git.stevedylan.dev

inputw: improve correctness and startup performance 77526f75

a massive amount of time inside readstdin() is spent trying to get the
max input width and then put it into inputw, only for it to get clamped
down to mw/3 inside setup().

it makes more sense to calculate inputw inside setup() once we have mw
available. similar to the last patch, i see noticeable startup
performance improvement:

before -> after
160ms  -> 60ms

additionally this will take fallback fonts into account compared to the
previous version, so it's not only more performant but also more correct.

NRK · 2022-03-24 00:37 1 file(s) · +9 −10

dmenu.c +9 −10

readstdin(void)
{
	char buf[sizeof text], *p;
	size_t i, imax = 0, size = 0;
	unsigned int tmpmax = 0;
	size_t i, size = 0;

	/* read each line from stdin and add it to the item list */
	for (i = 0; fgets(buf, sizeof buf, stdin); i++) {

		if (!(items[i].text = strdup(buf)))
			die("cannot strdup %u bytes:", strlen(buf) + 1);
		items[i].out = 0;
		drw_font_getexts(drw->fonts, buf, strlen(buf), &tmpmax, NULL);
		if (tmpmax > inputw) {
			inputw = tmpmax;
			imax = i;
		}
	}
	if (items)
		items[i].text = NULL;
	inputw = items ? TEXTW(items[imax].text) : 0;
	lines = MIN(lines, i);
}


setup(void)
{
	int x, y, i, j;
	unsigned int du;
	unsigned int du, tmp;
	XSetWindowAttributes swa;
	XIM xim;
	Window w, dw, *dws;
	XWindowAttributes wa;
	XClassHint ch = {"dmenu", "dmenu"};
	struct item *item;
#ifdef XINERAMA
	XineramaScreenInfo *info;
	Window pw;

		mw = wa.width;
	}
	promptw = (prompt && *prompt) ? TEXTW(prompt) - lrpad / 4 : 0;
	inputw = MIN(inputw, mw/3);
	for (item = items; item && item->text; ++item) {
		if ((tmp = textw_clamp(item->text, mw/3)) > inputw) {
			if ((inputw = tmp) == mw/3)
				break;
		}
	}
	match();

	/* create menu window */

547	547		readstdin(void)
548	548		{
549	549		char buf[sizeof text], *p;
550		-	size_t i, imax = 0, size = 0;
551		-	unsigned int tmpmax = 0;
	550	+	size_t i, size = 0;
552	551
553	552		/* read each line from stdin and add it to the item list */
554	553		for (i = 0; fgets(buf, sizeof buf, stdin); i++) {

560	559		if (!(items[i].text = strdup(buf)))
561	560		die("cannot strdup %u bytes:", strlen(buf) + 1);
562	561		items[i].out = 0;
563		-	drw_font_getexts(drw->fonts, buf, strlen(buf), &tmpmax, NULL);
564		-	if (tmpmax > inputw) {
565		-	inputw = tmpmax;
566		-	imax = i;
567		-	}
568	562		}
569	563		if (items)
570	564		items[i].text = NULL;
571		-	inputw = items ? TEXTW(items[imax].text) : 0;
572	565		lines = MIN(lines, i);
573	566		}
574	567

614	607		setup(void)
615	608		{
616	609		int x, y, i, j;
617		-	unsigned int du;
	610	+	unsigned int du, tmp;
618	611		XSetWindowAttributes swa;
619	612		XIM xim;
620	613		Window w, dw, *dws;
621	614		XWindowAttributes wa;
622	615		XClassHint ch = {"dmenu", "dmenu"};
	616	+	struct item *item;
623	617		#ifdef XINERAMA
624	618		XineramaScreenInfo *info;
625	619		Window pw;

677	671		mw = wa.width;
678	672		}
679	673		promptw = (prompt && *prompt) ? TEXTW(prompt) - lrpad / 4 : 0;
680		-	inputw = MIN(inputw, mw/3);
	674	+	for (item = items; item && item->text; ++item) {
	675	+	if ((tmp = textw_clamp(item->text, mw/3)) > inputw) {
	676	+	if ((inputw = tmp) == mw/3)
	677	+	break;
	678	+	}
	679	+	}
681	680		match();
682	681
683	682		/* create menu window */