OneWireArduinoSlaveATTINY85/SerialChannel.cpp

#include "Arduino.h"
#include "SerialChannel.h"

byte SerialChannel::nextId = 1;
SerialChannel* SerialChannel::first = 0;

SerialChannel::Message SerialChannel::buffer1[SerialChannel::MaxPendingMessages];
SerialChannel::Message SerialChannel::buffer2[SerialChannel::MaxPendingMessages];
volatile SerialChannel::Message* SerialChannel::backBuffer;
volatile byte SerialChannel::backBufferPos;
byte SerialChannel::frontBufferSize;

SerialChannel::Message dummyMessage;

SerialChannel::SerialChannel(const char* name_)
    : next(0)
    , id((byte)-1)
    , name(name_)
{
    if(first == 0)
        first = this;
    else
    {
        SerialChannel* c = first;
        while(c->next != 0) c = c->next;
        c->next = this;
    }
    
    id = nextId++;
}

void SerialChannel::beginWriteInChannel(byte id, short byteCount, unsigned long time)
{
	Serial.write("START");
	Serial.write(id);
	writeULong(time);
	writeShort(byteCount);
}

void SerialChannel::write(byte* data, short byteCount, unsigned long time)
{
	beginWrite(byteCount, time);
	continueWrite(data, byteCount);
}

void SerialChannel::beginWrite(short byteCount, unsigned long time)
{
	if (time == (unsigned long)-1)
		time = micros();

	handleConnection();

	beginWriteInChannel(id, byteCount, time);
}

void SerialChannel::continueWrite(byte* data, short byteCount)
{
	Serial.write(data, byteCount);
}

void SerialChannel::write(const char* text, unsigned long time)
{
    write((byte*)text, strlen(text), time);
}

SerialChannel::Message& SerialChannel::append(byte* data, short byteCount, unsigned long time)
{
	if (time == (unsigned long)-1)
		time = micros();

	if (backBufferPos >= MaxPendingMessages)
	{
		Message& msg = ((Message*)backBuffer)[MaxPendingMessages-1];
		msg.id = id;
		msg.data = (byte*)"OVERFLOW";
		msg.byteCount = 8;
		msg.time = time;
		msg.longArg0 = 0;

		return dummyMessage;
	}
	else
	{
		Message& msg = ((Message*)backBuffer)[backBufferPos++];
		msg.id = id;
		msg.data = data;
		msg.byteCount = byteCount;
		msg.time = time;
		msg.longArg0 = 0;

		return msg;
	}
}

void SerialChannel::append(const char* text, unsigned long time)
{
	append((byte*)text, strlen(text), time);
}

void SerialChannel::appendInt(const char* text, short textLength, int arg0, unsigned long time)
{
	Message& msg = append((byte*)text, textLength, time);
	msg.longArg0 = arg0 | 0x40000000;
}

void SerialChannel::swap()
{
	backBuffer = backBuffer == buffer1 ? buffer2 : buffer1;
	frontBufferSize = backBufferPos;
	backBufferPos = 0;
}

void SerialChannel::flush()
{
	handleConnection();

	Message* frontBuffer = backBuffer == buffer1 ? buffer2 : buffer1;
	for (Message* msg = frontBuffer; msg < frontBuffer + frontBufferSize; ++msg)
	{
		char params[32];
		params[0] = 0;

		if ((msg->longArg0 & 0x40000000) != 0)
			sprintf(params, ";arg0=%ld", msg->longArg0 & ~0x40000000);

		short paramsSize = strlen(params);

		beginWriteInChannel(msg->id, msg->byteCount + paramsSize, msg->time);
		Serial.write(msg->data, msg->byteCount);
		if (paramsSize > 0)
			Serial.write(params, paramsSize);

		Serial.flush();
	}
}

void SerialChannel::writeShort(short num)
{
    Serial.write((byte*)&num, 2);
}

void SerialChannel::writeULong(unsigned long num)
{
    Serial.write((byte*)&num, 4);
}

void SerialChannel::handleConnection()
{
    int b = Serial.read();
    if(b == (int)'C')
    {
		Serial.write("CONNECTION");
        SerialChannel* c = first;
        while(c)
        {
            Serial.write("START");
            Serial.write(0);
            Serial.write("ChannelInit");
            Serial.write(c->id);
            writeShort(strlen(c->name));
            Serial.write(c->name);
            c = c->next;
        }
		Serial.flush();
    }
}