cheat/vendor/golang.org/x/net/proxy/dial.go
Christopher Allen Lane 80c91cbdee feat(installer): use go-git to clone
Integrate `go-git` into the application, and use it to `git clone`
cheatsheets when the installer runs.

Previously, the installer required that `git` be installed on the system
`PATH`, so this change has to big advantages:

1. It removes that system dependency on `git`
2. It paves the way for implementing the `--update` command

Additionally, `cheat` now performs a `--depth=1` clone when installing
cheatsheets, which should at least somewhat improve installation times
(especially on slow network connections).
2022-08-27 21:00:46 -04:00

55 lines
1.6 KiB
Go

// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package proxy
import (
"context"
"net"
)
// A ContextDialer dials using a context.
type ContextDialer interface {
DialContext(ctx context.Context, network, address string) (net.Conn, error)
}
// Dial works like DialContext on net.Dialer but using a dialer returned by FromEnvironment.
//
// The passed ctx is only used for returning the Conn, not the lifetime of the Conn.
//
// Custom dialers (registered via RegisterDialerType) that do not implement ContextDialer
// can leak a goroutine for as long as it takes the underlying Dialer implementation to timeout.
//
// A Conn returned from a successful Dial after the context has been cancelled will be immediately closed.
func Dial(ctx context.Context, network, address string) (net.Conn, error) {
d := FromEnvironment()
if xd, ok := d.(ContextDialer); ok {
return xd.DialContext(ctx, network, address)
}
return dialContext(ctx, d, network, address)
}
// WARNING: this can leak a goroutine for as long as the underlying Dialer implementation takes to timeout
// A Conn returned from a successful Dial after the context has been cancelled will be immediately closed.
func dialContext(ctx context.Context, d Dialer, network, address string) (net.Conn, error) {
var (
conn net.Conn
done = make(chan struct{}, 1)
err error
)
go func() {
conn, err = d.Dial(network, address)
close(done)
if conn != nil && ctx.Err() != nil {
conn.Close()
}
}()
select {
case <-ctx.Done():
err = ctx.Err()
case <-done:
}
return conn, err
}