diff options
Diffstat (limited to 'mysys/my_handler.c')
| -rw-r--r-- | mysys/my_handler.c | 129 |
1 files changed, 104 insertions, 25 deletions
diff --git a/mysys/my_handler.c b/mysys/my_handler.c index bd1e313d066..8daa9af39a9 100644 --- a/mysys/my_handler.c +++ b/mysys/my_handler.c @@ -20,28 +20,29 @@ #include <my_base.h> #include <my_handler.h> #include <my_sys.h> - #include "my_handler_errors.h" #define CMP_NUM(a,b) (((a) < (b)) ? -1 : ((a) == (b)) ? 0 : 1) -int ha_compare_text(CHARSET_INFO *charset_info, uchar *a, uint a_length, - uchar *b, uint b_length, my_bool part_key, +int ha_compare_text(CHARSET_INFO *charset_info, const uchar *a, uint a_length, + const uchar *b, uint b_length, my_bool part_key, my_bool skip_end_space) { if (!part_key) return charset_info->coll->strnncollsp(charset_info, a, a_length, - b, b_length, (my_bool)!skip_end_space); + b, b_length, + (my_bool)!skip_end_space); return charset_info->coll->strnncoll(charset_info, a, a_length, b, b_length, part_key); } -static int compare_bin(uchar *a, uint a_length, uchar *b, uint b_length, +static int compare_bin(const uchar *a, uint a_length, + const uchar *b, uint b_length, my_bool part_key, my_bool skip_end_space) { uint length= min(a_length,b_length); - uchar *end= a+ length; + const uchar *end= a+ length; int flag; while (a < end) @@ -85,13 +86,15 @@ static int compare_bin(uchar *a, uint a_length, uchar *b, uint b_length, ha_key_cmp() keyseg Array of key segments of key to compare a First key to compare, in format from _mi_pack_key() - This is normally key specified by user - b Second key to compare. This is always from a row - key_length Length of key to compare. This can be shorter than - a to just compare sub keys + This is always from the row + b Second key to compare. This is from the row or the user + key_length Length of key to compare, based on key b. This can be shorter + than b to just compare sub keys next_flag How keys should be compared If bit SEARCH_FIND is not set the keys includes the row position and this should also be compared + If SEARCH_PAGE_KEY_HAS_TRANSID is set then 'a' has transid + If SEARCH_USER_KEY_HAS_TRANSID is set then 'b' has transid diff_pos OUT Number of first keypart where values differ, counting from one. diff_pos[1] OUT (b + diff_pos[1]) points to first value in tuple b @@ -120,8 +123,8 @@ static int compare_bin(uchar *a, uint a_length, uchar *b, uint b_length, #define FCMP(A,B) ((int) (A) - (int) (B)) -int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, - register uchar *b, uint key_length, uint nextflag, +int ha_key_cmp(register HA_KEYSEG *keyseg, register const uchar *a, + register const uchar *b, uint key_length, uint32 nextflag, uint *diff_pos) { int flag; @@ -131,12 +134,12 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, float f_1,f_2; double d_1,d_2; uint next_key_length; - uchar *orig_b= b; + const uchar *orig_b= b; *diff_pos=0; for ( ; (int) key_length >0 ; key_length=next_key_length, keyseg++) { - uchar *end; + const uchar *end; uint piks=! (keyseg->flag & HA_NO_SORT); (*diff_pos)++; diff_pos[1]= (uint)(b - orig_b); @@ -153,8 +156,13 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, b++; if (!*a++) /* If key was NULL */ { - if (nextflag == (SEARCH_FIND | SEARCH_UPDATE)) - nextflag=SEARCH_SAME; /* Allow duplicate keys */ + if ((nextflag & (SEARCH_FIND | SEARCH_UPDATE | SEARCH_INSERT | + SEARCH_NULL_ARE_EQUAL)) == + (SEARCH_FIND | SEARCH_UPDATE | SEARCH_INSERT)) + { + /* Allow duplicate keys */ + nextflag= (nextflag & ~(SEARCH_FIND | SEARCH_UPDATE)) | SEARCH_SAME; + } else if (nextflag & SEARCH_NULL_ARE_NOT_EQUAL) { /* @@ -367,7 +375,7 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, if (keyseg->flag & HA_REVERSE_SORT) { - swap_variables(uchar*, a, b); + swap_variables(const uchar*, a, b); swap_flag=1; /* Remember swap of a & b */ end= a+ (int) (end-b); } @@ -392,7 +400,7 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, if (*b != '-') return -1; a++; b++; - swap_variables(uchar*, a, b); + swap_variables(const uchar*, a, b); swap_variables(int, alength, blength); swap_flag=1-swap_flag; alength--; blength--; @@ -421,7 +429,7 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, } if (swap_flag) /* Restore pointers */ - swap_variables(uchar*, a, b); + swap_variables(const uchar*, a, b); break; } #ifdef HAVE_LONG_LONG @@ -456,18 +464,90 @@ int ha_key_cmp(register HA_KEYSEG *keyseg, register uchar *a, end: if (!(nextflag & SEARCH_FIND)) { + /* + Compare rowid and possible transid + This happens in the following case: + - INSERT, UPDATE, DELETE when we have not unique keys or + are using versioning + - SEARCH_NEXT, SEARCH_PREVIOUS when we need to restart search + + The logic for comparing transid are as follows: + Keys with have a transid have lowest bit in the rowidt. This means that + if we are comparing a key with a transid with another key that doesn't + have a tranid, we must reset the lowest bit for both keys. + + When we have transid, the keys are compared in transid order. + A key without a transid is regared to be smaller than a key with + a transid. + */ + uint i; + uchar key_mask, tmp_a, tmp_b; + if (nextflag & (SEARCH_NO_FIND | SEARCH_LAST)) /* Find record after key */ return (nextflag & (SEARCH_BIGGER | SEARCH_LAST)) ? -1 : 1; - flag=0; - for (i=keyseg->length ; i-- > 0 ; ) + key_mask= (uchar) 255; + + if (!(nextflag & (SEARCH_USER_KEY_HAS_TRANSID | + SEARCH_PAGE_KEY_HAS_TRANSID))) + { + /* + Neither key has a trid. Only compare row id's and don't + try to store rows in trid order + */ + key_length= keyseg->length; + nextflag&= ~SEARCH_INSERT; + } + else + { + /* + Set key_mask so that we reset the last bit in the rowid before + we compare it. This is needed as the lowest bit in the rowid is + used to mark if the key has a transid or not. + */ + key_mask= (uchar) 254; + if (!test_all_bits(nextflag, (SEARCH_USER_KEY_HAS_TRANSID | + SEARCH_PAGE_KEY_HAS_TRANSID))) + { + /* + No transaction id for user key or for key on page + Ignore transid as at least one of the keys are visible for all + */ + key_length= keyseg->length; + } + else + { + /* + Both keys have trids. No need of special handling of incomplete + trids below. + */ + nextflag&= ~SEARCH_INSERT; + } + } + DBUG_ASSERT(key_length > 0); + + for (i= key_length-1 ; (int) i-- > 0 ; ) { if (*a++ != *b++) { flag= FCMP(a[-1],b[-1]); - break; + goto found; } } + tmp_a= *a & key_mask; + tmp_b= *b & key_mask; + flag= FCMP(tmp_a, tmp_b); + + if (flag == 0 && (nextflag & SEARCH_INSERT)) + { + /* + Ensure that on insert we get rows stored in trid order. + If one of the parts doesn't have a trid, this should be regarded + as smaller than the other + */ + return (nextflag & SEARCH_USER_KEY_HAS_TRANSID) ? -1 : 1; + } +found: if (nextflag & SEARCH_SAME) return (flag); /* read same */ if (nextflag & SEARCH_BIGGER) @@ -499,11 +579,11 @@ end: NULLs. */ -HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, uchar *a) +HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, const uchar *a) { for (; (enum ha_base_keytype) keyseg->type != HA_KEYTYPE_END; keyseg++) { - uchar *end; + const uchar *end; if (keyseg->null_bit) { if (!*a++) @@ -568,7 +648,6 @@ HA_KEYSEG *ha_find_null(HA_KEYSEG *keyseg, uchar *a) } - /* Register handler error messages for usage with my_error() |