Buffer.cc

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#include "Buffer.h"
#include <string.h>

Buffer::Buffer(int size)
  : data(0), capacity(0), limit(0), position(0) {

  if (size > 0) {
    data = new char[size];
    capacity = size;
  } else {
    capacity = 0;
  }
  limit = capacity;
}

Buffer::Buffer(const Buffer& rhs)
  : data(0), capacity(0), limit(0), position(0) {
    
  *this = rhs;
}

Buffer::~Buffer() {
  delete[] data;
}

Buffer& Buffer::operator=(const Buffer& rhs) {
    
  if (this != &rhs) {
    if (capacity != rhs.GetCapacity()) {
      delete[] data;
      data = 0;
      capacity = rhs.GetCapacity();
      data = new char[capacity];
    }
    
    if (capacity > 0) {     
      memcpy(data, rhs.GetData(), capacity);
    }
    
    position = rhs.GetPosition();
    limit = rhs.GetLimit();
  }
  return *this;
}

void Buffer::SetPosition(int pos) {
  if (pos < 0) {
    position = 0;
  } else {
    position = min(pos, limit);
  }
}

void Buffer::SetLimit(int lim) {
  if (lim < 0) {
    limit = 0;
  } else {
    limit = min(lim, capacity);
  }
  position = min(position, limit);
}

void Buffer::SetCapacity(int size) {
  if (size == capacity) {
    return;
  }
  if (size > 0) {
    char* newData = new char[size];
    if (data != 0) {
      memcpy(newData, data, min(capacity, size)); 
    }
    capacity = size;
    delete[] data;
    data = newData;
  } else {
    capacity = 0;
    delete[] data;
    data = 0;
  }  
  limit = min(limit, capacity);
  position = min(position, limit);
}

bool Buffer::Fill(const char*&src, int& srcLen) {
  if ((src == 0) || (srcLen < 1)) {
    return IsFull();
  }
  
  const int charsToRead = limit - position;
  if (charsToRead < 1) {
    return true;
  }
  
  if (charsToRead > srcLen) {
    memcpy(&data[position], src, srcLen);
    position += srcLen;
    src += srcLen;
    srcLen = 0;
    return false;
  } else {
    memcpy(&data[position], src, charsToRead);
    position += charsToRead;
    src += charsToRead;
    srcLen -= charsToRead;
    return true;
  }
}

/*! @file
 * @brief Describes Buffer, a general memory management data structure, featuring position, limit, and capacity marks
 * @author Alexander Klyubin (A.Kljubin AT herts ac uk) (Creator)
 * Submitted as part of "Full-duplex Audio Streaming" patch
 */