disconnect.go

   1 //
   2 // Copyright © 2011-2018 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 /*
  20         Disconnect from a STOMP broker.
  21
  22         Shut down heart beats if necessary.
  23         Set connection status to false to disable further actions with this
  24         connection.
  25
  26
  27         Obtain a receipt unless the client specifically indicates a receipt request
  28         should be excluded.  If the client  actually asks for a receipt, use the
  29         supplied receipt id.  Otherwise generate a unique receipt id and add that
  30         to the DISCONNECT headers.
  31
  32         Example:
  33                 h := stompngo.Headers{HK_RECEIPT, "receipt-id1"} // Ask for a receipt
  34                 e := c.Disconnect(h)
  35                 if e != nil {
  36                         // Do something sane ...
  37                 }
  38                 fmt.Printf("%q\n", c.DisconnectReceipt)
  39                 // Or:
  40                 h := stompngo.Headers{"noreceipt", "true"} // Ask for a receipt
  41                 e := c.Disconnect(h)
  42                 if e != nil {
  43                         // Do something sane ...
  44                 }
  45                 fmt.Printf("%q\n", c.DisconnectReceipt)
  46
  47 */
  48 func (c *Connection) Disconnect(h Headers) error {
  49         c.discLock.Lock()
  50         defer c.discLock.Unlock()
  51         //
  52         if !c.connected {
  53                 return ECONBAD
  54         }
  55         c.log(DISCONNECT, "start", h)
  56         e := checkHeaders(h, c.Protocol())
  57         if e != nil {
  58                 return e
  59         }
  60         ch := h.Clone()
  61         // If the caller does not want a receipt do not ask for one.  Otherwise,
  62         // add a receipt request if caller did not specifically ask for one.  This is
  63         // in the spirit of the specification, and allows reasonable resource cleanup
  64         // in both the client and the message broker.
  65         _, cwr := ch.Contains("noreceipt")
  66         if !cwr {
  67                 if _, ok := ch.Contains(HK_RECEIPT); !ok {
  68                         ch = append(ch, HK_RECEIPT, Uuid())
  69                 }
  70         }
  71         //
  72         f := Frame{DISCONNECT, ch, NULLBUFF}
  73         //
  74         r := make(chan error)
  75         if e = c.writeWireData(wiredata{f, r}); e != nil {
  76                 return e
  77         }
  78         e = <-r
  79         // Drive shutdown logic
  80         // Only set DisconnectReceipt if we sucessfully received one.
  81         if !cwr && e == nil {
  82                 // Receipt
  83                 c.DisconnectReceipt = <-c.input
  84                 c.log(DISCONNECT, "dr", ch, c.DisconnectReceipt)
  85         }
  86         c.log(DISCONNECT, "ends", ch)
  87         c.shutdown()
  88         c.sysAbort()
  89         c.log(DISCONNECT, "system shutdown cannel closed")
  90         return e
  91 }