/*
 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
 * Copyright (c) 2008-2012 Zmanda, Inc.  All Rights Reserved.
 * Copyright (c) 2013-2016 Carbonite, Inc.  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  02111-1307 USA
 *
 * Contact information: Carbonite Inc., 756 N Pastoria Ave
 * Sunnyvale, CA 94085, or: http://www.zmanda.com
 */

#include "amanda.h"
#include "amutil.h"
#include "amxfer.h"

/*
 * Class declaration
 *
 * This declaration is entirely private; nothing but xfer_source_fd() references
 * it directly.
 */

GType xfer_source_fd_get_type(void);
#define XFER_SOURCE_FD_TYPE (xfer_source_fd_get_type())
#define XFER_SOURCE_FD(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_fd_get_type(), XferSourceFd)
#define XFER_SOURCE_FD_CONST(obj) G_TYPE_CHECK_INSTANCE_CAST((obj), xfer_source_fd_get_type(), XferSourceFd const)
#define XFER_SOURCE_FD_CLASS(klass) G_TYPE_CHECK_CLASS_CAST((klass), xfer_source_fd_get_type(), XferSourceFdClass)
#define IS_XFER_SOURCE_FD(obj) G_TYPE_CHECK_INSTANCE_TYPE((obj), xfer_source_fd_get_type ())
#define XFER_SOURCE_FD_GET_CLASS(obj) G_TYPE_INSTANCE_GET_CLASS((obj), xfer_source_fd_get_type(), XferSourceFdClass)

static GObjectClass *parent_class = NULL;

/*
 * Main object structure
 */

typedef struct XferSourceFd {
    XferElement __parent__;
} XferSourceFd;

/*
 * Class definition
 */

typedef struct {
    XferElementClass __parent__;
} XferSourceFdClass;

/*
 * Implementation
 */

static void
class_init(
    XferSourceFdClass * selfc)
{
    XferElementClass *klass = XFER_ELEMENT_CLASS(selfc);
    static xfer_element_mech_pair_t mech_pairs[] = {
	{ XFER_MECH_NONE, XFER_MECH_READFD, XFER_NROPS(0), XFER_NTHREADS(0), XFER_NALLOC(0) },
	{ XFER_MECH_NONE, XFER_MECH_NONE, XFER_NROPS(0), XFER_NTHREADS(0), XFER_NALLOC(0) },
    };

    klass->perl_class = "Amanda::Xfer::Source::Fd";
    klass->mech_pairs = mech_pairs;

    parent_class = g_type_class_peek_parent(selfc);
}

GType
xfer_source_fd_get_type (void)
{
    static GType type = 0;

    if (G_UNLIKELY(type == 0)) {
        static const GTypeInfo info = {
            sizeof (XferSourceFdClass),
            (GBaseInitFunc) NULL,
            (GBaseFinalizeFunc) NULL,
            (GClassInitFunc) class_init,
            (GClassFinalizeFunc) NULL,
            NULL /* class_data */,
            sizeof (XferSourceFd),
            0 /* n_preallocs */,
            (GInstanceInitFunc) NULL,
            NULL
        };

        type = g_type_register_static (XFER_ELEMENT_TYPE, "XferSourceFd", &info, 0);
    }

    return type;
}

/* create an element of this class; prototype is in xfer-element.h */
XferElement *
xfer_source_fd(
    int fd)
{
    XferSourceFd *self = (XferSourceFd *)g_object_new(XFER_SOURCE_FD_TYPE, NULL);
    XferElement *elt = XFER_ELEMENT(self);
    int old_fd;

    g_assert(fd >= 0);

    /* we read from a *copy* of this file descriptor, as the downstream element
     * will close output_fd on EOF */
    old_fd = xfer_element_swap_output_fd(elt, dup(fd));
    g_assert(old_fd == -1);

    return elt;
}