func escapeDhtKey(s string) (key.Key, error) {
	parts := strings.Split(s, "/")
	switch len(parts) {
	case 1:
		return key.B58KeyDecode(s), nil
	case 3:
		k := key.B58KeyDecode(parts[2])
		return key.Key(strings.Join(append(parts[:2], string(k)), "/")), nil
	default:
		return "", errors.New("invalid key")
	}
}

func escapeDhtKey(s string) (key.Key, error) {
	parts := path.SplitList(s)
	switch len(parts) {
	case 1:
		return key.B58KeyDecode(s), nil
	case 3:
		k := key.B58KeyDecode(parts[2])
		return key.Key(path.Join(append(parts[:2], k.String()))), nil
	default:
		return "", errors.New("invalid key")
	}
}

func AddMetadataTo(n *core.IpfsNode, skey string, m *ft.Metadata) (string, error) {
	ukey := key.B58KeyDecode(skey)

	nd, err := n.DAG.Get(n.Context(), ukey)
	if err != nil {
		return "", err
	}

	mdnode := new(dag.Node)
	mdata, err := ft.BytesForMetadata(m)
	if err != nil {
		return "", err
	}

	mdnode.Data = mdata
	if err := mdnode.AddNodeLinkClean("file", nd); err != nil {
		return "", err
	}

	nk, err := n.DAG.Add(mdnode)
	if err != nil {
		return "", err
	}

	return nk.B58String(), nil
}

// ResolveToKey resolves a path to a key.
//
// It first checks if the path is already in the form of just a key (<key> or
// /ipfs/<key>) and returns immediately if so. Otherwise, it falls back onto
// Resolve to perform resolution of the dagnode being referenced.
func ResolveToKey(ctx context.Context, n *IpfsNode, p path.Path) (key.Key, error) {

	// If the path is simply a key, parse and return it. Parsed paths are already
	// normalized (read: prepended with /ipfs/ if needed), so segment[1] should
	// always be the key.
	if p.IsJustAKey() {
		return key.B58KeyDecode(p.Segments()[1]), nil
	}

	// Fall back onto regular dagnode resolution. Retrieve the second-to-last
	// segment of the path and resolve its link to the last segment.
	head, tail, err := p.PopLastSegment()
	if err != nil {
		return key.Key(""), err
	}
	dagnode, err := Resolve(ctx, n, head)
	if err != nil {
		return key.Key(""), err
	}

	// Extract and return the key of the link to the target dag node.
	link, err := dagnode.GetNodeLink(tail)
	if err != nil {
		return key.Key(""), err
	}

	return key.Key(link.Hash), nil
}

//FromB58Slice makes and returns Key from B58String slice
func FromB58Slice(ks []string) Key {
	m := make(Key)
	for _, kk := range ks {
		k := key.B58KeyDecode(kk)
		m.Add(k)
	}
	return m
}

//nameResolve resole name hash using IPNS.
func (p *Peer) nameResolve() (key.Key, error) {
	log.Println("resolving", p.ID.Pretty())
	pt, err := p.myself.ipfsNode.Namesys.Resolve(p.myself.ctx, "/ipns/"+p.ID.Pretty())
	if log.If(err) {
		return "", err
	}
	log.Println("resolved", pt)
	seg := pt.Segments()
	return key.B58KeyDecode(seg[len(seg)-1]), nil
}

func Metadata(n *core.IpfsNode, skey string) (*ft.Metadata, error) {
	ukey := key.B58KeyDecode(skey)

	nd, err := n.DAG.Get(n.Context(), ukey)
	if err != nil {
		return nil, err
	}

	return ft.MetadataFromBytes(nd.Data)
}

// DelBlock deletes the block pointed to by `hash`.
func DelBlock(node *Node, hash gmh.Multihash) error {
	nd, err := node.proc()
	if err != nil {
		log.Warningf("ipfs block-del: %v", err)
		return err
	}

	k := key.B58KeyDecode(hash.B58String())
	return nd.Blocks.DeleteBlock(k)
}

func TestMetadata(t *testing.T) {
	ctx := context.Background()
	// Make some random node
	ds := getDagserv(t)
	data := make([]byte, 1000)
	u.NewTimeSeededRand().Read(data)
	r := bytes.NewReader(data)
	nd, err := importer.BuildDagFromReader(ds, chunk.DefaultSplitter(r))
	if err != nil {
		t.Fatal(err)
	}

	k, err := nd.Key()
	if err != nil {
		t.Fatal(err)
	}

	m := new(ft.Metadata)
	m.MimeType = "THIS IS A TEST"

	// Such effort, many compromise
	ipfsnode := &core.IpfsNode{DAG: ds}

	mdk, err := AddMetadataTo(ipfsnode, k.B58String(), m)
	if err != nil {
		t.Fatal(err)
	}

	rec, err := Metadata(ipfsnode, mdk)
	if err != nil {
		t.Fatal(err)
	}
	if rec.MimeType != m.MimeType {
		t.Fatalf("something went wrong in conversion: '%s' != '%s'", rec.MimeType, m.MimeType)
	}

	retnode, err := ds.Get(ctx, key.B58KeyDecode(mdk))
	if err != nil {
		t.Fatal(err)
	}

	ndr, err := uio.NewDagReader(ctx, retnode, ds)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(ndr)
	if err != nil {
		t.Fatal(err)
	}

	if !bytes.Equal(out, data) {
		t.Fatal("read incorrect data")
	}
}

func pin(n *core.IpfsNode, ctx context.Context, hash string) error {

	hashkey := key.B58KeyDecode(hash)
	node, err := n.DAG.Get(ctx, hashkey)
	if err != nil {
		return err
	}

	err = n.Pinning.Pin(ctx, node, false)
	return err

}

func addDefaultAssets(out io.Writer, repoRoot string) error {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	r, err := fsrepo.Open(repoRoot)
	if err != nil { // NB: repo is owned by the node
		return err
	}

	nd, err := core.NewIPFSNode(ctx, core.Offline(r))
	if err != nil {
		return err
	}
	defer nd.Close()

	dirb := uio.NewDirectory(nd.DAG)

	// add every file in the assets pkg
	for fname, file := range assets.Init_dir {
		buf := bytes.NewBufferString(file)
		s, err := coreunix.Add(nd, buf)
		if err != nil {
			return err
		}

		k := key.B58KeyDecode(s)
		if err := dirb.AddChild(fname, k); err != nil {
			return err
		}
	}

	dir := dirb.GetNode()
	dkey, err := nd.DAG.Add(dir)
	if err != nil {
		return err
	}

	if err := nd.Pinning.Pin(ctx, dir, true); err != nil {
		return err
	}

	if err := nd.Pinning.Flush(); err != nil {
		return err
	}

	if _, err = fmt.Fprintf(out, "to get started, enter:\n"); err != nil {
		return err
	}

	_, err = fmt.Fprintf(out, "\n\tipfs cat /ipfs/%s/readme\n\n", dkey)
	return err
}

// Locate finds the object pointed to by `hash`. It will wait
// for max `timeout` duration if it got less than `n` items in that time.
// If `n` is less than 0, all reachable peers that have `hash` will be returned.
// If `n` is 0, Locate will return immeditately.
// This operation requires online-mode.
func Locate(node *Node, hash gmh.Multihash, n int, t time.Duration) ([]*PeerInfo, error) {
	if n == 0 {
		return []*PeerInfo{}, nil
	}

	// Note: Do not use Maxint32. That makes ipfs allocate
	//       a whole lot of memory. Just assume that 100 is fine.
	if n < 0 {
		n = 100
	}

	if !node.IsOnline() {
		return nil, ErrIsOffline
	}

	nd, err := node.proc()
	if err != nil {
		log.Warningf("ipfs dht: %v", err)
		return nil, err
	}

	dht, ok := nd.Routing.(*ipdht.IpfsDHT)
	if !ok {
		return nil, commands.ErrNotDHT
	}

	ctx, cancel := context.WithTimeout(node.Context, t)
	defer cancel()

	k := key.B58KeyDecode(hash.B58String())
	peers := dht.FindProvidersAsync(ctx, k, n)
	infos := []*PeerInfo{}

	for info := range peers {
		// Converting equal struct into each other is my favourite thing.
		peerInfo := &PeerInfo{
			ID:     info.ID.Pretty(),
			PubKey: node.ipfsNode.Peerstore.PubKey(info.ID),
		}

		for _, addr := range info.Addrs {
			peerInfo.Addrs = append(peerInfo.Addrs, ma.Cast(addr.Bytes()))
		}

		infos = append(infos, peerInfo)
	}

	return infos, nil
}

func loadIndirPin(d ds.Datastore, k ds.Key) (*indirectPin, error) {
	var rcStore map[string]int
	err := loadSet(d, k, &rcStore)
	if err != nil {
		return nil, err
	}

	refcnt := make(map[key.Key]int)
	var keys []key.Key
	for encK, v := range rcStore {
		if v > 0 {
			k := key.B58KeyDecode(encK)
			keys = append(keys, k)
			refcnt[k] = v
		}
	}
	// log.Debugf("indirPin keys: %#v", keys)

	return &indirectPin{blockset: set.SimpleSetFromKeys(keys), refCounts: refcnt}, nil
}

func addLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 4 {
		return "", fmt.Errorf("not enough arguments for add-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]
	childk := key.B58KeyDecode(req.Arguments()[3])

	create, _, err := req.Option("create").Bool()
	if err != nil {
		return "", err
	}

	var createfunc func() *dag.Node
	if create {
		createfunc = func() *dag.Node {
			return &dag.Node{Data: ft.FolderPBData()}
		}
	}

	e := dagutils.NewDagEditor(nd.DAG, root)

	childnd, err := nd.DAG.Get(req.Context(), childk)
	if err != nil {
		return "", err
	}

	err = e.InsertNodeAtPath(req.Context(), path, childnd, createfunc)
	if err != nil {
		return "", err
	}

	nnode := e.GetNode()

	return nnode.Key()
}

func addLinkCaller(req cmds.Request, root *dag.Node) (key.Key, error) {
	if len(req.Arguments()) < 4 {
		return "", fmt.Errorf("not enough arguments for add-link")
	}

	nd, err := req.InvocContext().GetNode()
	if err != nil {
		return "", err
	}

	path := req.Arguments()[2]
	childk := key.B58KeyDecode(req.Arguments()[3])

	parts := strings.Split(path, "/")

	nnode, err := insertNodeAtPath(req.Context(), nd.DAG, root, parts, childk)
	if err != nil {
		return "", err
	}
	return nnode.Key()
}

// CatBlock retuns the data stored in the block pointed to by `hash`.
// It will timeout with util.ErrTimeout if the operation takes too long,
// this includes querying for an non-existing hash.
//
// This operation works offline and online, but if the block is stored
// elsewhere on the net, node must be online to find the block.
func CatBlock(node *Node, hash gmh.Multihash, timeout time.Duration) ([]byte, error) {
	nd, err := node.proc()
	if err != nil {
		log.Warningf("ipfs block-cat: %v", err)
		return nil, err
	}

	ctx, cancel := context.WithTimeout(node.Context, timeout)
	defer cancel()

	k := key.B58KeyDecode(hash.B58String())
	block, err := nd.Blocks.GetBlock(ctx, k)
	if err == context.DeadlineExceeded {
		return nil, util.ErrTimeout
	}

	if err != nil {
		return nil, err
	}

	return block.Data(), nil
}

func addAssetList(nd *core.IpfsNode, l []string) (*key.Key, error) {
	dirb := uio.NewDirectory(nd.DAG)

	for _, p := range l {
		d, err := Asset(p)
		if err != nil {
			return nil, fmt.Errorf("assets: could load Asset '%s': %s", p, err)
		}

		s, err := coreunix.Add(nd, bytes.NewBuffer(d))
		if err != nil {
			return nil, fmt.Errorf("assets: could not Add '%s': %s", p, err)
		}

		fname := filepath.Base(p)
		k := key.B58KeyDecode(s)
		if err := dirb.AddChild(nd.Context(), fname, k); err != nil {
			return nil, fmt.Errorf("assets: could not add '%s' as a child: %s", fname, err)
		}
	}

	dir := dirb.GetNode()
	dkey, err := nd.DAG.Add(dir)
	if err != nil {
		return nil, fmt.Errorf("assets: DAG.Add(dir) failed: %s", err)
	}

	if err := nd.Pinning.Pin(nd.Context(), dir, true); err != nil {
		return nil, fmt.Errorf("assets: Pinning on init-docu failed: %s", err)
	}

	if err := nd.Pinning.Flush(); err != nil {
		return nil, fmt.Errorf("assets: Pinning flush failed: %s", err)
	}

	return &dkey, nil
}

func (i *gatewayHandler) putHandler(w http.ResponseWriter, r *http.Request) {
	// TODO(cryptix): move me to ServeHTTP and pass into all handlers
	ctx, cancel := context.WithCancel(i.node.Context())
	defer cancel()

	rootPath, err := path.ParsePath(r.URL.Path)
	if err != nil {
		webError(w, "putHandler: ipfs path not valid", err, http.StatusBadRequest)
		return
	}

	rsegs := rootPath.Segments()
	if rsegs[0] == ipnsPathPrefix {
		webError(w, "putHandler: updating named entries not supported", errors.New("WritableGateway: ipns put not supported"), http.StatusBadRequest)
		return
	}

	var newnode *dag.Node
	if rsegs[len(rsegs)-1] == "QmUNLLsPACCz1vLxQVkXqqLX5R1X345qqfHbsf67hvA3Nn" {
		newnode = uio.NewEmptyDirectory()
	} else {
		putNode, err := i.newDagFromReader(r.Body)
		if err != nil {
			webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError)
			return
		}
		newnode = putNode
	}

	var newPath string
	if len(rsegs) > 1 {
		newPath = path.Join(rsegs[2:])
	}

	var newkey key.Key
	rnode, err := core.Resolve(ctx, i.node, rootPath)
	switch ev := err.(type) {
	case path.ErrNoLink:
		// ev.Node < node where resolve failed
		// ev.Name < new link
		// but we need to patch from the root
		rnode, err := i.node.DAG.Get(ctx, key.B58KeyDecode(rsegs[1]))
		if err != nil {
			webError(w, "putHandler: Could not create DAG from request", err, http.StatusInternalServerError)
			return
		}

		e := dagutils.NewDagEditor(rnode, i.node.DAG)
		err = e.InsertNodeAtPath(ctx, newPath, newnode, uio.NewEmptyDirectory)
		if err != nil {
			webError(w, "putHandler: InsertNodeAtPath failed", err, http.StatusInternalServerError)
			return
		}

		nnode, err := e.Finalize(i.node.DAG)
		if err != nil {
			webError(w, "putHandler: could not get node", err, http.StatusInternalServerError)
			return
		}

		newkey, err = nnode.Key()
		if err != nil {
			webError(w, "putHandler: could not get key of edited node", err, http.StatusInternalServerError)
			return
		}

	case nil:
		// object set-data case
		rnode.Data = newnode.Data

		newkey, err = i.node.DAG.Add(rnode)
		if err != nil {
			nnk, _ := newnode.Key()
			rk, _ := rnode.Key()
			webError(w, fmt.Sprintf("putHandler: Could not add newnode(%q) to root(%q)", nnk.B58String(), rk.B58String()), err, http.StatusInternalServerError)
			return
		}
	default:
		log.Warningf("putHandler: unhandled resolve error %T", ev)
		webError(w, "could not resolve root DAG", ev, http.StatusInternalServerError)
		return
	}

	i.addUserHeaders(w) // ok, _now_ write user's headers.
	w.Header().Set("IPFS-Hash", newkey.String())
	http.Redirect(w, r, gopath.Join(ipfsPathPrefix, newkey.String(), newPath), http.StatusCreated)
}

	"sync"
	"time"

	ds "github.com/ipfs/go-ipfs/Godeps/_workspace/src/github.com/ipfs/go-datastore"
	context "github.com/ipfs/go-ipfs/Godeps/_workspace/src/golang.org/x/net/context"
	key "github.com/ipfs/go-ipfs/blocks/key"
	"github.com/ipfs/go-ipfs/blocks/set"
	mdag "github.com/ipfs/go-ipfs/merkledag"
	logging "github.com/ipfs/go-ipfs/vendor/QmQg1J6vikuXF9oDvm4wpdeAUvvkVEKW1EYDw9HhTMnP2b/go-log"
)

var log = logging.Logger("pin")

var pinDatastoreKey = ds.NewKey("/local/pins")

var emptyKey = key.B58KeyDecode("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n")

const (
	linkDirect    = "direct"
	linkRecursive = "recursive"
)

type PinMode int

const (
	Recursive PinMode = iota
	Direct
	NotPinned
)

type Pinner interface {

//.........这里部分代码省略.........
	dataa := ioutil.NopCloser(bytes.NewBufferString("testfileA"))
	rfa := files.NewReaderFile("a", "a", dataa, nil)

	// make two files with pipes so we can 'pause' the add for timing of the test
	piper, pipew := io.Pipe()
	hangfile := files.NewReaderFile("b", "b", piper, nil)

	datad := ioutil.NopCloser(bytes.NewBufferString("testfileD"))
	rfd := files.NewReaderFile("d", "d", datad, nil)

	slf := files.NewSliceFile("files", "files", []files.File{rfa, hangfile, rfd})

	addDone := make(chan struct{})
	go func() {
		defer close(addDone)
		defer close(out)
		err := adder.AddFile(slf)

		if err != nil {
			t.Fatal(err)
		}

	}()

	addedHashes := make(map[string]struct{})
	select {
	case o := <-out:
		addedHashes[o.(*AddedObject).Hash] = struct{}{}
	case <-addDone:
		t.Fatal("add shouldnt complete yet")
	}

	var gcout <-chan key.Key
	gcstarted := make(chan struct{})
	go func() {
		defer close(gcstarted)
		gcchan, err := gc.GC(context.Background(), node.Blockstore, node.Pinning)
		if err != nil {
			log.Error("GC ERROR:", err)
			errs <- err
			return
		}

		gcout = gcchan
	}()

	// gc shouldnt start until we let the add finish its current file.
	pipew.Write([]byte("some data for file b"))

	select {
	case <-gcstarted:
		t.Fatal("gc shouldnt have started yet")
	case err := <-errs:
		t.Fatal(err)
	default:
	}

	time.Sleep(time.Millisecond * 100) // make sure gc gets to requesting lock

	// finish write and unblock gc
	pipew.Close()

	// receive next object from adder
	select {
	case o := <-out:
		addedHashes[o.(*AddedObject).Hash] = struct{}{}
	case err := <-errs:
		t.Fatal(err)
	}

	select {
	case <-gcstarted:
	case err := <-errs:
		t.Fatal(err)
	}

	for k := range gcout {
		if _, ok := addedHashes[k.B58String()]; ok {
			t.Fatal("gc'ed a hash we just added")
		}
	}

	var last key.Key
	for a := range out {
		// wait for it to finish
		last = key.B58KeyDecode(a.(*AddedObject).Hash)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
	defer cancel()
	root, err := node.DAG.Get(ctx, last)
	if err != nil {
		t.Fatal(err)
	}

	err = dag.EnumerateChildren(ctx, node.DAG, root, key.NewKeySet())
	if err != nil {
		t.Fatal(err)
	}
}