cubefs

1
/*
2
 *
3
 * Copyright 2020 gRPC authors.
4
 *
5
 * Licensed under the Apache License, Version 2.0 (the "License");
6
 * you may not use this file except in compliance with the License.
7
 * You may obtain a copy of the License at
8
 *
9
 *     http://www.apache.org/licenses/LICENSE-2.0
10
 *
11
 * Unless required by applicable law or agreed to in writing, software
12
 * distributed under the License is distributed on an "AS IS" BASIS,
13
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14
 * See the License for the specific language governing permissions and
15
 * limitations under the License.
16
 *
17
 */
18

19
// Package unix implements a resolver for unix targets.
20
package unix
21

22
import (
23
	"fmt"
24

25
	"google.golang.org/grpc/internal/transport/networktype"
26
	"google.golang.org/grpc/resolver"
27
)
28

29
const unixScheme = "unix"
30
const unixAbstractScheme = "unix-abstract"
31

32
type builder struct {
33
	scheme string
34
}
35

36
func (b *builder) Build(target resolver.Target, cc resolver.ClientConn, _ resolver.BuildOptions) (resolver.Resolver, error) {
37
	if target.Authority != "" {
38
		return nil, fmt.Errorf("invalid (non-empty) authority: %v", target.Authority)
39
	}
40
	addr := resolver.Address{Addr: target.Endpoint}
41
	if b.scheme == unixAbstractScheme {
42
		// prepend "\x00" to address for unix-abstract
43
		addr.Addr = "\x00" + addr.Addr
44
	}
45
	cc.UpdateState(resolver.State{Addresses: []resolver.Address{networktype.Set(addr, "unix")}})
46
	return &nopResolver{}, nil
47
}
48

49
func (b *builder) Scheme() string {
50
	return b.scheme
51
}
52

53
type nopResolver struct {
54
}
55

56
func (*nopResolver) ResolveNow(resolver.ResolveNowOptions) {}
57

58
func (*nopResolver) Close() {}
59

60
func init() {
61
	resolver.Register(&builder{scheme: unixScheme})
62
	resolver.Register(&builder{scheme: unixAbstractScheme})
63
}
64