Patch 7.1.235
Problem:Pattern matching is slow when using a lot of simple patterns.
Solution: Avoid allocating memory by not freeing it when it's not so much.
(Alexei Alexandrov)
Files: src/regexp.c
*** ../vim-7.1.234/src/regexp.c Wed Jan 2 15:34:48 2008
--- src/regexp.cFri Jan 18 20:35:21 2008
***
*** 378,391
static char_u *reg_prev_sub = NULL;
- #if defined(EXITFREE) || defined(PROTO)
- void
- free_regexp_stuff()
- {
- vim_free(reg_prev_sub);
- }
- #endif
-
/*
* REGEXP_INRANGE contains all characters which are always special in a []
* range after '\'.
--- 378,383
***
*** 3206,3217
} backpos_T;
/*
! * regstack and backpos are used by regmatch(). They are kept over calls to
! * avoid invoking malloc() and free() often.
*/
! static garray_T regstack; /* stack with regitem_T items, sometimes
! preceded by regstar_T or regbehind_T. */
! static garray_T backpos;/* table with backpos_T for BACK */
/*
* Get pointer to the line "lnum", which is relative to "reg_firstlnum".
--- 3198,3236
} backpos_T;
/*
! * "regstack" and "backpos" are used by regmatch(). They are kept over calls
! * to avoid invoking malloc() and free() often.
! * "regstack" is a stack with regitem_T items, sometimes preceded by regstar_T
! * or regbehind_T.
! * "backpos_T" is a table with backpos_T for BACK
! */
! static garray_T regstack = {0, 0, 0, 0, NULL};
! static garray_T backpos = {0, 0, 0, 0, NULL};
!
! /*
! * Both for regstack and backpos tables we use the following strategy of
! * allocation (to reduce malloc/free calls):
! * - Initial size is fairly small.
! * - When needed, the tables are grown bigger (8 times at first, double after
! * that).
! * - After executing the match we free the memory only if the array has grown.
! * Thus the memory is kept allocated when it's at the initial size.
! * This makes it fast while not keeping a lot of memory allocated.
! * A three times speed increase was observed when using many simple patterns.
*/
! #define REGSTACK_INITIAL 2048
! #define BACKPOS_INITIAL 64
!
! #if defined(EXITFREE) || defined(PROTO)
! void
! free_regexp_stuff()
! {
! ga_clear(®stack);
! ga_clear(&backpos);
! vim_free(reg_tofree);
! vim_free(reg_prev_sub);
! }
! #endif
/*
* Get pointer to the line "lnum", which is relative to "reg_firstlnum".
***
*** 3346,3360
char_u*s;
long retval = 0L;
! reg_tofree = NULL;
!
! /* Init the regstack empty. Use an item size of 1 byte, since we push
! * different things onto it. Use a large grow size to avoid reallocating
! * it too often. */
! ga_init2(®stack, 1, 1);
!
! /* Init the backpos table empty. */
! ga_init2(&backpos, sizeof(backpos_T), 10);
if (REG_MULTI)
{
--- 3365,3389
char_u*s;
long retval = 0L;
! /* Create "regstack" and "backpos" if they are not allocated yet.
! * We allocate *_INITIAL amount of bytes first and then set the grow size
! * to much bigger value to avoid many malloc calls in case of deep regular
! * expressions. */
! if (regstack.ga_data == NULL)
! {
! /* Use an item size of 1 byte, since we push different things
!* onto the regstack. */
! ga_init2(®stack, 1, REGSTACK_INITIAL);
! ga_grow(®stack, REGSTACK_INITIAL);
! regstack.ga_growsize = REGSTACK_INITIAL * 8;
! }
!
! if (backpos.ga_data == NULL)
! {
! ga_init2(&backpos, sizeof(backpos_T), BACKPOS_INITIAL);
! ga_grow(&backpos, BACKPOS_INITIAL);
! backpos.ga_growsize = BACKPOS_INITIAL * 8;
! }
if (REG_MULTI)
{
***
*** 3525,3533
}
theend:
! vim_free(reg_tofree);
! ga_clear(®stack);
! ga_clear(&backpos);
return retval;
}
--- 3554,3570
}
theend:
! /* Free "reg_tofree" when it's a bit big.
! * Free regstack and backpos if they are bigger than their initial size.
*/
! if (reg_tofreelen > 400)
! {
! vim_free(reg_tofree);
! reg_tofree = NULL;
! }
! if (regstack.ga_maxlen > REGSTACK_INITIAL)
! ga_clear(®stack);
! if (backpos.ga_maxlen > BACKPOS_INITIAL)
! ga_clear(&backpos);
return retval;
}
***
*** 3717,3724
#define RA_MATCH 4 /* successful match */
#define RA_NOMATCH5 /* didn't match */
! /* Init the regstack and backpos table empty. They are initialized and
!* freed in vim_regexec_both() to reduce malloc()/free() calls. */
regstack.ga_len = 0;
backpos.ga_le
