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         // fmt.Printf("Unsub Headers: %v\n", h)
  42         if !c.connected {
  43                 return ECONBAD
  44         }
  45         e := checkHeaders(h, c.Protocol())
  46         if e != nil {
  47                 return e
  48         }
  49
  50         // Specification Requirements:
  51         // 1.0) requires either a destination header or an id header
  52         // 1.1) ... requires ... the id header ....
  53         // 1.2) an id header MUST be included in the frame
  54         //
  55         _, okd := h.Contains(HK_DESTINATION)
  56         shid, oki := h.Contains(HK_ID)
  57         switch c.Protocol() {
  58         case SPL_12:
  59                 if !oki {
  60                         return EUNOSID
  61                 }
  62         case SPL_11:
  63                 if !oki {
  64                         return EUNOSID
  65                 }
  66         case SPL_10:
  67                 if !oki && !okd {
  68                         return EUNODSID
  69                 }
  70         default:
  71                 panic("unsubscribe version not supported: " + c.Protocol())
  72         }
  73         //
  74         shaid := Sha1(h.Value(HK_DESTINATION)) // Special for 1.0
  75         c.subsLock.RLock()
  76         _, p := c.subs[shid]
  77         _, ps := c.subs[shaid]
  78         c.subsLock.RUnlock()
  79         usekey := ""
  80
  81         switch c.Protocol() {
  82         case SPL_12:
  83                 fallthrough
  84         case SPL_11:
  85                 if !oki {
  86                         return EUNOSID // id required
  87                 }
  88                 if !p { // subscription does not exist
  89                         return EBADSID // invalid subscription-id
  90                 }
  91                 usekey = shid
  92         case SPL_10:
  93                 if !p && !ps {
  94                         return EUNODSID
  95                 }
  96                 usekey = shaid
  97         default:
  98                 panic("unsubscribe version not supported: " + c.Protocol())
  99         }
 100
 101         e = c.transmitCommon(UNSUBSCRIBE, h) // transmitCommon Clones() the headers
 102         if e != nil {
 103                 return e
 104         }
 105
 106         c.subsLock.Lock()
 107         delete(c.subs, usekey)
 108         c.subsLock.Unlock()
 109         c.log(UNSUBSCRIBE, "end", h)
 110         return nil
 111 }