git.stevedylan.dev

significantly improve performance on large strings 7269c535

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.

NRK · 2022-03-24 02:04 1 file(s) · +10 −3

dmenu.c +10 −3

static int (*fstrncmp)(const char *, const char *, size_t) = strncmp;
static char *(*fstrstr)(const char *, const char *) = strstr;

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)
{

		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;
}


		}
		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]);

58	58		static int (fstrncmp)(const char , const char *, size_t) = strncmp;
59	59		static char (fstrstr)(const char , const char ) = strstr;
60	60
	61	+	static unsigned int
	62	+	textw_clamp(const char *str, unsigned int n)
	63	+	{
	64	+	unsigned int w = drw_fontset_getwidth_clamp(drw, str, n) + lrpad;
	65	+	return MIN(w, n);
	66	+	}
	67	+
61	68		static void
62	69		appenditem(struct item item, struct item list, struct item *last)
63	70		{

82	89		n = mw - (promptw + inputw + TEXTW("<") + TEXTW(">"));
83	90		/* calculate which items will begin the next page and previous page */
84	91		for (i = 0, next = curr; next; next = next->right)
85		-	if ((i += (lines > 0) ? bh : MIN(TEXTW(next->text), n)) > n)
	92	+	if ((i += (lines > 0) ? bh : textw_clamp(next->text, n)) > n)
86	93		break;
87	94		for (i = 0, prev = curr; prev && prev->left; prev = prev->left)
88		-	if ((i += (lines > 0) ? bh : MIN(TEXTW(prev->left->text), n)) > n)
	95	+	if ((i += (lines > 0) ? bh : textw_clamp(prev->left->text, n)) > n)
89	96		break;
90	97		}
91	98

172	179		}
173	180		x += w;
174	181		for (item = curr; item != next; item = item->right)
175		-	x = drawitem(item, x, 0, MIN(TEXTW(item->text), mw - x - TEXTW(">")));
	182	+	x = drawitem(item, x, 0, textw_clamp(item->text, mw - x - TEXTW(">")));
176	183		if (next) {
177	184		w = TEXTW(">");
178	185		drw_setscheme(drw, scheme[SchemeNorm]);