/*
 *	Ivy League
 *
 *	Buffered streams
 *
 *	Copyright 1990-2000
 *	Laboratoire de Recherche en Informatique (LRI)
 *	Centre d'Etudes de la Navigation Aerienne (CENA)
 *
 *	by Stephane Chatty
 *	portions of code by Michel Beaudouin-Lafon
 *
 *	$Id$
 *
 */

#include "BufStream.h"
#include "error.h"

/*?
These constructors are similar to those of class \typ{IvlSocket}.
?*/
IvlBufStream :: IvlBufStream (IvlAddress* bindTo, IvlAddress* connectTo)
: IvlStream (bindTo, connectTo),
  InBuffer (),
  OutBuffer (),
  OutSize (128),
  Sync (false)
{
}

// *** this copy constructor might be automatically generated
/*?nodoc?*/
IvlBufStream :: IvlBufStream (const IvlBufStream& ms)
: IvlStream (ms),
  InBuffer (),
  OutBuffer (),
  OutSize (ms.OutSize),
  Sync (ms.Sync)
{
}

/*?nodoc?*/
IvlBufStream :: ~IvlBufStream ()
{
	Flush ();
	InBuffer.Clear ();
	OutBuffer.Clear ();
}

/*?nextdoc?*/
void
IvlBufStream :: InputBuffer (int min, int grow, int max)
{
	InBuffer.SetSizes (min, grow, max);
}

/*?
Set the input and output buffer sizes.
Default sizes are used if these functions are not called.
?*/
void
IvlBufStream :: OutputBuffer (int min, int grow, int max)
{
	OutBuffer.SetSizes (min, grow, max);
	OutSize = max;
}

/*?
Flush the output buffer.
This function is called automatically when the buffer exceeds its flush size,
or after each message when this stream is in synchronous mode.
It is also called from \fun{Ask} to wait for the answer.
?*/
void
IvlBufStream :: Flush ()
{
	if (OutBuffer.BufLength () == 0)
		return;
	int n = Write (OutBuffer);
	OutBuffer.Flush (n);
}

/*?nodoc?*/
void
IvlBufStream :: HandleWrite ()
{
	Flush ();
}

// read stream into input buffer
// delete the stream when an eof is received
// return the number of bytes read
//
/*?hidden?*/
int
IvlBufStream :: ReadInput ()
{
	/* read in buffer */
	if (InBuffer.BufLength () == 0)
		InBuffer.NeedSize (128);
	int n = Read (InBuffer);

	/* handle errors */
	if (n == -2) {
		InBuffer.Grow ();
		n = Read (InBuffer);
	}

#if 0
	if (n < 0)
		SysError (ErrWarn, "IvlBufStream::ReadInput");
	if (n <= 0)
		Closing (n < 0 ? false : true);
	return n;
#else
	/* new code taken from BusAccess.cc (27/11/2000) */
	if (n <= 0)
		delete this;
	return n;
	
#endif
}

/*?
This virtual function is called when an end of file is read, 
meaning that the communication is terminated.
It is also called if an error occurs while reading.
You can check the value of the global variable \var{errno}:
if it is non zero, \fun{Closing} was called because of an error. % wrong
By default this function does nothing.
?*/
void
IvlBufStream :: Closing (bool)
{
}

void
IvlBufStream :: WriteLong (lword l)
{
	OutBuffer << l;
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

void
IvlBufStream :: WriteShort (sword s)
{
	OutBuffer << s;
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

void
IvlBufStream :: WriteByte (byte b)
{
	OutBuffer << b;
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

void
IvlBufStream :: WriteChar (char c)
{
	OutBuffer << c;
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

void
IvlBufStream :: WriteString (const char* s)
{
	OutBuffer << s;
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

void
IvlBufStream :: WriteBuf (const byte* b, int n)
{
	OutBuffer.WriteBuf (b, n);
	if (Sync || OutBuffer.BufLength () >= OutSize)
		Flush ();
}

bool
IvlBufStream :: ReadLong (lword& l)
{
	return InBuffer.ReadLong (l);
}

bool
IvlBufStream :: ReadShort (sword& s)
{
	return InBuffer.ReadShort (s);
}

bool
IvlBufStream :: ReadByte (byte& b)
{
	return InBuffer.ReadByte (b);
}

bool
IvlBufStream :: ReadChar (char& c)
{
	return InBuffer.ReadChar (c);
}

int
IvlBufStream :: ReadString (char* s, int n)
{
	return InBuffer.ReadString (s, n);
}

int
IvlBufStream :: ReadString (IvlString& s)
{
	return InBuffer.ReadString (s);
}

bool
IvlBufStream :: ReadBuf (byte* b, int n)
{
	return InBuffer.ReadBuf (b, n);
}


#ifdef DOC
/*?
This function defines the size of the output buffer that triggers automatic flushing
in asynchronous mode. By default the flush size is the maximum size of the
output buffer. As a consequence, it is changed by \fun{OutBuffer}.
?*/
void
IvlBufStream :: FlushSize (int n)
{ }

/*?nextdoc?*/
void
IvlBufStream :: SetSyncMode (bool s)
{ }

/*?
A buffered stream can be in synchronous or asynchronous mode.
In asynchronous mode output is buffered while in synchronous mode it is not.
Synchronous mode is usually less efficient than asynchronous mode
because it makes more system calls to transfer data;
however synchronous mode can be useful for debugging applications.
?*/
bool
IvlBufStream :: GetSyncMode ()
{ }

#endif /* DOC */