handling buffers efficiently

[cppdud]

i am loosing data and feel like i need some little
good tutorial on how to implement an efficient circular buffer.
If i got a buffer of size k. how to add data to it
and at the same time read data out?. I hope this
make it real time like process so that data would
not get lost. any example,..??

[cilu]

At the point when the buffer gets fulled with written data, you must override the first elements.

Can you explain what are you actually trying to do?

[T.G.]

something like this?

class CircularBuffer
{
int size, front, back;
vector<int> data;

public:
CircularBuffer() : size(0), data(1), front(0), back(0) {}

CircularBuffer(int k) : size(k-1), data(k), front(0), back(0) {}

void push_back(int i) { if (++back>size) back=0; data[back]=i;}

void pop_back(int &i) { i=data[back];if (--back<0) back=size;}

void push_front(int i) { if (--front<0) front=size; data[front]=i;}

void pop_front(int &i) { i=data[front];if (++front>size) front=0;}
}

[cppdud]

can you add main() that uses this class as a ring or circular buffer?. i created template based of a ring buffer that works ok. i have to clean it up , then i 'll post it.

[cppdud]

two examples of circular buffer appliction that handles:
1) simultaneous read and write operations.
2) serialized read and write.
this is very important to me to understand if one has an exmples of each.

[cppdud]

like to fit "writetobuf" and "readnextbuf" into threads for fast speed
write / read but not quite sure how.
Any changes and adds that improve things be nice.

int InsertNextIndex = 0;
int ReadNextIndex = 0;

#define imgIndex  20
BYTE *images[imgIndex];
bool imgIndexUsed[imgIndex];


void SetImageSize(int height, int width, 
int numofbytesPerPixel = 4)
{
  imagesz = height*width*numofbytesPerPixel;
}


void BufInit(void)
{
  int i;
  for (i=0; i<imgIndex; i++)
  {
    imgIndexUsed[i] = false;
    images[i] = new BYTE[imagesz];
  }
}


bool WriteToBuf(BYTE *pdata)
{
  if (imgIndexUsed[InsertNextIndex])
    return(false);
  imgIndexUsed[InsertNextIndex] = true;

  memcpy(images[InsertNextIndex], pdata, imagesz);

  InsertNextIndex++;
  if (InsertNextIndex==imgIndex) InsertNextIndex = 0;

  return(true);
}


BYTE *ReadNextBuf(void)
{
  if (!imgIndexUsed[ReadNextIndex])
    return null;
  return(images[ReadNextIndex]);
}

void NextBufPrep(void)
{
  if (!imgIndexUsed[ReadNextIndex]) return;

  imgIndexUsed[ReadNextIndex] = false;
  ReadNextIndex++;
  if (ReadNextIndex==imgIndex) ReadNextIndex = 0;
}

void bufdestroy()
{
  int i;
  for (i=0; i<imgIndex; i++)
    delete [] images[i];
}