storj.io/minio@v0.0.0-20230509071714-0cbc90f649b1/pkg/dsync/rpc-client-impl_test.go (about)

     1  /*
     2   * Minio Cloud Storage, (C) 2016 Minio, Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package dsync_test
    18  
    19  import (
    20  	"context"
    21  	"net/rpc"
    22  	"sync"
    23  
    24  	. "storj.io/minio/pkg/dsync"
    25  )
    26  
    27  // ReconnectRPCClient is a wrapper type for rpc.Client which provides reconnect on first failure.
    28  type ReconnectRPCClient struct {
    29  	mutex    sync.Mutex
    30  	rpc      *rpc.Client
    31  	addr     string
    32  	endpoint string
    33  }
    34  
    35  // newClient constructs a ReconnectRPCClient object with addr and endpoint initialized.
    36  // It _doesn't_ connect to the remote endpoint. See Call method to see when the
    37  // connect happens.
    38  func newClient(addr, endpoint string) NetLocker {
    39  	return &ReconnectRPCClient{
    40  		addr:     addr,
    41  		endpoint: endpoint,
    42  	}
    43  }
    44  
    45  // Close closes the underlying socket file descriptor.
    46  func (rpcClient *ReconnectRPCClient) IsOnline() bool {
    47  	rpcClient.mutex.Lock()
    48  	defer rpcClient.mutex.Unlock()
    49  	// If rpc client has not connected yet there is nothing to close.
    50  	return rpcClient.rpc != nil
    51  }
    52  
    53  func (rpcClient *ReconnectRPCClient) IsLocal() bool {
    54  	return false
    55  }
    56  
    57  // Close closes the underlying socket file descriptor.
    58  func (rpcClient *ReconnectRPCClient) Close() error {
    59  	rpcClient.mutex.Lock()
    60  	defer rpcClient.mutex.Unlock()
    61  	// If rpc client has not connected yet there is nothing to close.
    62  	if rpcClient.rpc == nil {
    63  		return nil
    64  	}
    65  	// Reset rpcClient.rpc to allow for subsequent calls to use a new
    66  	// (socket) connection.
    67  	clnt := rpcClient.rpc
    68  	rpcClient.rpc = nil
    69  	return clnt.Close()
    70  }
    71  
    72  // Call makes a RPC call to the remote endpoint using the default codec, namely encoding/gob.
    73  func (rpcClient *ReconnectRPCClient) Call(serviceMethod string, args interface{}, reply interface{}) (err error) {
    74  	rpcClient.mutex.Lock()
    75  	defer rpcClient.mutex.Unlock()
    76  	dialCall := func() error {
    77  		// If the rpc.Client is nil, we attempt to (re)connect with the remote endpoint.
    78  		if rpcClient.rpc == nil {
    79  			clnt, derr := rpc.DialHTTPPath("tcp", rpcClient.addr, rpcClient.endpoint)
    80  			if derr != nil {
    81  				return derr
    82  			}
    83  			rpcClient.rpc = clnt
    84  		}
    85  		// If the RPC fails due to a network-related error, then we reset
    86  		// rpc.Client for a subsequent reconnect.
    87  		return rpcClient.rpc.Call(serviceMethod, args, reply)
    88  	}
    89  	if err = dialCall(); err == rpc.ErrShutdown {
    90  		rpcClient.rpc.Close()
    91  		rpcClient.rpc = nil
    92  		err = dialCall()
    93  	}
    94  	return err
    95  }
    96  
    97  func (rpcClient *ReconnectRPCClient) RLock(ctx context.Context, args LockArgs) (status bool, err error) {
    98  	err = rpcClient.Call("Dsync.RLock", &args, &status)
    99  	return status, err
   100  }
   101  
   102  func (rpcClient *ReconnectRPCClient) Lock(ctx context.Context, args LockArgs) (status bool, err error) {
   103  	err = rpcClient.Call("Dsync.Lock", &args, &status)
   104  	return status, err
   105  }
   106  
   107  func (rpcClient *ReconnectRPCClient) RUnlock(args LockArgs) (status bool, err error) {
   108  	err = rpcClient.Call("Dsync.RUnlock", &args, &status)
   109  	return status, err
   110  }
   111  
   112  func (rpcClient *ReconnectRPCClient) Unlock(args LockArgs) (status bool, err error) {
   113  	err = rpcClient.Call("Dsync.Unlock", &args, &status)
   114  	return status, err
   115  }
   116  
   117  func (rpcClient *ReconnectRPCClient) Refresh(ctx context.Context, args LockArgs) (refreshed bool, err error) {
   118  	err = rpcClient.Call("Dsync.Refresh", &args, &refreshed)
   119  	return refreshed, err
   120  }
   121  
   122  func (rpcClient *ReconnectRPCClient) ForceUnlock(ctx context.Context, args LockArgs) (reply bool, err error) {
   123  	err = rpcClient.Call("Dsync.ForceUnlock", &args, &reply)
   124  	return reply, err
   125  }
   126  
   127  func (rpcClient *ReconnectRPCClient) String() string {
   128  	return "http://" + rpcClient.addr + "/" + rpcClient.endpoint
   129  }