disconnect.go

   1 //
   2 // Copyright © 2011-2019 Guy M. Allard
   3 //
   4 // Licensed under the Apache License, Version 2.0 (the "License");
   5 // you may not use this file except in compliance with the License.
   6 // You may obtain a copy of the License at
   7 //
   8 //     http://www.apache.org/licenses/LICENSE-2.0
   9 //
  10 // Unless required by applicable law or agreed to in writing, software
  11 // distributed under the License is distributed on an "AS IS" BASIS,
  12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 // See the License for the specific language governing permissions and
  14 // limitations under the License.
  15 //
  16
  17 package stompngo
  18
  19 import "fmt"
  20
  21 /*
  22         Disconnect from a STOMP broker.
  23
  24         Shut down heart beats if necessary.
  25         Set connection status to false to disable further actions with this
  26         connection.
  27
  28
  29         Obtain a receipt unless the client specifically indicates a receipt request
  30         should be excluded.  If the client  actually asks for a receipt, use the
  31         supplied receipt id.  Otherwise generate a unique receipt id and add that
  32         to the DISCONNECT headers.
  33
  34         Example:
  35                 h := stompngo.Headers{HK_RECEIPT, "receipt-id1"} // Ask for a receipt
  36                 e := c.Disconnect(h)
  37                 if e != nil {
  38                         // Do something sane ...
  39                 }
  40                 fmt.Printf("%q\n", c.DisconnectReceipt)
  41                 // Or:
  42                 h := stompngo.Headers{"noreceipt", "true"} // Ask for a receipt
  43                 e := c.Disconnect(h)
  44                 if e != nil {
  45                         // Do something sane ...
  46                 }
  47                 fmt.Printf("%q\n", c.DisconnectReceipt)
  48
  49 */
  50 func (c *Connection) Disconnect(h Headers) error {
  51         c.discLock.Lock()
  52         defer c.discLock.Unlock()
  53         //
  54         if !c.isConnected() {
  55                 return ECONBAD
  56         }
  57         c.log(DISCONNECT, "start", h)
  58         e := checkHeaders(h, c.Protocol())
  59         if e != nil {
  60                 return e
  61         }
  62         ch := h.Clone()
  63         // If the caller does not want a receipt do not ask for one.  Otherwise,
  64         // add a receipt request if caller did not specifically ask for one.  This is
  65         // in the spirit of the specification, and allows reasonable resource cleanup
  66         // in both the client and the message broker.
  67         _, cwr := ch.Contains("noreceipt")
  68         if !cwr {
  69                 if _, ok := ch.Contains(HK_RECEIPT); !ok {
  70                         ch = append(ch, HK_RECEIPT, Uuid())
  71                 }
  72         }
  73         wrid := ""
  74         wrid, _ = ch.Contains(HK_RECEIPT)
  75         _ = wrid
  76         //
  77         f := Frame{DISCONNECT, ch, NULLBUFF}
  78         //
  79         r := make(chan error)
  80         if e = c.writeWireData(wiredata{f, r}); e != nil {
  81                 return e
  82         }
  83         e = <-r
  84         // Drive shutdown logic
  85         // Only set DisconnectReceipt if we sucessfully received one, and it is
  86         // the one we were expecting.
  87         if !cwr && e == nil {
  88                 // Can be RECEIPT or ERROR frame
  89                 mds := <-c.input
  90                 //
  91                 // fmt.Println(DISCONNECT, "sanchek", mds)
  92                 //
  93                 switch mds.Message.Command {
  94                 case ERROR:
  95                         e = fmt.Errorf("DISBRKERR -> %q", mds.Message)
  96                         c.log(DISCONNECT, "errf", e)
  97                 case RECEIPT:
  98                         gr := mds.Message.Headers.Value(HK_RECEIPT_ID)
  99                         if wrid != gr {
 100                                 e = fmt.Errorf("%s wanted:%s got:%s", EBADRID, wrid, gr)
 101                                 c.log(DISCONNECT, "nadrid", e)
 102                         } else {
 103                                 c.DisconnectReceipt = mds
 104                         }
 105                 default:
 106                         e = fmt.Errorf("DISBADFRM -> %q", mds.Message)
 107                         c.log(DISCONNECT, "badf", e)
 108                 }
 109         }
 110         c.log(DISCONNECT, "ends", ch)
 111         c.shutdown()
 112         c.sysAbort()
 113         c.log(DISCONNECT, "system shutdown cannel closed")
 114         return e
 115 }