1 package dbus 2 3 import ( 4 "context" 5 "errors" 6 ) 7 8 var errSignature = errors.New("dbus: mismatched signature") 9 10 // Call represents a pending or completed method call. 11 type Call struct { 12 Destination string 13 Path ObjectPath 14 Method string 15 Args []interface{} 16 17 // Strobes when the call is complete. 18 Done chan *Call 19 20 // After completion, the error status. If this is non-nil, it may be an 21 // error message from the peer (with Error as its type) or some other error. 22 Err error 23 24 // Holds the response once the call is done. 25 Body []interface{} 26 27 // ResponseSequence stores the sequence number of the DBus message containing 28 // the call response (or error). This can be compared to the sequence number 29 // of other call responses and signals on this connection to determine their 30 // relative ordering on the underlying DBus connection. 31 // For errors, ResponseSequence is populated only if the error came from a 32 // DBusMessage that was received or if there was an error receiving. In case of 33 // failure to make the call, ResponseSequence will be NoSequence. 34 ResponseSequence Sequence 35 36 // tracks context and canceler 37 ctx context.Context 38 ctxCanceler context.CancelFunc 39 } 40 41 func (c *Call) Context() context.Context { 42 if c.ctx == nil { 43 return context.Background() 44 } 45 46 return c.ctx 47 } 48 49 func (c *Call) ContextCancel() { 50 if c.ctxCanceler != nil { 51 c.ctxCanceler() 52 } 53 } 54 55 // Store stores the body of the reply into the provided pointers. It returns 56 // an error if the signatures of the body and retvalues don't match, or if 57 // the error status is not nil. 58 func (c *Call) Store(retvalues ...interface{}) error { 59 if c.Err != nil { 60 return c.Err 61 } 62 63 return Store(c.Body, retvalues...) 64 } 65 66 func (c *Call) done() { 67 c.Done <- c 68 c.ContextCancel() 69 } 70