add available cluster support

cluster/cluster_impl/available_cluster.go

@@ -0,0 +1,40 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cluster_impl
+
+import (
+	"github.com/apache/dubbo-go/cluster"
+	"github.com/apache/dubbo-go/common/extension"
+	"github.com/apache/dubbo-go/protocol"
+)
+
+type availableCluster struct{}
+
+const available = "available"
+
+func init() {
+	extension.SetCluster(available, NewAvailableCluster)
+}
+
+func NewAvailableCluster() cluster.Cluster {
+	return &availableCluster{}
+}
+
+func (cluser *availableCluster) Join(directory cluster.Directory) protocol.Invoker {
+	return NewAvailableClusterInvoker(directory)
+}

cluster/cluster_impl/available_cluster_invoker.go

@@ -0,0 +1,61 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cluster_impl
+
+import (
+	"fmt"
+)
+
+import (
+	"github.com/pkg/errors"
+)
+
+import (
+	"github.com/apache/dubbo-go/cluster"
+	"github.com/apache/dubbo-go/protocol"
+)
+
+type availableClusterInvoker struct {
+	baseClusterInvoker
+}
+
+func NewAvailableClusterInvoker(directory cluster.Directory) protocol.Invoker {
+	return &availableClusterInvoker{
+		baseClusterInvoker: newBaseClusterInvoker(directory),
+	}
+}
+
+func (invoker *availableClusterInvoker) Invoke(invocation protocol.Invocation) protocol.Result {
+	invokers := invoker.directory.List(invocation)
+	err := invoker.checkInvokers(invokers, invocation)
+	if err != nil {
+		return &protocol.RPCResult{Err: err}
+	}
+
+	err = invoker.checkWhetherDestroyed()
+	if err != nil {
+		return &protocol.RPCResult{Err: err}
+	}
+
+	for _, ivk := range invokers {
+		if ivk.IsAvailable() {
+			return ivk.Invoke(invocation)
+		}
+	}
+	return &protocol.RPCResult{Err: errors.New(fmt.Sprintf("no provider available in %v", invokers))}
+}

cluster/cluster_impl/available_cluster_invoker_test.go

@@ -0,0 +1,88 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cluster_impl
+
+import (
+	"context"
+	"strings"
+	"testing"
+)
+
+import (
+	"github.com/golang/mock/gomock"
+	"github.com/stretchr/testify/assert"
+)
+
+import (
+	"github.com/apache/dubbo-go/cluster/directory"
+	"github.com/apache/dubbo-go/cluster/loadbalance"
+	"github.com/apache/dubbo-go/common"
+	"github.com/apache/dubbo-go/common/extension"
+	"github.com/apache/dubbo-go/protocol"
+	"github.com/apache/dubbo-go/protocol/invocation"
+	"github.com/apache/dubbo-go/protocol/mock"
+)
+
+var (
+	availableUrl, _ = common.NewURL(context.Background(), "dubbo://192.168.1.1:20000/com.ikurento.user.UserProvider")
+)
+
+func registerAvailable(t *testing.T, invoker *mock.MockInvoker) protocol.Invoker {
+	extension.SetLoadbalance("random", loadbalance.NewRandomLoadBalance)
+	availableCluster := NewAvailableCluster()
+
+	invokers := []protocol.Invoker{}
+	invokers = append(invokers, invoker)
+	invoker.EXPECT().GetUrl().Return(availableUrl)
+
+	staticDir := directory.NewStaticDirectory(invokers)
+	clusterInvoker := availableCluster.Join(staticDir)
+	return clusterInvoker
+}
+
+func TestAvailableClusterInvokerSuccess(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	invoker := mock.NewMockInvoker(ctrl)
+	clusterInvoker := registerAvailable(t, invoker)
+
+	mockResult := &protocol.RPCResult{Rest: rest{tried: 0, success: true}}
+	invoker.EXPECT().IsAvailable().Return(true)
+	invoker.EXPECT().Invoke(gomock.Any()).Return(mockResult)
+
+	result := clusterInvoker.Invoke(&invocation.RPCInvocation{})
+
+	assert.Equal(t, mockResult, result)
+}
+
+func TestAvailableClusterInvokerNoAvail(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	invoker := mock.NewMockInvoker(ctrl)
+	clusterInvoker := registerAvailable(t, invoker)
+
+	invoker.EXPECT().IsAvailable().Return(false)
+
+	result := clusterInvoker.Invoke(&invocation.RPCInvocation{})
+
+	assert.NotNil(t, result.Error())
+	assert.True(t, strings.Contains(result.Error().Error(), "no provider available"))
+	assert.Nil(t, result.Result())
+}