GopherProxy

	significantly improve performance on large strings - dmenu - dynamic menu
	git clone git://git.suckless.org/dmenu
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	---
	commit 7269c5355d257dd2ad2c53f15dc9c1cf6796aea5
	parent 6be057f060543bb0f3ed9423904263617cdffffe
	Author: NRK <[email protected]>
	Date: Thu, 24 Mar 2022 02:04:04 +0600

	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.

	Diffstat:
	M dmenu.c \| 13 ++++++++++---

	1 file changed, 10 insertions(+), 3 deletions(-)
	---
	diff --git a/dmenu.c b/dmenu.c
	@@ -58,6 +58,13 @@ static Clr *scheme[SchemeLast];
	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)
	{
	@@ -82,10 +89,10 @@ 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)) …
	+ if ((i += (lines > 0) ? bh : textw_clamp(prev->left->text, n))…
	break;
	}

	@@ -172,7 +179,7 @@ drawmenu(void)
	}
	x += w;
	for (item = curr; item != next; item = item->right)
	- x = drawitem(item, x, 0, MIN(TEXTW(item->text), mw - x…
	+ x = drawitem(item, x, 0, textw_clamp(item->text, mw - …
	if (next) {
	w = TEXTW(">");
	drw_setscheme(drw, scheme[SchemeNorm]);