In the patch for BUG#21842, the code for handling old rows events were
refactored. There were a bug in the refactored code (possibly introduced
after the patch for BUG#21842) that caused caused the refactored old events
to read a columns bitmap after image even though there is no such bitmap
for old events. As a result, the reading got out of sync, and started reading
invalid data.
This patch removes all trace of the after image column bitmap from the refactored
old events and removes functions that are no longer needed because they are empty.
This patch has two purposes:
(1) To refactor the code so that
{Write|Update|Delete}_rows_log_event_old does not use code from
{Write|Update|Delete}_rows_log_event. Before refactoring there
was the following problem: whenever we modifed the code for new
events, it affected the old events. This is bad, as it makes
maintainance difficult. After refactoring, we can safely edit the
new code without affecting old events. So, if we for instance
modify the binary format of new events, we no longer need to worry
about how the new code reads old events.
(2) To fix BUG#31581.
These two objectives are reached by the following changes:
- Merged Rows_log_event into Old_rows_log_event and
{Write|Update|Delete}_rows_log_event into
{Write|Update|Delete}_rows_log_event_old.
- Fixed the bug by replacing {WRITE|UPDATE|DELETE}_ROWS_EVENT by
PRE_GA_{WRITE|UPDATE|DELETE}_ROWS_EVENT.
- Added comments to log_event_old.h
(This patch is identical to the previously committed patch which was
a collapse of three changesets, except that it adds assert(0) to
constructors for old types of row log events that should never be
called.)
using TPC-B):
Problem: A RBR event can contain incomplete row data (only key value and
fields which have been changed). In that case, when the row is unpacked
into record and written to a table, the missing fields get incorrect NULL
values leading to master-slave inconsistency.
Solution: Use values found in slave's table for columns which are not given
in the rows event. The code for writing a single row uses the following
algorithm:
1. unpack row_data into table->record[0],
2. try to insert record,
3. if duplicate record found, fetch it into table->record[0],
4. unpack row_data into table->record[0],
5. write table->record[0] into the table.
Where row_data is the row as stored in the data area of a rows event.
Thus:
a) unpacking of row_data happens at the time when row is written into
a table,
b) when unpacking (in step 4), only columns present in row_data are
overwritten - all other columns remain as they were found in the table.
Since all data needed for the above algorithm is stored inside
Rows_log_event class, functions which locate and write rows are turned
into methods of that class.
replace_record() -> Rows_log_event::write_row()
find_and_fetch_row() -> Rows_log_event::find_row()
Both methods take row data from event's data buffer - the row being
processed is pointed by m_curr_row. They unpack the data as needed into
table's record buffers record[0] or record[1]. When row is unpacked,
m_curr_row_end is set to point at next row in the data buffer.
Other changes introduced in this changeset:
- Change signature of unpack_row(): don't report errors and don't
setup table's rw_set here. Errors can happen only when setting default
values in prepare_record() function and are detected there.
- In Rows_log_event and derived classes, don't pass arguments to
the execution primitives (do_...() member functions) but use class
members instead.
- Move old row handling code into log_event_old.cc to be used by
*_rows_log_event_old classes.
Also, a new test rpl_ndb_2other is added which tests basic replication
from master using ndb tables to slave storing the same tables using
(possibly) different engine (myisam,innodb).
Test is based on existing tests rpl_ndb_2myisam and rpl_ndb_2innodb.
However, these tests doesn't work for various reasons and currently are
disabled (see BUG#19227).
The new test differs from the ones it is based on as follows:
1. Single test tests replication with different storage engines on slave
(myisam, innodb, ndb).
2. Include file extra/rpl_tests/rpl_ndb_2multi_eng.test containing
original tests is replaced by extra/rpl_tests/rpl_ndb_2multi_basic.test
which doesn't contain tests using partitioned tables as these don't work
currently. Instead, it tests replication to a slave which has more or
less columns than master.
3. Include file include/rpl_multi_engine3.inc is replaced with
include/rpl_multi_engine2.inc. The later differs by performing slightly
different operations (updating more than one row in the table) and
clearing table with "TRUNCATE TABLE" statement instead of "DELETE FROM"
as replication of "DELETE" doesn't work well in this setting.
4. Slave must use option --log-slave-updates=0 as otherwise execution of
replication events generated by ndb fails if table uses a different
storage engine on slave (see BUG#29569).
The following type conversions was done:
- Changed byte to uchar
- Changed gptr to uchar*
- Change my_string to char *
- Change my_size_t to size_t
- Change size_s to size_t
Removed declaration of byte, gptr, my_string, my_size_t and size_s.
Following function parameter changes was done:
- All string functions in mysys/strings was changed to use size_t
instead of uint for string lengths.
- All read()/write() functions changed to use size_t (including vio).
- All protocoll functions changed to use size_t instead of uint
- Functions that used a pointer to a string length was changed to use size_t*
- Changed malloc(), free() and related functions from using gptr to use void *
as this requires fewer casts in the code and is more in line with how the
standard functions work.
- Added extra length argument to dirname_part() to return the length of the
created string.
- Changed (at least) following functions to take uchar* as argument:
- db_dump()
- my_net_write()
- net_write_command()
- net_store_data()
- DBUG_DUMP()
- decimal2bin() & bin2decimal()
- Changed my_compress() and my_uncompress() to use size_t. Changed one
argument to my_uncompress() from a pointer to a value as we only return
one value (makes function easier to use).
- Changed type of 'pack_data' argument to packfrm() to avoid casts.
- Changed in readfrm() and writefrom(), ha_discover and handler::discover()
the type for argument 'frmdata' to uchar** to avoid casts.
- Changed most Field functions to use uchar* instead of char* (reduced a lot of
casts).
- Changed field->val_xxx(xxx, new_ptr) to take const pointers.
Other changes:
- Removed a lot of not needed casts
- Added a few new cast required by other changes
- Added some cast to my_multi_malloc() arguments for safety (as string lengths
needs to be uint, not size_t).
- Fixed all calls to hash-get-key functions to use size_t*. (Needed to be done
explicitely as this conflict was often hided by casting the function to
hash_get_key).
- Changed some buffers to memory regions to uchar* to avoid casts.
- Changed some string lengths from uint to size_t.
- Changed field->ptr to be uchar* instead of char*. This allowed us to
get rid of a lot of casts.
- Some changes from true -> TRUE, false -> FALSE, unsigned char -> uchar
- Include zlib.h in some files as we needed declaration of crc32()
- Changed MY_FILE_ERROR to be (size_t) -1.
- Changed many variables to hold the result of my_read() / my_write() to be
size_t. This was needed to properly detect errors (which are
returned as (size_t) -1).
- Removed some very old VMS code
- Changed packfrm()/unpackfrm() to not be depending on uint size
(portability fix)
- Removed windows specific code to restore cursor position as this
causes slowdown on windows and we should not mix read() and pread()
calls anyway as this is not thread safe. Updated function comment to
reflect this. Changed function that depended on original behavior of
my_pwrite() to itself restore the cursor position (one such case).
- Added some missing checking of return value of malloc().
- Changed definition of MOD_PAD_CHAR_TO_FULL_LENGTH to avoid 'long' overflow.
- Changed type of table_def::m_size from my_size_t to ulong to reflect that
m_size is the number of elements in the array, not a string/memory
length.
- Moved THD::max_row_length() to table.cc (as it's not depending on THD).
Inlined max_row_length_blob() into this function.
- More function comments
- Fixed some compiler warnings when compiled without partitions.
- Removed setting of LEX_STRING() arguments in declaration (portability fix).
- Some trivial indentation/variable name changes.
- Some trivial code simplifications:
- Replaced some calls to alloc_root + memcpy to use
strmake_root()/strdup_root().
- Changed some calls from memdup() to strmake() (Safety fix)
- Simpler loops in client-simple.c
configuration with HAVE_REPLICATION undefined, which causes the
*_rows_log_event_old classes to only have a default constructor. This
generates an error on some platforms, since the base classes does
not have a default constructor defined.
Updating signatures of do_prepare_row() for classes above, since
signatures in base classes changed.
Taking code from before BUG#22583 and incorporating as events to be able
to read old events. Also incorporating old pack and unpack functions
into patch.
