Golang Dir.CanWalk方法代碼示例

// Walk to the given rid checking out perms when t.ai is not nil.
// Returns also the gid and mode even when no perms are checked.
func (t *Lfs) canWalkTo(rid string, forwhat int) (string, uint64, error) {
	if !t.readattrs || rid == "/Ctl" {
		return dbg.Usr, 0777, nil
	}
	noperm := t.NoPermCheck || t.ai == nil
	elems := zx.Elems(rid)
	fpath := t.path
	pgid := ""
	var pmode uint64
	if len(elems) == 0 {
		elems = append(elems, "/")
	}
	for len(elems) > 0 {
		if noperm {
			// skip to just the final step
			if len(elems) > 1 {
				fpath = zx.Path(t.path, path.Dir(rid))
				elems = elems[len(elems)-1:]
			}
		}
		pd := zx.Dir{
			"name": elems[0],
		}
		fpath = zx.Path(fpath, elems[0])
		elems = elems[1:]

		st, err := os.Stat(fpath)
		if err != nil {
			return "", 0, err
		}
		mode := st.Mode()
		m := int64(mode & 0777)
		pd["mode"] = "0" + strconv.FormatInt(m, 8)
		t.fileAttrs(fpath, pd)
		if !noperm && len(elems) > 0 && !pd.CanWalk(t.ai) {
			return "", 0, dbg.ErrPerm
		}
		if len(elems) == 0 {
			pgid = pd["Gid"]
			pmode = uint64(pd.Int("mode"))
		}
		if !noperm && len(elems) == 0 && forwhat != 0 {
			if !pd.Can(t.ai, forwhat) {
				return "", 0, dbg.ErrPerm
			}
		}
	}
	if pgid == "" {
		pgid = dbg.Usr
	}
	if pmode == 0 {
		pmode = 0775
	}
	return pgid, pmode, nil
}

func (t *Fs) walk(rid string) (File, error) {
	rid, err := zx.AbsPath(rid)
	if err != nil {
		return nil, err
	}
	if rid == "/" {
		return t.root, nil
	}
	if rid == "/Ctl" {
		return nil, nil
	}
	els := zx.Elems(rid)
	f := t.root
	p := "/"
	var d zx.Dir
	for _, e := range els {
		t.Dprintf("walk %s %s...\n", f, e)
		d, err = f.Stat()
		if err != nil {
			t.Dprintf("\tstat: %s\n", f, err)
			return nil, err
		}
		if d["type"] != "d" {
			t.Dprintf("\tnot dir\n")
			return nil, fmt.Errorf("%s: %s", p, dbg.ErrNotDir)
		}
		if !t.NoPermCheck && !d.CanWalk(t.ai) {
			t.Dprintf("\tno perm\n")
			return nil, fmt.Errorf("%s: %s", p, dbg.ErrPerm)
		}
		wf, ok := f.(Walker)
		if !ok {
			t.Dprintf("\tnot walker\n")
			return nil, fmt.Errorf("%s: %s: %s", p, e, dbg.ErrNotExist)
		}
		f, err = wf.Walk(e)
		if err != nil {
			t.Dprintf("\twalk: %s\n", err)
			return nil, err
		}
		p = zx.Path(p, e)
		t.Dprintf("walked %s\n", f)
	}
	return f, nil
}

// d is a dup and can be changed.
func (t *Fs) find(f File, d zx.Dir, p *pred.Pred, spref, dpref string, lvl int,
	c chan<- zx.Dir, ai *auth.Info) {
	match, pruned, err := p.EvalAt(d, lvl)
	t.dprintf("find  at %v\n\t%v\n\t%v %v %v\n\n", d, p, match, pruned, err)
	if pruned {
		if !match {
			d["err"] = "pruned"
		}
		c <- d
		return
	}
	if d["type"] == "d" && err == nil {
		if !t.NoPermCheck && !d.CanWalk(ai) {
			err = dbg.ErrPerm
		}
	}
	if err != nil {
		d["err"] = err.Error()
		c <-d
		return
	}
	if d["rm"] != "" {
		return
	}
	if match {
		if ok := c <- d; !ok {
			return
		}
	}
	if d["type"] != "d" || f == nil {
		return
	}
	wf, ok := f.(Walker)
	if !ok {
		return
	}
	ns, err := wf.Getdir()
	if err != nil {
		return
	}
	sort.Sort(sort.StringSlice(ns))
	if d["name"] == "/" {
		cd := ctldir.Dup()
		if spref != dpref {
			cpath := cd["path"]
			suff := zx.Suffix(cpath, spref)
			cd["path"] = zx.Path(dpref, suff)
		}
		t.find(nil, cd, p, spref, dpref, lvl+1, c, ai)
	}
	for _, cnm := range ns {
		cf, err := wf.Walk(cnm)
		if err != nil {
			continue
		}
		cp := zx.Path(d["path"], cnm)
		cd, err := t.statf(cf, cp)
		if err != nil || cd["rm"] != "" {
			continue
		}
		cd = cd.Dup()
		if spref != dpref {
			cpath := cd["path"]
			suff := zx.Suffix(cpath, spref)
			cd["path"] = zx.Path(dpref, suff)
		}
		t.find(cf, cd, p, spref, dpref, lvl+1, c, ai)
	}
}

func (t *Fs) Find(rid, fpred, spref, dpref string, depth int) <-chan zx.Dir {
	t.dprintf("find %s '%s' '%s' '%s' %d\n", rid, fpred, spref, dpref, depth)
	cs := t.IOstats.NewCall(zx.Sfind)
	dc := make(chan zx.Dir)
	go func() {
		rid, err := zx.AbsPath(rid)
		if err != nil {
			cs.End(err != nil)
			t.dprintf("find %s: %s\n", rid, err)
			close(dc, err)
			return
		}
		f, err := t.walk(rid)
		if err != nil {
			cs.End(err != nil)
			t.dprintf("find %s: %s\n", rid, err)
			close(dc, err)
			return
		}
		p, err := pred.New(fpred)
		if err != nil {
			cs.End(err != nil)
			t.dprintf("find %s: %s\n", rid, err)
			close(dc, err)
			return
		}
		d, err := t.statf(f, rid)
		if err != nil {
			cs.End(err != nil)
//.........這裏部分代碼省略.........