unsubscribe.go

   1 //
   2 // Copyright © 2011-2017 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 //)
  22
  23 /*
  24         Unsubscribe from a STOMP subscription.
  25
  26         Headers MUST contain a "destination" header key, and for Stomp 1.1+,
  27         a "id" header key per the specifications.  The subscription MUST currently
  28         exist for this session.
  29
  30         Example:
  31                 // Possible additional Header keys: "id".
  32                 h := stompngo.Headers{stompngo.HK_DESTINATION, "/queue/myqueue"}
  33                 e := c.Unsubscribe(h)
  34                 if e != nil {
  35                         // Do something sane ...
  36                 }
  37
  38 */
  39 func (c *Connection) Unsubscribe(h Headers) error {
  40         c.log(UNSUBSCRIBE, "start", h)
  41         if !c.connected {
  42                 return ECONBAD
  43         }
  44         e := checkHeaders(h, c.Protocol())
  45         if e != nil {
  46                 return e
  47         }
  48
  49         //
  50         d, okd := h.Contains(HK_DESTINATION)
  51         //fmt.Printf("Unsubscribe Headers 01: <%q> <%t>\n", h, okd)
  52         _ = d
  53         if !okd {
  54                 return EREQDSTUNS
  55         }
  56         //
  57         shid, oki := h.Contains(HK_ID)
  58         shaid := Sha1(h.Value(HK_DESTINATION)) // Special for 1.0
  59         //fmt.Printf("Unsubscribe Headers 02: <%q> <%t>\n", h, oki)
  60         // This is a read lock
  61         //fmt.Printf("UNSUB DBG00 %q\n", c.subs)
  62         c.subsLock.RLock()
  63         _, p := c.subs[shid]
  64         _, ps := c.subs[shaid]
  65         c.subsLock.RUnlock()
  66         //fmt.Printf("UNSUB DBG01 %t %t\n", p, ps)
  67         usekey := ""
  68
  69         switch c.Protocol() {
  70         case SPL_12:
  71                 fallthrough
  72         case SPL_11:
  73                 if !oki {
  74                         return EUNOSID // id required
  75                 }
  76                 if !p { // subscription does not exist
  77                         return EBADSID // invalid subscription-id
  78                 }
  79                 usekey = shid
  80         case SPL_10:
  81                 //
  82                 //fmt.Printf("SPL_10 D01 %v %v %vn", oki, p, ps)
  83                 if !p && !ps {
  84                         return EUNOSID
  85                 }
  86                 usekey = shaid
  87         default:
  88                 panic("unsubscribe version not supported: " + c.Protocol())
  89         }
  90
  91         e = c.transmitCommon(UNSUBSCRIBE, h) // transmitCommon Clones() the headers
  92         if e != nil {
  93                 return e
  94         }
  95
  96         c.subsLock.Lock()
  97         delete(c.subs, usekey)
  98         c.subsLock.Unlock()
  99         c.log(UNSUBSCRIBE, "end", h)
 100         return nil
 101 }