git.stevedylan.dev

drw: minor improvement to the nomatches cache 7ab0cb5e

1. use `unsigned int` to store the codepoints, this avoids waste on
   common case where `long` is 64bits. and POSIX guarantees `int` to be
   at least 32bits so there's no risk of truncation.
2. since switching to `unsigned int` cuts down the memory requirement by
   half, double the cache size from 64 to 128.
3. instead of a linear search, use a simple hash-table for O(1) lookups.

NRK · 2023-07-07 17:00 3 file(s) · +13 −12

dmenu.c +0 −1

/* macros */
#define INTERSECT(x,y,w,h,r)  (MAX(0, MIN((x)+(w),(r).x_org+(r).width)  - MAX((x),(r).x_org)) \
                             * MAX(0, MIN((y)+(h),(r).y_org+(r).height) - MAX((y),(r).y_org)))
#define LENGTH(X)             (sizeof X / sizeof X[0])
#define TEXTW(X)              (drw_fontset_getwidth(drw, (X)) + lrpad)

/* enums */

drw.c +12 −11

int
drw_text(Drw *drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char *text, int invert)
{
	int i, ty, ellipsis_x = 0;
	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len;
	int ty, ellipsis_x = 0;
	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len, hash, h0, h1;
	XftDraw *d = NULL;
	Fnt *usedfont, *curfont, *nextfont;
	int utf8strlen, utf8charlen, render = x || y || w || h;

	XftResult result;
	int charexists = 0, overflow = 0;
	/* keep track of a couple codepoints for which we have no match. */
	enum { nomatches_len = 64 };
	static struct { long codepoint[nomatches_len]; unsigned int idx; } nomatches;
	static unsigned int ellipsis_width = 0;
	static unsigned int nomatches[128], ellipsis_width;

	if (!drw || (render && (!drw->scheme || !w)) || !text || !drw->fonts)
		return 0;

			 * character must be drawn. */
			charexists = 1;

			for (i = 0; i < nomatches_len; ++i) {
				/* avoid calling XftFontMatch if we know we won't find a match */
				if (utf8codepoint == nomatches.codepoint[i])
					goto no_match;
			}
			hash = (unsigned int)utf8codepoint;
			hash = ((hash >> 16) ^ hash) * 0x21F0AAAD;
			hash = ((hash >> 15) ^ hash) * 0xD35A2D97;
			h0 = ((hash >> 15) ^ hash) % LENGTH(nomatches);
			h1 = (hash >> 17) % LENGTH(nomatches);
			/* avoid expensive XftFontMatch call when we know we won't find a match */
			if (nomatches[h0] == utf8codepoint || nomatches[h1] == utf8codepoint)
				goto no_match;

			fccharset = FcCharSetCreate();
			FcCharSetAddChar(fccharset, utf8codepoint);

					curfont->next = usedfont;
				} else {
					xfont_free(usedfont);
					nomatches.codepoint[++nomatches.idx % nomatches_len] = utf8codepoint;
					nomatches[nomatches[h0] ? h1 : h0] = utf8codepoint;
no_match:
					usedfont = drw->fonts;
				}

util.h +1 −0

#define MAX(A, B)               ((A) > (B) ? (A) : (B))
#define MIN(A, B)               ((A) < (B) ? (A) : (B))
#define BETWEEN(X, A, B)        ((A) <= (X) && (X) <= (B))
#define LENGTH(X)               (sizeof (X) / sizeof (X)[0])

void die(const char *fmt, ...);
void *ecalloc(size_t nmemb, size_t size);

22	22		/* macros */
23	23		#define INTERSECT(x,y,w,h,r) (MAX(0, MIN((x)+(w),(r).x_org+(r).width) - MAX((x),(r).x_org)) \
24	24		* MAX(0, MIN((y)+(h),(r).y_org+(r).height) - MAX((y),(r).y_org)))
25		-	#define LENGTH(X) (sizeof X / sizeof X[0])
26	25		#define TEXTW(X) (drw_fontset_getwidth(drw, (X)) + lrpad)
27	26
28	27		/* enums */

238	238		int
239	239		drw_text(Drw drw, int x, int y, unsigned int w, unsigned int h, unsigned int lpad, const char text, int invert)
240	240		{
241		-	int i, ty, ellipsis_x = 0;
242		-	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len;
	241	+	int ty, ellipsis_x = 0;
	242	+	unsigned int tmpw, ew, ellipsis_w = 0, ellipsis_len, hash, h0, h1;
243	243		XftDraw *d = NULL;
244	244		Fnt usedfont, curfont, *nextfont;
245	245		int utf8strlen, utf8charlen, render = x \|\| y \|\| w \|\| h;

251	251		XftResult result;
252	252		int charexists = 0, overflow = 0;
253	253		/* keep track of a couple codepoints for which we have no match. */
254		-	enum { nomatches_len = 64 };
255		-	static struct { long codepoint[nomatches_len]; unsigned int idx; } nomatches;
256		-	static unsigned int ellipsis_width = 0;
	254	+	static unsigned int nomatches[128], ellipsis_width;
257	255
258	256		if (!drw \|\| (render && (!drw->scheme \|\| !w)) \|\| !text \|\| !drw->fonts)
259	257		return 0;

338	336		* character must be drawn. */
339	337		charexists = 1;
340	338
341		-	for (i = 0; i < nomatches_len; ++i) {
342		-	/* avoid calling XftFontMatch if we know we won't find a match */
343		-	if (utf8codepoint == nomatches.codepoint[i])
344		-	goto no_match;
345		-	}
	339	+	hash = (unsigned int)utf8codepoint;
	340	+	hash = ((hash >> 16) ^ hash) * 0x21F0AAAD;
	341	+	hash = ((hash >> 15) ^ hash) * 0xD35A2D97;
	342	+	h0 = ((hash >> 15) ^ hash) % LENGTH(nomatches);
	343	+	h1 = (hash >> 17) % LENGTH(nomatches);
	344	+	/* avoid expensive XftFontMatch call when we know we won't find a match */
	345	+	if (nomatches[h0] == utf8codepoint \|\| nomatches[h1] == utf8codepoint)
	346	+	goto no_match;
346	347
347	348		fccharset = FcCharSetCreate();
348	349		FcCharSetAddChar(fccharset, utf8codepoint);

371	372		curfont->next = usedfont;
372	373		} else {
373	374		xfont_free(usedfont);
374		-	nomatches.codepoint[++nomatches.idx % nomatches_len] = utf8codepoint;
	375	+	nomatches[nomatches[h0] ? h1 : h0] = utf8codepoint;
375	376		no_match:
376	377		usedfont = drw->fonts;
377	378		}

3	3		#define MAX(A, B) ((A) > (B) ? (A) : (B))
4	4		#define MIN(A, B) ((A) < (B) ? (A) : (B))
5	5		#define BETWEEN(X, A, B) ((A) <= (X) && (X) <= (B))
	6	+	#define LENGTH(X) (sizeof (X) / sizeof (X)[0])
6	7
7	8		void die(const char *fmt, ...);
8	9		void *ecalloc(size_t nmemb, size_t size);