mirror of https://github.com/minio/minio.git
90 lines
2.5 KiB
Go
90 lines
2.5 KiB
Go
/*
|
|
* 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 main
|
|
|
|
import (
|
|
"net/rpc"
|
|
"sync"
|
|
)
|
|
|
|
// RPCClient is a wrapper type for rpc.Client which provides reconnect on first failure.
|
|
type RPCClient struct {
|
|
sync.Mutex
|
|
rpc *rpc.Client
|
|
node string
|
|
rpcPath string
|
|
}
|
|
|
|
// newClient constructs a RPCClient object with node and rpcPath initialized.
|
|
// It _doesn't_ connect to the remote endpoint. See Call method to see when the
|
|
// connect happens.
|
|
func newClient(node, rpcPath string) *RPCClient {
|
|
return &RPCClient{
|
|
node: node,
|
|
rpcPath: rpcPath,
|
|
}
|
|
}
|
|
|
|
// Close closes the underlying socket file descriptor.
|
|
func (rpcClient *RPCClient) Close() error {
|
|
rpcClient.Lock()
|
|
defer rpcClient.Unlock()
|
|
// Reset rpcClient.rpc to allow for subsequent calls to use a new
|
|
// (socket) connection.
|
|
clnt := rpcClient.rpc
|
|
rpcClient.rpc = nil
|
|
return clnt.Close()
|
|
}
|
|
|
|
// Call makes a RPC call to the remote endpoint using the default codec, namely encoding/gob.
|
|
func (rpcClient *RPCClient) Call(serviceMethod string, args interface{}, reply interface{}) error {
|
|
rpcClient.Lock()
|
|
defer rpcClient.Unlock()
|
|
// If the rpc.Client is nil, we attempt to (re)connect with the remote endpoint.
|
|
if rpcClient.rpc == nil {
|
|
clnt, err := rpc.DialHTTPPath("tcp", rpcClient.node, rpcClient.rpcPath)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
rpcClient.rpc = clnt
|
|
}
|
|
|
|
// If the RPC fails due to a network-related error, then we reset
|
|
// rpc.Client for a subsequent reconnect.
|
|
err := rpcClient.rpc.Call(serviceMethod, args, reply)
|
|
if IsRPCError(err) {
|
|
rpcClient.rpc = nil
|
|
}
|
|
return err
|
|
|
|
}
|
|
|
|
// IsRPCError returns true if the error value is due to a network related
|
|
// failure, false otherwise.
|
|
func IsRPCError(err error) bool {
|
|
if err == nil {
|
|
return false
|
|
}
|
|
// The following are net/rpc specific errors that indicate that
|
|
// the connection may have been reset. Reset rpcClient.rpc to nil
|
|
// to trigger a reconnect in future.
|
|
if err == rpc.ErrShutdown {
|
|
return true
|
|
}
|
|
return false
|
|
}
|