pubsubclient/PubSubClient/PubSubClient.cpp

240 lines
6.2 KiB
C++

/*
PubSubClient.cpp - A simple client for MQTT.
Nicholas O'Leary
http://knolleary.net
*/
#include "PubSubClient.h"
#include "EthernetClient.h"
#include "string.h"
PubSubClient::PubSubClient() : _client() {
}
PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, void (*callback)(char*,uint8_t*,unsigned int)) : _client() {
this->callback = callback;
this->ip = ip;
this->port = port;
}
boolean PubSubClient::connect(char *id) {
return connect(id,0,0,0,0);
}
boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage) {
if (!connected()) {
if (_client.connect(this->ip, this->port)) {
nextMsgId = 1;
uint8_t d[9] = {0x00,0x06,'M','Q','I','s','d','p',MQTTPROTOCOLVERSION};
uint8_t length = 0;
unsigned int j;
for (j = 0;j<9;j++) {
buffer[length++] = d[j];
}
if (willTopic) {
buffer[length++] = 0x06|(willQos<<3)|(willRetain<<5);
} else {
buffer[length++] = 0x02;
}
buffer[length++] = ((MQTT_KEEPALIVE) >> 8);
buffer[length++] = ((MQTT_KEEPALIVE) & 0xff);
length = writeString(id,buffer,length);
if (willTopic) {
length = writeString(willTopic,buffer,length);
length = writeString(willMessage,buffer,length);
}
write(MQTTCONNECT,buffer,length);
lastOutActivity = millis();
lastInActivity = millis();
while (!_client.available()) {
unsigned long t= millis();
if (t-lastInActivity > MQTT_KEEPALIVE*1000) {
_client.stop();
return false;
}
}
uint16_t len = readPacket();
if (len == 4 && buffer[3] == 0) {
lastInActivity = millis();
pingOutstanding = false;
return true;
}
}
_client.stop();
}
return false;
}
uint8_t PubSubClient::readByte() {
while(!_client.available()) {}
return _client.read();
}
uint16_t PubSubClient::readPacket() {
uint16_t len = 0;
buffer[len++] = readByte();
uint8_t multiplier = 1;
uint16_t length = 0;
uint8_t digit = 0;
do {
digit = readByte();
buffer[len++] = digit;
length += (digit & 127) * multiplier;
multiplier *= 128;
} while ((digit & 128) != 0);
for (uint16_t i = 0;i<length;i++)
{
if (len < MQTT_MAX_PACKET_SIZE) {
buffer[len++] = readByte();
} else {
readByte();
len = 0; // This will cause the packet to be ignored.
}
}
return len;
}
boolean PubSubClient::loop() {
if (connected()) {
unsigned long t = millis();
if ((t - lastInActivity > MQTT_KEEPALIVE*1000) || (t - lastOutActivity > MQTT_KEEPALIVE*1000)) {
if (pingOutstanding) {
_client.stop();
return false;
} else {
_client.write(MQTTPINGREQ);
_client.write((uint8_t)0);
lastOutActivity = t;
lastInActivity = t;
pingOutstanding = true;
}
}
if (_client.available()) {
uint16_t len = readPacket();
if (len > 0) {
lastInActivity = t;
uint8_t type = buffer[0]&0xF0;
if (type == MQTTPUBLISH) {
if (callback) {
uint16_t tl = (buffer[2]<<8)+buffer[3];
char topic[tl+1];
for (uint16_t i=0;i<tl;i++) {
topic[i] = buffer[4+i];
}
topic[tl] = 0;
// ignore msgID - only support QoS 0 subs
uint8_t *payload = buffer+4+tl;
callback(topic,payload,len-4-tl);
}
} else if (type == MQTTPINGREQ) {
_client.write(MQTTPINGRESP);
_client.write((uint8_t)0);
} else if (type == MQTTPINGRESP) {
pingOutstanding = false;
}
}
}
return true;
}
return false;
}
boolean PubSubClient::publish(char* topic, char* payload) {
return publish(topic,(uint8_t*)payload,strlen(payload),false);
}
boolean PubSubClient::publish(char* topic, uint8_t* payload, unsigned int plength) {
return publish(topic, payload, plength, false);
}
boolean PubSubClient::publish(char* topic, uint8_t* payload, unsigned int plength, boolean retained) {
if (connected()) {
uint16_t length = writeString(topic,buffer,false);
uint16_t i;
for (i=0;i<plength;i++) {
buffer[length++] = payload[i];
}
uint8_t header = MQTTPUBLISH;
if (retained) {
header |= 1;
}
return write(header,buffer,length);
}
return false;
}
boolean PubSubClient::write(uint8_t header, uint8_t* buf, uint16_t length) {
uint8_t lenBuf[4];
uint8_t llen = 0;
uint8_t digit;
uint8_t pos = 0;
uint8_t rc;
uint8_t len = length;
do {
digit = len % 128;
len = len / 128;
if (len > 0) {
digit |= 0x80;
}
lenBuf[pos++] = digit;
llen++;
} while(len>0);
rc = _client.write(header);
rc += _client.write(lenBuf,llen);
rc += _client.write(buf,length);
lastOutActivity = millis();
return (rc == 1+llen+length);
}
boolean PubSubClient::subscribe(char* topic) {
if (connected()) {
uint16_t length = 2;
nextMsgId++;
if (nextMsgId == 0) {
nextMsgId = 1;
}
buffer[0] = nextMsgId >> 8;
buffer[1] = nextMsgId - (buffer[0]<<8);
length = writeString(topic, buffer,length);
buffer[length++] = 0; // Only do QoS 0 subs
return write(MQTTSUBSCRIBE|MQTTQOS1,buffer,length);
}
return false;
}
void PubSubClient::disconnect() {
_client.write(MQTTDISCONNECT);
_client.write((uint8_t)0);
_client.stop();
lastInActivity = millis();
lastOutActivity = millis();
}
uint16_t PubSubClient::writeString(char* string, uint8_t* buf, uint16_t pos) {
char* idp = string;
uint16_t i = 0;
pos += 2;
while (*idp) {
buf[pos++] = *idp++;
i++;
}
buf[pos-i-2] = 0;
buf[pos-i-1] = i;
return pos;
}
boolean PubSubClient::connected() {
int rc = (int)_client.connected();
if (!rc) _client.stop();
return rc;
}