Program to send NTP data to MQTT broker
Fork of MQTT by
MQTTClient.h
- Committer:
- icraggs
- Date:
- 2014-04-10
- Revision:
- 11:db15da110a37
- Parent:
- 9:01b8cc7d94cc
- Child:
- 13:fd82db992024
File content as of revision 11:db15da110a37:
/******************************************************************************* * 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" namespace MQTT { enum QoS { QOS0, QOS1, QOS2 }; struct Message { enum QoS qos; bool retained; bool dup; unsigned short msgid; void *payload; size_t payloadlen; }; template<class Network, class Timer, class Thread> class Client; class Result { /* success or failure result data */ Client<class Network, class Timer, class Thread>* client; }; class PacketId { public: PacketId(); int getNext(); private: static const int MAX_PACKET_ID = 65535; int next; }; typedef void (*resultHandler)(Result*); typedef void (*messageHandler)(Message*); template<class Network, class Timer, class Thread> class Client { public: Client(Network* network, Timer* timer, const int buffer_size = 100, const int command_timeout = 30); int connect(MQTTPacket_connectData* options = 0, resultHandler fn = 0); template<class T> int connect(MQTTPacket_connectData* options = 0, T *item = 0, void(T::*method)(Result *) = 0); // alternative to pass in pointer to member function int publish(const char* topic, Message* message, resultHandler rh = 0); int subscribe(const char* topicFilter, enum QoS qos, messageHandler mh, resultHandler rh = 0); int unsubscribe(char* topicFilter, resultHandler rh = 0); int disconnect(int timeout, resultHandler rh = 0); void run(void const *argument); private: int cycle(); int decodePacket(int* value, int timeout); int readPacket(int timeout = -1); int sendPacket(int length, int timeout = -1); Thread* thread; Network* ipstack; Timer* timer; char* buf; int buflen; char* readbuf; int readbuflen; int command_timeout; // max time to wait for any MQTT command to complete, in seconds int keepalive; PacketId packetid; typedef FP<void, Result*> resultHandlerFP; // how many concurrent operations should we allow? Each one will require a function pointer resultHandlerFP connectHandler; #define MAX_MESSAGE_HANDLERS 5 typedef FP<void, Message*> messageHandlerFP; messageHandlerFP messageHandlers[MAX_MESSAGE_HANDLERS]; // Linked list, or constructor parameter to limit array size? static void threadfn(void* arg); }; } template<class Network, class Timer, class Thread> void MQTT::Client<Network, Timer, Thread>::threadfn(void* arg) { ((Client<Network, Timer, Thread>*) arg)->run(NULL); } 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) : packetid() { buf = new char[buffer_size]; readbuf = new char[buffer_size]; buflen = readbuflen = buffer_size; this->command_timeout = command_timeout; this->thread = 0; this->ipstack = network; this->timer = timer; } 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) { 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; } template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::cycle() { int timeout = -1; /* 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(timeout); printf("packet type %d\n", packet_type); switch (packet_type) { case CONNACK: printf("connack received\n"); break; case PUBLISH: break; case PUBACK: break; case SUBACK: break; case PUBREC: break; case PUBCOMP: break; case PINGRESP: break; case -1: break; } return packet_type; } template<class Network, class Timer, class Thread> void MQTT::Client<Network, Timer, Thread>::run(void const *argument) { while (true) { cycle(); } } template<class Network, class Timer, class Thread> int MQTT::Client<Network, Timer, Thread>::connect(MQTTPacket_connectData* options, resultHandler 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 connectHandler.attach(resultHandler); // start background thread this->thread = new Thread((void (*)(void const *argument))&MQTT::Client<Network, Timer, Thread>::threadfn, (void*)this); } 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) { int rc = -1, len = 0; MQTTString topic = {(char*)topicFilter, 0, 0}; len = MQTTSerialize_subscribe(buf, buflen, 0, packetid.getNext(), 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, mypacketid; if (MQTTDeserialize_suback(&mypacketid, 1, &count, &grantedQoS, readbuf, readbuflen) == 1) rc = grantedQoS; // 0, 1, 2 or 0x80 } } else { // set subscribe response callback function } return rc; } #endif