github.com/digdeepmining/go-atheios@v1.5.13-0.20180902133602-d5687a2e6f43/rpc/client_context_go1.6.go (about)

     1  // Copyright 2016 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  // +build go1.6,!go1.7
    18  
    19  package rpc
    20  
    21  import (
    22  	"net"
    23  	"net/http"
    24  	"time"
    25  
    26  	"golang.org/x/net/context"
    27  )
    28  
    29  // In Go 1.6, net.Dialer gained the ability to cancel via a channel.
    30  
    31  // contextDialer returns a dialer that applies the deadline value from the given context.
    32  func contextDialer(ctx context.Context) *net.Dialer {
    33  	dialer := &net.Dialer{Cancel: ctx.Done(), KeepAlive: tcpKeepAliveInterval}
    34  	if deadline, ok := ctx.Deadline(); ok {
    35  		dialer.Deadline = deadline
    36  	} else {
    37  		dialer.Deadline = time.Now().Add(defaultDialTimeout)
    38  	}
    39  	return dialer
    40  }
    41  
    42  // dialContext connects to the given address, aborting the dial if ctx is canceled.
    43  func dialContext(ctx context.Context, network, addr string) (net.Conn, error) {
    44  	return contextDialer(ctx).Dial(network, addr)
    45  }
    46  
    47  // requestWithContext copies req, adding the cancelation channel and deadline from ctx.
    48  func requestWithContext(c *http.Client, req *http.Request, ctx context.Context) (*http.Client, *http.Request) {
    49  	// We set Timeout on the client for Go <= 1.5. There
    50  	// is no need to do that here because the dial will be canceled
    51  	// by package http.
    52  	req2 := *req
    53  	req2.Cancel = ctx.Done()
    54  	return c, &req2
    55  }