github.com/ethereumproject/go-ethereum@v5.5.2+incompatible/rpc/ipc.go (about)

     1  // Copyright 2015 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package rpc
    18  
    19  import (
    20  	"encoding/json"
    21  	"net"
    22  )
    23  
    24  // CreateIPCListener creates an listener, on Unix platforms this is a unix socket, on Windows this is a named pipe
    25  func CreateIPCListener(endpoint string) (net.Listener, error) {
    26  	return ipcListen(endpoint)
    27  }
    28  
    29  // ipcClient represent an IPC RPC client. It will connect to a given endpoint and tries to communicate with a node using
    30  // JSON serialization.
    31  type ipcClient struct {
    32  	endpoint string
    33  	conn     net.Conn
    34  	out      *json.Encoder
    35  	in       *json.Decoder
    36  }
    37  
    38  // newIPCClient create a new IPC client that will connect on the given endpoint. Messages are JSON encoded and encoded.
    39  // On Unix it assumes the endpoint is the full path to a unix socket, and Windows the endpoint is an identifier for a
    40  // named pipe.
    41  func newIPCClient(endpoint string) (Client, error) {
    42  	conn, err := newIPCConnection(endpoint)
    43  	if err != nil {
    44  		return nil, err
    45  	}
    46  	return &ipcClient{endpoint: endpoint, conn: conn, in: json.NewDecoder(conn), out: json.NewEncoder(conn)}, nil
    47  }
    48  
    49  // Send will serialize the given message and send it to the server.
    50  // When sending the message fails it will try to reconnect once and send the message again.
    51  func (client *ipcClient) Send(msg interface{}) error {
    52  	if err := client.out.Encode(msg); err == nil {
    53  		return nil
    54  	}
    55  
    56  	// retry once
    57  	client.conn.Close()
    58  
    59  	conn, err := newIPCConnection(client.endpoint)
    60  	if err != nil {
    61  		return err
    62  	}
    63  
    64  	client.conn = conn
    65  	client.in = json.NewDecoder(conn)
    66  	client.out = json.NewEncoder(conn)
    67  
    68  	return client.out.Encode(msg)
    69  }
    70  
    71  // Recv will read a message from the connection and tries to parse it. It assumes the received message is JSON encoded.
    72  func (client *ipcClient) Recv(msg interface{}) error {
    73  	return client.in.Decode(&msg)
    74  }
    75  
    76  // Close will close the underlying IPC connection
    77  func (client *ipcClient) Close() {
    78  	client.conn.Close()
    79  }
    80  
    81  // SupportedModules will return the collection of offered RPC modules.
    82  func (client *ipcClient) SupportedModules() (map[string]string, error) {
    83  	return SupportedModules(client)
    84  }