byte / 3 bits/page * 8192 (page size)= 170.7M
Note that values 1-3 may be adjust for each individual table based on
'min record length'. Tail pages are for overflow data which can be of
any size and thus doesn't have to be adjusted for different tables.
If we add more columns to the table, some of the originally calculated
'cut off' points may not be optimal, but they shouldn't be 'drasticly
wrong'.
When allocating data from the bitmap, we are trying to do it in a
'best fit' manner. Blobs and varchar blocks are given out in large
continuous extents to allow fast access to these. Before allowing a
row to 'flow over' to other blocks, we will compact the page and use
all space on it. If there is many rows in the page, we will ensure
there is *LEFT_TO_GROW_ON_SPLIT* bytes left on the page to allow other
rows to grow.
The bitmap format allows us to extend the row file in big chunks, if needed.
When calculating the size for a packed row, we will calculate the following
things separately:
- Row header + null_bits + empty_bits fixed size segments etc.
- Size of all char/varchar fields
- Size of each blob field
The bitmap handler will get all the above information and return
either one page or a set of pages to put the different parts.
Bitmaps are read on demand in response to insert/delete/update operations.
The following bitmap pointers will be cached and stored on disk on close:
- Current insert_bitmap; When inserting new data we will first try to
fill this one.
- First bitmap which is not completely full. This is updated when we
free data with an update or delete.
While flushing out bitmaps, we will cache the status of the bitmap in memory
to avoid having to read a bitmap for insert of new data that will not
be of any use
- Total empty space
- Largest number of continuous pages
Bitmap ONLY goes to disk in the following scenarios
- The file is closed (and we flush all changes to disk)
- On checkpoint
(Ie: When we do a checkpoint, we have to ensure that all bitmaps are
put on disk even if they are not in the page cache).
- When explicitly requested (for example on backup or after recovery,
to simplify things)
The flow of writing a row is that:
- Mark the bitmap not flushable (_ma_bitmap_flushable(X, 1))
- Lock the bitmap
- Decide which data pages we will write to
- Mark them full in the bitmap page so that other threads do not try to
use the same data pages as us
- We unlock the bitmap
- Write the data pages
- Lock the bitmap
- Correct the bitmap page with the true final occupation of the data
pages (that is, we marked pages full but when we are done we realize
we didn't fill them)
- Unlock the bitmap.
- Mark the bitmap flushable (_ma_bitmap_flushable(X, -1))
*/
#include "maria_def.h"
#include "ma_blockrec.h"
#define FULL_HEAD_PAGE 4
#define FULL_TAIL_PAGE 7
const char *bits_to_txt[]=
{
"empty", "00-30% full", "30-60% full", "60-90% full", "full",
"tail 00-40 % full", "tail 40-80 % full", "tail/blob full"
};
#define WRONG_BITMAP_FLUSH 0 /*define to 1 only for provoking bugs*/
static my_bool _ma_read_bitmap_page(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page);
static my_bool _ma_bitmap_create_missing(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page);
static void _ma_bitmap_unpin_all(MARIA_SHARE *share);
/* Write bitmap page to key cache */
static inline my_bool write_changed_bitmap(MARIA_SHARE *share,
MARIA_FILE_BITMAP *bitmap)
{
my_bool res;
DBUG_ENTER("write_changed_bitmap");
DBUG_ASSERT(share->pagecache->block_size == bitmap->block_size);
DBUG_ASSERT(bitmap->file.pre_write_hook != 0);
DBUG_PRINT("info", ("bitmap->non_flushable: %u", bitmap->non_flushable));
/*
Mark that a bitmap page has been written to page cache and we have
to flush it during checkpoint.
*/
bitmap->changed_not_flushed= 1;
if ((bitmap->non_flushable == 0) || WRONG_BITMAP_FLUSH)
{
res= pagecache_write(share->pagecache,
&bitmap->file, bitmap->page, 0,
bitmap->map, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_UNPINNED,
PAGECACHE_WRITE_DELAY, 0, LSN_IMPOSSIBLE);
DBUG_ASSERT(!res);
DBUG_RETURN(res);
}
else
{
/*
bitmap->non_flushable means that someone has changed the bitmap,
but it's not yet complete so it can't yet be written to disk.
In this case we write the changed bitmap to the disk cache,
but keep it pinned until the change is completed. The page will
be unpinned later by _ma_bitmap_unpin_all() as soon as non_flushable
is set back to 0.
*/
MARIA_PINNED_PAGE page_link;
DBUG_PRINT("info", ("Writing pinned bitmap page"));
res= pagecache_write(share->pagecache,
&bitmap->file, bitmap->page, 0,
bitmap->map, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, PAGECACHE_PIN,
PAGECACHE_WRITE_DELAY, &page_link.link,
LSN_IMPOSSIBLE);
page_link.unlock= PAGECACHE_LOCK_LEFT_UNLOCKED;
page_link.changed= 1;
push_dynamic(&bitmap->pinned_pages, (const uchar*) (void*) &page_link);
DBUG_ASSERT(!res);
DBUG_RETURN(res);
}
}
/*
Initialize bitmap variables in share
SYNOPSIS
_ma_bitmap_init()
share Share handler
file Data file handler
last_page Pointer to last page (max_file_size) that needs to be
mapped by the bitmap. This is adjusted to bitmap
alignment.
NOTES
This is called the first time a file is opened.
RETURN
0 ok
1 error
*/
my_bool _ma_bitmap_init(MARIA_SHARE *share, File file,
pgcache_page_no_t *last_page)
{
uint aligned_bit_blocks;
uint max_page_size;
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
uint size= share->block_size;
pgcache_page_no_t first_bitmap_with_space;
#ifndef DBUG_OFF
/* We want to have a copy of the bitmap to be able to print differences */
size*= 2;
#endif
if (((bitmap->map= (uchar*) my_malloc(size, MYF(MY_WME))) == NULL) ||
my_init_dynamic_array(&bitmap->pinned_pages,
sizeof(MARIA_PINNED_PAGE), 1, 1, MYF(0)))
return 1;
bitmap->share= share;
bitmap->block_size= share->block_size;
bitmap->file.file= file;
_ma_bitmap_set_pagecache_callbacks(&bitmap->file, share);
/* Size needs to be aligned on 6 */
aligned_bit_blocks= (share->block_size - PAGE_SUFFIX_SIZE) / 6;
bitmap->max_total_size= bitmap->total_size= aligned_bit_blocks * 6;
/*
In each 6 bytes, we have 6*8/3 = 16 pages covered
The +1 is to add the bitmap page, as this doesn't have to be covered
*/
bitmap->pages_covered= aligned_bit_blocks * 16 + 1;
bitmap->flush_all_requested= bitmap->waiting_for_flush_all_requested=
bitmap->waiting_for_non_flushable= 0;
bitmap->non_flushable= 0;
/* Update size for bits */
/* TODO; Make this dependent of the row size */
max_page_size= share->block_size - PAGE_OVERHEAD_SIZE(share) + DIR_ENTRY_SIZE;
bitmap->sizes[0]= max_page_size; /* Empty page */
bitmap->sizes[1]= max_page_size - max_page_size * 30 / 100;
bitmap->sizes[2]= max_page_size - max_page_size * 60 / 100;
bitmap->sizes[3]= max_page_size - max_page_size * 90 / 100;
bitmap->sizes[4]= 0; /* Full page */
bitmap->sizes[5]= max_page_size - max_page_size * 40 / 100;
bitmap->sizes[6]= max_page_size - max_page_size * 80 / 100;
bitmap->sizes[7]= 0;
mysql_mutex_init(key_SHARE_BITMAP_lock,
&share->bitmap.bitmap_lock, MY_MUTEX_INIT_SLOW);
mysql_cond_init(key_SHARE_BITMAP_cond,
&share->bitmap.bitmap_cond, 0);
first_bitmap_with_space= share->state.first_bitmap_with_space;
_ma_bitmap_reset_cache(share);
/*
The bitmap used to map the file are aligned on 6 bytes. We now
calculate the max file size that can be used by the bitmap. This
is needed to get ma_info() give a true file size so that the user can
estimate if there is still space free for records in the file.
*/
{
pgcache_page_no_t last_bitmap_page;
ulong blocks, bytes;
last_bitmap_page= *last_page - *last_page % bitmap->pages_covered;
blocks= (ulong) (*last_page - last_bitmap_page);
bytes= (blocks * 3) / 8; /* 3 bit per page / 8 bits per byte */
/* Size needs to be aligned on 6 */
bytes/= 6;
bytes*= 6;
bitmap->last_bitmap_page= last_bitmap_page;
bitmap->last_total_size= (uint)bytes;
*last_page= ((last_bitmap_page + bytes*8/3));
}
/* Restore first_bitmap_with_space if it's resonable */
if (first_bitmap_with_space <= (share->state.state.data_file_length /
share->block_size))
share->state.first_bitmap_with_space= first_bitmap_with_space;
return 0;
}
/*
Free data allocated by _ma_bitmap_init
SYNOPSIS
_ma_bitmap_end()
share Share handler
*/
my_bool _ma_bitmap_end(MARIA_SHARE *share)
{
my_bool res;
#ifndef DBUG_OFF
if (! share->internal_table)
mysql_mutex_assert_owner(&share->close_lock);
#endif
DBUG_ASSERT(share->bitmap.non_flushable == 0);
DBUG_ASSERT(share->bitmap.flush_all_requested == 0);
DBUG_ASSERT(share->bitmap.waiting_for_non_flushable == 0 &&
share->bitmap.waiting_for_flush_all_requested == 0);
DBUG_ASSERT(share->bitmap.pinned_pages.elements == 0);
res= _ma_bitmap_flush(share);
mysql_mutex_destroy(&share->bitmap.bitmap_lock);
mysql_cond_destroy(&share->bitmap.bitmap_cond);
delete_dynamic(&share->bitmap.pinned_pages);
my_free(share->bitmap.map);
share->bitmap.map= 0;
/*
This is to not get an assert in checkpoint. The bitmap will be flushed
at once by _ma_once_end_block_record() as part of the normal flush
of the kfile.
*/
share->bitmap.changed_not_flushed= 0;
return res;
}
/*
Ensure that we have incremented open count before we try to read/write
a page while we have the bitmap lock.
This is needed to ensure that we don't call _ma_mark_file_changed() as
part of flushing a page to disk, as this locks share->internal_lock
and then mutex lock would happen in the wrong order.
*/
static inline void _ma_bitmap_mark_file_changed(MARIA_SHARE *share,
my_bool flush_translog)
{
/*
It's extremely unlikely that the following test is true as it
only happens once if the table has changed.
*/
if (unlikely(!share->global_changed &&
(share->state.changed & STATE_CHANGED)))
{
/* purecov: begin inspected */
/* unlock mutex as it can't be hold during _ma_mark_file_changed() */
mysql_mutex_unlock(&share->bitmap.bitmap_lock);
/*
We have to flush the translog to ensure we have registered that the
table is open.
*/
if (flush_translog && share->now_transactional)
(void) translog_flush(share->state.logrec_file_id);
_ma_mark_file_changed_now(share);
mysql_mutex_lock(&share->bitmap.bitmap_lock);
/* purecov: end */
}
}
/*
Send updated bitmap to the page cache
SYNOPSIS
_ma_bitmap_flush()
share Share handler
NOTES
In the future, _ma_bitmap_flush() will be called to flush changes don't
by this thread (ie, checking the changed flag is ok). The reason we
check it again in the mutex is that if someone else did a flush at the
same time, we don't have to do the write.
This is also ok for _ma_scan_init_block_record() which does not want to
miss rows: it cares only for committed rows, that is, rows for which there
was a commit before our transaction started; as commit and transaction's
start are protected by the same LOCK_trn_list mutex, we see memory at
least as new as at other transaction's commit time, so if the committed
rows caused bitmap->changed to be true, we see it; if we see 0 it really
means a flush happened since then. So, it's ok to read without bitmap's
mutex.
RETURN
0 ok
1 error
*/
my_bool _ma_bitmap_flush(MARIA_SHARE *share)
{
my_bool res= 0;
DBUG_ENTER("_ma_bitmap_flush");
if (share->bitmap.changed)
{
mysql_mutex_lock(&share->bitmap.bitmap_lock);
if (share->bitmap.changed)
{
/*
We have to mark the file changed here, as otherwise the following
write to pagecache may force a page out from this file, which would
cause _ma_mark_file_changed() to be called with bitmaplock hold!
*/
_ma_bitmap_mark_file_changed(share, 1);
res= write_changed_bitmap(share, &share->bitmap);
share->bitmap.changed= 0;
}
mysql_mutex_unlock(&share->bitmap.bitmap_lock);
}
DBUG_RETURN(res);
}
/**
Dirty-page filtering criteria for bitmap pages
@param type Page's type
@param pageno Page's number
@param rec_lsn Page's rec_lsn
@param arg pages_covered of bitmap
*/
static enum pagecache_flush_filter_result
filter_flush_bitmap_pages(enum pagecache_page_type type
__attribute__ ((unused)),
pgcache_page_no_t pageno,
LSN rec_lsn __attribute__ ((unused)),
void *arg)
{
return ((pageno % (*(ulong*)arg)) == 0);
}
/**
Flushes current bitmap page to the pagecache, and then all bitmap pages
from pagecache to the file. Used by Checkpoint.
@param share Table's share
*/
my_bool _ma_bitmap_flush_all(MARIA_SHARE *share)
{
my_bool res= 0;
uint send_signal= 0;
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
DBUG_ENTER("_ma_bitmap_flush_all");
#ifdef EXTRA_DEBUG_BITMAP
{
char buff[160];
uint len= my_sprintf(buff,
(buff, "bitmap_flush: fd: %d id: %u "
"changed: %d changed_not_flushed: %d "
"flush_all_requested: %d",
share->bitmap.file.file,
share->id,
bitmap->changed,
bitmap->changed_not_flushed,
bitmap->flush_all_requested));
(void) translog_log_debug_info(0, LOGREC_DEBUG_INFO_QUERY,
(uchar*) buff, len);
}
#endif
mysql_mutex_lock(&bitmap->bitmap_lock);
if (!bitmap->changed && !bitmap->changed_not_flushed)
{
mysql_mutex_unlock(&bitmap->bitmap_lock);
DBUG_RETURN(0);
}
_ma_bitmap_mark_file_changed(share, 0);
/*
The following should be true as it was tested above. We have to test
this again as _ma_bitmap_mark_file_changed() did temporarly release
the bitmap mutex.
*/
if (bitmap->changed || bitmap->changed_not_flushed)
{
bitmap->flush_all_requested++;
bitmap->waiting_for_non_flushable++;
#if !WRONG_BITMAP_FLUSH
while (bitmap->non_flushable > 0)
{
DBUG_PRINT("info", ("waiting for bitmap to be flushable"));
mysql_cond_wait(&bitmap->bitmap_cond, &bitmap->bitmap_lock);
}
#endif
bitmap->waiting_for_non_flushable--;
#ifdef EXTRA_DEBUG_BITMAP
{
char tmp[MAX_BITMAP_INFO_LENGTH];
_ma_get_bitmap_description(bitmap, bitmap->map, bitmap->page, tmp);
(void) translog_log_debug_info(0, LOGREC_DEBUG_INFO_QUERY,
(uchar*) tmp, strlen(tmp));
}
#endif
DBUG_ASSERT(bitmap->flush_all_requested == 1);
/*
Bitmap is in a flushable state: its contents in memory are reflected by
log records (complete REDO-UNDO groups) and all bitmap pages are
unpinned. We keep the mutex to preserve this situation, and flush to the
file.
*/
if (bitmap->changed)
{
bitmap->changed= FALSE;
res= write_changed_bitmap(share, bitmap);
}
/*
We do NOT use FLUSH_KEEP_LAZY because we must be sure that bitmap
pages have been flushed. That's a condition of correctness of
Recovery: data pages may have been all flushed, if we write the
checkpoint record Recovery will start from after their REDOs. If
bitmap page was not flushed, as the REDOs about it will be skipped, it
will wrongly not be recovered. If bitmap pages had a rec_lsn it would
be different.
There should be no pinned pages as bitmap->non_flushable==0.
*/
if (flush_pagecache_blocks_with_filter(share->pagecache,
&bitmap->file, FLUSH_KEEP,
filter_flush_bitmap_pages,
&bitmap->pages_covered) &
PCFLUSH_PINNED_AND_ERROR)
res= TRUE;
bitmap->changed_not_flushed= FALSE;
bitmap->flush_all_requested--;
/*
Some well-behaved threads may be waiting for flush_all_requested to
become false, wake them up.
*/
DBUG_PRINT("info", ("bitmap flusher waking up others"));
send_signal= (bitmap->waiting_for_flush_all_requested |
bitmap->waiting_for_non_flushable);
}
mysql_mutex_unlock(&bitmap->bitmap_lock);
if (send_signal)
mysql_cond_broadcast(&bitmap->bitmap_cond);
DBUG_RETURN(res);
}
/**
@brief Lock bitmap from being used by another thread
@fn _ma_bitmap_lock()
@param share Table's share
@notes
This is a temporary solution for allowing someone to delete an inserted
duplicate-key row while someone else is doing concurrent inserts.
This is ok for now as duplicate key errors are not that common.
In the future we will add locks for row-pages to ensure two threads doesn't
work at the same time on the same page.
*/
void _ma_bitmap_lock(MARIA_SHARE *share)
{
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
DBUG_ENTER("_ma_bitmap_lock");
if (!share->now_transactional)
DBUG_VOID_RETURN;
mysql_mutex_lock(&bitmap->bitmap_lock);
bitmap->flush_all_requested++;
bitmap->waiting_for_non_flushable++;
while (bitmap->non_flushable)
{
DBUG_PRINT("info", ("waiting for bitmap to be flushable"));
mysql_cond_wait(&bitmap->bitmap_cond, &bitmap->bitmap_lock);
}
bitmap->waiting_for_non_flushable--;
/*
Ensure that _ma_bitmap_flush_all() and _ma_bitmap_lock() are blocked.
ma_bitmap_flushable() is blocked thanks to 'flush_all_requested'.
*/
bitmap->non_flushable= 1;
mysql_mutex_unlock(&bitmap->bitmap_lock);
DBUG_VOID_RETURN;
}
/**
@brief Unlock bitmap after _ma_bitmap_lock()
@fn _ma_bitmap_unlock()
@param share Table's share
*/
void _ma_bitmap_unlock(MARIA_SHARE *share)
{
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
uint send_signal;
DBUG_ENTER("_ma_bitmap_unlock");
if (!share->now_transactional)
DBUG_VOID_RETURN;
DBUG_ASSERT(bitmap->flush_all_requested > 0 && bitmap->non_flushable == 1);
mysql_mutex_lock(&bitmap->bitmap_lock);
bitmap->non_flushable= 0;
_ma_bitmap_unpin_all(share);
send_signal= bitmap->waiting_for_non_flushable;
if (!--bitmap->flush_all_requested)
send_signal|= bitmap->waiting_for_flush_all_requested;
mysql_mutex_unlock(&bitmap->bitmap_lock);
if (send_signal)
mysql_cond_broadcast(&bitmap->bitmap_cond);
DBUG_VOID_RETURN;
}
/**
@brief Unpin all pinned bitmap pages
@param share Table's share
@return Operation status
@retval 0 ok
@note This unpins pages pinned by other threads.
*/
static void _ma_bitmap_unpin_all(MARIA_SHARE *share)
{
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
MARIA_PINNED_PAGE *page_link= ((MARIA_PINNED_PAGE*)
dynamic_array_ptr(&bitmap->pinned_pages, 0));
MARIA_PINNED_PAGE *pinned_page= page_link + bitmap->pinned_pages.elements;
DBUG_ENTER("_ma_bitmap_unpin_all");
DBUG_PRINT("info", ("pinned: %u", bitmap->pinned_pages.elements));
while (pinned_page-- != page_link)
pagecache_unlock_by_link(share->pagecache, pinned_page->link,
pinned_page->unlock, PAGECACHE_UNPIN,
LSN_IMPOSSIBLE, LSN_IMPOSSIBLE, FALSE, TRUE);
bitmap->pinned_pages.elements= 0;
DBUG_VOID_RETURN;
}
/*
Intialize bitmap in memory to a zero bitmap
SYNOPSIS
_ma_bitmap_delete_all()
share Share handler
NOTES
This is called on maria_delete_all_rows (truncate data file).
*/
void _ma_bitmap_delete_all(MARIA_SHARE *share)
{
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
DBUG_ENTER("_ma_bitmap_delete_all");
if (bitmap->map) /* Not in create */
{
bzero(bitmap->map, bitmap->block_size);
bitmap->changed= 1;
bitmap->page= 0;
bitmap->used_size= bitmap->total_size= bitmap->max_total_size;
}
DBUG_VOID_RETURN;
}
/**
@brief Reset bitmap caches
@fn _ma_bitmap_reset_cache()
@param share Maria share
@notes
This is called after we have swapped file descriptors and we want
bitmap to forget all cached information.
It's also called directly after we have opened a file.
*/
void _ma_bitmap_reset_cache(MARIA_SHARE *share)
{
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
if (bitmap->map) /* If using bitmap */
{
/* Forget changes in current bitmap page */
bitmap->changed= 0;
/*
We can't read a page yet, as in some case we don't have an active
page cache yet.
Pretend we have a dummy, full and not changed bitmap page in memory.
We set bitmap->page to a value so that if we use it in
move_to_next_bitmap() it will point to page 0.
(This can only happen if writing to a bitmap page fails)
*/
bitmap->page= ((pgcache_page_no_t) 0) - bitmap->pages_covered;
bitmap->used_size= bitmap->total_size= bitmap->max_total_size;
bfill(bitmap->map, share->block_size, 255);
#ifndef DBUG_OFF
memcpy(bitmap->map + bitmap->block_size, bitmap->map, bitmap->block_size);
#endif
/* Start scanning for free space from start of file */
share->state.first_bitmap_with_space = 0;
}
}
/*
Return bitmap pattern for the smallest head block that can hold 'size'
SYNOPSIS
size_to_head_pattern()
bitmap Bitmap
size Requested size
RETURN
0-3 For a description of the bitmap sizes, see the header
*/
static uint size_to_head_pattern(MARIA_FILE_BITMAP *bitmap, uint size)
{
if (size <= bitmap->sizes[3])
return 3;
if (size <= bitmap->sizes[2])
return 2;
if (size <= bitmap->sizes[1])
return 1;
DBUG_ASSERT(size <= bitmap->sizes[0]);
return 0;
}
/*
Return bitmap pattern for head block where there is size bytes free
SYNOPSIS
_ma_free_size_to_head_pattern()
bitmap Bitmap
size Requested size
RETURN
0-4 (Possible bitmap patterns for head block)
*/
uint _ma_free_size_to_head_pattern(MARIA_FILE_BITMAP *bitmap, uint size)
{
if (size < bitmap->sizes[3])
return 4;
if (size < bitmap->sizes[2])
return 3;
if (size < bitmap->sizes[1])
return 2;
return (size < bitmap->sizes[0]) ? 1 : 0;
}
/*
Return bitmap pattern for the smallest tail block that can hold 'size'
SYNOPSIS
size_to_tail_pattern()
bitmap Bitmap
size Requested size
RETURN
0, 5 or 6 For a description of the bitmap sizes, see the header
*/
static uint size_to_tail_pattern(MARIA_FILE_BITMAP *bitmap, uint size)
{
if (size <= bitmap->sizes[6])
return 6;
if (size <= bitmap->sizes[5])
return 5;
DBUG_ASSERT(size <= bitmap->sizes[0]);
return 0;
}
/*
Return bitmap pattern for tail block where there is size bytes free
SYNOPSIS
free_size_to_tail_pattern()
bitmap Bitmap
size Requested size
RETURN
0, 5, 6, 7 For a description of the bitmap sizes, see the header
*/
static uint free_size_to_tail_pattern(MARIA_FILE_BITMAP *bitmap, uint size)
{
if (size >= bitmap->sizes[0])
return 0; /* Revert to empty page */
if (size < bitmap->sizes[6])
return 7;
if (size < bitmap->sizes[5])
return 6;
return 5;
}
/*
Return size guranteed to be available on a page
SYNOPSIS
pattern_to_head_size()
bitmap Bitmap
pattern Pattern (0-7)
RETURN
0 - block_size
*/
static inline uint pattern_to_size(MARIA_FILE_BITMAP *bitmap, uint pattern)
{
DBUG_ASSERT(pattern <= 7);
return bitmap->sizes[pattern];
}
/*
Print bitmap for debugging
SYNOPSIS
_ma_print_bitmap_changes()
bitmap Bitmap to print
IMPLEMENTATION
Prints all changed bits since last call to _ma_print_bitmap().
This is done by having a copy of the last bitmap in
bitmap->map+bitmap->block_size.
*/
#ifndef DBUG_OFF
static void _ma_print_bitmap_changes(MARIA_FILE_BITMAP *bitmap)
{
uchar *pos, *end, *org_pos;
ulong page;
DBUG_ENTER("_ma_print_bitmap_changes");
end= bitmap->map + bitmap->used_size;
DBUG_LOCK_FILE;
fprintf(DBUG_FILE,"\nBitmap page changes at page: %lu bitmap: 0x%lx\n",
(ulong) bitmap->page, (long) bitmap->map);
page= (ulong) bitmap->page+1;
for (pos= bitmap->map, org_pos= bitmap->map + bitmap->block_size ;
pos < end ;
pos+= 6, org_pos+= 6)
{
ulonglong bits= uint6korr(pos); /* 6 bytes = 6*8/3= 16 patterns */
ulonglong org_bits= uint6korr(org_pos);
uint i;
/*
Test if there is any changes in the next 16 bitmaps (to not have to
loop through all bits if we know they are the same)
*/
if (bits != org_bits)
{
for (i= 0; i < 16 ; i++, bits>>= 3, org_bits>>= 3)
{
if ((bits & 7) != (org_bits & 7))
fprintf(DBUG_FILE, "Page: %8lu %s -> %s\n", page+i,
bits_to_txt[org_bits & 7], bits_to_txt[bits & 7]);
}
}
page+= 16;
}
fputc('\n', DBUG_FILE);
DBUG_UNLOCK_FILE;
memcpy(bitmap->map + bitmap->block_size, bitmap->map, bitmap->block_size);
DBUG_VOID_RETURN;
}
/* Print content of bitmap for debugging */
void _ma_print_bitmap(MARIA_FILE_BITMAP *bitmap, uchar *data,
pgcache_page_no_t page)
{
uchar *pos, *end;
char llbuff[22];
DBUG_LOCK_FILE;
fprintf(DBUG_FILE,"\nDump of bitmap page at %s\n", llstr(page, llbuff));
page++; /* Skip bitmap page */
for (pos= data, end= pos + bitmap->max_total_size;
pos < end ;
pos+= 6)
{
ulonglong bits= uint6korr(pos); /* 6 bytes = 6*8/3= 16 patterns */
/*
Test if there is any changes in the next 16 bitmaps (to not have to
loop through all bits if we know they are the same)
*/
if (bits)
{
uint i;
for (i= 0; i < 16 ; i++, bits>>= 3)
{
if (bits & 7)
fprintf(DBUG_FILE, "Page: %8s %s\n", llstr(page+i, llbuff),
bits_to_txt[bits & 7]);
}
}
page+= 16;
}
fputc('\n', DBUG_FILE);
DBUG_UNLOCK_FILE;
}
#endif /* DBUG_OFF */
/*
Return content of bitmap as a printable string
*/
void _ma_get_bitmap_description(MARIA_FILE_BITMAP *bitmap,
uchar *bitmap_data,
pgcache_page_no_t page,
char *out)
{
uchar *pos, *end;
uint count=0, dot_printed= 0, len;
char buff[80], last[80];
page++;
last[0]=0;
for (pos= bitmap_data, end= pos+ bitmap->used_size ; pos < end ; pos+= 6)
{
ulonglong bits= uint6korr(pos); /* 6 bytes = 6*8/3= 16 patterns */
uint i;
for (i= 0; i < 16 ; i++, bits>>= 3)
{
if (count > 60)
{
if (memcmp(buff, last, count))
{
memcpy(last, buff, count);
len= sprintf(out, "%8lu: ", (ulong) page - count);
memcpy(out+len, buff, count);
out+= len + count + 1;
out[-1]= '\n';
dot_printed= 0;
}
else if (!(dot_printed++))
{
out= strmov(out, "...\n");
}
count= 0;
}
buff[count++]= '0' + (uint) (bits & 7);
page++;
}
}
len= sprintf(out, "%8lu: ", (ulong) page - count);
memcpy(out+len, buff, count);
out[len + count]= '\n';
out[len + count + 1]= 0;
}
/*
Adjust bitmap->total_size to not go over max_data_file_size
*/
static void adjust_total_size(MARIA_HA *info, pgcache_page_no_t page)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
if (page < bitmap->last_bitmap_page)
bitmap->total_size= bitmap->max_total_size; /* Use all bits in bitmap */
else
bitmap->total_size= bitmap->last_total_size;
}
/***************************************************************************
Reading & writing bitmap pages
***************************************************************************/
/*
Read a given bitmap page
SYNOPSIS
_ma_read_bitmap_page()
info Maria handler
bitmap Bitmap handler
page Page to read
TODO
Update 'bitmap->used_size' to real size of used bitmap
NOTE
We don't always have share->bitmap.bitmap_lock here
(when called from_ma_check_bitmap_data() for example).
RETURN
0 ok
1 error (Error writing old bitmap or reading bitmap page)
*/
static my_bool _ma_read_bitmap_page(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page)
{
MARIA_SHARE *share= info->s;
my_bool res;
DBUG_ENTER("_ma_read_bitmap_page");
DBUG_ASSERT(page % bitmap->pages_covered == 0);
DBUG_ASSERT(!bitmap->changed);
bitmap->page= page;
if ((page + 1) * bitmap->block_size > share->state.state.data_file_length)
{
/* Inexistent or half-created page */
res= _ma_bitmap_create_missing(info, bitmap, page);
if (!res)
adjust_total_size(info, page);
DBUG_RETURN(res);
}
adjust_total_size(info, page);
bitmap->used_size= bitmap->total_size;
DBUG_ASSERT(share->pagecache->block_size == bitmap->block_size);
res= pagecache_read(share->pagecache,
&bitmap->file, page, 0,
bitmap->map, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED, 0) == NULL;
/*
We can't check maria_bitmap_marker here as if the bitmap page
previously had a true checksum and the user switched mode to not checksum
this may have any value, except maria_normal_page_marker.
Using maria_normal_page_marker gives us a protection against bugs
when running without any checksums.
*/
#ifndef DBUG_OFF
if (!res)
memcpy(bitmap->map + bitmap->block_size, bitmap->map, bitmap->block_size);
#endif
DBUG_RETURN(res);
}
/*
Change to another bitmap page
SYNOPSIS
_ma_change_bitmap_page()
info Maria handler
bitmap Bitmap handler
page Bitmap page to read
NOTES
If old bitmap was changed, write it out before reading new one
We return empty bitmap if page is outside of file size
RETURN
0 ok
1 error (Error writing old bitmap or reading bitmap page)
*/
static my_bool _ma_change_bitmap_page(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page)
{
DBUG_ENTER("_ma_change_bitmap_page");
/*
We have to mark the file changed here, as otherwise the following
read/write to pagecache may force a page out from this file, which would
cause _ma_mark_file_changed() to be called with bitmaplock hold!
*/
_ma_bitmap_mark_file_changed(info->s, 1);
if (bitmap->changed)
{
if (write_changed_bitmap(info->s, bitmap))
DBUG_RETURN(1);
bitmap->changed= 0;
}
DBUG_RETURN(_ma_read_bitmap_page(info, bitmap, page));
}
/*
Read next suitable bitmap
SYNOPSIS
move_to_next_bitmap()
bitmap Bitmap handle
NOTES
The found bitmap may be full, so calling function may need to call this
repeatedly until it finds enough space.
TODO
Add cache of bitmaps to not read something that is not usable
RETURN
0 ok
1 error (either couldn't save old bitmap or read new one)
*/
static my_bool move_to_next_bitmap(MARIA_HA *info, MARIA_FILE_BITMAP *bitmap)
{
pgcache_page_no_t page= bitmap->page;
MARIA_STATE_INFO *state= &info->s->state;
DBUG_ENTER("move_to_next_bitmap");
if (state->first_bitmap_with_space != ~(pgcache_page_no_t) 0 &&
state->first_bitmap_with_space != page)
{
page= state->first_bitmap_with_space;
state->first_bitmap_with_space= ~(pgcache_page_no_t) 0;
DBUG_ASSERT(page % bitmap->pages_covered == 0);
}
else
{
page+= bitmap->pages_covered;
DBUG_ASSERT(page % bitmap->pages_covered == 0);
}
DBUG_RETURN(_ma_change_bitmap_page(info, bitmap, page));
}
/****************************************************************************
Allocate data in bitmaps
****************************************************************************/
/*
Store data in 'block' and mark the place used in the bitmap
SYNOPSIS
fill_block()
bitmap Bitmap handle
block Store data about what we found
best_data Pointer to best 6 uchar aligned area in bitmap->map
best_pos Which bit in *best_data the area starts
0 = first bit pattern, 1 second bit pattern etc
best_bits The original value of the bits at best_pos
fill_pattern Bitmap pattern to store in best_data[best_pos]
NOTES
We mark all pages to be 'TAIL's, which means that
block->page_count is really a row position inside the page.
*/
static void fill_block(MARIA_FILE_BITMAP *bitmap,
MARIA_BITMAP_BLOCK *block,
uchar *best_data, uint best_pos, uint best_bits,
uint fill_pattern)
{
uint page, offset, tmp;
uchar *data;
DBUG_ENTER("fill_block");
/* For each 6 bytes we have 6*8/3= 16 patterns */
page= ((uint) (best_data - bitmap->map)) / 6 * 16 + best_pos;
DBUG_ASSERT(page + 1 < bitmap->pages_covered);
block->page= bitmap->page + 1 + page;
block->page_count= TAIL_PAGE_COUNT_MARKER;
block->empty_space= pattern_to_size(bitmap, best_bits);
block->sub_blocks= 0;
block->org_bitmap_value= best_bits;
block->used= BLOCKUSED_TAIL; /* See _ma_bitmap_release_unused() */
/*
Mark place used by reading/writing 2 bytes at a time to handle
bitmaps in overlapping bytes
*/
best_pos*= 3;
data= best_data+ best_pos / 8;
offset= best_pos & 7;
tmp= uint2korr(data);
/* we turn off the 3 bits and replace them with fill_pattern */
tmp= (tmp & ~(7 << offset)) | (fill_pattern << offset);
int2store(data, tmp);
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
DBUG_VOID_RETURN;
}
/*
Allocate data for head block
SYNOPSIS
allocate_head()
bitmap bitmap
size Size of data region we need to store
block Store found information here
IMPLEMENTATION
Find the best-fit page to put a region of 'size'
This is defined as the first page of the set of pages
with the smallest free space that can hold 'size'.
RETURN
0 ok (block is updated)
1 error (no space in bitmap; block is not touched)
*/
static my_bool allocate_head(MARIA_FILE_BITMAP *bitmap, uint size,
MARIA_BITMAP_BLOCK *block)
{
uint min_bits= size_to_head_pattern(bitmap, size);
uchar *data= bitmap->map, *end= data + bitmap->used_size;
uchar *best_data= 0;
uint best_bits= (uint) -1, UNINIT_VAR(best_pos);
uint first_pattern= 0; /* if doing insert_order */
MARIA_SHARE *share= bitmap->share;
my_bool insert_order=
MY_TEST(share->base.extra_options & MA_EXTRA_OPTIONS_INSERT_ORDER);
DBUG_ENTER("allocate_head");
DBUG_ASSERT(size <= FULL_PAGE_SIZE(share));
if (insert_order && bitmap->page == share->last_insert_bitmap)
{
uint last_insert_page= share->last_insert_page;
uint byte= 6 * (last_insert_page / 16);
first_pattern= last_insert_page % 16;
DBUG_ASSERT(data + byte < end);
data+= byte;
}
for (; data < end; data+= 6)
{
ulonglong bits= uint6korr(data); /* 6 bytes = 6*8/3= 16 patterns */
uint i;
/*
Skip common patterns
We can skip empty pages (if we already found a match) or
anything matching the following pattern as this will be either
a full page or a tail page
*/
if ((!bits && best_data) ||
((bits & 04444444444444444LL) == 04444444444444444LL))
{
first_pattern= 0; // always restart from 0 when moving to new 6-byte
continue;
}
for (i= first_pattern, bits >>= (3 * first_pattern); i < 16 ;
i++, bits >>= 3)
{
uint pattern= (uint) (bits & 7);
if (pattern <= min_bits)
{
/* There is enough space here */
if ((int) pattern > (int) best_bits)
{
/*
There is more than enough space here and it's better than what
we have found so far. Remember it, as we will choose it if we
don't find anything in this bitmap page.
*/
best_bits= pattern;
best_data= data;
best_pos= i;
if (pattern == min_bits)
goto found; /* Best possible match */
}
}
}
first_pattern= 0; // always restart from 0 when moving to new 6-byte
}
if (!best_data) /* Found no place */
{
if (data >= bitmap->map + bitmap->total_size)
DBUG_RETURN(1); /* No space in bitmap */
/* Allocate data at end of bitmap */
bitmap->used_size+= 6;
set_if_smaller(bitmap->used_size, bitmap->total_size);
best_data= data;
best_pos= best_bits= 0;
}
found:
if (insert_order)
{
share->last_insert_page=
((uint) (best_data - bitmap->map)) / 6 * 16 + best_pos;
share->last_insert_bitmap= bitmap->page;
}
fill_block(bitmap, block, best_data, best_pos, best_bits, FULL_HEAD_PAGE);
DBUG_RETURN(0);
}
/*
Allocate data for tail block
SYNOPSIS
allocate_tail()
bitmap bitmap
size Size of block we need to find
block Store found information here
RETURN
0 ok (block is updated)
1 error (no space in bitmap; block is not touched)
*/
static my_bool allocate_tail(MARIA_FILE_BITMAP *bitmap, uint size,
MARIA_BITMAP_BLOCK *block)
{
uint min_bits= size_to_tail_pattern(bitmap, size);
uchar *data= bitmap->map, *end= data + bitmap->used_size;
uchar *best_data= 0;
uint best_bits= (uint) -1, UNINIT_VAR(best_pos);
DBUG_ENTER("allocate_tail");
DBUG_PRINT("enter", ("size: %u", size));
/*
We have to add DIR_ENTRY_SIZE here as this is not part of the data size
See call to allocate_tail() in find_tail().
*/
DBUG_ASSERT(size <= MAX_TAIL_SIZE(bitmap->block_size) + DIR_ENTRY_SIZE);
for (; data < end; data += 6)
{
ulonglong bits= uint6korr(data); /* 6 bytes = 6*8/3= 16 patterns */
uint i;
/*
Skip common patterns
We can skip empty pages (if we already found a match) or
the following patterns: 1-4 (head pages, not suitable for tail) or
7 (full tail page). See 'Dynamic size records' comment at start of file.
At the moment we only skip full head and tail pages (ie, all bits are
set) as this is easy to detect with one simple test and is a
quite common case if we have blobs.
*/
if ((!bits && best_data) || bits == 0xffffffffffffLL ||
bits == 04444444444444444LL)
continue;
for (i= 0; i < 16; i++, bits >>= 3)
{
uint pattern= (uint) (bits & 7);
if (pattern <= min_bits && (!pattern || pattern >= 5))
{
if ((int) pattern > (int) best_bits)
{
best_bits= pattern;
best_data= data;
best_pos= i;
if (pattern == min_bits)
goto found; /* Can't be better */
}
}
}
}
if (!best_data)
{
if (data >= bitmap->map + bitmap->total_size)
DBUG_RETURN(1);
/* Allocate data at end of bitmap */
best_data= data;
bitmap->used_size+= 6;
set_if_smaller(bitmap->used_size, bitmap->total_size);
best_pos= best_bits= 0;
}
found:
fill_block(bitmap, block, best_data, best_pos, best_bits, FULL_TAIL_PAGE);
DBUG_RETURN(0);
}
/*
Allocate data for full blocks
SYNOPSIS
allocate_full_pages()
bitmap bitmap
pages_needed Total size in pages (bitmap->total_size) we would like to have
block Store found information here
full_page 1 if we are not allowed to split extent
IMPLEMENTATION
We will return the smallest area >= size. If there is no such
block, we will return the biggest area that satisfies
area_size >= MY_MIN(BLOB_SEGMENT_MIN_SIZE*full_page_size, size)
To speed up searches, we will only consider areas that has at least 16 free
pages starting on an even boundary. When finding such an area, we will
extend it with all previous and following free pages. This will ensure
we don't get holes between areas
RETURN
# Blocks used
0 error (no space in bitmap; block is not touched)
*/
static ulong allocate_full_pages(MARIA_FILE_BITMAP *bitmap,
ulong pages_needed,
MARIA_BITMAP_BLOCK *block, my_bool full_page)
{
uchar *data= bitmap->map, *data_end= data + bitmap->used_size;
uchar *page_end= data + bitmap->total_size;
uchar *best_data= 0;
uint min_size;
uint best_area_size, UNINIT_VAR(best_prefix_area_size);
uint page, size;
ulonglong UNINIT_VAR(best_prefix_bits);
DBUG_ENTER("allocate_full_pages");
DBUG_PRINT("enter", ("pages_needed: %lu", pages_needed));
min_size= pages_needed;
if (!full_page && min_size > BLOB_SEGMENT_MIN_SIZE)
min_size= BLOB_SEGMENT_MIN_SIZE;
best_area_size= ~(uint) 0;
for (; data < page_end; data+= 6)
{
ulonglong bits= uint6korr(data); /* 6 bytes = 6*8/3= 16 patterns */
uchar *data_start;
ulonglong prefix_bits= 0;
uint area_size, prefix_area_size, suffix_area_size;
/* Find area with at least 16 free pages */
if (bits)
continue;
data_start= data;
/* Find size of area */
for (data+=6 ; data < data_end ; data+= 6)
{
if ((bits= uint6korr(data)))
break;
}
area_size= (uint) (data - data_start) / 6 * 16;
if (area_size >= best_area_size)
continue;
prefix_area_size= suffix_area_size= 0;
if (!bits)
{
/*
End of page; All the rest of the bits on page are part of area
This is needed because bitmap->used_size only covers the set bits
in the bitmap.
*/
area_size+= (uint) (page_end - data) / 6 * 16;
if (area_size >= best_area_size)
break;
data= page_end;
}
else
{
/* Add bits at end of page */
for (; !(bits & 7); bits >>= 3)
suffix_area_size++;
area_size+= suffix_area_size;
}
if (data_start != bitmap->map)
{
/* Add bits before page */
bits= prefix_bits= uint6korr(data_start - 6);
DBUG_ASSERT(bits != 0);
/* 111 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 */
if (!(bits & 07000000000000000LL))
{
data_start-= 6;
do
{
prefix_area_size++;
bits<<= 3;
} while (!(bits & 07000000000000000LL));
area_size+= prefix_area_size;
/* Calculate offset to page from data_start */
prefix_area_size= 16 - prefix_area_size;
}
}
if (area_size >= min_size && area_size <= best_area_size)
{
best_data= data_start;
best_area_size= area_size;
best_prefix_bits= prefix_bits;
best_prefix_area_size= prefix_area_size;
/* Prefer to put data in biggest possible area */
if (area_size <= pages_needed)
min_size= area_size;
else
min_size= pages_needed;
}
}
if (!best_data)
DBUG_RETURN(0); /* No room on page */
/*
Now allocate MY_MIN(pages_needed, area_size), starting from
best_start + best_prefix_area_size
*/
if (best_area_size > pages_needed)
best_area_size= pages_needed;
/* For each 6 bytes we have 6*8/3= 16 patterns */
page= ((uint) (best_data - bitmap->map) * 8) / 3 + best_prefix_area_size;
block->page= bitmap->page + 1 + page;
block->page_count= best_area_size;
block->empty_space= 0;
block->sub_blocks= 0;
block->org_bitmap_value= 0;
block->used= 0;
DBUG_ASSERT(page + best_area_size < bitmap->pages_covered);
DBUG_PRINT("info", ("page: %lu page_count: %u",
(ulong) block->page, block->page_count));
if (best_prefix_area_size)
{
ulonglong tmp;
/* Convert offset back to bits */
best_prefix_area_size= 16 - best_prefix_area_size;
if (best_area_size < best_prefix_area_size)
{
tmp= (1LL << best_area_size*3) - 1;
best_area_size= best_prefix_area_size; /* for easy end test */
}
else
tmp= (1LL << best_prefix_area_size*3) - 1;
tmp<<= (16 - best_prefix_area_size) * 3;
DBUG_ASSERT((best_prefix_bits & tmp) == 0);
best_prefix_bits|= tmp;
int6store(best_data, best_prefix_bits);
if (!(best_area_size-= best_prefix_area_size))
goto end;
best_data+= 6;
}
best_area_size*= 3; /* Bits to set */
size= best_area_size/8; /* Bytes to set */
bfill(best_data, size, 255);
best_data+= size;
if ((best_area_size-= size * 8))
{
/* fill last uchar */
*best_data|= (uchar) ((1 << best_area_size) -1);
best_data++;
}
if (data_end < best_data)
{
bitmap->used_size= (uint) (best_data - bitmap->map);
DBUG_ASSERT(bitmap->used_size <= bitmap->total_size);
}
end:
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
DBUG_RETURN(block->page_count);
}
/****************************************************************************
Find right bitmaps where to store data
****************************************************************************/
/*
Find right bitmap and position for head block
SYNOPSIS
find_head()
info Maria handler
length Size of data region we need store
position Position in bitmap_blocks where to store the
information for the head block.
RETURN
0 ok
1 error
*/
static my_bool find_head(MARIA_HA *info, uint length, uint position)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
MARIA_BITMAP_BLOCK *block;
/*
There is always place for the head block in bitmap_blocks as these are
preallocated at _ma_init_block_record().
*/
block= dynamic_element(&info->bitmap_blocks, position, MARIA_BITMAP_BLOCK *);
if (info->s->base.extra_options & MA_EXTRA_OPTIONS_INSERT_ORDER)
{
if (bitmap->page != info->s->last_insert_bitmap &&
_ma_change_bitmap_page(info, bitmap,
info->s->last_insert_bitmap))
return 1;
/* Don't allocate any blocks from earlier pages */
info->s->state.first_bitmap_with_space= info->s->last_insert_bitmap;
}
/*
We need to have DIRENTRY_SIZE here to take into account that we may
need an extra directory entry for the row
*/
while (allocate_head(bitmap, length + DIR_ENTRY_SIZE, block))
if (move_to_next_bitmap(info, bitmap))
return 1;
return 0;
}
/*
Find right bitmap and position for tail
SYNOPSIS
find_tail()
info Maria handler
length Size of data region we need store
position Position in bitmap_blocks where to store the
information for the head block.
RETURN
0 ok
1 error
*/
static my_bool find_tail(MARIA_HA *info, uint length, uint position)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
MARIA_BITMAP_BLOCK *block;
DBUG_ENTER("find_tail");
DBUG_ASSERT(length <= info->s->block_size - PAGE_OVERHEAD_SIZE(info->s));
/* Needed, as there is no error checking in dynamic_element */
if (allocate_dynamic(&info->bitmap_blocks, position))
DBUG_RETURN(1);
block= dynamic_element(&info->bitmap_blocks, position, MARIA_BITMAP_BLOCK *);
/*
We have to add DIR_ENTRY_SIZE to ensure we have space for the tail and
it's directroy entry on the page
*/
while (allocate_tail(bitmap, length + DIR_ENTRY_SIZE, block))
if (move_to_next_bitmap(info, bitmap))
DBUG_RETURN(1);
DBUG_RETURN(0);
}
/*
Find right bitmap and position for full blocks in one extent
SYNOPSIS
find_mid()
info Maria handler.
pages How many pages to allocate.
position Position in bitmap_blocks where to store the
information for the head block.
NOTES
This is used to allocate the main extent after the 'head' block
(Ie, the middle part of the head-middle-tail entry)
RETURN
0 ok
1 error
*/
static my_bool find_mid(MARIA_HA *info, ulong pages, uint position)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
MARIA_BITMAP_BLOCK *block;
block= dynamic_element(&info->bitmap_blocks, position, MARIA_BITMAP_BLOCK *);
while (!allocate_full_pages(bitmap, pages, block, 1))
{
if (move_to_next_bitmap(info, bitmap))
return 1;
}
return 0;
}
/*
Find right bitmap and position for putting a blob
SYNOPSIS
find_blob()
info Maria handler.
length Length of the blob
NOTES
The extents are stored last in info->bitmap_blocks
IMPLEMENTATION
Allocate all full pages for the block + optionally one tail
RETURN
0 ok
1 error
*/
static my_bool find_blob(MARIA_HA *info, ulong length)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
uint full_page_size= FULL_PAGE_SIZE(info->s);
ulong pages;
uint rest_length, used;
uint UNINIT_VAR(first_block_pos);
MARIA_BITMAP_BLOCK *first_block= 0;
DBUG_ENTER("find_blob");
DBUG_PRINT("enter", ("length: %lu", length));
pages= length / full_page_size;
rest_length= (uint) (length - pages * full_page_size);
if (rest_length >= MAX_TAIL_SIZE(info->s->block_size))
{
pages++;
rest_length= 0;
}
first_block_pos= info->bitmap_blocks.elements;
if (pages)
{
MARIA_BITMAP_BLOCK *block;
if (allocate_dynamic(&info->bitmap_blocks,
info->bitmap_blocks.elements +
pages / BLOB_SEGMENT_MIN_SIZE + 2))
DBUG_RETURN(1);
block= dynamic_element(&info->bitmap_blocks, info->bitmap_blocks.elements,
MARIA_BITMAP_BLOCK*);
do
{
/*
We use 0x3fff here as the two upmost bits are reserved for
TAIL_BIT and START_EXTENT_BIT
*/
used= allocate_full_pages(bitmap,
(pages >= 0x3fff ? 0x3fff : (uint) pages),
block, 0);
if (!used)
{
if (move_to_next_bitmap(info, bitmap))
DBUG_RETURN(1);
}
else
{
pages-= used;
info->bitmap_blocks.elements++;
block++;
}
} while (pages != 0);
}
if (rest_length && find_tail(info, rest_length,
info->bitmap_blocks.elements++))
DBUG_RETURN(1);
first_block= dynamic_element(&info->bitmap_blocks, first_block_pos,
MARIA_BITMAP_BLOCK*);
first_block->sub_blocks= info->bitmap_blocks.elements - first_block_pos;
DBUG_RETURN(0);
}
/*
Find pages to put ALL blobs
SYNOPSIS
allocate_blobs()
info Maria handler
row Information of what is in the row (from calc_record_size())
RETURN
0 ok
1 error
*/
static my_bool allocate_blobs(MARIA_HA *info, MARIA_ROW *row)
{
ulong *length, *end;
uint elements;
/*
Reserve size for:
head block
one extent
tail block
*/
elements= info->bitmap_blocks.elements;
for (length= row->blob_lengths, end= length + info->s->base.blobs;
length < end; length++)
{
if (*length && find_blob(info, *length))
return 1;
}
row->extents_count= (info->bitmap_blocks.elements - elements);
return 0;
}
/*
Store in the bitmap the new size for a head page
SYNOPSIS
use_head()
info Maria handler
page Page number to update
(Note that caller guarantees this is in the active
bitmap)
size How much free space is left on the page
block_position In which info->bitmap_block we have the
information about the head block.
NOTES
This is used on update where we are updating an existing head page
*/
static void use_head(MARIA_HA *info, pgcache_page_no_t page, uint size,
uint block_position)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
MARIA_BITMAP_BLOCK *block;
uchar *data;
uint offset, tmp, offset_page;
DBUG_ENTER("use_head");
DBUG_ASSERT(page % bitmap->pages_covered);
block= dynamic_element(&info->bitmap_blocks, block_position,
MARIA_BITMAP_BLOCK*);
block->page= page;
block->page_count= 1 + TAIL_BIT;
block->empty_space= size;
block->used= BLOCKUSED_TAIL;
/*
Mark place used by reading/writing 2 bytes at a time to handle
bitmaps in overlapping bytes
*/
offset_page= (uint) (page - bitmap->page - 1) * 3;
offset= offset_page & 7;
data= bitmap->map + offset_page / 8;
tmp= uint2korr(data);
block->org_bitmap_value= (tmp >> offset) & 7;
tmp= (tmp & ~(7 << offset)) | (FULL_HEAD_PAGE << offset);
int2store(data, tmp);
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
DBUG_VOID_RETURN;
}
/*
Find out where to split the row (ie, what goes in head, middle, tail etc)
SYNOPSIS
find_where_to_split_row()
share Maria share
row Information of what is in the row (from calc_record_size())
extents Max number of extents we have to store in header
split_size Free size on the page (The head length must be less
than this)
RETURN
row_length for the head block.
*/
static uint find_where_to_split_row(MARIA_SHARE *share, MARIA_ROW *row,
uint extents, uint split_size)
{
uint *lengths, *lengths_end;
/*
Ensure we have the minimum required space on head page:
- Header + length of field lengths (row->min_length)
- Number of extents
- One extent
*/
uint row_length= (row->min_length +
size_to_store_key_length(extents) +
ROW_EXTENT_SIZE);
DBUG_ASSERT(row_length <= split_size);
/*
Store first in all_field_lengths the different parts that are written
to the row. This needs to be in same order as in
ma_block_rec.c::write_block_record()
*/
row->null_field_lengths[-3]= extents * ROW_EXTENT_SIZE;
row->null_field_lengths[-2]= share->base.fixed_not_null_fields_length;
row->null_field_lengths[-1]= row->field_lengths_length;
for (lengths= row->null_field_lengths - EXTRA_LENGTH_FIELDS,
lengths_end= (lengths + share->base.fields - share->base.blobs +
EXTRA_LENGTH_FIELDS); lengths < lengths_end; lengths++)
{
if (row_length + *lengths > split_size)
break;
row_length+= *lengths;
}
return row_length;
}
/*
Find where to write the middle parts of the row and the tail
SYNOPSIS
write_rest_of_head()
info Maria handler
position Position in bitmap_blocks. Is 0 for rows that needs
full blocks (ie, has a head, middle part and optional tail)
rest_length How much left of the head block to write.
RETURN
0 ok
1 error
*/
static my_bool write_rest_of_head(MARIA_HA *info, uint position,
ulong rest_length)
{
MARIA_SHARE *share= info->s;
uint full_page_size= FULL_PAGE_SIZE(share);
MARIA_BITMAP_BLOCK *block;
DBUG_ENTER("write_rest_of_head");
DBUG_PRINT("enter", ("position: %u rest_length: %lu", position,
rest_length));
if (position == 0)
{
/* Write out full pages */
uint pages= rest_length / full_page_size;
rest_length%= full_page_size;
if (rest_length >= MAX_TAIL_SIZE(share->block_size))
{
/* Put tail on a full page */
pages++;
rest_length= 0;
}
if (find_mid(info, pages, 1))
DBUG_RETURN(1);
/*
Insert empty block after full pages, to allow write_block_record() to
split segment into used + free page
*/
block= dynamic_element(&info->bitmap_blocks, 2, MARIA_BITMAP_BLOCK*);
block->page_count= 0;
block->used= 0;
}
if (rest_length)
{
if (find_tail(info, rest_length, ELEMENTS_RESERVED_FOR_MAIN_PART - 1))
DBUG_RETURN(1);
}
else
{
/* Empty tail block */
block= dynamic_element(&info->bitmap_blocks,
ELEMENTS_RESERVED_FOR_MAIN_PART - 1,
MARIA_BITMAP_BLOCK *);
block->page_count= 0;
block->used= 0;
}
DBUG_RETURN(0);
}
/*
Find where to store one row
SYNPOSIS
_ma_bitmap_find_place()
info Maria handler
row Information about row to write
blocks Store data about allocated places here
RETURN
0 ok
row->space_on_head_page contains minimum number of bytes we
expect to put on the head page.
1 error
my_errno is set to error
*/
my_bool _ma_bitmap_find_place(MARIA_HA *info, MARIA_ROW *row,
MARIA_BITMAP_BLOCKS *blocks)
{
MARIA_SHARE *share= info->s;
my_bool res= 1;
uint full_page_size, position, max_page_size;
uint head_length, row_length, rest_length, extents_length;
DBUG_ENTER("_ma_bitmap_find_place");
blocks->count= 0;
blocks->tail_page_skipped= blocks->page_skipped= 0;
row->extents_count= 0;
/*
Reserve place for the following blocks:
- Head block
- Full page block
- Marker block to allow write_block_record() to split full page blocks
into full and free part
- Tail block
*/
info->bitmap_blocks.elements= ELEMENTS_RESERVED_FOR_MAIN_PART;
max_page_size= (share->block_size - PAGE_OVERHEAD_SIZE(share));
mysql_mutex_lock(&share->bitmap.bitmap_lock);
if (row->total_length <= max_page_size)
{
/* Row fits in one page */
position= ELEMENTS_RESERVED_FOR_MAIN_PART - 1;
if (find_head(info, (uint) row->total_length, position))
goto abort;
row->space_on_head_page= row->total_length;
goto end;
}
/*
First allocate all blobs so that we can find out the needed size for
the main block.
*/
if (row->blob_length && allocate_blobs(info, row))
goto abort;
extents_length= row->extents_count * ROW_EXTENT_SIZE;
/*
The + 3 is reserved for storing the number of segments in the row header.
*/
if ((head_length= (row->head_length + extents_length + 3)) <=
max_page_size)
{
/* Main row part fits into one page */
position= ELEMENTS_RESERVED_FOR_MAIN_PART - 1;
if (find_head(info, head_length, position))
goto abort;
row->space_on_head_page= head_length;
goto end;
}
/* Allocate enough space */
head_length+= ELEMENTS_RESERVED_FOR_MAIN_PART * ROW_EXTENT_SIZE;
/* The first segment size is stored in 'row_length' */
row_length= find_where_to_split_row(share, row, row->extents_count +
ELEMENTS_RESERVED_FOR_MAIN_PART-1,
max_page_size);
full_page_size= MAX_TAIL_SIZE(share->block_size);
position= 0;
rest_length= head_length - row_length;
if (rest_length <= full_page_size)
position= ELEMENTS_RESERVED_FOR_MAIN_PART -2; /* Only head and tail */
if (find_head(info, row_length, position))
goto abort;
row->space_on_head_page= row_length;
if (write_rest_of_head(info, position, rest_length))
goto abort;
end:
blocks->block= dynamic_element(&info->bitmap_blocks, position,
MARIA_BITMAP_BLOCK*);
blocks->block->sub_blocks= ELEMENTS_RESERVED_FOR_MAIN_PART - position;
/* First block's page_count is for all blocks */
blocks->count= info->bitmap_blocks.elements - position;
res= 0;
abort:
mysql_mutex_unlock(&share->bitmap.bitmap_lock);
DBUG_RETURN(res);
}
/*
Find where to put row on update (when head page is already defined)
SYNPOSIS
_ma_bitmap_find_new_place()
info Maria handler
row Information about row to write
page On which page original row was stored
free_size Free size on head page
blocks Store data about allocated places here
NOTES
This function is only called when the new row can't fit in the space of
the old row in the head page.
This is essently same as _ma_bitmap_find_place() except that
we don't call find_head() to search in bitmaps where to put the page.
RETURN
0 ok
1 error
*/
my_bool _ma_bitmap_find_new_place(MARIA_HA *info, MARIA_ROW *row,
pgcache_page_no_t page, uint free_size,
MARIA_BITMAP_BLOCKS *blocks)
{
MARIA_SHARE *share= info->s;
my_bool res= 1;
uint position;
uint head_length, row_length, rest_length, extents_length;
ulonglong bitmap_page;
DBUG_ENTER("_ma_bitmap_find_new_place");
blocks->count= 0;
blocks->tail_page_skipped= blocks->page_skipped= 0;
row->extents_count= 0;
info->bitmap_blocks.elements= ELEMENTS_RESERVED_FOR_MAIN_PART;
mysql_mutex_lock(&share->bitmap.bitmap_lock);
/*
First allocate all blobs (so that we can find out the needed size for
the main block.
*/
if (row->blob_length && allocate_blobs(info, row))
goto abort;
/* Switch bitmap to current head page */
bitmap_page= page - page % share->bitmap.pages_covered;
if (share->bitmap.page != bitmap_page &&
_ma_change_bitmap_page(info, &share->bitmap, bitmap_page))
goto abort;
extents_length= row->extents_count * ROW_EXTENT_SIZE;
if ((head_length= (row->head_length + extents_length + 3)) <= free_size)
{
/* Main row part fits into one page */
position= ELEMENTS_RESERVED_FOR_MAIN_PART - 1;
use_head(info, page, head_length, position);
row->space_on_head_page= head_length;
goto end;
}
/* Allocate enough space */
head_length+= ELEMENTS_RESERVED_FOR_MAIN_PART * ROW_EXTENT_SIZE;
/*
The first segment size is stored in 'row_length'
We have to add ELEMENTS_RESERVED_FOR_MAIN_PART here as the extent
information may be up to this size when the header splits.
*/
row_length= find_where_to_split_row(share, row, row->extents_count +
ELEMENTS_RESERVED_FOR_MAIN_PART-1,
free_size);
position= 0;
rest_length= head_length - row_length;
if (rest_length <= MAX_TAIL_SIZE(share->block_size))
position= ELEMENTS_RESERVED_FOR_MAIN_PART -2; /* Only head and tail */
use_head(info, page, row_length, position);
row->space_on_head_page= row_length;
if (write_rest_of_head(info, position, rest_length))
goto abort;
end:
blocks->block= dynamic_element(&info->bitmap_blocks, position,
MARIA_BITMAP_BLOCK*);
blocks->block->sub_blocks= ELEMENTS_RESERVED_FOR_MAIN_PART - position;
/* First block's page_count is for all blocks */
blocks->count= info->bitmap_blocks.elements - position;
res= 0;
abort:
mysql_mutex_unlock(&share->bitmap.bitmap_lock);
DBUG_RETURN(res);
}
/****************************************************************************
Clear and reset bits
****************************************************************************/
/*
Set fill pattern for a page
set_page_bits()
info Maria handler
bitmap Bitmap handler
page Adress to page
fill_pattern Pattern (not size) for page
NOTES
Page may not be part of active bitmap
RETURN
0 ok
1 error
*/
static my_bool set_page_bits(MARIA_HA *info, MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page, uint fill_pattern)
{
pgcache_page_no_t bitmap_page;
uint offset_page, offset, tmp, org_tmp;
uchar *data;
DBUG_ENTER("set_page_bits");
DBUG_ASSERT(fill_pattern <= 7);
bitmap_page= page - page % bitmap->pages_covered;
if (bitmap_page != bitmap->page &&
_ma_change_bitmap_page(info, bitmap, bitmap_page))
DBUG_RETURN(1);
/* Find page number from start of bitmap */
offset_page= (uint) (page - bitmap->page - 1);
/*
Mark place used by reading/writing 2 bytes at a time to handle
bitmaps in overlapping bytes
*/
offset_page*= 3;
offset= offset_page & 7;
data= bitmap->map + offset_page / 8;
org_tmp= tmp= uint2korr(data);
tmp= (tmp & ~(7 << offset)) | (fill_pattern << offset);
if (tmp == org_tmp)
DBUG_RETURN(0); /* No changes */
int2store(data, tmp);
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
if (fill_pattern != 3 && fill_pattern != 7)
set_if_smaller(info->s->state.first_bitmap_with_space, bitmap_page);
/*
Note that if the condition above is false (page is full), and all pages of
this bitmap are now full, and that bitmap page was
first_bitmap_with_space, we don't modify first_bitmap_with_space, indeed
its value still tells us where to start our search for a bitmap with space
(which is for sure after this full one).
That does mean that first_bitmap_with_space is only a lower bound.
*/
DBUG_RETURN(0);
}
/*
Get bitmap pattern for a given page
SYNOPSIS
bitmap_get_page_bits()
info Maria handler
bitmap Bitmap handler
page Page number
RETURN
0-7 Bitmap pattern
~0 Error (couldn't read page)
*/
static uint bitmap_get_page_bits(MARIA_HA *info, MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page)
{
pgcache_page_no_t bitmap_page;
uint offset_page, offset, tmp;
uchar *data;
DBUG_ENTER("_ma_bitmap_get_page_bits");
bitmap_page= page - page % bitmap->pages_covered;
if (bitmap_page != bitmap->page &&
_ma_change_bitmap_page(info, bitmap, bitmap_page))
DBUG_RETURN(~ (uint) 0);
/* Find page number from start of bitmap */
offset_page= (uint) (page - bitmap->page - 1);
/*
Mark place used by reading/writing 2 bytes at a time to handle
bitmaps in overlapping bytes
*/
offset_page*= 3;
offset= offset_page & 7;
data= bitmap->map + offset_page / 8;
tmp= uint2korr(data);
DBUG_RETURN((tmp >> offset) & 7);
}
/* As above, but take a lock while getting the data */
uint _ma_bitmap_get_page_bits(MARIA_HA *info, MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page)
{
uint tmp;
mysql_mutex_lock(&bitmap->bitmap_lock);
tmp= bitmap_get_page_bits(info, bitmap, page);
mysql_mutex_unlock(&bitmap->bitmap_lock);
return tmp;
}
/*
Mark all pages in a region as free
SYNOPSIS
_ma_bitmap_reset_full_page_bits()
info Maria handler
bitmap Bitmap handler
page Start page
page_count Number of pages
NOTES
We assume that all pages in region is covered by same bitmap
One must have a lock on info->s->bitmap.bitmap_lock
RETURN
0 ok
1 Error (when reading bitmap)
*/
my_bool _ma_bitmap_reset_full_page_bits(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page,
uint page_count)
{
ulonglong bitmap_page;
uint offset, bit_start, bit_count, tmp;
uchar *data;
DBUG_ENTER("_ma_bitmap_reset_full_page_bits");
DBUG_PRINT("enter", ("page: %lu page_count: %u", (ulong) page, page_count));
mysql_mutex_assert_owner(&info->s->bitmap.bitmap_lock);
bitmap_page= page - page % bitmap->pages_covered;
DBUG_ASSERT(page != bitmap_page);
if (bitmap_page != bitmap->page &&
_ma_change_bitmap_page(info, bitmap, bitmap_page))
DBUG_RETURN(1);
/* Find page number from start of bitmap */
offset= (uint) (page - bitmap->page - 1);
/* Clear bits from 'page * 3' -> '(page + page_count) * 3' */
bit_start= offset * 3;
bit_count= page_count * 3;
data= bitmap->map + bit_start / 8;
offset= bit_start & 7;
tmp= (255 << offset); /* Bits to keep */
if (bit_count + offset < 8)
{
/* Only clear bits between 'offset' and 'offset+bit_count-1' */
tmp^= (255 << (offset + bit_count));
}
*data&= ~tmp;
if ((int) (bit_count-= (8 - offset)) > 0)
{
uint fill;
data++;
/*
-1 is here to avoid one 'if' statement and to let the following code
handle the last byte
*/
if ((fill= (bit_count - 1) / 8))
{
bzero(data, fill);
data+= fill;
}
bit_count-= fill * 8; /* Bits left to clear */
tmp= (1 << bit_count) - 1;
*data&= ~tmp;
}
set_if_smaller(info->s->state.first_bitmap_with_space, bitmap_page);
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
DBUG_RETURN(0);
}
/*
Set all pages in a region as used
SYNOPSIS
_ma_bitmap_set_full_page_bits()
info Maria handler
bitmap Bitmap handler
page Start page
page_count Number of pages
NOTES
We assume that all pages in region is covered by same bitmap
One must have a lock on info->s->bitmap.bitmap_lock
RETURN
0 ok
1 Error (when reading bitmap)
*/
my_bool _ma_bitmap_set_full_page_bits(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page, uint page_count)
{
ulonglong bitmap_page;
uint offset, bit_start, bit_count, tmp;
uchar *data;
DBUG_ENTER("_ma_bitmap_set_full_page_bits");
DBUG_PRINT("enter", ("page: %lu page_count: %u", (ulong) page, page_count));
mysql_mutex_assert_owner(&info->s->bitmap.bitmap_lock);
bitmap_page= page - page % bitmap->pages_covered;
if (page == bitmap_page ||
page + page_count > bitmap_page + bitmap->pages_covered)
{
DBUG_ASSERT(0); /* Wrong in data */
DBUG_RETURN(1);
}
if (bitmap_page != bitmap->page &&
_ma_change_bitmap_page(info, bitmap, bitmap_page))
DBUG_RETURN(1);
/* Find page number from start of bitmap */
offset= (uint) (page - bitmap->page - 1);
/* Set bits from 'page * 3' -> '(page + page_count) * 3' */
bit_start= offset * 3;
bit_count= page_count * 3;
data= bitmap->map + bit_start / 8;
offset= bit_start & 7;
tmp= (255 << offset); /* Bits to keep */
if (bit_count + offset < 8)
{
/* Only set bits between 'offset' and 'offset+bit_count-1' */
tmp^= (255 << (offset + bit_count));
}
*data|= tmp;
if ((int) (bit_count-= (8 - offset)) > 0)
{
uint fill;
data++;
/*
-1 is here to avoid one 'if' statement and to let the following code
handle the last byte
*/
if ((fill= (bit_count - 1) / 8))
{
bfill(data, fill, 255);
data+= fill;
}
bit_count-= fill * 8; /* Bits left to set */
tmp= (1 << bit_count) - 1;
*data|= tmp;
}
bitmap->changed= 1;
DBUG_EXECUTE("bitmap", _ma_print_bitmap_changes(bitmap););
DBUG_RETURN(0);
}
/**
@brief
Make a transition of MARIA_FILE_BITMAP::non_flushable.
If the bitmap becomes flushable, which requires that REDO-UNDO has been
logged and all bitmap pages touched by the thread have a correct
allocation, it unpins all bitmap pages, and if _ma_bitmap_flush_all() is
waiting (in practice it is a checkpoint), it wakes it up.
If the bitmap becomes or stays unflushable, the function merely records it
unless a concurrent _ma_bitmap_flush_all() is happening, in which case the
function first waits for the flush to be done.
@note
this sets info->non_flushable_state to 1 if we have incremented
bitmap->non_flushable and not yet decremented it.
@param share Table's share
@param non_flushable_inc Increment of MARIA_FILE_BITMAP::non_flushable
(-1 or +1).
*/
void _ma_bitmap_flushable(MARIA_HA *info, int non_flushable_inc)
{
MARIA_SHARE *share= info->s;
MARIA_FILE_BITMAP *bitmap;
DBUG_ENTER("_ma_bitmap_flushable");
/*
Not transactional tables are never automaticly flushed and needs no
protection
*/
if (!share->now_transactional)
DBUG_VOID_RETURN;
bitmap= &share->bitmap;
mysql_mutex_lock(&bitmap->bitmap_lock);
if (non_flushable_inc == -1)
{
DBUG_ASSERT((int) bitmap->non_flushable > 0);
DBUG_ASSERT(info->non_flushable_state == 1);
if (--bitmap->non_flushable == 0)
{
/*
We unlock and unpin pages locked and pinned by other threads. It does
not seem to be an issue as all bitmap changes are serialized with
the bitmap's mutex.
*/
_ma_bitmap_unpin_all(share);
if (unlikely(bitmap->waiting_for_non_flushable))
{
DBUG_PRINT("info", ("bitmap flushable waking up flusher"));
mysql_cond_broadcast(&bitmap->bitmap_cond);
}
}
DBUG_PRINT("info", ("bitmap->non_flushable: %u", bitmap->non_flushable));
mysql_mutex_unlock(&bitmap->bitmap_lock);
info->non_flushable_state= 0;
DBUG_VOID_RETURN;
}
DBUG_ASSERT(non_flushable_inc == 1);
DBUG_ASSERT(info->non_flushable_state == 0);
bitmap->waiting_for_flush_all_requested++;
while (unlikely(bitmap->flush_all_requested))
{
/*
Some other thread is waiting for the bitmap to become
flushable. Not the moment to make the bitmap unflushable or more
unflushable; let's rather back off and wait. If we didn't do this, with
multiple writers, there may always be one thread causing the bitmap to
be unflushable and _ma_bitmap_flush_all() would wait for long.
There should not be a deadlock because if our thread increased
non_flushable (and thus _ma_bitmap_flush_all() is waiting for at least
our thread), it is not going to increase it more so is not going to come
here.
*/
DBUG_PRINT("info", ("waiting for bitmap flusher"));
mysql_cond_wait(&bitmap->bitmap_cond, &bitmap->bitmap_lock);
}
bitmap->waiting_for_flush_all_requested--;
bitmap->non_flushable++;
DBUG_PRINT("info", ("bitmap->non_flushable: %u", bitmap->non_flushable));
mysql_mutex_unlock(&bitmap->bitmap_lock);
info->non_flushable_state= 1;
DBUG_VOID_RETURN;
}
/*
Correct bitmap pages to reflect the true allocation
SYNOPSIS
_ma_bitmap_release_unused()
info Maria handle
blocks Bitmap blocks
IMPLEMENTATION
If block->used & BLOCKUSED_TAIL is set:
If block->used & BLOCKUSED_USED is set, then the bits for the
corresponding page is set according to block->empty_space
If block->used & BLOCKUSED_USED is not set, then the bits for
the corresponding page is set to org_bitmap_value;
If block->used & BLOCKUSED_TAIL is not set:
if block->used is not set, the bits for the corresponding page are
cleared
For the first block (head block) the logic is same as for a tail block
Note that we may have 'filler blocks' that are used to split a block
in half; These can be recognized by that they have page_count == 0.
This code also reverse the effect of ma_bitmap_flushable(.., 1);
RETURN
0 ok
1 error (Couldn't write or read bitmap page)
*/
my_bool _ma_bitmap_release_unused(MARIA_HA *info, MARIA_BITMAP_BLOCKS *blocks)
{
MARIA_BITMAP_BLOCK *block= blocks->block, *end= block + blocks->count;
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
uint bits, current_bitmap_value;
DBUG_ENTER("_ma_bitmap_release_unused");
/*
We can skip FULL_HEAD_PAGE (4) as the page was marked as 'full'
when we allocated space in the page
*/
current_bitmap_value= FULL_HEAD_PAGE;
mysql_mutex_lock(&bitmap->bitmap_lock);
/* First handle head block */
if (block->used & BLOCKUSED_USED)
{
DBUG_PRINT("info", ("head page: %lu empty_space: %u",
(ulong) block->page, block->empty_space));
bits= _ma_free_size_to_head_pattern(bitmap, block->empty_space);
if (block->used & BLOCKUSED_USE_ORG_BITMAP)
current_bitmap_value= block->org_bitmap_value;
}
else
bits= block->org_bitmap_value;
if (bits != current_bitmap_value)
{
if (set_page_bits(info, bitmap, block->page, bits))
goto err;
}
else
{
DBUG_ASSERT(current_bitmap_value ==
bitmap_get_page_bits(info, bitmap, block->page));
}
/* Handle all full pages and tail pages (for head page and blob) */
for (block++; block < end; block++)
{
uint page_count;
if (!block->page_count)
continue; /* Skip 'filler blocks' */
page_count= block->page_count;
if (block->used & BLOCKUSED_TAIL)
{
current_bitmap_value= FULL_TAIL_PAGE;
/* The bitmap page is only one page */
page_count= 1;
if (block->used & BLOCKUSED_USED)
{
DBUG_PRINT("info", ("tail page: %lu empty_space: %u",
(ulong) block->page, block->empty_space));
bits= free_size_to_tail_pattern(bitmap, block->empty_space);
if (block->used & BLOCKUSED_USE_ORG_BITMAP)
current_bitmap_value= block->org_bitmap_value;
}
else
bits= block->org_bitmap_value;
/*
The page has all bits set; The following test is an optimization
to not set the bits to the same value as before.
*/
DBUG_ASSERT(current_bitmap_value ==
bitmap_get_page_bits(info, bitmap, block->page));
if (bits != current_bitmap_value)
{
if (set_page_bits(info, bitmap, block->page, bits))
goto err;
}
}
else if (!(block->used & BLOCKUSED_USED) &&
_ma_bitmap_reset_full_page_bits(info, bitmap,
block->page, page_count))
goto err;
}
/* This duplicates ma_bitmap_flushable(-1) except it already has mutex */
if (info->non_flushable_state)
{
DBUG_ASSERT(((int) (bitmap->non_flushable)) > 0);
info->non_flushable_state= 0;
if (--bitmap->non_flushable == 0)
{
_ma_bitmap_unpin_all(info->s);
if (unlikely(bitmap->waiting_for_non_flushable))
{
DBUG_PRINT("info", ("bitmap flushable waking up flusher"));
mysql_cond_broadcast(&bitmap->bitmap_cond);
}
}
}
DBUG_PRINT("info", ("bitmap->non_flushable: %u", bitmap->non_flushable));
mysql_mutex_unlock(&bitmap->bitmap_lock);
DBUG_RETURN(0);
err:
mysql_mutex_unlock(&bitmap->bitmap_lock);
DBUG_RETURN(1);
}
/*
Free full pages from bitmap and pagecache
SYNOPSIS
_ma_bitmap_free_full_pages()
info Maria handle
extents Extents (as stored on disk)
count Number of extents
IMPLEMENTATION
Mark all full pages (not tails) from extents as free, both in bitmap
and page cache.
RETURN
0 ok
1 error (Couldn't write or read bitmap page)
*/
my_bool _ma_bitmap_free_full_pages(MARIA_HA *info, const uchar *extents,
uint count)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
my_bool res;
DBUG_ENTER("_ma_bitmap_free_full_pages");
for (; count--; extents+= ROW_EXTENT_SIZE)
{
pgcache_page_no_t page= uint5korr(extents);
uint page_count= (uint2korr(extents + ROW_EXTENT_PAGE_SIZE) &
~START_EXTENT_BIT);
if (!(page_count & TAIL_BIT))
{
if (page == 0 && page_count == 0)
continue; /* Not used extent */
if (pagecache_delete_pages(info->s->pagecache, &info->dfile, page,
page_count, PAGECACHE_LOCK_WRITE, 1))
DBUG_RETURN(1);
mysql_mutex_lock(&bitmap->bitmap_lock);
res= _ma_bitmap_reset_full_page_bits(info, bitmap, page, page_count);
mysql_mutex_unlock(&bitmap->bitmap_lock);
if (res)
DBUG_RETURN(1);
}
}
DBUG_RETURN(0);
}
/*
Mark in the bitmap how much free space there is on a page
SYNOPSIS
_ma_bitmap_set()
info Maria handler
page Adress to page
head 1 if page is a head page, 0 if tail page
empty_space How much empty space there is on page
RETURN
0 ok
1 error
*/
my_bool _ma_bitmap_set(MARIA_HA *info, pgcache_page_no_t page, my_bool head,
uint empty_space)
{
MARIA_FILE_BITMAP *bitmap= &info->s->bitmap;
uint bits;
my_bool res;
DBUG_ENTER("_ma_bitmap_set");
DBUG_PRINT("enter", ("page: %lu head: %d empty_space: %u",
(ulong) page, head, empty_space));
mysql_mutex_lock(&info->s->bitmap.bitmap_lock);
bits= (head ?
_ma_free_size_to_head_pattern(bitmap, empty_space) :
free_size_to_tail_pattern(bitmap, empty_space));
res= set_page_bits(info, bitmap, page, bits);
mysql_mutex_unlock(&info->s->bitmap.bitmap_lock);
DBUG_RETURN(res);
}
/*
Check that bitmap pattern is correct for a page
NOTES
Used in maria_chk
SYNOPSIS
_ma_check_bitmap_data()
info Maria handler
page_type What kind of page this is
page Adress to page
empty_space Empty space on page
bitmap_pattern Bitmap pattern for page (from bitmap)
RETURN
0 ok
1 error
*/
my_bool _ma_check_bitmap_data(MARIA_HA *info, enum en_page_type page_type,
uint empty_space, uint bitmap_pattern)
{
uint bits;
switch (page_type) {
case UNALLOCATED_PAGE:
case MAX_PAGE_TYPE:
bits= 0;
break;
case HEAD_PAGE:
bits= _ma_free_size_to_head_pattern(&info->s->bitmap, empty_space);
break;
case TAIL_PAGE:
bits= free_size_to_tail_pattern(&info->s->bitmap, empty_space);
break;
case BLOB_PAGE:
bits= FULL_TAIL_PAGE;
break;
default:
bits= 0; /* to satisfy compiler */
DBUG_ASSERT(0);
}
return (bitmap_pattern != bits);
}
/*
Check if the page type matches the one that we have in the bitmap
SYNOPSIS
_ma_check_if_right_bitmap_type()
info Maria handler
page_type What kind of page this is
page Adress to page
bitmap_pattern Store here the pattern that was in the bitmap for the
page. This is always updated.
NOTES
Used in maria_chk
RETURN
0 ok
1 error
*/
my_bool _ma_check_if_right_bitmap_type(MARIA_HA *info,
enum en_page_type page_type,
pgcache_page_no_t page,
uint *bitmap_pattern)
{
if ((*bitmap_pattern= _ma_bitmap_get_page_bits(info, &info->s->bitmap,
page)) > 7)
return 1; /* Couldn't read page */
switch (page_type) {
case HEAD_PAGE:
return *bitmap_pattern < 1 || *bitmap_pattern > 4;
case TAIL_PAGE:
return *bitmap_pattern < 5;
case BLOB_PAGE:
return *bitmap_pattern != 7;
default:
break;
}
DBUG_ASSERT(0);
return 1;
}
/**
@brief create the first bitmap page of a freshly created data file
@param share table's share
@return Operation status
@retval 0 OK
@retval !=0 Error
*/
int _ma_bitmap_create_first(MARIA_SHARE *share)
{
uint block_size= share->bitmap.block_size;
File file= share->bitmap.file.file;
uchar marker[CRC_SIZE];
/*
Next write operation of the page will write correct CRC
if it is needed
*/
int4store(marker, MARIA_NO_CRC_BITMAP_PAGE);
if (mysql_file_chsize(file, block_size - sizeof(marker),
0, MYF(MY_WME)) ||
my_pwrite(file, marker, sizeof(marker),
block_size - sizeof(marker),
MYF(MY_NABP | MY_WME)))
return 1;
share->state.state.data_file_length= block_size;
_ma_bitmap_delete_all(share);
return 0;
}
/**
@brief Pagecache callback to get the TRANSLOG_ADDRESS to flush up to, when a
bitmap page needs to be flushed.
@param page Page's content
@param page_no Page's number (<offset>/<page length>)
@param data_ptr Callback data pointer (pointer to MARIA_SHARE)
@retval TRANSLOG_ADDRESS to flush up to.
*/
static my_bool
flush_log_for_bitmap(PAGECACHE_IO_HOOK_ARGS *args __attribute__ ((unused)))
{
#ifndef DBUG_OFF
const MARIA_SHARE *share= (MARIA_SHARE*)args->data;
#endif
DBUG_ENTER("flush_log_for_bitmap");
DBUG_ASSERT(share->now_transactional);
/*
WAL imposes that UNDOs reach disk before bitmap is flushed. We don't know
the LSN of the last UNDO about this bitmap page, so we flush whole log.
*/
DBUG_RETURN(translog_flush(translog_get_horizon()));
}
/**
@brief Set callbacks for bitmap pages
@note
We don't use pagecache_file_init here, as we want to keep the
code readable
*/
void _ma_bitmap_set_pagecache_callbacks(PAGECACHE_FILE *file,
MARIA_SHARE *share)
{
pagecache_file_set_null_hooks(file);
file->callback_data= (uchar*) share;
file->flush_log_callback= maria_flush_log_for_page_none;
file->post_write_hook= maria_page_write_failure;
if (share->temporary)
{
file->post_read_hook= &maria_page_crc_check_none;
file->pre_write_hook= &maria_page_filler_set_none;
}
else
{
file->post_read_hook= &maria_page_crc_check_bitmap;
if (share->options & HA_OPTION_PAGE_CHECKSUM)
file->pre_write_hook= &maria_page_crc_set_normal;
else
file->pre_write_hook= &maria_page_filler_set_bitmap;
if (share->now_transactional)
file->flush_log_callback= flush_log_for_bitmap;
}
}
/**
Extends data file with zeroes and creates new bitmap pages into page cache.
Writes all bitmap pages in [from, to].
Non-bitmap pages of zeroes are correct as they are marked empty in
bitmaps. Bitmap pages will not be zeroes: they will get their CRC fixed when
flushed. And if there is a crash before flush (so they are zeroes at
restart), a REDO will re-create them in page cache.
*/
static my_bool
_ma_bitmap_create_missing_into_pagecache(MARIA_SHARE *share,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t from,
pgcache_page_no_t to,
uchar *zeroes)
{
pgcache_page_no_t i;
/*
We do not use my_chsize() because there can be a race between when it
reads the physical size and when it writes (assume data_file_length is 10,
physical length is 8 and two data pages are in cache, and here we do a
my_chsize: my_chsize sees physical length is 8, then the two data pages go
to disk then my_chsize writes from page 8 and so overwrites the two data
pages, wrongly).
We instead rely on the filesystem filling gaps with zeroes.
*/
for (i= from; i <= to; i+= bitmap->pages_covered)
{
/**
No need to keep them pinned, they are new so flushable.
@todo but we may want to keep them pinned, as an optimization: if they
are not pinned they may go to disk before the data pages go (so, the
physical pages would be in non-ascending "sparse" order on disk), or the
filesystem may fill gaps with zeroes physically which is a waste of
time.
*/
if (pagecache_write(share->pagecache,
&bitmap->file, i, 0,
zeroes, PAGECACHE_PLAIN_PAGE,
PAGECACHE_LOCK_LEFT_UNLOCKED,
PAGECACHE_PIN_LEFT_UNPINNED,
PAGECACHE_WRITE_DELAY, 0, LSN_IMPOSSIBLE))
goto err;
}
/*
Data pages after data_file_length are full of zeroes but that is allowed
as they are marked empty in the bitmap.
*/
return FALSE;
err:
return TRUE;
}
/**
Creates missing bitmaps when we extend the data file.
At run-time, when we need a new bitmap page we come here; and only one bitmap
page at a time is created.
In some recovery cases we insert at a large offset in the data file, way
beyond state.data_file_length, so can need to create more than one bitmap
page in one go. Known case is:
Start a transaction in Maria;
delete last row of very large table (with delete_row)
do a bulk insert
crash
Then UNDO_BULK_INSERT will truncate table files, and
UNDO_ROW_DELETE will want to put the row back to its original position,
extending the data file a lot: bitmap page*s* in the hole must be created,
or he table would look corrupted.
We need to log REDOs for bitmap creation, consider: we apply a REDO for a
data page, which creates the first data page covered by a new bitmap
not yet created. If the data page is flushed but the bitmap page is not and
there is a crash, re-execution of the REDO will complain about the zeroed
bitmap page (see it as corruption). Thus a REDO is needed to re-create the
bitmap.
@param info Maria handler
@param bitmap Bitmap handler
@param page Last bitmap page to create
@note When this function is called this must be true:
((page + 1) * bitmap->block_size > info->s->state.state.data_file_length)
*/
static my_bool _ma_bitmap_create_missing(MARIA_HA *info,
MARIA_FILE_BITMAP *bitmap,
pgcache_page_no_t page)
{
MARIA_SHARE *share= info->s;
uint block_size= bitmap->block_size;
pgcache_page_no_t from, to;
my_off_t data_file_length= share->state.state.data_file_length;
DBUG_ENTER("_ma_bitmap_create_missing");
/* First (in offset order) bitmap page to create */
if (data_file_length < block_size)
goto err; /* corrupted, should have first bitmap page */
if (page * block_size >= share->base.max_data_file_length)
{
my_errno= HA_ERR_RECORD_FILE_FULL;
goto err;
}
from= (data_file_length / block_size - 1) / bitmap->pages_covered + 1;
from*= bitmap->pages_covered;
/*
page>=from because:
(page + 1) * bs > dfl, and page == k * pc so:
(k * pc + 1) * bs > dfl; k * pc + 1 > dfl / bs; k * pc > dfl / bs - 1
k > (dfl / bs - 1) / pc; k >= (dfl / bs - 1) / pc + 1
k * pc >= ((dfl / bs - 1) / pc + 1) * pc == from.
*/
DBUG_ASSERT(page >= from);
if (share->now_transactional)
{
LSN lsn;
uchar log_data[FILEID_STORE_SIZE + PAGE_STORE_SIZE * 2];
LEX_CUSTRING log_array[TRANSLOG_INTERNAL_PARTS + 1];
page_store(log_data + FILEID_STORE_SIZE, from);
page_store(log_data + FILEID_STORE_SIZE + PAGE_STORE_SIZE, page);
log_array[TRANSLOG_INTERNAL_PARTS + 0].str= log_data;
log_array[TRANSLOG_INTERNAL_PARTS + 0].length= sizeof(log_data);
/*
We don't use info->trn so that this REDO is always executed even though
the UNDO does not reach disk due to crash. This is also consistent with
the fact that the new bitmap pages are not pinned.
*/
if (translog_write_record(&lsn, LOGREC_REDO_BITMAP_NEW_PAGE,
&dummy_transaction_object, info,
(translog_size_t)sizeof(log_data),
TRANSLOG_INTERNAL_PARTS + 1, log_array,
log_data, NULL))
goto err;
/*
No need to flush the log: the bitmap pages we are going to create will
flush it when they go to disk.
*/
}
/*
Last bitmap page. It has special creation: will go to the page cache
only later as we are going to modify it very soon.
*/
bzero(bitmap->map, bitmap->block_size);
bitmap->used_size= 0;
#ifndef DBUG_OFF
/*
Make a copy of the page to be able to print out bitmap changes during
debugging
*/
memcpy(bitmap->map + bitmap->block_size, bitmap->map, bitmap->block_size);
#endif
/* Last bitmap page to create before 'page' */
DBUG_ASSERT(page >= bitmap->pages_covered);
to= page - bitmap->pages_covered;
/*
In run-time situations, from>=to is always false, i.e. we always create
one bitmap at a time ('page').
*/
if ((from <= to) &&
_ma_bitmap_create_missing_into_pagecache(share, bitmap, from, to,
bitmap->map))
goto err;
share->state.state.data_file_length= (page + 1) * bitmap->block_size;
DBUG_RETURN(FALSE);
err:
DBUG_RETURN(TRUE);
}
my_bool _ma_apply_redo_bitmap_new_page(MARIA_HA *info,
LSN lsn __attribute__ ((unused)),
const uchar *header)
{
MARIA_SHARE *share= info->s;
MARIA_FILE_BITMAP *bitmap= &share->bitmap;
my_bool error;
pgcache_page_no_t from, to, min_from;
DBUG_ENTER("_ma_apply_redo_bitmap_new_page");
from= page_korr(header);
to= page_korr(header + PAGE_STORE_SIZE);
DBUG_PRINT("info", ("from: %lu to: %lu", (ulong)from, (ulong)to));
if ((from > to) ||
(from % bitmap->pages_covered) != 0 ||
(to % bitmap->pages_covered) != 0)
{
error= TRUE; /* corrupted log record */
goto err;
}
min_from= (share->state.state.data_file_length / bitmap->block_size - 1) /
bitmap->pages_covered + 1;
min_from*= bitmap->pages_covered;
if (from < min_from)
{
DBUG_PRINT("info", ("overwrite bitmap pages from %lu", (ulong)min_from));
/*
We have to overwrite. It could be that there was a bitmap page in
memory, covering a data page which went to disk, then crash: the
bitmap page is now full of zeros and is ==min_from, we have to overwrite
it with correct checksum.
*/
}
share->state.changed|= STATE_CHANGED;
bzero(info->buff, bitmap->block_size);
if (!(error=
_ma_bitmap_create_missing_into_pagecache(share, bitmap, from, to,
info->buff)))
share->state.state.data_file_length= (to + 1) * bitmap->block_size;
err:
DBUG_RETURN(error);
}