libisofs/libisofs/filter.h

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/*
* Copyright (c) 2008 Vreixo Formoso
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* or later as published by the Free Software Foundation.
* See COPYING file for details.
*/
#ifndef LIBISO_FILTER_H_
#define LIBISO_FILTER_H_
/*
* Definitions of filters.
*/
/* dev_id for stream identification */
/* libisofs/filters/xor_encrypt.c */
#define XOR_ENCRYPT_DEV_ID 1
/* libisofs/filters/external.c */
#define ISO_FILTER_EXTERNAL_DEV_ID 2
/* libisofs/filters/zisofs.c */
#define ISO_FILTER_ZISOFS_DEV_ID 3
/* libisofs/filters/gzip.c */
#define ISO_FILTER_GZIP_DEV_ID 4
typedef struct filter_context FilterContext;
struct filter_context {
int version; /* reserved for future usage, set to 0 */
int refcount;
/** filter specific shared data */
void *data;
/**
* Factory method to create a filtered stream from another stream.
*
* @param original
* The original stream to be filtered. If the filter needs a ref to
* it (most cases), it should take a ref to it with iso_stream_ref().
* @param filtered
* Will be filled with the filtered IsoStream (reference belongs to
* caller).
* @return
* 1 on success, < 0 on error
*/
int (*get_filter)(FilterContext *filter, IsoStream *original,
IsoStream **filtered);
/**
* Free implementation specific data. Should never be called by user.
* Use iso_filter_unref() instead.
*/
void (*free)(FilterContext *filter);
};
/**
*
* @param flag
* Reserved for future usage, pass always 0 for now.
* TODO in a future a different value can mean filter caching, where
* the filter is applied once and the filtered file is stored in a temp
* dir. This prevent filter to be applied several times.
*/
int iso_file_add_filter(IsoFile *file, FilterContext *filter, int flag);
void iso_filter_ref(FilterContext *filter);
void iso_filter_unref(FilterContext *filter);
#endif /*LIBISO_FILTER_H_*/