Also fixes:
MDEV-30982 UBSAN: runtime error: null pointer passed as argument 2, which is declared to never be null in my_strnncoll_binary on DELETE
Calling memcmp() with a NULL pointer is undefined behaviour
according to the C standard, even if the length argument is 0.
Adding tests for length==0 before calling memcmp() into:
- my_strnncoll_binary()
- my_strnncoll_8bit_bin
This is a non-functional change. It changes the way how case folding data
and weight data (for simple Unicode collations) are stored:
- Removing data types MY_UNICASE_CHARACTER, MY_UNICASE_INFO
- Using data types MY_CASEFOLD_CHARACTER, MY_CASEFOLD_INFO instead.
This patch changes simple Unicode collations in a similar way
how MDEV-30695 previously changed Asian collations.
No new MTR tests are needed. The underlying code is thoroughly
covered by a number of ctype_*_ws.test and ctype_*_casefold.test
files, which were added recently as a preparation
for this change.
Old and new Unicode data layout
-------------------------------
Case folding data is now stored in separate tables
consisting of MY_CASEFOLD_CHARACTER elements with two members:
typedef struct casefold_info_char_t
{
uint32 toupper;
uint32 tolower;
} MY_CASEFOLD_CHARACTER;
while weight data (for simple non-UCA collations xxx_general_ci
and xxx_general_mysql500_ci) is stored in separate arrays of
uint16 elements.
Before this change case folding data and simple weight data were
stored together, in tables of the following elements with three members:
typedef struct unicase_info_char_st
{
uint32 toupper;
uint32 tolower;
uint32 sort; /* weights for simple collations */
} MY_UNICASE_CHARACTER;
This data format was redundant, because weights (the "sort" member) were
needed only for these two simple Unicode collations:
- xxx_general_ci
- xxx_general_mysql500_ci
Adding case folding information for Unicode-14.0.0 using the old
format would waste memory without purpose.
Detailed changes
----------------
- Changing the underlying data types as described above
- Including unidata-dump.c into the sources.
This program was earlier used to dump UnicodeData.txt
(e.g. https://www.unicode.org/Public/14.0.0/ucd/UnicodeData.txt)
into MySQL / MariaDB source files.
It was originally written in 2002, but has not been distributed yet
together with MySQL / MariaDB sources.
- Removing the old format Unicode data earlier dumped from UnicodeData.txt
(versions 3.0.0 and 5.2.0) from ctype-utf8.c.
Adding Unicode data in the new format into separate header files,
to maintain the code easier:
- ctype-unicode300-casefold.h
- ctype-unicode300-casefold-tr.h
- ctype-unicode300-general_ci.h
- ctype-unicode300-general_mysql500_ci.h
- ctype-unicode520-casefold.h
- Adding a new file ctype-unidata.c as an aggregator for
the header files listed above.
- Adding a new argument "flag" to MY_COLLATION_HANDLER::strnncollsp_nchars()
and a flag MY_STRNNCOLLSP_NCHARS_EMULATE_TRIMMED_TRAILING_SPACES.
The flag defines if strnncollsp_nchars() should emulate trailing spaces
which were possibly trimmed earlier (e.g. in InnoDB CHAR compression).
This is important for NOPAD collations.
For example, with this input:
- str1= 'a ' (Latin letter a followed by one space)
- str2= 'a ' (Latin letter a followed by two spaces)
- nchars= 3
if the flag is given, strnncollsp_nchars() will virtually restore
one trailing space to str1 up to nchars (3) characters and compare two
strings as equal:
- str1= 'a ' (one extra trailing space emulated)
- str2= 'a ' (as is)
If the flag is not given, strnncollsp_nchars() does not add trailing
virtual spaces, so in case of a NOPAD collation, str1 will be compared
as less than str2 because it is shorter.
- Field_string::cmp_prefix() now passes the new flag.
Field_varstring::cmp_prefix() and Field_blob::cmp_prefix() do
not pass the new flag.
- The branch in cmp_whole_field() in storage/innobase/rem/rem0cmp.cc
(which handles the CHAR data type) now also passed the new flag.
- Fixing UCA collations to respect the new flag.
Other collations are possibly also affected, however
I had no success in making an SQL script demonstrating the problem.
Other collations will be extended to respect this flags in a separate
patch later.
- Changing the meaning of the last parameter of Field::cmp_prefix()
from "number of bytes" (internal length)
to "number of characters" (user visible length).
The code calling cmp_prefix() from handler.cc was wrong.
After this change, the call in handler.cc became correct.
The code calling cmp_prefix() from key_rec_cmp() in key.cc
was adjusted according to this change.
- Old strnncollsp_nchar() related tests in unittest/strings/strings-t.c
now pass the new flag.
A few new tests also were added, without the flag.
This is a non-functional change and should not change the server behavior.
Casefolding information is now stored in items of a new data type MY_CASEFOLD_CHARACTER:
typedef struct casefold_info_char_t
{
uint32 toupper;
uint32 tolower;
} MY_CASEFOLD_CHARACTER;
Before this change, casefolding tables for Asian collations were stored in:
typedef struct unicase_info_char_st
{
uint32 toupper;
uint32 tolower;
uint32 sort;
} MY_UNICASE_CHARACTER;
The "sort" member was not used in the code handling Asian collations,
it only wasted space.
(it's only used by Unicode _general_ci and _general_mysql500_ci collations).
Unicode collations (at least UCA and _bin) should also be refactored later,
but under terms of a separate task.
String length growth during upper/lower conversion
in Unicode collations depends only on the underlying MY_UNICASE_INFO
used in the collation.
Maintaining a separate member CHARSET_INFO::caseup_multiply and
CHARSET_INFO::casedn_multiply duplicated this information
and caused bugs like this (when MY_UNICASE_INFO and case??_multiply
when out of sync because of incomplete CHARSET_INFO initialization).
Fix:
Changing CHARSET_INFO::caseup_multiply and CHARSET_INFO::casedn_multiply
from members to virtual functions.
The virtual functions in Unicode collations calculate case conversion
growth factors from the MY_UNICASE_INFO. This guarantees that the growth
factors are always in sync with the MY_UNICASE_INFO.
- Added one neutral and 22 tailored (language specific) collations based on
Unicode Collation Algorithm version 14.0.0.
Collations were added for Unicode character sets
utf8mb3, utf8mb4, ucs2, utf16, utf32.
Every tailoring was added with four accent and case
sensitivity flag combinations, e.g:
* utf8mb4_uca1400_swedish_as_cs
* utf8mb4_uca1400_swedish_as_ci
* utf8mb4_uca1400_swedish_ai_cs
* utf8mb4_uca1400_swedish_ai_ci
and their _nopad_ variants:
* utf8mb4_uca1400_swedish_nopad_as_cs
* utf8mb4_uca1400_swedish_nopad_as_ci
* utf8mb4_uca1400_swedish_nopad_ai_cs
* utf8mb4_uca1400_swedish_nopad_ai_ci
- Introducing a conception of contextually typed named collations:
CREATE DATABASE db1 CHARACTER SET utf8mb4;
CREATE TABLE db1.t1 (a CHAR(10) COLLATE uca1400_as_ci);
The idea is that there is no a need to specify the character set prefix
in the new collation names. It's enough to type just the suffix
"uca1400_as_ci". The character set is taken from the context.
In the above example script the context character set is utf8mb4.
So the CREATE TABLE will make a column with the collation
utf8mb4_uca1400_as_ci.
Short collations names can be used in any parts of the SQL syntax
where the COLLATE clause is understood.
- New collations are displayed only one time
(without character set combinations) by these statements:
SELECT * FROM INFORMATION_SCHEMA.COLLATIONS;
SHOW COLLATION;
For example, all these collations:
- utf8mb3_uca1400_swedish_as_ci
- utf8mb4_uca1400_swedish_as_ci
- ucs2_uca1400_swedish_as_ci
- utf16_uca1400_swedish_as_ci
- utf32_uca1400_swedish_as_ci
have just one entry in INFORMATION_SCHEMA.COLLATIONS and SHOW COLLATION,
with COLLATION_NAME equal to "uca1400_swedish_as_ci", which is the suffix
without the character set name:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+
| COLLATION_NAME |
+-----------------------+
| uca1400_swedish_as_ci |
+-----------------------+
Note, the behaviour of old collations did not change.
Non-unicode collations (e.g. latin1_swedish_ci) and
old UCA-4.0.0 collations (e.g. utf8mb4_unicode_ci)
are still displayed with the character set prefix, as before.
- The structure of the table INFORMATION_SCHEMA.COLLATIONS was changed.
The NOT NULL constraint was removed from these columns:
- CHARACTER_SET_NAME
- ID
- IS_DEFAULT
and from the corresponding columns in SHOW COLLATION.
For example:
SELECT COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATIONS
WHERE COLLATION_NAME LIKE '%uca1400_swedish_as_ci';
+-----------------------+--------------------+------+------------+
| COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------+--------------------+------+------------+
| uca1400_swedish_as_ci | NULL | NULL | NULL |
+-----------------------+--------------------+------+------------+
The NULL value in these columns now means that the collation
is applicable to multiple character sets.
The behavioir of old collations did not change.
Make sure your client programs can handle NULL values in these columns.
- The structure of the table
INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY was changed.
Three new NOT NULL columns were added:
- FULL_COLLATION_NAME
- ID
- IS_DEFAULT
New collations have multiple entries in COLLATION_CHARACTER_SET_APPLICABILITY.
The column COLLATION_NAME contains the collation name without the character
set prefix. The column FULL_COLLATION_NAME contains the collation name with
the character set prefix.
Old collations have full collation name in both FULL_COLLATION_NAME and
COLLATION_NAME.
SELECT COLLATION_NAME, FULL_COLLATION_NAME, CHARACTER_SET_NAME, ID, IS_DEFAULT
FROM INFORMATION_SCHEMA.COLLATION_CHARACTER_SET_APPLICABILITY
WHERE FULL_COLLATION_NAME RLIKE '^(utf8mb4|latin1).*swedish.*ci$';
+-----------------------------+-------------------------------------+--------------------+------+------------+
| COLLATION_NAME | FULL_COLLATION_NAME | CHARACTER_SET_NAME | ID | IS_DEFAULT |
+-----------------------------+-------------------------------------+--------------------+------+------------+
| latin1_swedish_ci | latin1_swedish_ci | latin1 | 8 | Yes |
| latin1_swedish_nopad_ci | latin1_swedish_nopad_ci | latin1 | 1032 | |
| utf8mb4_swedish_ci | utf8mb4_swedish_ci | utf8mb4 | 232 | |
| uca1400_swedish_ai_ci | utf8mb4_uca1400_swedish_ai_ci | utf8mb4 | 2368 | |
| uca1400_swedish_as_ci | utf8mb4_uca1400_swedish_as_ci | utf8mb4 | 2370 | |
| uca1400_swedish_nopad_ai_ci | utf8mb4_uca1400_swedish_nopad_ai_ci | utf8mb4 | 2372 | |
| uca1400_swedish_nopad_as_ci | utf8mb4_uca1400_swedish_nopad_as_ci | utf8mb4 | 2374 | |
+-----------------------------+-------------------------------------+--------------------+------+------------+
- Other INFORMATION_SCHEMA queries:
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.PARAMETERS;
SELECT TABLE_COLLATION FROM INFORMATION_SCHEMA.TABLES;
SELECT DEFAULT_COLLATION_NAME FROM INFORMATION_SCHEMA.SCHEMATA;
SELECT COLLATION_NAME FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.EVENTS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.EVENTS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.ROUTINES;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT DATABASE_COLLATION FROM INFORMATION_SCHEMA.TRIGGERS;
SELECT COLLATION_CONNECTION FROM INFORMATION_SCHEMA.VIEWS;
display full collation names, including character sets prefix,
for all collations, including new collations.
Corresponding SHOW commands also display full collation names
in collation related columns:
SHOW CREATE TABLE t1;
SHOW CREATE DATABASE db1;
SHOW TABLE STATUS;
SHOW CREATE FUNCTION f1;
SHOW CREATE PROCEDURE p1;
SHOW CREATE EVENT ev1;
SHOW CREATE TRIGGER tr1;
SHOW CREATE VIEW;
These INFORMATION_SCHEMA queries and SHOW statements may change in
the future, to display show collation names.
This patch also fixes:
MDEV-27690 Crash on `CHARACTER SET csname COLLATE DEFAULT` in column definition
MDEV-27853 Wrong data type on column `COLLATE DEFAULT` and table `COLLATE some_non_default_collation`
MDEV-28067 Multiple conflicting column COLLATE clauses are not rejected
MDEV-28118 Wrong collation of `CAST(.. AS CHAR COLLATE DEFAULT)`
MDEV-28119 Wrong column collation on MODIFY + CONVERT
This change removed 68 explict strlen() calls from the code.
The following renames was done to ensure we don't use the old names
when merging code from earlier releases, as using the new variables
for print function could result in crashes:
- charset->csname renamed to charset->cs_name
- charset->name renamed to charset->coll_name
Almost everything where mechanical changes except:
- Changed to use the new Protocol::store(LEX_CSTRING..) when possible
- Changed to use field->store(LEX_CSTRING*, CHARSET_INFO*) when possible
- Changed to use String->append(LEX_CSTRING&) when possible
Other things:
- There where compiler issues with ensuring that all character set names
points to the same string: gcc doesn't allow one to use integer constants
when defining global structures (constant char * pointers works fine).
To get around this, I declared defines for each character set name
length.
This follows up commit
commit 94a520ddbe and
commit 7c5519c12d.
After these changes, the default test suites on a
cmake -DWITH_UBSAN=ON build no longer fail due to passing
null pointers as parameters that are declared to never be null,
but plenty of other runtime errors remain.
This patch ensures that all identical character sets shares the same
cs->csname.
This allows us to replace strcmp() in my_charset_same() with comparisons
of pointers. This fixes a long standing performance issue that could cause
as strcmp() for every item sent trough the protocol class to the end user.
One consequence of this patch is that we don't allow one to add a character
definition in the Index.xml file that changes the csname of an existing
character set. This is by design as changing character set names of existing
ones is extremely dangerous, especially as some storage engines just records
character set numbers.
As we now have a hash over character set's csname, we can in the future
use that for faster access to a specific character set. This could be done
by changing the hash to non unique and use the hash to find the next
character set with same csname.
The code did not take into account that:
- U+005C (backslash) can occupy more than mbminlen characters (e.g. in sjis)
- Some character sets do not have a code for U+005C (e.g. swe7)
Adding a new function my_wc_to_printable into MY_CHARSET_HANDLER to
cover all special cases easier.
After the MDEV-13118 fix there's no code in the server that
wants caseup/casedn to change the argument in place for simple
charsets. Let's remove this logic and always return the result in a
new string for all charsets, both simple and complex.
1. Removing the optimization that *some* character sets used in casedn()
and caseup(), which allowed (and required) to change the case in-place,
overwriting the string passed as the "src" argument.
Now all CHARSET_INFO's work in the same way:
non of them change the source string in-place, all of them now convert
case from the source string to the destination string, leaving
the source string untouched.
2. Adding "const" qualifier to the "char *src" parameter
to caseup() and casedn().
3. Removing duplicate implementations in ctype-mb.c.
Now both caseup() and casedn() implementations for all CJK character sets
use internally the same function my_casefold_mb()
(the former my_casefold_mb_varlen()).
4. Removing the "unused" attribute from parameters of some my_case{up|dn}_xxx()
implementations, as the affected parameters are now *used* in the code.
Previously these parameters were used only in DBUG_ASSERT().
- Removing the "diff_if_only_endspace_difference" argument from
MY_COLLATION_HANDLER::strnncollsp(), my_strnncollsp_simple(),
as well as in the function template MY_FUNCTION_NAME(strnncollsp)
in strcoll.ic
- Removing the "diff_if_only_space_different" from ha_compare_text(),
hp_rec_key_cmp().
- Adding a new function my_strnncollsp_padspace_bin() and reusing
it instead of duplicate code pieces in my_strnncollsp_8bit_bin(),
my_strnncollsp_latin1_de(), my_strnncollsp_tis620(),
my_strnncollsp_utf8_cs().
- Adding more tests for better coverage of the trailing space handling.
- Removing the unused definition of HA_END_SPACE_ARE_EQUAL
Note, the patch for MDEV-8661 unintentionally fixed MDEV-8694 as well,
as a side effect. Adding a real clear fix: implementing
Item_func_like::propagate_equal_fields() with comments.
This is a pre-requisite patch for:
- MDEV-8433 Make field<'broken-string' use indexes
- MDEV-8625 Bad result set with ignorable characters when using a prefix key
- MDEV-8626 Bad result set with contractions when using a prefix key
Adding a new virtual function MY_CHARSET_HANDLER::copy_abort().
Moving character set specific code into the correspoding implementations
(for simple, multi-byte and mbmaxlen>1 character sets).
The problem was that my_hash_sort didn't properly delete end-space characters properly, so strings that should compare
identically was seen as different strings. (Space was handled correctly, but not NBSP)
This caused duplicate key errors when a heap table was converted to Aria as part of overflow in group by.
Fixed by removing all characters that compares as end space when creating a hash.
Other things:
- Fixed that --sorted_results also works for errors in mysqltest.
- Speed up hash by not comparing strings that has different hash.
- Speed up many my_hash_sort functions by using registers to calculate hash instead of pointers.
This was previously done for some functions, but not for all.
- Made a macro of the hash function, to simplify code and to be able to experiment with new hash functions.
client/mysqltest.cc:
Fixed that --sorted_results also works for error messages.
mysql-test/r/ctype_partitions.result:
New test to ensure that partitions on hash works
mysql-test/suite/multi_source/gtid.result:
Updated result
mysql-test/suite/multi_source/gtid.test:
Test that --sorted_result works for error messages
mysql-test/suite/multi_source/gtid_ignore_duplicates.result:
Updated result
mysql-test/suite/multi_source/gtid_ignore_duplicates.test:
Updated result
mysql-test/suite/multi_source/load_data.result:
Updated result
mysql-test/suite/multi_source/load_data.test:
Updated result
mysql-test/t/ctype_partitions.test:
New test to ensure that partitions on hash works
storage/heap/hp_write.c:
Speed up hash by not comparing strings that has different hash.
storage/maria/ma_check.c:
Extra debug
strings/ctype-bin.c:
Use macro for hash function
strings/ctype-latin1.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-mb.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-simple.c:
Use macro for hash function
Use same variable names as in other my_hash_sort functions.
Update my_hash_sort_simple() to properly remove end space (patch by Bar)
strings/ctype-uca.c:
Ignore duplicated space inside strings and end space in my_hash_sort_uca(). This fixed MDEV-6255
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-ucs2.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/ctype-utf8.c:
Use macro for hash function
Use registers to calculate hash (speedup)
strings/strings_def.h:
Made a macro of the hash function, to simplify code and to be able to experiment with new hash functions.
~40% bugfixed(*) applied
~40$ bugfixed reverted (incorrect or we're not buggy)
~20% bugfixed applied, despite us being not buggy
(*) only changes in the server code, e.g. not cmakefiles
Reduced number of my_hash_sort_bin() calls from 4 to 1 per query.
Reduced number of memory accesses done by my_hash_sort_bin().
Details:
- let MDL subsystem use pre-calculated hash value for hash
inserts and deletes
- let table cache use pre-calculated MDL hash value
- MDL namespace is excluded from hash value calculation, so that
hash value can be used by table cache as is
- hash value for MDL is calculated as resulting hash value + MDL
namespace
- extended hash implementation to accept user defined hash function
