Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
137 lines (124 sloc) 3.64 KB
/*
* Copyright (c) 2013 IBM Corp.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Seth Hoenig
* Allan Stockdill-Mander
* Mike Robertson
*/
package mqtt
import (
"fmt"
"strconv"
"github.com/eclipse/paho.mqtt.golang/packets"
)
const (
inboundPrefix = "i."
outboundPrefix = "o."
)
// Store is an interface which can be used to provide implementations
// for message persistence.
// Because we may have to store distinct messages with the same
// message ID, we need a unique key for each message. This is
// possible by prepending "i." or "o." to each message id
type Store interface {
Open()
Put(key string, message packets.ControlPacket)
Get(key string) packets.ControlPacket
All() []string
Del(key string)
Close()
Reset()
}
// A key MUST have the form "X.[messageid]"
// where X is 'i' or 'o'
func mIDFromKey(key string) uint16 {
s := key[2:]
i, err := strconv.Atoi(s)
chkerr(err)
return uint16(i)
}
// Return true if key prefix is outbound
func isKeyOutbound(key string) bool {
return key[:2] == outboundPrefix
}
// Return true if key prefix is inbound
func isKeyInbound(key string) bool {
return key[:2] == inboundPrefix
}
// Return a string of the form "i.[id]"
func inboundKeyFromMID(id uint16) string {
return fmt.Sprintf("%s%d", inboundPrefix, id)
}
// Return a string of the form "o.[id]"
func outboundKeyFromMID(id uint16) string {
return fmt.Sprintf("%s%d", outboundPrefix, id)
}
// govern which outgoing messages are persisted
func persistOutbound(s Store, m packets.ControlPacket) {
switch m.Details().Qos {
case 0:
switch m.(type) {
case *packets.PubackPacket, *packets.PubcompPacket:
// Sending puback. delete matching publish
// from ibound
s.Del(inboundKeyFromMID(m.Details().MessageID))
}
case 1:
switch m.(type) {
case *packets.PublishPacket, *packets.PubrelPacket, *packets.SubscribePacket, *packets.UnsubscribePacket:
// Sending publish. store in obound
// until puback received
s.Put(outboundKeyFromMID(m.Details().MessageID), m)
default:
ERROR.Println(STR, "Asked to persist an invalid message type")
}
case 2:
switch m.(type) {
case *packets.PublishPacket:
// Sending publish. store in obound
// until pubrel received
s.Put(outboundKeyFromMID(m.Details().MessageID), m)
default:
ERROR.Println(STR, "Asked to persist an invalid message type")
}
}
}
// govern which incoming messages are persisted
func persistInbound(s Store, m packets.ControlPacket) {
switch m.Details().Qos {
case 0:
switch m.(type) {
case *packets.PubackPacket, *packets.SubackPacket, *packets.UnsubackPacket, *packets.PubcompPacket:
// Received a puback. delete matching publish
// from obound
s.Del(outboundKeyFromMID(m.Details().MessageID))
case *packets.PublishPacket, *packets.PubrecPacket, *packets.PingrespPacket, *packets.ConnackPacket:
default:
ERROR.Println(STR, "Asked to persist an invalid messages type")
}
case 1:
switch m.(type) {
case *packets.PublishPacket, *packets.PubrelPacket:
// Received a publish. store it in ibound
// until puback sent
s.Put(inboundKeyFromMID(m.Details().MessageID), m)
default:
ERROR.Println(STR, "Asked to persist an invalid messages type")
}
case 2:
switch m.(type) {
case *packets.PublishPacket:
// Received a publish. store it in ibound
// until pubrel received
s.Put(inboundKeyFromMID(m.Details().MessageID), m)
default:
ERROR.Println(STR, "Asked to persist an invalid messages type")
}
}
}
You can’t perform that action at this time.