(From: gkodinov)
Use and int * where possible to scan for trailing space in a
string instead of always iterating char-by-char.
Using the attached benchmark file on a 32 bit Intel Core 2
Duo CPU I've got 43485 ms run with the fix compared to 44373
without it.
Backported to 5.6.0 (next-mr-runtime)
6.0-codebase revid: 2476.1362.1
Problem:
HASH indexes on VARCHAR columns with binary collations did not ignore trailing spaces from strings before comparisons. This could result in duplicate records being successfully inserted into a MEMORY table with unique key constraints.
As a direct consequence of the above, internal MEMORY tables used for GROUP BY calculation in testcases for bug #27643 contained duplicate rows which resulted in duplicate key errors when converting those temporary tables to MyISAM. Additionally, that error was incorrectly converted to the 'table is full' error.
Solution:
- ignore trailing spaces in VARCHAR fields with binary collations when calculating hashes.
- return a proper error from create_myisam_from_heap() when conversion fails.
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
- Removed not used variables and functions
- Added #ifdef around code that is not used
- Renamed variables and functions to avoid conflicts
- Removed some not used arguments
Fixed some class/struct warnings in ndb
Added define IS_LONGDATA() to simplify code in libmysql.c
I did run gcov on the changes and added 'purecov' comments on almost all lines that was not just variable name changes
Problem: SHOW CREATE TABLE printed garbage in table
name for tables having TURKISH I
(i.e. LATIN CAPITABLE LETTER I WITH DOT ABOVE)
when lower-case-table-name=1.
Reason: In some cases during lower/upper conversion in utf8,
the result string can be shorter the original string
(including the above letter). Old implementation of caseup_str()
and casedn_str() didn't handle the result length properly,
assuming that length cannot change.
This fix changes the result type of cs->cset->casedn_str()
and cs->cset->caseup_str() from VOID to UINT, to return
the result length, as well as put '\0' terminator on a
proper place.
Also, my_caseup_str_utf8() and my_casedn_str_utf8() were
rewritten not to use strlen() for performance purposes.
It was done with help of adding of new functions - my_utf8_uni_no_range()
and my_uni_utf8_no_range() - for null terminated strings.
The problem was that when converting a string to an exact number,
rounding didn't work, because conversion didn't understand
approximate numbers notation.
Fix: a new function for string-to-number conversion was implemented,
which is aware of approxinate number notation (with decimal point
and exponent, e.g. -19.55e-1)
A prerequisite for several fulltext and XML bugs.
MY_CHARSET_HANDLER now has a new function "ctype"
to detect a type of the next character in a string
(i.e. digit, letter, space, punctuation, control, etc),
which now works correctly for both 8bit and multibyte charsets.
Previously only 8bit charsets worked correctly,
while any multibyte character was considered as letter
in multibyte charsets.
Many files:
Adding new function
Makefile.am:
Adding build rules for uctypedump,
a dump tool to create my_uctype.h
using Unicode Character Database file.
m_ctype.h:
Adding declaration of my_uni_ctype,
ctype data for Unicode.
Adding new member into MY_CHARSET_HANDLER
Makefile.am:
Adding my_uctype.h into noinst_HEADERS
my_uctype.h, uctypedump.c:
new files:
ctype data for unicode,
and the tool to generate it from
a Unicode Character Database file.
into parts when converting to Unicode.
m_ctype.h:
Reorganizing mb_wc return codes to be able
to return "an unassigned N-byte-long character".
sql_string.cc:
Adding code to detect and properly handle
unassigned characters (i.e. the those character
which are correctly formed according to the
character specifications, but don't have Unicode
mapping).
Many files:
Fixing conversion function to return new codes.
ctype_ujis.test, ctype_gbk.test, ctype_big5.test:
Adding a test case.
ctype_ujis.result, ctype_gbk.result, ctype_big5.result:
Fixing results accordingly.
field::sort_key() now adds length last for varbinary/blob
VARBINARY/BLOB is now sorted by filesort so that shorter strings comes before longer ones
Fixed issues in test cases from last merge
new file
mysql_fix_privilege_tables.sql, mysql_create_system_tables.sh:
Adding true BINARY/VARBINARY: fixing "password" type, not to be 0x00-padding.
Many files:
Adding true BINARY/VARBINARY: fixing tests not to output 0x00 bytes.
Adding true BINARY/VARBINARY: new pad_char structure member.
ctype-bin.c:
Adding true BINARY/VARBINARY: new pad_char structure member.
New strnxfrm, with two trailing length bytes.
field.cc:
Adding true BINARY/VARBINARY.
In cp932, '\' character can be the second byte in a
multi-byte character stream. This makes it difficult to use
mysql_escape_string. Added flag to indicate which languages allow
'\' as second byte of multibyte sequence so that when putting a prepared
statement into the binlog we can decide at runtime whether hex encoding
is really needed.
UPPER/LOWER now can return a string with different length.
mi_test1.c:
Adding new arguments.
Many files:
Changeing caseup/casedn to return a result with different
length than argument.
sql_string.h:
Removing unused method,
mysql_priv.h:
Removing unused method
Renamed HA_VAR_LENGTH to HA_VAR_LENGTH_PART
Renamed in all files FIELD_TYPE_STRING and FIELD_TYPE_VAR_STRING to MYSQL_TYPE_STRING and MYSQL_TYPE_VAR_STRING to make it easy to catch all possible errors
Added support for VARCHAR KEYS to heap
Removed support for ISAM
Now only long VARCHAR columns are changed to TEXT on demand (not CHAR)
Internal temporary files can now use fixed length tables if the used VARCHAR columns are short
Fix for binary collations for MyISAM and HEAP BTREE.
This patch also changes trailing spaces behaviour for
binary collations. Binary collations now have PAD
characteristic too.
