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:
- to be independent of any system library: hence templates parameters for networking, timer and threading classes
- not to rely on heap storage, only automatic (I think this is a good thing)
- to limit memory use, for instance by defining the size of the buffers and arrays used at object creation time
Revision 16:91c2f9a144d4, committed 2014-04-14
- Comitter:
- icraggs
- Date:
- Mon Apr 14 18:51:52 2014 +0000
- Parent:
- 15:64a57183aa03
- Child:
- 17:4f914fd9ee12
- Commit message:
- Add subscriptions
Changed in this revision
--- a/MQTTClient.h Sun Apr 13 22:32:28 2014 +0000 +++ b/MQTTClient.h Mon Apr 14 18:51:52 2014 +0000 @@ -38,7 +38,6 @@ size_t payloadlen; }; -template<class Network, class Timer, class Thread> class Client; class PacketId { @@ -53,8 +52,25 @@ }; typedef void (*messageHandler)(Message*); + +typedef struct limits +{ + int MAX_MQTT_PACKET_SIZE; // + int MAX_MESSAGE_HANDLERS; // each subscription requires a message handler + int MAX_CONCURRENT_OPERATIONS; // each command which runs concurrently can have a result handler, when we are in multi-threaded mode + int command_timeout; + + limits() + { + MAX_MQTT_PACKET_SIZE = 100; + MAX_MESSAGE_HANDLERS = 5; + MAX_CONCURRENT_OPERATIONS = 1; // 1 indicates single-threaded mode - set to >1 for multithreaded mode + command_timeout = 30; + } +} Limits; -template<class Network, class Timer, class Thread> class Client + +template<class Network, class Timer, class Thread, class Mutex> class Client { public: @@ -62,30 +78,14 @@ struct Result { /* success or failure result data */ - Client<Network, Timer, Thread>* client; + Client<Network, Timer, Thread, Mutex>* client; int connack_rc; }; - typedef void (*resultHandler)(Result*); - - struct limits - { - int MAX_MQTT_PACKET_SIZE; // - int MAX_MESSAGE_HANDLERS; // 5 - each subscription requires a message handler - int MAX_CONCURRENT_OPERATIONS; // each command which runs concurrently can have a result handler, when we are in multi-threaded mode - int command_timeout; - - limits() - { - MAX_MQTT_PACKET_SIZE = 100; - MAX_MESSAGE_HANDLERS = 5; - MAX_CONCURRENT_OPERATIONS= 5; - command_timeout = 30; - } - }; + typedef void (*resultHandler)(Result*); - Client(Network* network, const int MAX_MQTT_PACKET_SIZE = 100, const int command_timeout = 30); - + Client(Network* network, const Limits limits = Limits()); + int connect(MQTTPacket_connectData* options = 0, resultHandler fn = 0); template<class T> @@ -104,48 +104,48 @@ private: int cycle(int timeout); + int waitfor(int packet_type, Timer& atimer); int keepalive(); + int findFreeOperation(); int decodePacket(int* value, int timeout); - int readPacket(int timeout = -1); - int sendPacket(int length, int timeout = -1); + int readPacket(int timeout); + int sendPacket(int length, int timeout); int deliverMessage(MQTTString* topic, Message* message); Thread* thread; Network* ipstack; - Timer command_timer, ping_timer; + + Limits limits; - char buf[]; - int buflen; - + char* buf; char* readbuf; - int readbuflen; + Timer ping_timer, connect_timer; unsigned int keepAliveInterval; bool ping_outstanding; - int command_timeout; // max time to wait for any MQTT command to complete, in seconds PacketId packetid; typedef FP<void, Result*> resultHandlerFP; resultHandlerFP connectHandler; - #define MAX_MESSAGE_HANDLERS 5 typedef FP<void, Message*> messageHandlerFP; - struct + struct MessageHandlers { - char* topic; + const char* topic; messageHandlerFP fp; - } messageHandlers[MAX_MESSAGE_HANDLERS]; // Message handlers are linked to a subscription topic + } *messageHandlers; // Message handlers are indexed by subscription topic // how many concurrent operations should we allow? Each one will require a function pointer - struct + struct Operations { unsigned short id; resultHandlerFP fp; - MQTTString* topic; // if this is a publish, store topic name in case republishing is required - Message* message; // for publish, - } *operations; // result handlers are indexed by packet ids + const char* topic; // if this is a publish, store topic name in case republishing is required + Message* message; // for publish, + Timer timer; // to check if the command has timed out + } *operations; // result handlers are indexed by packet ids static void threadfn(void* arg); @@ -154,40 +154,44 @@ } -template<class Network, class Timer, class Thread> void MQTT::Client<Network, Timer, Thread>::threadfn(void* arg) +template<class Network, class Timer, class Thread, class Mutex> void MQTT::Client<Network, Timer, Thread, Mutex>::threadfn(void* arg) { - ((Client<Network, Timer, Thread>*) arg)->run(NULL); + ((Client<Network, Timer, Thread, Mutex>*) arg)->run(NULL); } -template<class Network, class Timer, class Thread> MQTT::Client<Network, Timer, Thread>::Client(Network* network, const int MAX_MQTT_PACKET_SIZE, const int command_timeout) : packetid() +template<class Network, class Timer, class Thread, class Mutex> MQTT::Client<Network, Timer, Thread, Mutex>::Client(Network* network, Limits limits) : limits(limits), packetid() { - //buf = new char[MAX_MQTT_PACKET_SIZE]; - readbuf = new char[MAX_MQTT_PACKET_SIZE]; - buflen = readbuflen = MAX_MQTT_PACKET_SIZE; - - this->command_timeout = command_timeout; - this->thread = 0; - this->ipstack = network; - this->command_timer = Timer(); - this->ping_timer = Timer(); - this->ping_outstanding = 0; + this->thread = 0; + this->ipstack = network; + this->ping_timer = Timer(); + this->ping_outstanding = 0; + + // How to make these memory allocations portable? I was hoping to avoid the heap + buf = new char[limits.MAX_MQTT_PACKET_SIZE]; + readbuf = new char[limits.MAX_MQTT_PACKET_SIZE]; + this->operations = new struct Operations[limits.MAX_CONCURRENT_OPERATIONS]; + for (int i = 0; i < limits.MAX_CONCURRENT_OPERATIONS; ++i) + operations[i].id = 0; + this->messageHandlers = new struct MessageHandlers[limits.MAX_MESSAGE_HANDLERS]; + for (int i = 0; i < limits.MAX_MESSAGE_HANDLERS; ++i) + messageHandlers[i].topic = 0; } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::sendPacket(int length, int timeout) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::sendPacket(int length, int timeout) { int sent = 0; while (sent < length) - sent += ipstack->write(&buf[sent], length, -1); + sent += ipstack->write(&buf[sent], length, timeout); if (sent == length) - ping_timer.reset(); // record the fact that we have successfully sent the packet + ping_timer.countdown(this->keepAliveInterval); // record the fact that we have successfully sent the packet return sent; } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::decodePacket(int* value, int timeout) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::decodePacket(int* value, int timeout) { char c; int multiplier = 1; @@ -221,7 +225,7 @@ * @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) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::readPacket(int timeout) { int rc = -1; MQTTHeader header = {0}; @@ -248,12 +252,26 @@ } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::deliverMessage(MQTTString* topic, Message* message) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::deliverMessage(MQTTString* topic, Message* message) { + int rc = -1; + + // we have to find the right message handler - indexed by topic + for (int i = 0; i < limits.MAX_MESSAGE_HANDLERS; ++i) + { + if (messageHandlers[i].topic && MQTTPacket_equals(topic, (char*)messageHandlers[i].topic)) + { + messageHandlers[i].fp(message); + rc = 0; + break; + } + } + + return rc; } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::cycle(int timeout) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::cycle(int timeout) { /* get one piece of work off the wire and one pass through */ @@ -269,29 +287,32 @@ if (this->thread) { Result res = {this, 0}; - if (MQTTDeserialize_connack(&res.connack_rc, readbuf, readbuflen) == 1) + if (MQTTDeserialize_connack(&res.connack_rc, readbuf, limits.MAX_MQTT_PACKET_SIZE) == 1) ; connectHandler(&res); connectHandler.detach(); // only invoke the callback once } + break; case PUBACK: + if (this->thread) + ; //call resultHandler case SUBACK: break; case PUBLISH: MQTTString topicName; Message msg; rc = MQTTDeserialize_publish((int*)&msg.dup, (int*)&msg.qos, (int*)&msg.retained, (int*)&msg.id, &topicName, - (char**)&msg.payload, (int*)&msg.payloadlen, readbuf, readbuflen); + (char**)&msg.payload, (int*)&msg.payloadlen, readbuf, limits.MAX_MQTT_PACKET_SIZE); if (msg.qos == QOS0) deliverMessage(&topicName, &msg); break; case PUBREC: int type, dup, mypacketid; - if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1) + if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, limits.MAX_MQTT_PACKET_SIZE) == 1) ; // must lock this access against the application thread, if we are multi-threaded - len = MQTTSerialize_ack(buf, buflen, PUBREL, 0, mypacketid); - rc = sendPacket(len); // send the subscribe packet + len = MQTTSerialize_ack(buf, limits.MAX_MQTT_PACKET_SIZE, PUBREL, 0, mypacketid); + rc = sendPacket(len, timeout); // send the PUBREL packet if (rc != len) goto exit; // there was a problem @@ -308,21 +329,21 @@ } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::keepalive() +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::keepalive() { int rc = 0; if (keepAliveInterval == 0) goto exit; - if (ping_timer.read_ms() >= (keepAliveInterval * 1000)) + if (ping_timer.expired()) { if (ping_outstanding) rc = -1; else { - int len = MQTTSerialize_pingreq(buf, buflen); - rc = sendPacket(len); // send the connect packet + int len = MQTTSerialize_pingreq(buf, limits.MAX_MQTT_PACKET_SIZE); + rc = sendPacket(len, 1000); // send the ping packet if (rc != len) rc = -1; // indicate there's a problem else @@ -335,40 +356,53 @@ } -template<class Network, class Timer, class Thread> void MQTT::Client<Network, Timer, Thread>::run(void const *argument) +template<class Network, class Timer, class Thread, class Mutex> void MQTT::Client<Network, Timer, Thread, Mutex>::run(void const *argument) { while (true) - cycle((keepAliveInterval * 1000) - ping_timer.read_ms()); + cycle(ping_timer.left_ms()); } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::connect(MQTTPacket_connectData* options, resultHandler resultHandler) +// only used in single-threaded mode where one command at a time is in process +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::waitfor(int packet_type, Timer& atimer) { - command_timer.start(); + int rc = -1; + + do + { + if (atimer.expired()) + break; // we timed out + } + while ((rc = cycle(atimer.left_ms())) != packet_type); + + return rc; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::connect(MQTTPacket_connectData* options, resultHandler resultHandler) +{ + connect_timer.countdown(limits.command_timeout); MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer; if (options == 0) options = &default_options; // set default options if none were supplied this->keepAliveInterval = options->keepAliveInterval; - ping_timer.start(); - int len = MQTTSerialize_connect(buf, buflen, options); - int rc = sendPacket(len); // send the connect packet + ping_timer.countdown(this->keepAliveInterval); + int len = MQTTSerialize_connect(buf, limits.MAX_MQTT_PACKET_SIZE, options); + int rc = sendPacket(len, connect_timer.left_ms()); // send the connect packet if (rc != len) goto exit; // there was a problem if (resultHandler == 0) // wait until the connack is received { // this will be a blocking call, wait for the connack - do - { - if (command_timer.read_ms() > (command_timeout * 1000)) - goto exit; // we timed out - } - while (cycle(command_timeout - command_timer.read_ms()) != CONNACK); - int connack_rc = -1; - if (MQTTDeserialize_connack(&connack_rc, readbuf, readbuflen) == 1) - rc = connack_rc; + if (waitfor(CONNACK, connect_timer) == CONNACK) + { + int connack_rc = -1; + if (MQTTDeserialize_connack(&connack_rc, readbuf, limits.MAX_MQTT_PACKET_SIZE) == 1) + rc = connack_rc; + } } else { @@ -376,24 +410,41 @@ connectHandler.attach(resultHandler); // start background thread - this->thread = new Thread((void (*)(void const *argument))&MQTT::Client<Network, Timer, Thread>::threadfn, (void*)this); + this->thread = new Thread((void (*)(void const *argument))&MQTT::Client<Network, Timer, Thread, Mutex>::threadfn, (void*)this); } exit: - command_timer.stop(); - command_timer.reset(); return rc; } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::subscribe(const char* topicFilter, enum QoS qos, messageHandler messageHandler, resultHandler resultHandler) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::findFreeOperation() { - command_timer.start(); + int found = -1; + for (int i = 0; i < limits.MAX_CONCURRENT_OPERATIONS; ++i) + { + if (operations[i].id == 0) + { + found = i; + break; + } + } + return found; +} + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::subscribe(const char* topicFilter, enum QoS qos, messageHandler messageHandler, resultHandler resultHandler) +{ + int index = 0; + if (this->thread) + index = findFreeOperation(); + Timer& atimer = operations[index].timer; + + atimer.countdown(limits.command_timeout); MQTTString topic = {(char*)topicFilter, 0, 0}; - int len = MQTTSerialize_subscribe(buf, buflen, 0, packetid.getNext(), 1, &topic, (int*)&qos); - int rc = sendPacket(len); // send the subscribe packet + int len = MQTTSerialize_subscribe(buf, limits.MAX_MQTT_PACKET_SIZE, 0, packetid.getNext(), 1, &topic, (int*)&qos); + int rc = sendPacket(len, atimer.left_ms()); // send the subscribe packet if (rc != len) goto exit; // there was a problem @@ -401,11 +452,24 @@ if (resultHandler == 0) { // this will block - if (cycle(command_timeout - command_timer.read_ms()) == SUBACK) + if (waitfor(SUBACK, atimer) == SUBACK) { int count = 0, grantedQoS = -1, mypacketid; - if (MQTTDeserialize_suback(&mypacketid, 1, &count, &grantedQoS, readbuf, readbuflen) == 1) + if (MQTTDeserialize_suback(&mypacketid, 1, &count, &grantedQoS, readbuf, limits.MAX_MQTT_PACKET_SIZE) == 1) rc = grantedQoS; // 0, 1, 2 or 0x80 + if (rc != 0x80) + { + for (int i = 0; i < limits.MAX_MESSAGE_HANDLERS; ++i) + { + if (messageHandlers[i].topic == 0) + { + messageHandlers[i].topic = topicFilter; + messageHandlers[i].fp.attach(messageHandler); + rc = 0; + break; + } + } + } } } else @@ -415,28 +479,29 @@ } exit: - command_timer.stop(); - command_timer.reset(); return rc; } -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::unsubscribe(const char* topicFilter, resultHandler resultHandler) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::unsubscribe(const char* topicFilter, resultHandler resultHandler) { - command_timer.start(); + int index = 0; + if (this->thread) + index = findFreeOperation(); + Timer& atimer = operations[index].timer; MQTTString topic = {(char*)topicFilter, 0, 0}; int len = MQTTSerialize_unsubscribe(buf, buflen, 0, packetid.getNext(), 1, &topic); - int rc = sendPacket(len); // send the subscribe packet + int rc = sendPacket(len, atimer); // send the subscribe packet if (rc != len) goto exit; // there was a problem - /* wait for suback */ + /* wait for unsuback */ if (resultHandler == 0) { // this will block - if (cycle(command_timeout - command_timer.read_ms()) == UNSUBACK) + if (waitfor(UNSUBACK) == UNSUBACK) { int mypacketid; if (MQTTDeserialize_unsuback(&mypacketid, readbuf, readbuflen) == 1) @@ -457,7 +522,7 @@ -template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::publish(const char* topicName, Message* message, resultHandler resultHandler) +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::publish(const char* topicName, Message* message, resultHandler resultHandler) { command_timer.start(); @@ -475,7 +540,7 @@ { if (message->qos == QOS1) { - if (cycle(command_timeout - command_timer.read_ms()) == PUBACK) + if (waitfor(PUBACK) == PUBACK) { int type, dup, mypacketid; if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1) @@ -484,7 +549,7 @@ } else if (message->qos == QOS2) { - if (cycle(command_timeout - command_timer.read_ms()) == PUBCOMP) + if (waitfor(PUBCOMP) == PUBCOMP) { int type, dup, mypacketid; if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1)
--- a/MQTTPacket.lib Sun Apr 13 22:32:28 2014 +0000 +++ b/MQTTPacket.lib Mon Apr 14 18:51:52 2014 +0000 @@ -1,1 +1,1 @@ -http://mbed.org/teams/mqtt/code/MQTTPacket/#c502573c6016 +http://mbed.org/teams/mqtt/code/MQTTPacket/#eea71419676a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/MQTTSingle.h Mon Apr 14 18:51:52 2014 +0000 @@ -0,0 +1,428 @@ +/******************************************************************************* + * 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(MQTTSINGLE_H) +#define MQTTSINGLE_H + +#include "FP.h" +#include "MQTTPacket.h" +#include "stdio.h" + +namespace MQTT +{ + + +enum QoS { QOS0, QOS1, QOS2 }; + + +struct Message +{ + enum QoS qos; + bool retained; + bool dup; + unsigned short id; + void *payload; + size_t payloadlen; +}; + + +class PacketId +{ +public: + PacketId(); + + int getNext(); + +private: + static const int MAX_PACKET_ID = 65535; + int next; +}; + +typedef void (*messageHandler)(Message*); + +typedef struct limits +{ + int MAX_MQTT_PACKET_SIZE; // + int MAX_MESSAGE_HANDLERS; // each subscription requires a message handler + int command_timeout; + + limits() + { + MAX_MQTT_PACKET_SIZE = 100; + MAX_MESSAGE_HANDLERS = 5; + command_timeout = 30; + } +} Limits; + + +template<class Network, class Timer> class Client +{ + +public: + + Client(Network* network, Limits* limits = 0); + + int connect(MQTTPacket_connectData* options = 0); + + int publish(const char* topic, Message* message); + + int subscribe(const char* topicFilter, enum QoS qos, messageHandler mh); + + int unsubscribe(const char* topicFilter); + + int disconnect(int timeout); + +private: + + int cycle(int timeout); + int keepalive(); + + int decodePacket(int* value, int timeout); + int readPacket(int timeout = -1); + int sendPacket(int length, int timeout = -1); + int deliverMessage(MQTTString* topic, Message* message); + + Network* ipstack; + Timer command_timer, ping_timer; + + char* buf; + int buflen; + + char* readbuf; + int readbuflen; + + unsigned int keepAliveInterval; + bool ping_outstanding; + + int command_timeout; // max time to wait for any MQTT command to complete, in seconds + PacketId packetid; + + typedef FP<void, Message*> messageHandlerFP; + struct MessageHandlers + { + char* topic; + messageHandlerFP fp; + } *messageHandlers; // Message handlers are linked to a subscription topic + int messageHandlerCount; + +}; + +} + +template<class Network, class Timer, class Thread, class Mutex> MQTT::Client<Network, Timer, Thread, Mutex>::Client(Network* network, Limits* limits) : packetid() +{ + Limits default_limits = Limits(); + + if (limits == 0) + limits = &default_limits; + + this->command_timeout = limits->command_timeout; + this->ipstack = network; + this->command_timer = Timer(); + this->ping_timer = Timer(); + this->ping_outstanding = 0; + + // How to make these memory allocations portable? I was hoping to avoid the heap + buflen = readbuflen = limits->MAX_MQTT_PACKET_SIZE; + buf = new char[limits->MAX_MQTT_PACKET_SIZE]; + readbuf = new char[limits->MAX_MQTT_PACKET_SIZE]; + this->messageHandlers = new struct MessageHandlers[limits->MAX_MESSAGE_HANDLERS]; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::sendPacket(int length, int timeout) +{ + int sent = 0; + + while (sent < length) + sent += ipstack->write(&buf[sent], length, -1); + if (sent == length) + ping_timer.reset(); // record the fact that we have successfully sent the packet + return sent; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::decodePacket(int* value, int timeout) +{ + 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, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::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; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::deliverMessage(MQTTString* topic, Message* message) +{ + // we have to find the right message handler - indexed by topic +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::cycle(int timeout) +{ + /* get one piece of work off the wire and one pass through */ + + // read the socket, see what work is due + int packet_type = readPacket(timeout); + + int len, rc; + switch (packet_type) + { + case CONNACK: + case PUBACK: + case SUBACK: + break; + case PUBLISH: + MQTTString topicName; + Message msg; + rc = MQTTDeserialize_publish((int*)&msg.dup, (int*)&msg.qos, (int*)&msg.retained, (int*)&msg.id, &topicName, + (char**)&msg.payload, (int*)&msg.payloadlen, readbuf, readbuflen); + if (msg.qos == QOS0) + deliverMessage(&topicName, &msg); + break; + case PUBREC: + int type, dup, mypacketid; + if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1) + ; + // must lock this access against the application thread, if we are multi-threaded + len = MQTTSerialize_ack(buf, buflen, PUBREL, 0, mypacketid); + rc = sendPacket(len); // send the subscribe packet + if (rc != len) + goto exit; // there was a problem + + break; + case PUBCOMP: + break; + case PINGRESP: + ping_outstanding = false; + break; + } + keepalive(); +exit: + return packet_type; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::keepalive() +{ + int rc = 0; + + if (keepAliveInterval == 0) + goto exit; + + if (ping_timer.read_ms() >= (keepAliveInterval * 1000)) + { + if (ping_outstanding) + rc = -1; + else + { + int len = MQTTSerialize_pingreq(buf, buflen); + rc = sendPacket(len); // send the connect packet + if (rc != len) + rc = -1; // indicate there's a problem + else + ping_outstanding = true; + } + } + +exit: + return rc; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::connect(MQTTPacket_connectData* options, resultHandler resultHandler) +{ + command_timer.start(); + + MQTTPacket_connectData default_options = MQTTPacket_connectData_initializer; + if (options == 0) + options = &default_options; // set default options if none were supplied + + this->keepAliveInterval = options->keepAliveInterval; + ping_timer.start(); + int len = MQTTSerialize_connect(buf, buflen, options); + int rc = sendPacket(len); // send the connect packet + if (rc != len) + goto exit; // there was a problem + + // this will be a blocking call, wait for the connack + do + { + if (command_timer.read_ms() > (command_timeout * 1000)) + goto exit; // we timed out + } + while (cycle(command_timeout - command_timer.read_ms()) != CONNACK); + int connack_rc = -1; + if (MQTTDeserialize_connack(&connack_rc, readbuf, readbuflen) == 1) + rc = connack_rc; + +exit: + command_timer.stop(); + command_timer.reset(); + return rc; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::subscribe(const char* topicFilter, enum QoS qos, messageHandler messageHandler) +{ + command_timer.start(); + + MQTTString topic = {(char*)topicFilter, 0, 0}; + + int len = MQTTSerialize_subscribe(buf, buflen, 0, packetid.getNext(), 1, &topic, (int*)&qos); + int rc = sendPacket(len); // send the subscribe packet + if (rc != len) + goto exit; // there was a problem + + // wait for suback - this will block + if (cycle(command_timeout - command_timer.read_ms()) == SUBACK) + { + int count = 0, grantedQoS = -1, mypacketid; + if (MQTTDeserialize_suback(&mypacketid, 1, &count, &grantedQoS, readbuf, readbuflen) == 1) + rc = grantedQoS; // 0, 1, 2 or 0x80 + if (rc != 0x80) + } + +exit: + command_timer.stop(); + command_timer.reset(); + return rc; +} + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::unsubscribe(const char* topicFilter, resultHandler resultHandler) +{ + command_timer.start(); + + MQTTString topic = {(char*)topicFilter, 0, 0}; + + int len = MQTTSerialize_unsubscribe(buf, buflen, 0, packetid.getNext(), 1, &topic); + int rc = sendPacket(len); // send the subscribe packet + if (rc != len) + goto exit; // there was a problem + + // this will block + if (cycle(command_timeout - command_timer.read_ms()) == UNSUBACK) + { + int mypacketid; + if (MQTTDeserialize_unsuback(&mypacketid, readbuf, readbuflen) == 1) + rc = 0; + } + +exit: + command_timer.stop(); + command_timer.reset(); + return rc; +} + + + +template<class Network, class Timer, class Thread, class Mutex> int MQTT::Client<Network, Timer, Thread, Mutex>::publish(const char* topicName, Message* message, resultHandler resultHandler) +{ + command_timer.start(); + + MQTTString topic = {(char*)topicName, 0, 0}; + + message->id = packetid.getNext(); + + int len = MQTTSerialize_publish(buf, buflen, 0, message->qos, message->retained, message->id, topic, message->payload, message->payloadlen); + int rc = sendPacket(len); // send the subscribe packet + if (rc != len) + goto exit; // there was a problem + + /* wait for acks */ + if (resultHandler == 0) + { + if (message->qos == QOS1) + { + if (cycle(command_timeout - command_timer.read_ms()) == PUBACK) + { + int type, dup, mypacketid; + if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1) + rc = 0; + } + } + else if (message->qos == QOS2) + { + if (cycle(command_timeout - command_timer.read_ms()) == PUBCOMP) + { + int type, dup, mypacketid; + if (MQTTDeserialize_ack(&type, &dup, &mypacketid, readbuf, readbuflen) == 1) + rc = 0; + } + + } + } + +exit: + command_timer.stop(); + command_timer.reset(); + return rc; +} + + +#endif