significantly improve performance on large strings

this replaces inefficient pattern of `MIN(TEXTW(..), n)` with
drw_fontset_getwidth_clamp() instead, which is far more efficient when
we only want up to a certain width.

dumping a decently sized (unicode) emoji file into dmenu, I see the
startup time drop significantly with this patch.

before -> after
360ms  -> 160ms

this should also noticeably improve input latency (responsiveness) given
that calcoffsets() and drawmenu() are pretty hot functions.
main
NRK 2022-03-24 02:04:04 +06:00 committed by Chewing_Bever
parent 576d46bf00
commit 49c6f40235
Signed by: Jef Roosens
GPG Key ID: B75D4F293C7052DB
1 changed files with 10 additions and 3 deletions

13
dmenu.c
View File

@ -61,6 +61,13 @@ static char * cistrstr(const char *s, const char *sub);
static int (*fstrncmp)(const char *, const char *, size_t) = strncasecmp;
static char *(*fstrstr)(const char *, const char *) = cistrstr;
static unsigned int
textw_clamp(const char *str, unsigned int n)
{
unsigned int w = drw_fontset_getwidth_clamp(drw, str, n) + lrpad;
return MIN(w, n);
}
static void
appenditem(struct item *item, struct item **list, struct item **last)
{
@ -85,10 +92,10 @@ calcoffsets(void)
n = mw - (promptw + inputw + TEXTW("<") + TEXTW(">"));
/* calculate which items will begin the next page and previous page */
for (i = 0, next = curr; next; next = next->right)
if ((i += (lines > 0) ? bh : MIN(TEXTW(next->text), n)) > n)
if ((i += (lines > 0) ? bh : textw_clamp(next->text, n)) > n)
break;
for (i = 0, prev = curr; prev && prev->left; prev = prev->left)
if ((i += (lines > 0) ? bh : MIN(TEXTW(prev->left->text), n)) > n)
if ((i += (lines > 0) ? bh : textw_clamp(prev->left->text, n)) > n)
break;
}
@ -175,7 +182,7 @@ drawmenu(void)
}
x += w;
for (item = curr; item != next; item = item->right)
x = drawitem(item, x, 0, MIN(TEXTW(item->text), mw - x - TEXTW(">")));
x = drawitem(item, x, 0, textw_clamp(item->text, mw - x - TEXTW(">")));
if (next) {
w = TEXTW(">");
drw_setscheme(drw, scheme[SchemeNorm]);