An API for using MQTT over multiple transports

Dependencies:   FP MQTTPacket

Dependents:   Cellular_HelloMQTT IoTStarterKit GSwifiInterface_HelloMQTT IBMIoTClientEthernetExample ... more

This library is part of the EclipseTM Paho project; specifically the embedded client.

The goals of this API are:

  1. to be independent of any system library: hence templates parameters for networking, timer and threading classes
  2. not to rely on heap storage, only automatic (I think this is a good thing)
  3. to limit memory use, for instance by defining the size of the buffers and arrays used at object creation time
Revision:
8:c46930bd6c82
Parent:
7:f9d690fb6dad
Child:
9:01b8cc7d94cc
--- a/MQTTClient.cpp	Wed Apr 09 11:37:28 2014 +0100
+++ b/MQTTClient.cpp	Wed Apr 09 13:48:20 2014 +0000
@@ -17,193 +17,9 @@
 #include "MQTTClient.h"
 #include "MQTTPacket.h"
 
-template<class Network, class Timer, class Thread> MQTT::Client<Network, Timer, Thread>::Client(Network* network, Timer* timer, const int buffer_size, const int command_timeout)
-{
-    
-   buf = new char[buffer_size];
-   readbuf = new char[buffer_size];
-   buflen = readbuflen = buffer_size;
-   this->command_timeout = command_timeout;
-   //this->thread = new Thread(0); // only need a background thread for non-blocking mode
-   this->ipstack = network;
-   this->packetid = 0;
-   this->timer = timer;
-}
 
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::getPacketId()
-{
-	return this->packetid = (this->packetid == MAX_PACKET_ID) ? 1 : ++this->packetid;
-}
-
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::sendPacket(int length, int timeout)
-{
-    int sent = 0;
-    
-    while (sent < length)
-        sent += ipstack->write(&buf[sent], length, -1);
-        
-    return sent;
-}
-
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::decodePacket(int* value, int timeout)
+void MQTT::threadfn(void* arg)
 {
-    char c;
-    int multiplier = 1;
-    int len = 0;
-#define 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, class Thread> int MQTT::Client<Network, Timer, Thread>::readPacket(int timeout) 
-{
-    int rc = -1;
-    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, timeout) != 1)
-        goto exit;
-
-    len = 1;
-    /* 2. read the remaining length.  This is variable in itself */
-    decodePacket(&rem_len, timeout);
-    len += MQTTPacket_encode(readbuf + 1, rem_len); /* put the original remaining length back into the buffer */
-
-    /* 3. read the rest of the buffer using a callback to supply the rest of the data */
-    if (ipstack->read(readbuf + len, rem_len, timeout) != rem_len)
-        goto exit;
-
-    header.byte = readbuf[0];
-    rc = header.bits.type;
-exit:
-    return rc;
+   ((Client<Network, Timer, Thread>*) arg)->run(NULL);
 }
 
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::cycle()
-{
-    int timeout = 1000L;
-    /* get one piece of work off the wire and one pass through */
-    
-    // 1. read the socket, see what work is due. 
-    int packet_type = readPacket(-1);
-
-	printf("packet type %d\n", packet_type);
-    
-    switch (packet_type)
-    {
-        case CONNACK:
-			printf("connack received\n");
-            break;
-        case PUBACK:
-            break;
-        case SUBACK:
-            break;
-        case PUBREC:
-            break;
-        case PUBCOMP:
-            break;
-        case PINGRESP:
-            break;
-    }
-    return packet_type;
-}
-
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::connect(MQTTPacket_connectData* options, FP<void, MQTT::Result*> *resultHandler)
-{
-	int len = 0;
-	int rc = -99;
-	MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer;
-
-    /* 2. if the connect was successful, send the MQTT connect packet */   
-	if (options == 0)
-	{
-		default_options.clientID.cstring = "me";
-		options = &default_options;
-	}
-	
-	this->keepalive = options->keepAliveInterval;
-	len = MQTTSerialize_connect(buf, buflen, options);
-	printf("len from send is %d %d\n", len, buflen);
-    rc = sendPacket(len); // send the connect packet
-	printf("rc from send is %d\n", rc);
-    
-    /* 3. wait until the connack is received */
-    if (resultHandler == 0)
-    {
-        // this will be a blocking call, wait for the connack
-		if (cycle() == CONNACK)
-		{
-			int connack_rc = -1;
-			if (MQTTDeserialize_connack(&connack_rc, readbuf, readbuflen) == 1)
-				rc = connack_rc;
-		}
-    }
-    else
-    {
-        // set connect response callback function
-    }
-    
-    return rc;
-}
-
-
-template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::subscribe(const char* topicFilter, enum QoS qos, FP<void, Message*> messageHandler, 
-		FP<void, Result*> *resultHandler)
-{
-	int rc = -1, 
-	    len = 0;
-	MQTTString topic = {(char*)topicFilter, 0, 0};
-	
-	len = MQTTSerialize_subscribe(buf, buflen, 0, getPacketId(), 1, &topic, (int*)&qos);
-	rc = sendPacket(len); // send the subscribe packet
-	
-	/* wait for suback */
-    if (resultHandler == 0)
-    {
-        // this will block
-		if (cycle() == SUBACK)
-		{
-			int count = 0, grantedQoS = -1;
-			if (MQTTDeserialize_suback(&packetid, 1, &count, &grantedQoS, readbuf, readbuflen) == 1)
-				rc = grantedQoS; // 0, 1, 2 or 0x80 
-		}
-    }
-    else
-    {
-        // set subscribe response callback function
-        
-    }
-	
-	return rc;
-}