pn_buffer.c

/*
 * Copyright (C) 2006-2009 Felipe Contreras.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "pn_buffer.h"

#define BUFFER_SIZE 0x1000

struct pn_buffer *
pn_buffer_new (void)
{
    struct pn_buffer *buffer;
    buffer = g_new (struct pn_buffer, 1);
    buffer->data = NULL;
    buffer->alloc_data = NULL;
    buffer->size = 0;
    buffer->len = 0;
    return buffer;
}

struct pn_buffer *
pn_buffer_new_and_alloc (gsize size)
{
    struct pn_buffer *buffer;

    if (size <= 0)
        size = BUFFER_SIZE;

    buffer = g_new (struct pn_buffer, 1);
    buffer->data = buffer->alloc_data = g_malloc (size);
    buffer->size = size;
    buffer->len = 0;
    return buffer;
}

struct pn_buffer *
pn_buffer_new_memdup (gpointer data,
                      gsize size)
{
    struct pn_buffer *buffer;

    buffer = g_new (struct pn_buffer, 1);
    buffer->size = buffer->len = size;
    buffer->data = buffer->alloc_data = g_memdup (data, size);

    return buffer;
}

void
pn_buffer_free (struct pn_buffer *buffer)
{
    if (!buffer)
        return;

    g_free (buffer->alloc_data);
    g_free (buffer);
}

void
pn_buffer_resize (struct pn_buffer *buffer,
                  gsize new_size)
{
    new_size = ((new_size / BUFFER_SIZE) + 1) * BUFFER_SIZE;
    buffer->data = buffer->alloc_data = g_realloc (buffer->data, new_size);
    buffer->size = new_size;
}

void
pn_buffer_prepare (struct pn_buffer *buffer,
                   gsize extra_size)
{
    if (extra_size <= buffer->size - buffer->len)
        return;

    pn_buffer_resize (buffer, buffer->len + extra_size);
}