1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
package dbus
import (
"context"
"errors"
"strings"
)
// BusObject is the interface of a remote object on which methods can be
// invoked.
type BusObject interface {
Call(method string, flags Flags, args ...interface{}) *Call
CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call
Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call
GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call
AddMatchSignal(iface, member string, options ...MatchOption) *Call
RemoveMatchSignal(iface, member string, options ...MatchOption) *Call
GetProperty(p string) (Variant, error)
Destination() string
Path() ObjectPath
}
// Object represents a remote object on which methods can be invoked.
type Object struct {
conn *Conn
dest string
path ObjectPath
}
// Call calls a method with (*Object).Go and waits for its reply.
func (o *Object) Call(method string, flags Flags, args ...interface{}) *Call {
return <-o.createCall(context.Background(), method, flags, make(chan *Call, 1), args...).Done
}
// CallWithContext acts like Call but takes a context
func (o *Object) CallWithContext(ctx context.Context, method string, flags Flags, args ...interface{}) *Call {
return <-o.createCall(ctx, method, flags, make(chan *Call, 1), args...).Done
}
// MatchOption specifies option for dbus routing match rule. Options can be constructed with WithMatch* helpers.
// For full list of available options consult
// https://dbus.freedesktop.org/doc/dbus-specification.html#message-bus-routing-match-rules
type MatchOption struct {
key string
value string
}
// WithMatchOption creates match option with given key and value
func WithMatchOption(key, value string) MatchOption {
return MatchOption{key, value}
}
// WithMatchObjectPath creates match option that filters events based on given path
func WithMatchObjectPath(path ObjectPath) MatchOption {
return MatchOption{"path", string(path)}
}
func formatMatchOptions(options []MatchOption) string {
items := make([]string, 0, len(options))
for _, option := range options {
items = append(items, option.key+"='"+option.value+"'")
}
return strings.Join(items, ",")
}
// AddMatchSignal subscribes BusObject to signals from specified interface,
// method (member). Additional filter rules can be added via WithMatch* option constructors.
// Note: To filter events by object path you have to specify this path via an option.
func (o *Object) AddMatchSignal(iface, member string, options ...MatchOption) *Call {
base := []MatchOption{
{"type", "signal"},
{"interface", iface},
{"member", member},
}
options = append(base, options...)
return o.conn.BusObject().Call(
"org.freedesktop.DBus.AddMatch",
0,
formatMatchOptions(options),
)
}
// RemoveMatchSignal unsubscribes BusObject from signals from specified interface,
// method (member). Additional filter rules can be added via WithMatch* option constructors
func (o *Object) RemoveMatchSignal(iface, member string, options ...MatchOption) *Call {
base := []MatchOption{
{"type", "signal"},
{"interface", iface},
{"member", member},
}
options = append(base, options...)
return o.conn.BusObject().Call(
"org.freedesktop.DBus.RemoveMatch",
0,
formatMatchOptions(options),
)
}
// Go calls a method with the given arguments asynchronously. It returns a
// Call structure representing this method call. The passed channel will
// return the same value once the call is done. If ch is nil, a new channel
// will be allocated. Otherwise, ch has to be buffered or Go will panic.
//
// If the flags include FlagNoReplyExpected, ch is ignored and a Call structure
// is returned with any error in Err and a closed channel in Done containing
// the returned Call as it's one entry.
//
// If the method parameter contains a dot ('.'), the part before the last dot
// specifies the interface on which the method is called.
func (o *Object) Go(method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
return o.createCall(context.Background(), method, flags, ch, args...)
}
// GoWithContext acts like Go but takes a context
func (o *Object) GoWithContext(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
return o.createCall(ctx, method, flags, ch, args...)
}
func (o *Object) createCall(ctx context.Context, method string, flags Flags, ch chan *Call, args ...interface{}) *Call {
if ctx == nil {
panic("nil context")
}
iface := ""
i := strings.LastIndex(method, ".")
if i != -1 {
iface = method[:i]
}
method = method[i+1:]
msg := new(Message)
msg.Type = TypeMethodCall
msg.serial = o.conn.getSerial()
msg.Flags = flags & (FlagNoAutoStart | FlagNoReplyExpected)
msg.Headers = make(map[HeaderField]Variant)
msg.Headers[FieldPath] = MakeVariant(o.path)
msg.Headers[FieldDestination] = MakeVariant(o.dest)
msg.Headers[FieldMember] = MakeVariant(method)
if iface != "" {
msg.Headers[FieldInterface] = MakeVariant(iface)
}
msg.Body = args
if len(args) > 0 {
msg.Headers[FieldSignature] = MakeVariant(SignatureOf(args...))
}
if msg.Flags&FlagNoReplyExpected == 0 {
if ch == nil {
ch = make(chan *Call, 10)
} else if cap(ch) == 0 {
panic("dbus: unbuffered channel passed to (*Object).Go")
}
ctx, cancel := context.WithCancel(ctx)
call := &Call{
Destination: o.dest,
Path: o.path,
Method: method,
Args: args,
Done: ch,
ctxCanceler: cancel,
ctx: ctx,
}
o.conn.calls.track(msg.serial, call)
o.conn.sendMessageAndIfClosed(msg, func() {
o.conn.calls.handleSendError(msg, ErrClosed)
cancel()
})
go func() {
<-ctx.Done()
o.conn.calls.handleSendError(msg, ctx.Err())
}()
return call
}
done := make(chan *Call, 1)
call := &Call{
Err: nil,
Done: done,
}
defer func() {
call.Done <- call
close(done)
}()
o.conn.sendMessageAndIfClosed(msg, func() {
call.Err = ErrClosed
})
return call
}
// GetProperty calls org.freedesktop.DBus.Properties.GetProperty on the given
// object. The property name must be given in interface.member notation.
func (o *Object) GetProperty(p string) (Variant, error) {
idx := strings.LastIndex(p, ".")
if idx == -1 || idx+1 == len(p) {
return Variant{}, errors.New("dbus: invalid property " + p)
}
iface := p[:idx]
prop := p[idx+1:]
result := Variant{}
err := o.Call("org.freedesktop.DBus.Properties.Get", 0, iface, prop).Store(&result)
if err != nil {
return Variant{}, err
}
return result, nil
}
// Destination returns the destination that calls on (o *Object) are sent to.
func (o *Object) Destination() string {
return o.dest
}
// Path returns the path that calls on (o *Object") are sent to.
func (o *Object) Path() ObjectPath {
return o.path
}
|
