Add missing rpc-client.go - missing in previous commit.

vendor/github.com/minio/dsync/rpc-client.go

@@ -0,0 +1,82 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed 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 dsync
+
+import (
+	"net/rpc"
+	"reflect"
+	"sync"
+)
+
+// Wrapper type for rpc.Client that provides connection management like
+// reconnect on first failure.
+type RPCClient struct {
+	sync.Mutex
+	rpc     *rpc.Client
+	node    string
+	rpcPath string
+}
+
+func newClient(node, rpcPath string) *RPCClient {
+	return &RPCClient{
+		node:    node,
+		rpcPath: rpcPath,
+	}
+}
+
+func (rpcClient *RPCClient) SetRPC(rpc *rpc.Client) {
+	rpcClient.Lock()
+	defer rpcClient.Unlock()
+	rpcClient.rpc = rpc
+}
+func (rpcClient *RPCClient) Close() error {
+	rpcClient.Lock()
+	defer rpcClient.Unlock()
+	return rpcClient.rpc.Close()
+}
+
+func (rpcClient *RPCClient) Call(serviceMethod string, args interface{}, reply interface{}) error {
+	rpcClient.Lock()
+	defer rpcClient.Unlock()
+	if rpcClient.rpc == nil {
+		return rpc.ErrShutdown
+	}
+	err := rpcClient.rpc.Call(serviceMethod, args, reply)
+	return err
+
+}
+
+func (rpcClient *RPCClient) Reconnect() error {
+	rpcClient.Lock()
+	defer rpcClient.Unlock()
+	clnt, err := rpc.DialHTTPPath("tcp", rpcClient.node, rpcClient.rpcPath)
+	if err != nil {
+		return err
+	}
+	rpcClient.rpc = clnt
+	return nil
+}
+
+func IsRPCError(err error) bool {
+	// The following are net/rpc specific errors that indicate that
+	// the connection may have been reset.
+	if err == rpc.ErrShutdown ||
+		reflect.TypeOf(err) == reflect.TypeOf((*rpc.ServerError)(nil)).Elem() {
+		return true
+	}
+	return false
+}