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 (
  20         "fmt"
  21         "os"
  22         "time"
  23 )
  24
  25 /*
  26         Disconnect from a STOMP broker.
  27
  28         Shut down heart beats if necessary.
  29         Set connection status to false to disable further actions with this
  30         connection.
  31
  32
  33         Obtain a receipt unless the client specifically indicates a receipt request
  34         should be excluded.  If the client  actually asks for a receipt, use the
  35         supplied receipt id.  Otherwise generate a unique receipt id and add that
  36         to the DISCONNECT headers.
  37
  38         Example:
  39                 h := stompngo.Headers{HK_RECEIPT, "receipt-id1"} // Ask for a receipt
  40                 e := c.Disconnect(h)
  41                 if e != nil {
  42                         // Do something sane ...
  43                 }
  44                 fmt.Printf("%q\n", c.DisconnectReceipt)
  45                 // Or:
  46                 h := stompngo.Headers{"noreceipt", "true"} // Ask for a receipt
  47                 e := c.Disconnect(h)
  48                 if e != nil {
  49                         // Do something sane ...
  50                 }
  51                 fmt.Printf("%q\n", c.DisconnectReceipt)
  52
  53 */
  54 func (c *Connection) Disconnect(h Headers) error {
  55         c.discLock.Lock()
  56         defer c.discLock.Unlock()
  57         //
  58         if !c.isConnected() {
  59                 return ECONBAD
  60         }
  61         c.log(DISCONNECT, "start", h)
  62         e := checkHeaders(h, c.Protocol())
  63         if e != nil {
  64                 return e
  65         }
  66         ch := h.Clone()
  67         // If the caller does not want a receipt do not ask for one.  Otherwise,
  68         // add a receipt request if caller did not specifically ask for one.  This is
  69         // in the spirit of the specification, and allows reasonable resource cleanup
  70         // in both the client and the message broker.
  71         _, cwr := ch.Contains("noreceipt")
  72         if !cwr {
  73                 if _, ok := ch.Contains(HK_RECEIPT); !ok {
  74                         ch = append(ch, HK_RECEIPT, Uuid())
  75                 }
  76         }
  77         wrid := ""
  78         wrid, _ = ch.Contains(HK_RECEIPT)
  79         _ = wrid
  80         //
  81         f := Frame{DISCONNECT, ch, NULLBUFF}
  82         //
  83         r := make(chan error)
  84         if e = c.writeWireData(wiredata{f, r}); e != nil {
  85                 return e
  86         }
  87         e = <-r
  88         // Drive shutdown logic
  89         // Only set DisconnectReceipt if we sucessfully received one, and it is
  90         // the one we were expecting.
  91         if !cwr && e == nil {
  92                 // Can be RECEIPT or ERROR frame
  93                 mds, e := c.getMessageData()
  94                 //
  95                 // fmt.Println(DISCONNECT, "sanchek", mds)
  96                 //
  97                 switch mds.Message.Command {
  98                 case ERROR:
  99                         e = fmt.Errorf("DISBRKERR -> %q", mds.Message)
 100                         c.log(DISCONNECT, "errf", e)
 101                 case RECEIPT:
 102                         gr := mds.Message.Headers.Value(HK_RECEIPT_ID)
 103                         if wrid != gr {
 104                                 e = fmt.Errorf("%s wanted:%s got:%s", EBADRID, wrid, gr)
 105                                 c.log(DISCONNECT, "nadrid", e)
 106                         } else {
 107                                 c.DisconnectReceipt = mds
 108                                 c.log(DISCONNECT, "OK")
 109                         }
 110                 default:
 111                         e = fmt.Errorf("DISBADFRM -> %q", mds.Message)
 112                         c.log(DISCONNECT, "badf", e)
 113                 }
 114         }
 115         c.log(DISCONNECT, "ends", ch)
 116         c.shutdown()
 117         c.sysAbort()
 118         c.log(DISCONNECT, "system shutdown cannel closed")
 119         return e
 120 }
 121
 122 func (c *Connection) getMessageData() (MessageData, error) {
 123         var md MessageData
 124         var me error
 125         me = nil
 126         if os.Getenv("STOMP_MAXDISCTO") != "" {
 127                 d, e := time.ParseDuration(os.Getenv("STOMP_MAXDISCTO"))
 128                 if e != nil {
 129                         c.log("DISCGETMD PDERROR -> ", e)
 130                         md = <-c.input
 131                 } else {
 132                         c.log("DISCGETMD DUR -> ", d)
 133                         ticker := time.NewTicker(d)
 134                         select {
 135                         case _ = <-ticker.C:
 136                                 me = EDISCTO
 137                                 ticker.Stop()
 138                         case md = <-c.input:
 139                                 ticker.Stop()
 140                         }
 141                 }
 142         } else {
 143                 c.log("DISNOMAX", me)
 144                 md = <-c.input
 145         }
 146         //
 147         return md, me
 148 }