view.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

{
	Xentry *t = (Xentry*)tt;

	if(t->nkid >= 0)
		return;

	t->nkid = 1;
	t->kid = mallocz(sizeof(t->kid[0])*t->nkid, 1);
	t->kid[0] = initxsource(t->e, 1);
}

Tnode*
initxentry(Entry e)
{
	Xentry *t;

	t = mallocz(sizeof *t, 1);
	t->nkid = -1;
	t->str = smprint("Entry gen=%#ux psize=%d dsize=%d depth=%d flags=%#ux size=%lld score=%V",
		e.gen, e.psize, e.dsize, e.depth, e.flags, e.size, e.score);
	if(e.flags & VtEntryLocal)
		t->str = smprint("%s archive=%d snap=%d tag=%#ux", t->str, e.archive, e.snap, e.tag);
	t->expand = xentryexpand;
	t->e = e;
	return t;	
}

int
ptrgen(void *v, Block *b, int o, Tnode **tp)
{
	Entry *ed;
	Entry e;

	ed = v;
	if(o >= ed->psize/VtScoreSize)
		return -1;

	e = *ed;
	e.depth--;
	memmove(e.score, b->data+o*VtScoreSize, VtScoreSize);
	if(memcmp(e.score, vtZeroScore, VtScoreSize) == 0)
		return 0;
	*tp = initxsource(e, 0);
	return 1;
}

static int
etype(int flags, int depth)
{
	uint t;

	if(flags&VtEntryDir)
		t = BtDir;
	else
		t = BtData;
	return t+depth;
}

Tnode*
initxsource(Entry e, int dowrap)
{
	Block *b;
	Tnode *t, *tt;

	b = dataBlock(e.score, etype(e.flags, e.depth), e.tag);
	if(b == nil)
		return stringnode("dataBlock: %r");

	if((e.flags & VtEntryActive) == 0)
		return stringnode("inactive Entry");

	if(e.depth == 0){
		if(e.flags & VtEntryDir)
			tt = initxentryblock(b, copyEntry(e));
		else
			tt = initxdatablock(b, e.dsize);
	}else{
		tt = initxblock(b, smprint("%s+%d pointer", (e.flags & VtEntryDir) ? "BtDir" : "BtData", e.depth),
			ptrgen, copyEntry(e));
	}

	/*
	 * wrap the contents of the Source in a Source node,
	 * just so it's closer to what you see in the code.
	 */
	if(dowrap){
		t = stringnode("Source");
		t->nkid = 1;
		t->kid = mallocz(sizeof(Tnode*)*1, 1);
		t->kid[0] = tt;
		tt = t;
	}
	return tt;
}

int
xlocalrootgen(void*, Block *b, int o, Tnode **tp)
{
	Entry e;

	if(o >= 1)
		return -1;
	entryUnpack(&e, b->data, o);
	*tp = initxentry(e);
	return 1;
}

Tnode*
initxlocalroot(char *name, u32int addr)
{
	uchar score[VtScoreSize];
	Block *b;

	localToGlobal(addr, score);
	b = dataBlock(score, BtDir, RootTag);
	if(b == nil)
		return stringnode("read data block %#ux: %R", addr);
	return initxblock(b, smprint("'%s' fs root", name), xlocalrootgen, nil);
}

int
xvacrootgen(void*, Block *b, int o, Tnode **tp)
{
	Entry e;

	if(o >= 3)
		return -1;
	entryUnpack(&e, b->data, o);
	*tp = initxentry(e);
	return 1;
}

Tnode*
initxroot(char *name, uchar score[VtScoreSize])
{
	Block *b;

	b = dataBlock(score, BtDir, RootTag);
	if(b == nil)
		return stringnode("read data block %V: %R", score);
	return initxblock(b, smprint("'%s' fs root", name), xvacrootgen, nil);
}
Tnode*
initxdirentry(MetaEntry *me)
{
	DirEntry dir;
	Tnode *t;

	if(!deUnpack(&dir, me))
		return stringnode("deUnpack: %R");

	t = stringnode("dirEntry elem=%s size=%llud data=%#lux/%#lux meta=%#lux/%#lux", dir.elem, dir.size, dir.entry, dir.gen, dir.mentry, dir.mgen);
	t->nkid = 1;
	t->kid = mallocz(sizeof(t->kid[0])*1, 1);
	t->kid[0] = stringnode(
		"qid=%#llux\n"
		"uid=%s gid=%s mid=%s\n"
		"mtime=%lud mcount=%lud ctime=%lud atime=%lud\n"
		"mode=%luo\n"
		"plan9 %d p9path %#llux p9version %lud\n"
		"qidSpace %d offset %#llux max %#llux",
		dir.qid,
		dir.uid, dir.gid, dir.mid,
		dir.mtime, dir.mcount, dir.ctime, dir.atime,
		dir.mode,
		dir.plan9, dir.p9path, dir.p9version,
		dir.qidSpace, dir.qidOffset, dir.qidMax);
	return t;
}

int
metaentrygen(void *v, Block*, int o, Tnode **tp)
{
	Tnode *t;
	MetaBlock *mb;
	MetaEntry me;

	mb = v;
	if(o >= mb->nindex)
		return -1;
	meUnpack(&me, mb, o);

	t = stringnode("MetaEntry %d bytes", mb->size);
	t->kid = mallocz(sizeof(t->kid[0])*1, 1);
	t->kid[0] = initxdirentry(&me);
	t->nkid = 1;
	*tp = t;
	return 1;
}

int
metablockgen(void *v, Block *b, int o, Tnode **tp)
{
	Xblock *t;
	MetaBlock *mb;

	if(o >= 1)
		return -1;

	/* hack: reuse initxblock as a generic iterator */
	mb = v;
	t = (Xblock*)initxblock(b, "", metaentrygen, mb);
	t->str = smprint("MetaBlock %d/%d space used, %d add'l free %d/%d table used%s",
		mb->size, mb->maxsize, mb->free, mb->nindex, mb->maxindex,
		mb->botch ? " [BOTCH]" : "");
	t->printlabel = 0;
	*tp = t;
	return 1;
}

/*
 * attempt to guess at the type of data in the block.
 * it could just be data from a file, but we're hoping it's MetaBlocks.
 */
Tnode*
initxdatablock(Block *b, uint n)
{
	MetaBlock mb;

	if(n > h.blockSize)
		n = h.blockSize;

	if(mbUnpack(&mb, b->data, n))
		return initxblock(b, "metadata", metablockgen, copyMetaBlock(mb));

	return initxblock(b, "data", nil, nil);
}

int
parseScore(uchar *score, char *buf, int n)
{
	int i, c;

	memset(score, 0, VtScoreSize);

	if(n < VtScoreSize*2)
		return 0;
	for(i=0; i<VtScoreSize*2; i++){
		if(buf[i] >= '0' && buf[i] <= '9')
			c = buf[i] - '0';
		else if(buf[i] >= 'a' && buf[i] <= 'f')
			c = buf[i] - 'a' + 10;
		else if(buf[i] >= 'A' && buf[i] <= 'F')
			c = buf[i] - 'A' + 10;
		else{
			return 0;
		}

		if((i & 1) == 0)
			c <<= 4;
	
		score[i>>1] |= c;
	}
	return 1;
}

int
scoreFmt(Fmt *f)
{
	uchar *v;
	int i;
	u32int addr;

	v = va_arg(f->args, uchar*);
	if(v == nil){
		fmtprint(f, "*");
	}else if((addr = globalToLocal(v)) != NilBlock)
		fmtprint(f, "0x%.8ux", addr);
	else{
		for(i = 0; i < VtScoreSize; i++)
			fmtprint(f, "%2.2ux", v[i]);
	}

	return 0;
}

Atree*
atreeinit(char *arg)
{
	Atree *a;
	uchar score[VtScoreSize];

	vtAttach();

	fmtinstall('V', scoreFmt);
	fmtinstall('R', vtErrFmt);

	z = vtDial(nil, 1);
	if(z == nil)
		fprint(2, "warning: cannot dial venti: %R\n");
	if(!vtConnect(z, 0)){
		fprint(2, "warning: cannot connect to venti: %R\n");
		z = nil;
	}
	a = mallocz(sizeof(Atree), 1);
	if(strncmp(arg, "vac:", 4) == 0){
		if(!parseScore(score, arg+4, strlen(arg+4))){
			fprint(2, "cannot parse score\n");
			return nil;
		}
		a->root = initxvacroot(score);
	}else
		a->root = initxcache(arg);
	a->resizefd = -1;
	return a;
}

/* --- tree.c */
enum
{
	Nubwidth = 11,
	Nubheight = 11,
	Linewidth = Nubwidth*2+4,
};

uint
drawtext(char *s, Image *m, Image *clipr, Point o)
{
	char *t, *nt, *e;
	uint dy;

	if(s == nil)
		s = "???";

	dy = 0;
	for(t=s; t&&*t; t=nt){
		if(nt = strchr(t, '\n')){
			e = nt;
			nt++;
		}else
			e = t+strlen(t);

		_string(m, Pt(o.x, o.y+dy), display->black, ZP, display->defaultfont,
			t, nil, e-t, clipr->clipr, nil, ZP, SoverD);
		dy += display->defaultfont->height;
	}
	return dy;
}

void
drawnub(Image *m, Image *clipr, Point o, Tnode *t)
{
	clipr = nil;

	if(t->nkid == 0)
		return;
	if(t->nkid == -1 && t->expand == nil)
		return;

	o.y += (display->defaultfont->height-Nubheight)/2;
	draw(m, rectaddpt(Rect(0,0,1,Nubheight), o), display->black, clipr, ZP);
	draw(m, rectaddpt(Rect(0,0,Nubwidth,1), o), display->black, clipr, o);
	draw(m, rectaddpt(Rect(Nubwidth-1,0,Nubwidth,Nubheight), o), 
		display->black, clipr, addpt(o, Pt(Nubwidth-1, 0)));
	draw(m, rectaddpt(Rect(0, Nubheight-1, Nubwidth, Nubheight), o),
		display->black, clipr, addpt(o, Pt(0, Nubheight-1)));

	draw(m, rectaddpt(Rect(0, Nubheight/2, Nubwidth, Nubheight/2+1), o),
		display->black, clipr, addpt(o, Pt(0, Nubheight/2)));
	if(!t->expanded)
		draw(m, rectaddpt(Rect(Nubwidth/2, 0, Nubwidth/2+1, Nubheight), o),
			display->black, clipr, addpt(o, Pt(Nubwidth/2, 0)));

}

uint
drawnode(Tnode *t, Image *m, Image *clipr, Point o)
{
	int i;
	char *fs, *s;
	uint dy;
	Point oo;

	if(t == nil)
		return 0;

	t->offset = o;

	oo = Pt(o.x+Nubwidth+2, o.y);
//	if(t->draw)
//		dy = (*t->draw)(t, m, clipr, oo);
//	else{
		fs = nil;
		if(t->str)
			s = t->str;
	//	else if(t->strfn)
	//		fs = s = (*t->strfn)(t);
		else
			s = "???";
		dy = drawtext(s, m, clipr, oo);
		free(fs);
//	}

	if(t->expanded){
		if(t->nkid == -1 && t->expand)
			(*t->expand)(t);
		oo = Pt(o.x+Nubwidth+(Linewidth-Nubwidth)/2, o.y+dy);
		for(i=0; i<t->nkid; i++)
			oo.y += drawnode(t->kid[i], m, clipr, oo);
		dy = oo.y - o.y;
	}
	drawnub(m, clipr, o, t);
	return dy;
}

void
drawtree(Tree *t, Image *m, Rectangle r)
{
	Point p;

	draw(m, r, display->white, nil, ZP);

	replclipr(t->clipr, 1, r);
	p = addpt(t->offset, r.min);
	drawnode(t->root, m, t->clipr, p);
}

Tnode*
findnode(Tnode *t, Point p)
{
	int i;
	Tnode *tt;

	if(ptinrect(p, rectaddpt(Rect(0,0,Nubwidth, Nubheight), t->offset)))
		return t;
	if(!t->expanded)
		return nil;
	for(i=0; i<t->nkid; i++)
		if(tt = findnode(t->kid[i], p))
			return tt;
	return nil;
}

void
usage(void)
{
	fprint(2, "usage: vtree /dev/sdC0/fossil\n");
	exits("usage");
}

Tree t;

void
eresized(int new)
{
	Rectangle r;
	r = screen->r;
	if(new && getwindow(display, Refnone) < 0)
		fprint(2,"can't reattach to window");
	drawtree(&t, screen, screen->r);
}

enum
{
	Left = 1<<0,
	Middle = 1<<1,
	Right = 1<<2,

	MMenu = 2,
};

char *items[] = { "exit", 0 };
enum { IExit, };

Menu menu;

void
main(int argc, char **argv)
{
	int n;
	char *dir;
	Event e;
	Point op, p;
	Tnode *tn;
	Mouse m;
	int Eready;
	Atree *fs;

	ARGBEGIN{
	case 'a':
		showinactive = 1;
		break;
	default:
		usage();
	}ARGEND

	switch(argc){
	default:
		usage();
	case 1:
		dir = argv[0];
		break;
	}

	fs = atreeinit(dir);
	initdraw(0, "/lib/font/bit/lucidasans/unicode.8.font", "tree");
	t.root = fs->root;
	t.offset = ZP;
	t.clipr = allocimage(display, Rect(0,0,1,1), GREY1, 1, DOpaque);

	eresized(0);
	flushimage(display, 1);

	einit(Emouse);

	menu.item = items;
	menu.gen = 0;
	menu.lasthit = 0;
	if(fs->resizefd > 0){
		Eready = 1<<3;
		estart(Eready, fs->resizefd, 1);
	}else
		Eready = 0;

	for(;;){
		switch(n=eread(Emouse|Eready, &e)){
		default:
			if(Eready && n==Eready)
				eresized(0);
			break;
		case Emouse:
			m = e.mouse;
			switch(m.buttons){
			case Left:
				op = t.offset;
				p = m.xy;
				do {
					t.offset = addpt(t.offset, subpt(m.xy, p));
					p = m.xy;
					eresized(0);
					m = emouse();
				}while(m.buttons == Left);
				if(m.buttons){
					t.offset = op;
					eresized(0);
				}
				break;
			case Middle:
				n = emenuhit(MMenu, &m, &menu);
				if(n == -1)
					break;
				switch(n){
				case IExit:
					exits(nil);
				}
				break;
			case Right:
				do
					m = emouse();
				while(m.buttons == Right);
				if(m.buttons)
					break;
				tn = findnode(t.root, m.xy);
				if(tn){
					tn->expanded = !tn->expanded;
					eresized(0);
				}
				break;
			}
		}
	}
}