mariadb/mysql-test/r/mysqlbinlog_base64.result
unknown 6f6951d218 Fix for BUG#25628: "mysqlbinlog crashes while processing binary logs".
mysqlbinlog prints all row-based events of a single statement as a
single "BINLOG" statement containing the concatenation of those events.
Big (i.e. >64k) concatenations of row-based events
(e.g. Write_rows_log_event) caused mysqlbinlog's IO_CACHE to overflow
to a temporary file but the IO_CACHE had not been inited with
open_cached_file(), so it tried to create a temporary file in
an uninitialized directory (thus failing to create, then to write;
some OS errors were printed, and it finally segfaulted).
After fixing this, it appeared that mysqlbinlog was printing only
a piece of big concatenations of row-based events (it printed
at most the size of the IO_CACHE's buffer i.e. 64k); that caused data
loss at restore. We fix and test that.
Last, mysqlbinlog's printouts looked a bit strange with the informative
header (#-prefixed) of groupped Rows_log_event all on one line,
so we insert \n. After that, a small bug in the --hexdump code appeared
(only if the string to hex-print had its length a multiple of 16),
we fix it.



client/mysqlbinlog.cc:
  if we write to IO_CACHE more than can fit into its memory buffer,
  it will try to overflow into a file; for that to work, IO_CACHE
  must be inited via open_cached_file().
mysql-test/r/mysqlbinlog_base64.result:
  result update
mysql-test/t/mysqlbinlog_base64.test:
  test for BUG#25628: test that mysqlbinlog does not have OS errors
  with big concatenations of row-based events
  (e.g. Write_rows_log_event), and prints those concatenations entirely
  (testing by piping the output back into the server and comparing data).
mysys/mf_iocache2.c:
  my_b_copy_to_file() had a problem: it assumed that bytes_in_cache
  are all the bytes to copy to the file, while it only tells how many
  bytes are in the buffer; so the code forgot to copy what had already
  overflown into a temporary file. Thus any big event was printed only
  partially by mysqlbinlog (loss of data at restore). The fix is
  inspired by MYSQL_BIN_LOG::write_cache().
sql/log_event.cc:
  Several Table_map/Write_rows events generated by one single statement
  get groupped together in mysqlbinlog's output; it printed things like
  #718 7:30:51 server id 12 end_log_pos 988      Write_rows: table id 17#718 7:30:51 server id 12 #718 7:30:51 server id 12  end_log_pos 988      Write_rows: table id 17#718 7:30:51 server id 12 end_log_pos 1413 <cut>
  It didn't look nice to have printouts glued like this without line
  breaks. Adding a line break.
  Doing this, when using --hexdump the result was:
  #718 7:30:51 server id 12 end_log_pos 988
  # <hexdump output>
  # Write_rows: table id 17
  which is correct; unfortunately if the hex dump had only full lines
  (i.e the string to print in hex had its length a multiple of 16),
  then the # in front of Write_rows was not printed. Fixed.
sql/log_event.h:
  removing strcpy() (one less function call).
  If we write to IO_CACHE more than can fit into its memory buffer,
  it will try to overflow into a file; for that to work, IO_CACHE
  must be inited via open_cached_file().
  open_cached_file(), like init_io_cache(), can fail; we make sure to
  catch this constructor's problem via the init_ok() method.
2007-02-23 22:23:54 +01:00

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create table t1 (a int);
insert into t1 values (1);
insert into t1 values (2);
insert into t1 values (3);
update t1 set a=a+2 where a=2;
update t1 set a=a+2 where a=3;
create table t2 (word varchar(20));
load data infile '../std_data_ln/words.dat' into table t2;
flush logs;
drop table t1;
drop table t2;
select * from t1;
a
1
4
5
select * from t2;
word
Aarhus
Aaron
Ababa
aback
abaft
abandon
abandoned
abandoning
abandonment
abandons
Aarhus
Aaron
Ababa
aback
abaft
abandon
abandoned
abandoning
abandonment
abandons
abase
abased
abasement
abasements
abases
abash
abashed
abashes
abashing
abasing
abate
abated
abatement
abatements
abater
abates
abating
Abba
abbe
abbey
abbeys
abbot
abbots
Abbott
abbreviate
abbreviated
abbreviates
abbreviating
abbreviation
abbreviations
Abby
abdomen
abdomens
abdominal
abduct
abducted
abduction
abductions
abductor
abductors
abducts
Abe
abed
Abel
Abelian
Abelson
Aberdeen
Abernathy
aberrant
aberration
flush logs;
drop table t2;
create table t2 (word varchar(20));
load data infile '../std_data_ln/words.dat' into table t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
insert into t2 select * from t2;
select count(*) from t2;
count(*)
35840
flush logs;
select count(*) from t2;
count(*)
35840
drop table t1;
drop table t2;