Program to send NTP data to MQTT broker
Fork of MQTT by
Diff: MQTTClient.h
- Revision:
- 16:91c2f9a144d4
- Parent:
- 15:64a57183aa03
- Child:
- 19:57f6f976e878
--- 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)