esp32-nmea2000-obp60/lib/queue/GwBuffer.cpp

145 lines
4.0 KiB
C++

#include "GwBuffer.h"
void GwBuffer::lp(const char *fkt, int p)
{
LOG_DEBUG(GwLog::DEBUG + 1, "Buffer[%s]: buf=%p,wp=%d,rp=%d,used=%d,free=%d, p=%d",
fkt, buffer, offset(writePointer), offset(readPointer), usedSpace(), freeSpace(), p);
}
GwBuffer::GwBuffer(GwLog *logger)
{
this->logger = logger;
}
void GwBuffer::reset()
{
writePointer = buffer;
readPointer = buffer;
lp("reset");
}
size_t GwBuffer::freeSpace()
{
if (readPointer < writePointer)
{
size_t rt = BUFFER_SIZE - offset(writePointer) - 1 + offset(readPointer);
return rt;
}
if (readPointer == writePointer)
return BUFFER_SIZE - 1;
return readPointer - writePointer - 1;
}
size_t GwBuffer::usedSpace()
{
if (readPointer == writePointer)
return 0;
if (readPointer < writePointer)
return writePointer - readPointer;
return BUFFER_SIZE - offset(readPointer) - 1 + offset(writePointer);
}
size_t GwBuffer::addData(const uint8_t *data, size_t len)
{
lp("addDataE", len);
if (len == 0)
return 0;
if (freeSpace() < len)
return 0;
size_t written = 0;
if (writePointer >= readPointer)
{
written = BUFFER_SIZE - offset(writePointer) - 1;
if (written > len)
written = len;
if (written)
{
memcpy(writePointer, data, written);
len -= written;
data += written;
writePointer += written;
if (offset(writePointer) >= (BUFFER_SIZE - 1))
writePointer = buffer;
}
lp("addData1", written);
if (len <= 0)
{
return written;
}
}
//now we have the write pointer before the read pointer
//and we did the length check before - so we can safely copy
memcpy(writePointer, data, len);
writePointer += len;
lp("addData2", len);
return len + written;
}
/**
* write some data to the buffer writer
* return an error if the buffer writer returned < 0
*/
GwBuffer::WriteStatus GwBuffer::fetchData(GwBufferWriter *writer, bool errorIf0 )
{
lp("fetchDataE");
size_t len = usedSpace();
if (len == 0)
return OK;
size_t written = 0;
size_t plen = len;
if (writePointer < readPointer)
{
//we need to write from readPointer till end and then till writePointer-1
plen = BUFFER_SIZE - offset(readPointer) - 1;
int rt = writer->write(readPointer, plen);
lp("fetchData1", rt);
if (rt < 0)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write returns error %d", rt);
return ERROR;
}
if (rt > plen)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write too many bytes(1) %d", rt);
return ERROR;
}
if (rt == 0)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write returns 0 (1)");
return (errorIf0 ? ERROR : AGAIN);
}
readPointer += rt;
if (offset(readPointer) >= (BUFFER_SIZE - 1))
readPointer = buffer;
if (rt < plen)
return AGAIN;
if (plen >= len)
return OK;
len -= rt;
written += rt;
//next part - readPointer should be at buffer now
}
plen = writePointer - readPointer;
if (plen == 0)
return OK;
int rt = writer->write(readPointer, plen);
lp("fetchData2", rt);
if (rt < 0)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write returns error %d", rt);
return ERROR;
}
if (rt == 0)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write returns 0 (1)");
return (errorIf0 ? ERROR : AGAIN);
}
if (rt > plen)
{
LOG_DEBUG(GwLog::DEBUG + 1, "buffer: write too many bytes(2)");
return ERROR;
}
readPointer += rt;
if (offset(readPointer) >= (BUFFER_SIZE - 1))
readPointer = buffer;
lp("fetchData3");
written += rt;
if (written < len)
return AGAIN;
return OK;
}