Diff: MQTT/MQTTClient.h

Revision:

9:58eb378727d9

Parent:

8:80d49dd91542

Child:

10:0b5e0dfee08e

diff -r 80d49dd91542 -r 58eb378727d9 MQTT/MQTTClient.h
--- a/MQTT/MQTTClient.h	Wed Oct 01 13:27:35 2014 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,875 +0,0 @@
-/*******************************************************************************
- * Copyright (c) 2014 IBM Corp.
- *
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * and Eclipse Distribution License v1.0 which accompany this distribution.
- *
- * The Eclipse Public License is available at
- *    http://www.eclipse.org/legal/epl-v10.html
- * and the Eclipse Distribution License is available at
- *   http://www.eclipse.org/org/documents/edl-v10.php.
- *
- * Contributors:
- *    Ian Craggs - initial API and implementation and/or initial documentation
- *******************************************************************************/
-
-#if !defined(MQTTCLIENT_H)
-#define MQTTCLIENT_H
-
-#include "FP.h"
-#include "MQTTPacket.h"
-#include "stdio.h"
-#include "MQTTLogging.h"
-
-#if !defined(MQTTCLIENT_QOS1)
-    #define MQTTCLIENT_QOS1 1
-#endif
-#if !defined(MQTTCLIENT_QOS2)
-    #define MQTTCLIENT_QOS2 0
-#endif
-
-namespace MQTT
-{
-
-
-enum QoS { QOS0, QOS1, QOS2 };
-
-// all failure return codes must be negative
-enum returnCode { BUFFER_OVERFLOW = -2, FAILURE = -1, SUCCESS = 0 };
-
-
-struct Message
-{
-    enum QoS qos;
-    bool retained;
-    bool dup;
-    unsigned short id;
-    void *payload;
-    size_t payloadlen;
-};
-
-
-struct MessageData
-{
-    MessageData(MQTTString &aTopicName, struct Message &aMessage)  : message(aMessage), topicName(aTopicName)
-    { }
-
-    struct Message &message;
-    MQTTString &topicName;
-};
-
-
-class PacketId
-{
-public:
-    PacketId()
-    {
-        next = 0;
-    }
-
-    int getNext()
-    {
-        return next = (next == MAX_PACKET_ID) ? 1 : ++next;
-    }
-
-private:
-    static const int MAX_PACKET_ID = 65535;
-    int next;
-};
-
-
-/**
- * @class Client
- * @brief blocking, non-threaded MQTT client API
- *
- * This version of the API blocks on all method calls, until they are complete.  This means that only one
- * MQTT request can be in process at any one time.
- * @param Network a network class which supports send, receive
- * @param Timer a timer class with the methods:
- */
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE = 100, int MAX_MESSAGE_HANDLERS = 5>
-class Client
-{
-
-public:
-
-    typedef void (*messageHandler)(MessageData&);
-
-    /** Construct the client
-     *  @param network - pointer to an instance of the Network class - must be connected to the endpoint
-     *      before calling MQTT connect
-     *  @param limits an instance of the Limit class - to alter limits as required
-     */
-    Client(Network& network, unsigned int command_timeout_ms = 30000);
-
-    /** Set the default message handling callback - used for any message which does not match a subscription message handler
-     *  @param mh - pointer to the callback function
-     */
-    void setDefaultMessageHandler(messageHandler mh)
-    {
-        defaultMessageHandler.attach(mh);
-    }
-
-    /** MQTT Connect - send an MQTT connect packet down the network and wait for a Connack
-     *  The nework object must be connected to the network endpoint before calling this
-     *  Default connect options are used
-     *  @return success code -
-     */
-    int connect();
-    
-    /** MQTT Connect - send an MQTT connect packet down the network and wait for a Connack
-     *  The nework object must be connected to the network endpoint before calling this
-     *  @param options - connect options
-     *  @return success code -
-     */
-    int connect(MQTTPacket_connectData& options);
-
-    /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs
-     *  @param topic - the topic to publish to
-     *  @param message - the message to send
-     *  @return success code -
-     */
-    int publish(const char* topicName, Message& message);
-    
-    /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs
-     *  @param topic - the topic to publish to
-     *  @param payload - the data to send
-     *  @param payloadlen - the length of the data
-     *  @param qos - the QoS to send the publish at
-     *  @param retained - whether the message should be retained
-     *  @return success code -
-     */
-    int publish(const char* topicName, void* payload, size_t payloadlen, enum QoS qos = QOS0, bool retained = false);
-    
-    /** MQTT Publish - send an MQTT publish packet and wait for all acks to complete for all QoSs
-     *  @param topic - the topic to publish to
-     *  @param payload - the data to send
-     *  @param payloadlen - the length of the data
-     *  @param id - the packet id used - returned 
-     *  @param qos - the QoS to send the publish at
-     *  @param retained - whether the message should be retained
-     *  @return success code -
-     */
-    int publish(const char* topicName, void* payload, size_t payloadlen, unsigned short& id, enum QoS qos = QOS1, bool retained = false);
-
-    /** MQTT Subscribe - send an MQTT subscribe packet and wait for the suback
-     *  @param topicFilter - a topic pattern which can include wildcards
-     *  @param qos - the MQTT QoS to subscribe at
-     *  @param mh - the callback function to be invoked when a message is received for this subscription
-     *  @return success code -
-     */
-    int subscribe(const char* topicFilter, enum QoS qos, messageHandler mh);
-
-    /** MQTT Unsubscribe - send an MQTT unsubscribe packet and wait for the unsuback
-     *  @param topicFilter - a topic pattern which can include wildcards
-     *  @return success code -
-     */
-    int unsubscribe(const char* topicFilter);
-
-    /** MQTT Disconnect - send an MQTT disconnect packet, and clean up any state
-     *  @return success code -
-     */
-    int disconnect();
-
-    /** A call to this API must be made within the keepAlive interval to keep the MQTT connection alive
-     *  yield can be called if no other MQTT operation is needed.  This will also allow messages to be
-     *  received.
-     *  @param timeout_ms the time to wait, in milliseconds
-     *  @return success code - on failure, this means the client has disconnected
-     */
-    int yield(unsigned long timeout_ms = 1000L);
-
-    /** Is the client connected?
-     *  @return flag - is the client connected or not?
-     */
-    bool isConnected()
-    {
-        return isconnected;
-    }
-
-private:
-
-    int cycle(Timer& timer);
-    int waitfor(int packet_type, Timer& timer);
-    int keepalive();
-    int publish(int len, Timer& timer, enum QoS qos);
-
-    int decodePacket(int* value, int timeout);
-    int readPacket(Timer& timer);
-    int sendPacket(int length, Timer& timer);
-    int deliverMessage(MQTTString& topicName, Message& message);
-    bool isTopicMatched(char* topicFilter, MQTTString& topicName);
-
-    Network& ipstack;
-    unsigned long command_timeout_ms;
-
-    unsigned char sendbuf[MAX_MQTT_PACKET_SIZE];
-    unsigned char readbuf[MAX_MQTT_PACKET_SIZE];
-
-    Timer last_sent, last_received;
-    unsigned int keepAliveInterval;
-    bool ping_outstanding;
-    bool cleansession;
-
-    PacketId packetid;
-
-    struct MessageHandlers
-    {
-        const char* topicFilter;
-        FP<void, MessageData&> fp;
-    } messageHandlers[MAX_MESSAGE_HANDLERS];      // Message handlers are indexed by subscription topic
-
-    FP<void, MessageData&> defaultMessageHandler;
-
-    bool isconnected;
-
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-    unsigned char pubbuf[MAX_MQTT_PACKET_SIZE];  // store the last publish for sending on reconnect
-    int inflightLen;
-    unsigned short inflightMsgid;
-    enum QoS inflightQoS;
-#endif
-
-#if MQTTCLIENT_QOS2
-    bool pubrel;
-    #if !defined(MAX_INCOMING_QOS2_MESSAGES)
-        #define MAX_INCOMING_QOS2_MESSAGES 10
-    #endif
-    unsigned short incomingQoS2messages[MAX_INCOMING_QOS2_MESSAGES];
-    bool isQoS2msgidFree(unsigned short id);
-    bool useQoS2msgid(unsigned short id);
-#endif
-
-};
-
-}
-
-
-template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS>
-MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::Client(Network& network, unsigned int command_timeout_ms)  : ipstack(network), packetid()
-{
-    last_sent = Timer();
-    last_received = Timer();
-    ping_outstanding = false;
-    for (int i = 0; i < MAX_MESSAGE_HANDLERS; ++i)
-        messageHandlers[i].topicFilter = 0;
-    this->command_timeout_ms = command_timeout_ms;
-    isconnected = false;
-    
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-    inflightMsgid = 0;
-    inflightQoS = QOS0;
-#endif
-
-    
-#if MQTTCLIENT_QOS2
-    pubrel = false;
-    for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i)
-        incomingQoS2messages[i] = 0;
-#endif
-}
-
-#if MQTTCLIENT_QOS2
-template<class Network, class Timer, int a, int b>
-bool MQTT::Client<Network, Timer, a, b>::isQoS2msgidFree(unsigned short id)
-{
-    for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i)
-    {
-        if (incomingQoS2messages[i] == id)
-            return false;
-    }
-    return true;
-}
-
-
-template<class Network, class Timer, int a, int b>
-bool MQTT::Client<Network, Timer, a, b>::useQoS2msgid(unsigned short id)
-{
-    for (int i = 0; i < MAX_INCOMING_QOS2_MESSAGES; ++i)
-    {
-        if (incomingQoS2messages[i] == 0)
-        {
-            incomingQoS2messages[i] = id;
-            return true;
-        }
-    }
-    return false;
-}
-#endif
-
-
-template<class Network, class Timer, int a, int b>
-int MQTT::Client<Network, Timer, a, b>::sendPacket(int length, Timer& timer)
-{
-    int rc = FAILURE,
-        sent = 0;
-
-    while (sent < length && !timer.expired())
-    {
-        rc = ipstack.write(&sendbuf[sent], length, timer.left_ms());
-        if (rc < 0)  // there was an error writing the data
-            break;
-        sent += rc;
-    }
-    if (sent == length)
-    {
-        if (this->keepAliveInterval > 0)
-            last_sent.countdown(this->keepAliveInterval); // record the fact that we have successfully sent the packet
-        rc = SUCCESS;
-    }
-    else
-        rc = FAILURE;
-        
-#if defined(MQTT_DEBUG)
-    char printbuf[50];
-    DEBUG("Rc %d from sending packet %s\n", rc, MQTTPacket_toString(printbuf, sizeof(printbuf), sendbuf, length));
-#endif
-    return rc;
-}
-
-
-template<class Network, class Timer, int a, int b>
-int MQTT::Client<Network, Timer, a, b>::decodePacket(int* value, int timeout)
-{
-    unsigned char c;
-    int multiplier = 1;
-    int len = 0;
-    const int MAX_NO_OF_REMAINING_LENGTH_BYTES = 4;
-
-    *value = 0;
-    do
-    {
-        int rc = MQTTPACKET_READ_ERROR;
-
-        if (++len > MAX_NO_OF_REMAINING_LENGTH_BYTES)
-        {
-            rc = MQTTPACKET_READ_ERROR; /* bad data */
-            goto exit;
-        }
-        rc = ipstack.read(&c, 1, timeout);
-        if (rc != 1)
-            goto exit;
-        *value += (c & 127) * multiplier;
-        multiplier *= 128;
-    } while ((c & 128) != 0);
-exit:
-    return len;
-}
-
-
-/**
- * If any read fails in this method, then we should disconnect from the network, as on reconnect
- * the packets can be retried.
- * @param timeout the max time to wait for the packet read to complete, in milliseconds
- * @return the MQTT packet type, or -1 if none
- */
-template<class Network, class Timer, int a, int b>
-int MQTT::Client<Network, Timer, a, b>::readPacket(Timer& timer)
-{
-    int rc = FAILURE;
-    MQTTHeader header = {0};
-    int len = 0;
-    int rem_len = 0;
-
-    /* 1. read the header byte.  This has the packet type in it */
-    if (ipstack.read(readbuf, 1, timer.left_ms()) != 1)
-        goto exit;
-
-    len = 1;
-    /* 2. read the remaining length.  This is variable in itself */
-    decodePacket(&rem_len, timer.left_ms());
-    len += MQTTPacket_encode(readbuf + 1, rem_len); /* put the original remaining length into the buffer */
-
-    /* 3. read the rest of the buffer using a callback to supply the rest of the data */
-    if (rem_len > 0 && (ipstack.read(readbuf + len, rem_len, timer.left_ms()) != rem_len))
-        goto exit;
-
-    header.byte = readbuf[0];
-    rc = header.bits.type;
-    if (this->keepAliveInterval > 0)
-        last_received.countdown(this->keepAliveInterval); // record the fact that we have successfully received a packet
-exit:
-        
-#if defined(MQTT_DEBUG)
-    char printbuf[50];
-    DEBUG("Rc %d from receiving packet %s\n", rc, MQTTPacket_toString(printbuf, sizeof(printbuf), readbuf, len));
-#endif
-    return rc;
-}
-
-
-// assume topic filter and name is in correct format
-// # can only be at end
-// + and # can only be next to separator
-template<class Network, class Timer, int a, int b>
-bool MQTT::Client<Network, Timer, a, b>::isTopicMatched(char* topicFilter, MQTTString& topicName)
-{
-    char* curf = topicFilter;
-    char* curn = topicName.lenstring.data;
-    char* curn_end = curn + topicName.lenstring.len;
-
-    while (*curf && curn < curn_end)
-    {
-        if (*curn == '/' && *curf != '/')
-            break;
-        if (*curf != '+' && *curf != '#' && *curf != *curn)
-            break;
-        if (*curf == '+')
-        {   // skip until we meet the next separator, or end of string
-            char* nextpos = curn + 1;
-            while (nextpos < curn_end && *nextpos != '/')
-                nextpos = ++curn + 1;
-        }
-        else if (*curf == '#')
-            curn = curn_end - 1;    // skip until end of string
-        curf++;
-        curn++;
-    };
-
-    return (curn == curn_end) && (*curf == '\0');
-}
-
-
-
-template<class Network, class Timer, int a, int MAX_MESSAGE_HANDLERS>
-int MQTT::Client<Network, Timer, a, MAX_MESSAGE_HANDLERS>::deliverMessage(MQTTString& topicName, Message& message)
-{
-    int rc = FAILURE;
-
-    // we have to find the right message handler - indexed by topic
-    for (int i = 0; i < MAX_MESSAGE_HANDLERS; ++i)
-    {
-        if (messageHandlers[i].topicFilter != 0 && (MQTTPacket_equals(&topicName, (char*)messageHandlers[i].topicFilter) ||
-                isTopicMatched((char*)messageHandlers[i].topicFilter, topicName)))
-        {
-            if (messageHandlers[i].fp.attached())
-            {
-                MessageData md(topicName, message);
-                messageHandlers[i].fp(md);
-                rc = SUCCESS;
-            }
-        }
-    }
-
-    if (rc == FAILURE && defaultMessageHandler.attached())
-    {
-        MessageData md(topicName, message);
-        defaultMessageHandler(md);
-        rc = SUCCESS;
-    }
-
-    return rc;
-}
-
-
-
-template<class Network, class Timer, int a, int b>
-int MQTT::Client<Network, Timer, a, b>::yield(unsigned long timeout_ms)
-{
-    int rc = SUCCESS;
-    Timer timer = Timer();
-
-    timer.countdown_ms(timeout_ms);
-    while (!timer.expired())
-    {
-        if (cycle(timer) == FAILURE)
-        {
-            rc = FAILURE;
-            break;
-        }
-    }
-
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::cycle(Timer& timer)
-{
-    /* get one piece of work off the wire and one pass through */
-
-    // read the socket, see what work is due
-    unsigned short packet_type = readPacket(timer);
-
-    int len = 0,
-        rc = SUCCESS;
-
-    switch (packet_type)
-    {
-        case CONNACK:
-        case PUBACK:
-        case SUBACK:
-            break;
-        case PUBLISH:
-            MQTTString topicName;
-            Message msg;
-            if (MQTTDeserialize_publish((unsigned char*)&msg.dup, (int*)&msg.qos, (unsigned char*)&msg.retained, (unsigned short*)&msg.id, &topicName,
-                                 (unsigned char**)&msg.payload, (int*)&msg.payloadlen, readbuf, MAX_MQTT_PACKET_SIZE) != 1)
-                goto exit;
-#if MQTTCLIENT_QOS2
-            if (msg.qos != QOS2)
-#endif
-                deliverMessage(topicName, msg);
-#if MQTTCLIENT_QOS2
-            else if (isQoS2msgidFree(msg.id))
-            {
-                if (useQoS2msgid(msg.id))
-                    deliverMessage(topicName, msg);
-                else
-                    WARN("Maximum number of incoming QoS2 messages exceeded");
-            }   
-#endif
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-            if (msg.qos != QOS0)
-            {
-                if (msg.qos == QOS1)
-                    len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBACK, 0, msg.id);
-                else if (msg.qos == QOS2)
-                    len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBREC, 0, msg.id);
-                if (len <= 0)
-                    rc = FAILURE;
-                else
-                    rc = sendPacket(len, timer);
-                if (rc == FAILURE)
-                    goto exit; // there was a problem
-            }
-            break;
-#endif
-#if MQTTCLIENT_QOS2
-        case PUBREC:
-            unsigned short mypacketid;
-            unsigned char dup, type;
-            if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1)
-                rc = FAILURE;
-            else if ((len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBREL, 0, mypacketid)) <= 0)
-                rc = FAILURE;
-            else if ((rc = sendPacket(len, timer)) != SUCCESS) // send the PUBREL packet
-                rc = FAILURE; // there was a problem
-            if (rc == FAILURE)
-                goto exit; // there was a problem
-            break;
-        case PUBCOMP:
-            break;
-#endif
-        case PINGRESP:
-            ping_outstanding = false;
-            break;
-    }
-    keepalive();
-exit:
-    if (rc == SUCCESS)
-        rc = packet_type;
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::keepalive()
-{
-    int rc = FAILURE;
-
-    if (keepAliveInterval == 0)
-    {
-        rc = SUCCESS;
-        goto exit;
-    }
-
-    if (last_sent.expired() || last_received.expired())
-    {
-        if (!ping_outstanding)
-        {
-            Timer timer = Timer(1000);
-            int len = MQTTSerialize_pingreq(sendbuf, MAX_MQTT_PACKET_SIZE);
-            if (len > 0 && (rc = sendPacket(len, timer)) == SUCCESS) // send the ping packet
-                ping_outstanding = true;
-        }
-    }
-
-exit:
-    return rc;
-}
-
-
-// only used in single-threaded mode where one command at a time is in process
-template<class Network, class Timer, int a, int b>
-int MQTT::Client<Network, Timer, a, b>::waitfor(int packet_type, Timer& timer)
-{
-    int rc = FAILURE;
-
-    do
-    {
-        if (timer.expired())
-            break; // we timed out
-    }
-    while ((rc = cycle(timer)) != packet_type);
-
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::connect(MQTTPacket_connectData& options)
-{
-    Timer connect_timer = Timer(command_timeout_ms);
-    int rc = FAILURE;
-    int len = 0;
-
-    if (isconnected) // don't send connect packet again if we are already connected
-        goto exit;
-
-    this->keepAliveInterval = options.keepAliveInterval;
-    this->cleansession = options.cleansession;
-    if ((len = MQTTSerialize_connect(sendbuf, MAX_MQTT_PACKET_SIZE, &options)) <= 0)
-        goto exit;
-    if ((rc = sendPacket(len, connect_timer)) != SUCCESS)  // send the connect packet
-        goto exit; // there was a problem
-
-    if (this->keepAliveInterval > 0)
-        last_received.countdown(this->keepAliveInterval);
-    // this will be a blocking call, wait for the connack
-    if (waitfor(CONNACK, connect_timer) == CONNACK)
-    {
-        unsigned char connack_rc = 255;
-        bool sessionPresent = false;
-        if (MQTTDeserialize_connack((unsigned char*)&sessionPresent, &connack_rc, readbuf, MAX_MQTT_PACKET_SIZE) == 1)
-            rc = connack_rc;
-        else
-            rc = FAILURE;
-    }
-    else
-        rc = FAILURE;
-        
-#if MQTTCLIENT_QOS2
-    // resend an inflight publish
-    if (inflightMsgid >0 && inflightQoS == QOS2 && pubrel)
-    {
-        if ((len = MQTTSerialize_ack(sendbuf, MAX_MQTT_PACKET_SIZE, PUBREL, 0, inflightMsgid)) <= 0)
-            rc = FAILURE;
-        else
-            rc = publish(len, connect_timer, inflightQoS);
-    }
-    else
-#endif
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-    if (inflightMsgid > 0)
-    {
-        memcpy(sendbuf, pubbuf, MAX_MQTT_PACKET_SIZE);
-        rc = publish(inflightLen, connect_timer, inflightQoS);
-    }
-#endif
-
-exit:
-    if (rc == SUCCESS)
-        isconnected = true;
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::connect()
-{
-    MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer;
-    return connect(default_options);
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::subscribe(const char* topicFilter, enum QoS qos, messageHandler messageHandler)
-{
-    int rc = FAILURE;
-    Timer timer = Timer(command_timeout_ms);
-    int len = 0;
-    MQTTString topic = {(char*)topicFilter, 0, 0};
-
-    if (!isconnected)
-        goto exit;
-
-    len = MQTTSerialize_subscribe(sendbuf, MAX_MQTT_PACKET_SIZE, 0, packetid.getNext(), 1, &topic, (int*)&qos);
-    if (len <= 0)
-        goto exit;
-    if ((rc = sendPacket(len, timer)) != SUCCESS) // send the subscribe packet
-        goto exit;             // there was a problem
-
-    if (waitfor(SUBACK, timer) == SUBACK)      // wait for suback
-    {
-        int count = 0, grantedQoS = -1;
-        unsigned short mypacketid;
-        if (MQTTDeserialize_suback(&mypacketid, 1, &count, &grantedQoS, readbuf, MAX_MQTT_PACKET_SIZE) == 1)
-            rc = grantedQoS; // 0, 1, 2 or 0x80
-        if (rc != 0x80)
-        {
-            for (int i = 0; i < MAX_MESSAGE_HANDLERS; ++i)
-            {
-                if (messageHandlers[i].topicFilter == 0)
-                {
-                    messageHandlers[i].topicFilter = topicFilter;
-                    messageHandlers[i].fp.attach(messageHandler);
-                    rc = 0;
-                    break;
-                }
-            }
-        }
-    }
-    else
-        rc = FAILURE;
-
-exit:
-    if (rc != SUCCESS)
-        isconnected = false;
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int MAX_MESSAGE_HANDLERS>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, MAX_MESSAGE_HANDLERS>::unsubscribe(const char* topicFilter)
-{
-    int rc = FAILURE;
-    Timer timer = Timer(command_timeout_ms);
-    MQTTString topic = {(char*)topicFilter, 0, 0};
-    int len = 0;
-
-    if (!isconnected)
-        goto exit;
-
-    if ((len = MQTTSerialize_unsubscribe(sendbuf, MAX_MQTT_PACKET_SIZE, 0, packetid.getNext(), 1, &topic)) <= 0)
-        goto exit;
-    if ((rc = sendPacket(len, timer)) != SUCCESS) // send the unsubscribe packet
-        goto exit; // there was a problem
-
-    if (waitfor(UNSUBACK, timer) == UNSUBACK)
-    {
-        unsigned short mypacketid;  // should be the same as the packetid above
-        if (MQTTDeserialize_unsuback(&mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) == 1)
-            rc = 0;
-    }
-    else
-        rc = FAILURE;
-
-exit:
-    if (rc != SUCCESS)
-        isconnected = false;
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(int len, Timer& timer, enum QoS qos)
-{
-    int rc;
-    
-    if ((rc = sendPacket(len, timer)) != SUCCESS) // send the publish packet
-        goto exit; // there was a problem
-
-#if MQTTCLIENT_QOS1 
-    if (qos == QOS1)
-    {
-        if (waitfor(PUBACK, timer) == PUBACK)
-        {
-            unsigned short mypacketid;
-            unsigned char dup, type;
-            if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1)
-                rc = FAILURE;
-            else if (inflightMsgid == mypacketid)
-                inflightMsgid = 0;
-        }
-        else
-            rc = FAILURE;
-    }
-#elif MQTTCLIENT_QOS2
-    else if (qos == QOS2)
-    {
-        if (waitfor(PUBCOMP, timer) == PUBCOMP)
-        {
-            unsigned short mypacketid;
-            unsigned char dup, type;
-            if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, MAX_MQTT_PACKET_SIZE) != 1)
-                rc = FAILURE;
-            else if (inflightMsgid == mypacketid)
-                inflightMsgid = 0;
-        }
-        else
-            rc = FAILURE;
-    }
-#endif
-
-exit:
-    if (rc != SUCCESS)
-        isconnected = false;
-    return rc;
-}
-
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, void* payload, size_t payloadlen, unsigned short& id, enum QoS qos, bool retained)
-{
-    int rc = FAILURE;
-    Timer timer = Timer(command_timeout_ms);
-    MQTTString topicString = MQTTString_initializer;
-    int len = 0;
-
-    if (!isconnected)
-        goto exit;
-        
-    topicString.cstring = (char*)topicName;
-
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-    if (qos == QOS1 || qos == QOS2)
-        id = packetid.getNext();
-#endif
-
-    len = MQTTSerialize_publish(sendbuf, MAX_MQTT_PACKET_SIZE, 0, qos, retained, id,
-              topicString, (unsigned char*)payload, payloadlen);
-    if (len <= 0)
-        goto exit;
-        
-#if MQTTCLIENT_QOS1 || MQTTCLIENT_QOS2
-    if (!cleansession)
-    {
-        memcpy(pubbuf, sendbuf, len);
-        inflightMsgid = id;
-        inflightLen = len;
-        inflightQoS = qos;
-#if MQTTCLIENT_QOS2
-        pubrel = false;
-#endif
-    }
-#endif
-        
-    rc = publish(len, timer, qos);
-exit:
-    return rc;
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, void* payload, size_t payloadlen, enum QoS qos, bool retained)
-{
-    unsigned short id = 0;  // dummy - not used for anything
-    return publish(topicName, payload, payloadlen, id, qos, retained);
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::publish(const char* topicName, Message& message)
-{
-    return publish(topicName, message.payload, message.payloadlen, message.qos, message.retained);
-}
-
-
-template<class Network, class Timer, int MAX_MQTT_PACKET_SIZE, int b>
-int MQTT::Client<Network, Timer, MAX_MQTT_PACKET_SIZE, b>::disconnect()
-{
-    int rc = FAILURE;
-    Timer timer = Timer(command_timeout_ms);     // we might wait for incomplete incoming publishes to complete
-    int len = MQTTSerialize_disconnect(buf, MAX_MQTT_PACKET_SIZE);
-    if (len > 0)
-        rc = sendPacket(len, timer);            // send the disconnect packet
-
-    isconnected = false;
-    return rc;
-}
-
-
-#endif