taper-source.h

开源备份软件源码 AMANDA, the Advanced Maryland Automatic Network Disk Archiver, is a backup system that a

/*
 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
 * Copyright (c) 2006 Zmanda Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/* The taper source object abstracts the different ways that taper can
 * retrieve and buffer data on its way to the device. It handles all
 * splitting up and re-reading of split-tape parts, as well as all
 * holding-disk related actions. */

#include <glib.h>
#include <glib-object.h>

#include <amanda.h>
#include "server_util.h"
#include "fileheader.h"
#include "queueing.h"

#ifndef __TAPER_SOURCE_H__
#define __TAPER_SOURCE_H__


/*
 * Type checking and casting macros
 */
#define TAPER_TYPE_SOURCE	(taper_source_get_type())
#define TAPER_SOURCE(obj)	G_TYPE_CHECK_INSTANCE_CAST((obj), taper_source_get_type(), TaperSource)
#define TAPER_SOURCE_CONST(obj)	G_TYPE_CHECK_INSTANCE_CAST((obj), taper_source_get_type(), TaperSource const)
#define TAPER_SOURCE_CLASS(klass)	G_TYPE_CHECK_CLASS_CAST((klass), taper_source_get_type(), TaperSourceClass)
#define TAPER_IS_SOURCE(obj)	G_TYPE_CHECK_INSTANCE_TYPE((obj), taper_source_get_type ())

#define TAPER_SOURCE_GET_CLASS(obj)	G_TYPE_INSTANCE_GET_CLASS((obj), taper_source_get_type(), TaperSourceClass)

/*
 * Main object structure
 */
#ifndef __TYPEDEF_TAPER_SOURCE__
#define __TYPEDEF_TAPER_SOURCE__
typedef struct _TaperSource TaperSource;
#endif
struct _TaperSource {
    GObject __parent__;
    /*< private >*/
    gboolean end_of_data; /* protected */
    gboolean end_of_part; /* protected */
    guint64 max_part_size; /* protected */
    dumpfile_t * first_header;
    char * driver_handle;
};

/*
 * Class definition
 */
typedef struct _TaperSourceClass TaperSourceClass;
struct _TaperSourceClass {
    GObjectClass __parent__;
    ssize_t (* read) (TaperSource * self, void * buf, size_t count);
    gboolean (* seek_to_part_start) (TaperSource * self);
    void (* start_new_part) (TaperSource * self);
    gboolean (* is_partial) (TaperSource * self);
    gboolean (* get_end_of_data)(TaperSource * self);
    gboolean (* get_end_of_part)(TaperSource * self);
    dumpfile_t * (* get_first_header)(TaperSource * self);
    int (* predict_parts)(TaperSource * self);
};


/*
 * Public methods
 */
GType	taper_source_get_type	(void);
ssize_t 	taper_source_read	(TaperSource * self,
					void * buf,
					size_t count);
gboolean 	taper_source_get_end_of_data	(TaperSource * self);
gboolean 	taper_source_get_end_of_part	(TaperSource * self);
dumpfile_t *    taper_source_get_first_header   (TaperSource * self);
/* Returns -1 for an unknown number of splits, or a positive integer if the
 * number of splits is exactly known. Should never return zero. */
int             taper_source_predict_parts      (TaperSource * self);

/* You can only call this function (and expect to get an accurate
   result) if taper_source_get_end_of_data() has already returned
   TRUE. */
gboolean        taper_source_is_partial         (TaperSource * self);

gboolean 	taper_source_seek_to_part_start	(TaperSource * self);
void 	taper_source_start_new_part	(TaperSource * self);

/* This function is how you get a taper source. Call it with the
   relevant parameters, and the return value is yours to
   keep. Arguments must be consistant (e.g., if you specify FILE_WRITE
   mode, then you must provide a holding disk file). Input strings are
   copied internally. */
TaperSource * taper_source_new(char * handle,
                               cmd_t mode, char * holding_disk_file,
                               int socket_fd,
                               char * split_disk_buffer,
                               guint64 splitsize,
                               guint64 fallback_splitsize);

/* This function is a ProducerFunctor, as that type is defined in
   device-src/queueing.h. */
producer_result_t taper_source_producer(gpointer taper_source,
                                        queue_buffer_t * buffer,
                                        int hint_size);

#endif