Golang KVFlags Examples

Example #1

File: kv.go Project: kunalkushwaha/openstorage

func cas(t *testing.T) {
	fmt.Println("cas")

	kv := kvdb.Instance()
	assert.NotNil(t, kv, "Default KVDB is not set")
	key := "foo/docker"
	val := "great"
	defer func() {
		kv.Delete(key)
	}()

	kvPair, err := kv.Put(key, []byte(val), 10)
	assert.NoError(t, err, "Unxpected error in Put")

	kvPair, err = kv.Get(key)
	assert.NoError(t, err, "Failed in Get")

	_, err = kv.CompareAndSet(kvPair, kvdb.KVFlags(0), []byte("badval"))
	assert.Error(t, err, "CompareAndSet should fail on an incorrect previous value")

	kvPair.ModifiedIndex++
	_, err = kv.CompareAndSet(kvPair, kvdb.KVModifiedIndex, nil)
	assert.Error(t, err, "CompareAndSet should fail on an incorrect modified index")

	kvPair.ModifiedIndex--
	kvPair, err = kv.CompareAndSet(kvPair, kvdb.KVModifiedIndex, nil)
	assert.NoError(t, err, "CompareAndSet should succeed on an correct modified index")

	kvPair, err = kv.CompareAndSet(kvPair, kvdb.KVFlags(0), []byte(val))
	assert.NoError(t, err, "CompareAndSet should succeed on an correct value")

	kvPair, err = kv.CompareAndSet(kvPair, kvdb.KVModifiedIndex, []byte(val))
	assert.NoError(t, err, "CompareAndSet should succeed on an correct value and modified index")
}

Example #2

File: kv.go Project: portworx/kvdb

func cas(kv kvdb.Kvdb, t *testing.T) {
	fmt.Println("\ncas")

	key := "foo/docker"
	val := "great"
	defer func() {
		kv.Delete(key)
	}()

	kvPair, err := kv.Put(key, []byte(val), 0)
	assert.NoError(t, err, "Unxpected error in Put")

	kvPair, err = kv.Get(key)
	assert.NoError(t, err, "Failed in Get")

	_, err = kv.CompareAndSet(kvPair, kvdb.KVFlags(0), []byte("badval"))
	assert.Error(t, err, "CompareAndSet should fail on an incorrect previous value")
	//assert.EqualError(t, err, kvdb.ErrValueMismatch.Error(), "CompareAndSet should return value mismatch error")

	copyKVPair := *kvPair
	copyKVPair.ModifiedIndex++
	_, err = kv.CompareAndSet(&copyKVPair, kvdb.KVModifiedIndex, nil)
	assert.Error(t, err, "CompareAndSet should fail on an incorrect modified index")

	//kvPair.ModifiedIndex--
	copyKVPair.ModifiedIndex--
	kvPair, err = kv.CompareAndSet(&copyKVPair, kvdb.KVModifiedIndex, nil)
	assert.NoError(t, err, "CompareAndSet should succeed on an correct modified index")

	kvPairNew, err := kv.CompareAndSet(kvPair, kvdb.KVFlags(0), []byte(val))
	if err != nil {
		// consul does not handle this kind of compare and set
		assert.EqualError(t, err, kvdb.ErrNotSupported.Error(), "Invalid error returned : %v", err)
	} else {
		assert.NoError(t, err, "CompareAndSet should succeed on an correct value")
	}

	if kvPairNew != nil {
		kvPair = kvPairNew
	}

	kvPair, err = kv.CompareAndSet(kvPair, kvdb.KVModifiedIndex, []byte(val))
	assert.NoError(t, err, "CompareAndSet should succeed on an correct value and modified index")
}

Example #3

File: kv_mem.go Project: pombredanne/openstorage

func (kv *MemKV) CompareAndDelete(kvp *kvdb.KVPair, flags kvdb.KVFlags) (*kvdb.KVPair, error) {
	if flags != kvdb.KVFlags(0) {
		return nil, kvdb.ErrNotSupported
	}
	if result, err := kv.Get(kvp.Key); err != nil {
		return nil, err
	} else if !bytes.Equal(result.Value, kvp.Value) {
		return nil, kvdb.ErrNotFound
	}
	return kv.Delete(kvp.Key)
}

Example #4

File: kv_etcd.go Project: portworx/kvdb

func (kv *etcdKV) Unlock(kvp *kvdb.KVPair) error {
	l, ok := kvp.Lock.(*etcdLock)
	if !ok {
		return fmt.Errorf("Invalid lock structure for key %v", string(kvp.Key))
	}
	l.Lock()
	// Don't modify kvp here, CompareAndDelete does that.
	_, err := kv.CompareAndDelete(kvp, kvdb.KVFlags(0))
	if err == nil {
		l.unlocked = true
		l.Unlock()
		l.done <- struct{}{}
		return nil
	}
	l.Unlock()
	return err
}

Example #5

File: alerts_kvdb.go Project: ModelRocket/openstorage

func getNextIdFromKVDB() (int64, error) {

	kv := kvdb.Instance()

	nextAlertsId := 0
	kvp, err := kv.Create(getNextAlertsIdKey(), strconv.FormatInt(int64(nextAlertsId+1), 10), 0)

	for err != nil {
		kvp, err = kv.GetVal(getNextAlertsIdKey(), &nextAlertsId)
		if err != nil {
			err = ErrNotInitialized
			return int64(nextAlertsId), err
		}
		prevValue := kvp.Value
		kvp.Value = []byte(strconv.FormatInt(int64(nextAlertsId+1), 10))
		kvp, err = kv.CompareAndSet(kvp, kvdb.KVFlags(0), prevValue)
	}

	return int64(nextAlertsId), err
}

Example #6

File: kv_mem.go Project: pombredanne/openstorage

func (kv *MemKV) Unlock(kvp *kvdb.KVPair) error {
	_, err := kv.CompareAndDelete(kvp, kvdb.KVFlags(0))
	return err
}

Example #7

File: kv_etcd.go Project: pombredanne/openstorage

func (kv *EtcdKV) Unlock(kvp *kvdb.KVPair) error {
	// Don't modify kvp here, CompareAndDelete does that.
	_, err := kv.CompareAndDelete(kvp, kvdb.KVFlags(0))
	return err
}