Golang go-datastore.NewKey函數代碼示例

func (ks *DSSuite) TestBasic(c *C) {
	var size = 1000

	d, err := lru.NewDatastore(size)
	c.Check(err, Equals, nil)

	for i := 0; i < size; i++ {
		err := d.Put(ds.NewKey(strconv.Itoa(i)), i)
		c.Check(err, Equals, nil)
	}

	for i := 0; i < size; i++ {
		j, err := d.Get(ds.NewKey(strconv.Itoa(i)))
		c.Check(j, Equals, i)
		c.Check(err, Equals, nil)
	}

	for i := 0; i < size; i++ {
		err := d.Put(ds.NewKey(strconv.Itoa(i+size)), i)
		c.Check(err, Equals, nil)
	}

	for i := 0; i < size; i++ {
		j, err := d.Get(ds.NewKey(strconv.Itoa(i)))
		c.Check(j, Equals, nil)
		c.Check(err, Equals, ds.ErrNotFound)
	}

	for i := 0; i < size; i++ {
		j, err := d.Get(ds.NewKey(strconv.Itoa(i + size)))
		c.Check(j, Equals, i)
		c.Check(err, Equals, nil)
	}
}

func TestCoalesceSamePutDiffPut(t *testing.T) {
	m := setup()
	done := make(chan struct{})

	go func() {
		m.ds.Put(ds.NewKey("foo"), "bar")
		done <- struct{}{}
	}()
	go func() {
		m.ds.Put(ds.NewKey("foo"), "bar")
		done <- struct{}{}
	}()
	go func() {
		m.ds.Put(ds.NewKey("foo"), "bar2")
		done <- struct{}{}
	}()
	go func() {
		m.ds.Put(ds.NewKey("foo"), "bar3")
		done <- struct{}{}
	}()

	<-done
	<-done
	<-done
	<-done

	if m.inside != 3 {
		t.Error("incalls should be 3", m.inside)
	}

	if m.outside != 4 {
		t.Error("outcalls should be 4", m.outside)
	}
}

func TestCoalesceHas(t *testing.T) {
	m := setup()
	done := make(chan struct{})
	errs := make(chan error, 30)

	m.ds.Put(ds.NewKey("foo1"), "bar")
	m.ds.Put(ds.NewKey("foo2"), "baz")

	for i := 0; i < 10; i++ {
		go func() {
			v, err := m.ds.Has(ds.NewKey("foo1"))
			if err != nil {
				errs <- err
			}
			if !v {
				errs <- fmt.Errorf("should have foo1")
			}
			done <- struct{}{}
		}()
	}
	for i := 0; i < 10; i++ {
		go func() {
			v, err := m.ds.Has(ds.NewKey("foo2"))
			if err != nil {
				errs <- err
			}
			if !v {
				errs <- fmt.Errorf("should have foo2")
			}
			done <- struct{}{}
		}()
	}
	for i := 0; i < 10; i++ {
		go func() {
			v, err := m.ds.Has(ds.NewKey("foo3"))
			if err != nil {
				errs <- err
			}
			if v {
				errs <- fmt.Errorf("should not have foo3")
			}
			done <- struct{}{}
		}()
	}

	for i := 0; i < 30; i++ {
		<-done
	}

	if m.inside != 5 {
		t.Error("incalls should be 3", m.inside)
	}

	if m.outside != 32 {
		t.Error("outcalls should be 30", m.outside)
	}
}

func TestCoalesceSameGet(t *testing.T) {
	m := setup()
	done := make(chan struct{})
	errs := make(chan error, 30)

	m.ds.Put(ds.NewKey("foo1"), "bar")
	m.ds.Put(ds.NewKey("foo2"), "baz")

	for i := 0; i < 10; i++ {
		go func() {
			v, err := m.ds.Get(ds.NewKey("foo1"))
			if err != nil {
				errs <- err
			}
			if v != "bar" {
				errs <- fmt.Errorf("v is not bar", v)
			}
			done <- struct{}{}
		}()
	}
	for i := 0; i < 10; i++ {
		go func() {
			v, err := m.ds.Get(ds.NewKey("foo2"))
			if err != nil {
				errs <- err
			}
			if v != "baz" {
				errs <- fmt.Errorf("v is not baz", v)
			}
			done <- struct{}{}
		}()
	}
	for i := 0; i < 10; i++ {
		go func() {
			_, err := m.ds.Get(ds.NewKey("foo3"))
			if err == nil {
				errs <- fmt.Errorf("no error")
			}
			done <- struct{}{}
		}()
	}

	for i := 0; i < 30; i++ {
		<-done
	}

	if m.inside != 5 {
		t.Error("incalls should be 3", m.inside)
	}

	if m.outside != 32 {
		t.Error("outcalls should be 30", m.outside)
	}
}

func (ks *DSSuite) TestBasic(c *C) {

	mpds := ds.NewMapDatastore()
	nsds := ns.Wrap(mpds, ds.NewKey("abc"))

	keys := strsToKeys([]string{
		"foo",
		"foo/bar",
		"foo/bar/baz",
		"foo/barb",
		"foo/bar/bazb",
		"foo/bar/baz/barb",
	})

	for _, k := range keys {
		err := nsds.Put(k, []byte(k.String()))
		c.Check(err, Equals, nil)
	}

	for _, k := range keys {
		v1, err := nsds.Get(k)
		c.Check(err, Equals, nil)
		c.Check(bytes.Equal(v1.([]byte), []byte(k.String())), Equals, true)

		v2, err := mpds.Get(ds.NewKey("abc").Child(k))
		c.Check(err, Equals, nil)
		c.Check(bytes.Equal(v2.([]byte), []byte(k.String())), Equals, true)
	}

	run := func(d ds.Datastore, q dsq.Query) []ds.Key {
		r, err := d.Query(q)
		c.Check(err, Equals, nil)

		e, err := r.Rest()
		c.Check(err, Equals, nil)

		return ds.EntryKeys(e)
	}

	listA := run(mpds, dsq.Query{})
	listB := run(nsds, dsq.Query{})
	c.Check(len(listA), Equals, len(listB))

	// sort them cause yeah.
	sort.Sort(ds.KeySlice(listA))
	sort.Sort(ds.KeySlice(listB))

	for i, kA := range listA {
		kB := listB[i]
		c.Check(nsds.InvertKey(kA), Equals, kB)
		c.Check(kA, Equals, nsds.ConvertKey(kB))
	}
}

// Query implements Datastore.Query
func (d *Datastore) Query(q query.Query) (query.Results, error) {

	results := make(chan query.Result)

	walkFn := func(path string, info os.FileInfo, err error) error {
		// remove ds path prefix
		if strings.HasPrefix(path, d.path) {
			path = path[len(d.path):]
		}

		if !info.IsDir() {
			if strings.HasSuffix(path, ObjectKeySuffix) {
				path = path[:len(path)-len(ObjectKeySuffix)]
			}
			key := ds.NewKey(path)
			entry := query.Entry{Key: key.String(), Value: query.NotFetched}
			results <- query.Result{Entry: entry}
		}
		return nil
	}

	go func() {
		filepath.Walk(d.path, walkFn)
		close(results)
	}()
	r := query.ResultsWithChan(q, results)
	r = query.NaiveQueryApply(q, r)
	return r, nil
}

func strsToKeys(strs []string) []ds.Key {
	keys := make([]ds.Key, len(strs))
	for i, s := range strs {
		keys[i] = ds.NewKey(s)
	}
	return keys
}

// ConvertKey returns a B58 encoded Datastore key
// TODO: this is hacky because it encodes every path component. some
// path components may be proper strings already...
func (b58KeyConverter) ConvertKey(dsk ds.Key) ds.Key {
	k := ds.NewKey("/")
	for _, n := range dsk.Namespaces() {
		k = k.ChildString(b58.Encode([]byte(n)))
	}
	return k
}

// Query implements Query, inverting keys on the way back out.
func (d *datastore) Query(q dsq.Query) (dsq.Results, error) {
	qr, err := d.raw.Query(q)
	if err != nil {
		return nil, err
	}

	ch := make(chan dsq.Result)
	go func() {
		defer close(ch)
		defer qr.Close()

		for r := range qr.Next() {
			if r.Error != nil {
				ch <- r
				continue
			}

			k := ds.NewKey(r.Entry.Key)
			if !d.prefix.IsAncestorOf(k) {
				continue
			}

			r.Entry.Key = d.Datastore.InvertKey(k).String()
			ch <- r
		}
	}()

	return dsq.DerivedResults(qr, ch), nil
}

func Example() {
	mp := ds.NewMapDatastore()
	ns := nsds.Wrap(mp, ds.NewKey("/foo/bar"))

	k := ds.NewKey("/beep")
	v := "boop"

	ns.Put(k, v)
	fmt.Printf("ns.Put %s %s\n", k, v)

	v2, _ := ns.Get(k)
	fmt.Printf("ns.Get %s -> %s\n", k, v2)

	k3 := ds.NewKey("/foo/bar/beep")
	v3, _ := mp.Get(k3)
	fmt.Printf("mp.Get %s -> %s\n", k3, v3)
	// Output:
	// ns.Put /beep boop
	// ns.Get /beep -> boop
	// mp.Get /foo/bar/beep -> boop
}

func addTestCases(t *testing.T, d Datastore, testcases map[string]string) {
	for k, v := range testcases {
		dsk := ds.NewKey(k)
		if err := d.Put(dsk, []byte(v)); err != nil {
			t.Fatal(err)
		}
	}

	for k, v := range testcases {
		dsk := ds.NewKey(k)
		v2, err := d.Get(dsk)
		if err != nil {
			t.Fatal(err)
		}
		v2b := v2.([]byte)
		if string(v2b) != v {
			t.Errorf("%s values differ: %s != %s", k, v, v2)
		}
	}

}

func RunBatchTest(t *testing.T, ds dstore.BatchingDatastore) {
	batch, err := ds.Batch()
	if err != nil {
		t.Fatal(err)
	}

	r := rand.New()
	var blocks [][]byte
	var keys []dstore.Key
	for i := 0; i < 20; i++ {
		blk := make([]byte, 256*1024)
		r.Read(blk)
		blocks = append(blocks, blk)

		key := dstore.NewKey(base32.StdEncoding.EncodeToString(blk[:8]))
		keys = append(keys, key)

		err := batch.Put(key, blk)
		if err != nil {
			t.Fatal(err)
		}
	}

	// Ensure they are not in the datastore before comitting
	for _, k := range keys {
		_, err := ds.Get(k)
		if err == nil {
			t.Fatal("should not have found this block")
		}
	}

	// commit, write them to the datastore
	err = batch.Commit()
	if err != nil {
		t.Fatal(err)
	}

	for i, k := range keys {
		blk, err := ds.Get(k)
		if err != nil {
			t.Fatal(err)
		}

		if !bytes.Equal(blk.([]byte), blocks[i]) {
			t.Fatal("blocks not correct!")
		}
	}
}

func TestPutGetBytes(t *testing.T) {
	client := clientOrAbort(t)
	ds, err := NewDatastore(client)
	if err != nil {
		t.Fatal(err)
	}
	key, val := datastore.NewKey("foo"), []byte("bar")
	dstest.Nil(ds.Put(key, val), t)
	v, err := ds.Get(key)
	if err != nil {
		t.Fatal(err)
	}
	if bytes.Compare(v.([]byte), val) != 0 {
		t.Fail()
	}
}

func TestDelete(t *testing.T) {
	client := clientOrAbort(t)
	ds, err := NewDatastore(client)
	if err != nil {
		t.Fatal(err)
	}
	key, val := datastore.NewKey("foo"), []byte("bar")
	dstest.Nil(ds.Put(key, val), t)
	dstest.Nil(ds.Delete(key), t)

	hasAfterDelete, err := ds.Has(key)
	if err != nil {
		t.Fatal(err)
	}
	if hasAfterDelete {
		t.Fail()
	}
}

// PrefixTransform constructs a KeyTransform with a pair of functions that
// add or remove the given prefix key.
//
// Warning: will panic if prefix not found when it should be there. This is
// to avoid insidious data inconsistency errors.
func PrefixTransform(prefix ds.Key) ktds.KeyTransform {
	return &ktds.Pair{

		// Convert adds the prefix
		Convert: func(k ds.Key) ds.Key {
			return prefix.Child(k)
		},

		// Invert removes the prefix. panics if prefix not found.
		Invert: func(k ds.Key) ds.Key {
			if !prefix.IsAncestorOf(k) {
				fmt.Errorf("Expected prefix (%s) in key (%s)", prefix, k)
				panic("expected prefix not found")
			}

			s := strings.TrimPrefix(k.String(), prefix.String())
			return ds.NewKey(s)
		},
	}
}