Golang clientv3.Version函数代码示例

// compact compacts etcd store and returns current rev.
// It will return the current compact time and global revision if no error occurred.
// Note that CAS fail will not incur any error.
func compact(ctx context.Context, client *clientv3.Client, t, rev int64) (int64, int64, error) {
	resp, err := client.KV.Txn(ctx).If(
		clientv3.Compare(clientv3.Version(compactRevKey), "=", t),
	).Then(
		clientv3.OpPut(compactRevKey, strconv.FormatInt(rev, 10)), // Expect side effect: increment Version
	).Else(
		clientv3.OpGet(compactRevKey),
	).Commit()
	if err != nil {
		return t, rev, err
	}

	curRev := resp.Header.Revision

	if !resp.Succeeded {
		curTime := resp.Responses[0].GetResponseRange().Kvs[0].Version
		return curTime, curRev, nil
	}
	curTime := t + 1

	if rev == 0 {
		// We don't compact on bootstrap.
		return curTime, curRev, nil
	}
	if _, err = client.Compact(ctx, rev); err != nil {
		return curTime, curRev, err
	}
	glog.Infof("etcd: compacted rev (%d), endpoints (%v)", rev, client.Endpoints())
	return curTime, curRev, nil
}

func (b *blockEtcd) CreateBlockVolume(volume *models.Volume) error {
	new, err := b.AtomicModifyKey([]byte(etcd.MkKey("meta", "volumeminter")), etcd.BytesAddOne)
	volume.Id = new.(uint64)
	if err != nil {
		return err
	}
	vbytes, err := volume.Marshal()
	if err != nil {
		return err
	}
	inodeBytes := torus.NewINodeRef(torus.VolumeID(volume.Id), 1).ToBytes()

	do := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(etcd.MkKey("volumes", volume.Name)), "=", 0),
	).Then(
		etcdv3.OpPut(etcd.MkKey("volumes", volume.Name), string(etcd.Uint64ToBytes(volume.Id))),
		etcdv3.OpPut(etcd.MkKey("volumeid", etcd.Uint64ToHex(volume.Id)), string(vbytes)),
		etcdv3.OpPut(etcd.MkKey("volumemeta", etcd.Uint64ToHex(volume.Id), "inode"), string(etcd.Uint64ToBytes(1))),
		etcdv3.OpPut(etcd.MkKey("volumemeta", etcd.Uint64ToHex(volume.Id), "blockinode"), string(inodeBytes)),
	)
	resp, err := do.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrExists
	}
	return nil
}

func (c *etcdCtx) SetRing(ring torus.Ring) error {
	oldr, etcdver, err := c.getRing()
	if err != nil {
		return err
	}
	if oldr.Version() != ring.Version()-1 {
		return torus.ErrNonSequentialRing
	}
	b, err := ring.Marshal()
	if err != nil {
		return err
	}
	key := MkKey("meta", "the-one-ring")
	txn := c.etcd.Client.Txn(c.getContext()).If(
		etcdv3.Compare(etcdv3.Version(key), "=", etcdver),
	).Then(
		etcdv3.OpPut(key, string(b)),
	)
	resp, err := txn.Commit()
	if err != nil {
		return err
	}
	if resp.Succeeded {
		return nil
	}
	return torus.ErrAgain
}

func (b *blockEtcd) SaveSnapshot(name string) error {
	vid := uint64(b.vid)
	for {
		sshotKey := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "snapshots", name)
		inoKey := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blockinode")
		tx := b.Etcd.Client.Txn(b.getContext()).If(
			etcdv3.Compare(etcdv3.Version(sshotKey), "=", 0),
		).Then(
			etcdv3.OpGet(inoKey),
		)
		resp, err := tx.Commit()
		if err != nil {
			return err
		}
		if !resp.Succeeded {
			return torus.ErrExists
		}
		v := resp.Responses[0].GetResponseRange().Kvs[0]
		inode := Snapshot{
			Name:     name,
			When:     time.Now(),
			INodeRef: v.Value,
		}
		bytes, err := json.Marshal(inode)
		if err != nil {
			return err
		}
		tx = b.Etcd.Client.Txn(b.getContext()).If(
			etcdv3.Compare(etcdv3.Version(inoKey), "=", v.Version),
		).Then(
			etcdv3.OpPut(sshotKey, string(bytes)),
		)
		resp, err = tx.Commit()
		if err != nil {
			return err
		}
		if !resp.Succeeded {
			continue
		}
		return nil
	}

}

// putNewKV attempts to create the given key, only succeeding if the key did
// not yet exist.
func putNewKV(kv v3.KV, key, val string, leaseID v3.LeaseID) (int64, error) {
	cmp := v3.Compare(v3.Version(key), "=", 0)
	req := v3.OpPut(key, val, v3.WithLease(leaseID))
	txnresp, err := kv.Txn(context.TODO()).If(cmp).Then(req).Commit()
	if err != nil {
		return 0, err
	}
	if !txnresp.Succeeded {
		return 0, ErrKeyExists
	}
	return txnresp.Header.Revision, nil
}

func parseCompare(line string) (*clientv3.Cmp, error) {
	var (
		key string
		op  string
		val string
	)

	lparenSplit := strings.SplitN(line, "(", 2)
	if len(lparenSplit) != 2 {
		return nil, fmt.Errorf("malformed comparison: %s", line)
	}

	target := lparenSplit[0]
	n, serr := fmt.Sscanf(lparenSplit[1], "%q) %s %q", &key, &op, &val)
	if n != 3 {
		return nil, fmt.Errorf("malformed comparison: %s; got %s(%q) %s %q", line, target, key, op, val)
	}
	if serr != nil {
		return nil, fmt.Errorf("malformed comparison: %s (%v)", line, serr)
	}

	var (
		v   int64
		err error
		cmp clientv3.Cmp
	)
	switch target {
	case "ver", "version":
		if v, err = strconv.ParseInt(val, 10, 64); err == nil {
			cmp = clientv3.Compare(clientv3.Version(key), op, v)
		}
	case "c", "create":
		if v, err = strconv.ParseInt(val, 10, 64); err == nil {
			cmp = clientv3.Compare(clientv3.CreateRevision(key), op, v)
		}
	case "m", "mod":
		if v, err = strconv.ParseInt(val, 10, 64); err == nil {
			cmp = clientv3.Compare(clientv3.ModRevision(key), op, v)
		}
	case "val", "value":
		cmp = clientv3.Compare(clientv3.Value(key), op, val)
	default:
		return nil, fmt.Errorf("malformed comparison: %s (unknown target %s)", line, target)
	}

	if err != nil {
		return nil, fmt.Errorf("invalid txn compare request: %s", line)
	}

	return &cmp, nil
}

func (b *blockEtcd) DeleteSnapshot(name string) error {
	vid := uint64(b.vid)
	k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "snapshots", name)
	tx := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(k), ">", 0),
	).Then(
		etcdv3.OpDelete(k),
	)
	resp, err := tx.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrLocked
	}
	return nil
}

func (b *blockEtcd) Unlock() error {
	vid := uint64(b.vid)
	k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")
	tx := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(k), ">", 0),
		etcdv3.Compare(etcdv3.Value(k), "=", b.Etcd.UUID()),
	).Then(
		etcdv3.OpDelete(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")),
	)
	resp, err := tx.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrLocked
	}
	return nil
}

func (b *blockEtcd) Lock(lease int64) error {
	if lease == 0 {
		return torus.ErrInvalid
	}
	k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(uint64(b.vid)), "blocklock")
	tx := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(k), "=", 0),
	).Then(
		etcdv3.OpPut(k, b.Etcd.UUID(), etcdv3.WithLease(etcdv3.LeaseID(lease))),
	)
	resp, err := tx.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrLocked
	}
	return nil
}

func (b *blockEtcd) DeleteVolume() error {
	vid := uint64(b.vid)
	tx := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")), "=", 0),
	).Then(
		etcdv3.OpDelete(etcd.MkKey("volumes", b.name)),
		etcdv3.OpDelete(etcd.MkKey("volumeid", etcd.Uint64ToHex(vid))),
		etcdv3.OpDelete(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid)), etcdv3.WithPrefix()),
	)
	resp, err := tx.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrLocked
	}
	return nil

}

func (b *blockEtcd) SyncINode(inode torus.INodeRef) error {
	vid := uint64(inode.Volume())
	inodeBytes := string(inode.ToBytes())
	k := etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blocklock")
	tx := b.Etcd.Client.Txn(b.getContext()).If(
		etcdv3.Compare(etcdv3.Version(k), ">", 0),
		etcdv3.Compare(etcdv3.Value(k), "=", b.Etcd.UUID()),
	).Then(
		etcdv3.OpPut(etcd.MkKey("volumemeta", etcd.Uint64ToHex(vid), "blockinode"), inodeBytes),
	)
	resp, err := tx.Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrLocked
	}
	return nil
}

func initEtcdMetadata(cfg torus.Config, gmd torus.GlobalMetadata, ringType torus.RingType) error {
	gmdbytes, err := json.Marshal(gmd)
	if err != nil {
		return err
	}
	emptyRing, err := ring.CreateRing(&models.Ring{
		Type:              uint32(ringType),
		Version:           1,
		ReplicationFactor: 2,
	})
	if err != nil {
		return err
	}
	ringb, err := emptyRing.Marshal()
	if err != nil {
		return err
	}

	client, err := etcdv3.New(etcdv3.Config{Endpoints: []string{cfg.MetadataAddress}, TLS: cfg.TLS})
	if err != nil {
		return err
	}
	defer client.Close()

	txn := client.Txn(context.Background())
	resp, err := txn.If(
		etcdv3.Compare(etcdv3.Version(MkKey("meta", "globalmetadata")), "=", 0),
	).Then(
		etcdv3.OpPut(MkKey("meta", "volumeminter"), string(Uint64ToBytes(1))),
		etcdv3.OpPut(MkKey("meta", "globalmetadata"), string(gmdbytes)),
	).Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrExists
	}
	_, err = client.Put(context.Background(), MkKey("meta", "the-one-ring"), string(ringb))
	if err != nil {
		return err
	}
	return nil
}

func (c *etcdCtx) AtomicModifyKey(k []byte, f AtomicModifyFunc) (interface{}, error) {
	key := string(k)
	resp, err := c.etcd.Client.Get(c.getContext(), key)
	if err != nil {
		return nil, err
	}
	var version int64
	var value []byte
	if len(resp.Kvs) != 1 {
		version = 0
		value = []byte{}
	} else {
		kv := resp.Kvs[0]
		version = kv.Version
		value = kv.Value
	}
	for {
		newBytes, fval, err := f(value)
		if err != nil {
			return nil, err
		}
		txn := c.etcd.Client.Txn(c.getContext()).If(
			etcdv3.Compare(etcdv3.Version(key), "=", version),
		).Then(
			etcdv3.OpPut(key, string(newBytes)),
		).Else(
			etcdv3.OpGet(key),
		)
		resp, err := txn.Commit()
		if err != nil {
			return nil, err
		}
		if resp.Succeeded {
			return fval, nil
		}
		promAtomicRetries.WithLabelValues(string(key)).Inc()
		kv := resp.Responses[0].GetResponseRange().Kvs[0]
		version = kv.Version
		value = kv.Value
	}
}

func (e *Etcd) getGlobalMetadata() error {
	txn := e.Client.Txn(context.Background())
	resp, err := txn.If(
		etcdv3.Compare(etcdv3.Version(MkKey("meta", "globalmetadata")), ">", 0),
	).Then(
		etcdv3.OpGet(MkKey("meta", "globalmetadata")),
	).Commit()
	if err != nil {
		return err
	}
	if !resp.Succeeded {
		return torus.ErrNoGlobalMetadata
	}

	var gmd torus.GlobalMetadata
	err = json.Unmarshal(resp.Responses[0].GetResponseRange().Kvs[0].Value, &gmd)
	if err != nil {
		return err
	}
	e.global = gmd
	return nil
}