//
//	tardy - a tar post-processor
//	Copyright (C) 2003 Peter Miller;
//	All rights reserved.
//
//	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, USA.
//
// MANIFEST: functions to manipulate buffers
//

#pragma implementation "file_output_buffer"

#include <ac/string.h>
#include <file/output/buffer.h>


file_output_buffer::~file_output_buffer()
{
    if (pos > 0)
    {
	deeper->write(buffer, pos);
	pos = 0;
    }
    delete buffer;
    buffer = 0;
    delete deeper;
    deeper = 0;
}


file_output_buffer::file_output_buffer(file_output *arg1, int arg2) :
    deeper(arg1),
    blocksize(arg2 > 0 ? arg2 : 512),
    buffer(0),
    pos(0)
{
}


const char *
file_output_buffer::filename()
    const
{
    return deeper->filename();
}


void
file_output_buffer::write(const void *data, int nbytes)
{
    while (nbytes > 0)
    {
	//
	// Don't double handle the data if we can avoid it.
	// (But only write `blocksize' bytes at a time.)
	//
	if (pos == 0 && nbytes >= blocksize)
	{
	    deeper->write(data, blocksize);
	    data = (char *)data + blocksize;
	    nbytes -= blocksize;
	    continue;
	}

	//
	// Add the data to the end of the buffer.
	//
	int len = blocksize - pos;
	if (len > nbytes)
	    len = nbytes;
	if (!buffer)
	    buffer = new char[blocksize];
	memcpy(buffer + pos, data, len);
	pos += len;
	if (pos >= blocksize)
	{
	    //
	    // If the buffer is full,
	    // write it out and start again.
	    //
	    deeper->write(buffer, pos);
	    pos = 0;
	}
	data = (char *)data + len;
	nbytes -= len;
    }
}