/*
 * PVVMUD a 3D MUD
 * Copyright (C) 1998-1999  Programvareverkstedet (pvv@pvv.org)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */
#include "pvvmud.H"
#include <unistd.h>
#include <iostream.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include "stream.H"

#define INC_START if (++start >= STREAMSIZE) start = 0; size--
#define INC_STOP if (++stop >= STREAMSIZE) stop = 0; size++

/////////////////////////////////////////////////////////////////////////////
// Stream exceptions
CEmptyStreamException::CEmptyStreamException()
  :CException("Empty stream exception"){

}

CEOFException::CEOFException():CException("EOF exception"){
}

CIOException::CIOException():CException("IO exception"){
}

/////////////////////////////////////////////////////////////////////////////
// Constructor and destructor

CStream::CStream(int fd){
  start = stop = size = 0;
  this->fd = fd;
}

CStream::~CStream(){
  close(fd);
}

/////////////////////////////////////////////////////////////////////////////
// Private functions
/////////////////////////////////////////////////////////////////////////////

int CStream::writeInBuf(char * msg, int length){
  int nn = 0;
  if ((STREAMSIZE - size) < length) return FALSE;
  while (nn < length){
    buf[stop] = msg[nn++];
    INC_STOP;
  }
  return TRUE;
}

unsigned long totalread = 0;
unsigned long totalwrite = 0;

int CStream::fillBuf(){
  long length,max;
  char rbuf[STREAMSIZE];

  max = MIN(STREAMSIZE-size,READBUFSIZE);

#ifndef CRYPTO
  length=::read(fd,&rbuf,max);
  if (length > 0) {
    totalread+=length;
    writeInBuf(rbuf,length);
  };
#else
  length=CCrypto::read(fd,&m_rbuf,(STREAMSIZE-size));
  if (length > 0) {
    totalread+=length;
    writeInBuf(m_rbuf,length);
  };
#endif
  // Check for errors 
  if ((max != 0) && (length == 0)){
    throw new CEOFException();
  } else if (length == -1){
    switch(errno){
    case EAGAIN:  // Non-blocking I/O
      break;
    default:
      cdebug << "Error reading socket: " << strerror(errno) << "\n";
      throw new CIOException();
      break;
    }
  }

  return size;
}


/////////////////////////////////////////////////////////////////////////////
// Public functions
/////////////////////////////////////////////////////////////////////////////


/////////////////////////////////////////////////////////////////////////////
// peepByte 
//
// Description: Returning first byte in input stream without removing it from
//              input buf.
//
// Return     : First byte in input stream
//
// Exceptions : CEmptyStreamException, CEOFException, CIOException
//

BYTE CStream::peepByte(){
  fillBuf();
  if (size < 1) throw new CEmptyStreamException();
  return buf[start];
}


/////////////////////////////////////////////////////////////////////////////
// readBuf 
//
// Description: Read length bytes from stream
//
// Return     : Number of bytes read or -1 if read would have blocked 
//
// Exceptions : CEOFException , CIOException
//

int CStream::readBuf(BYTE * msg, int length){
  if (fillBuf() == 0) return -1;
  int nn = 0;
  while ((size >= 1) && (nn < length)){
    msg[nn++] = buf[start];
    INC_START;
    if (size == 0) fillBuf();
  }
  return nn;
}


/////////////////////////////////////////////////////////////////////////////
// writeBuf 
//
// Description: Write length bytes to stream
//
// Return     : Number of bytes writen or -1 if write would have blocked 
//
// Exceptions : CEOFException , CIOException
//

int CStream::writeBuf(BYTE * buf,int length){
#ifdef CRYPTO
  int num = CCrypto::write(fd,buf,length);
#else
  int num = ::write(fd,buf,length);
#endif
  if (num >= 0){
    totalwrite += num;
  } else {
    if (num == -2) return -1; // Error handling in crypto-routines
    switch (errno){
    case EPIPE:
      throw new CEOFException();
      break;
    case EAGAIN: // Non-Blocking I/O
      return -1;
      break;
    default:
      throw new CIOException();
      break;
    }
  }
  return num;
}