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/* SPDX-License-Identifier: GPL-3.0-or-later */
#ifndef COMPRESS_H
#define COMPRESS_H
#include <sys/types.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "squashfs.h"
typedef struct compressor_t compressor_t;
/* Encapsultes a compressor with a simple interface to compress or
uncompress/extract blocks of data. */
struct compressor_t {
/* Write compressor options to the output file if necessary.
Returns the number of bytes written or -1 on failure.
Internally prints error messages to stderr. */
int (*write_options)(compressor_t *cmp, int fd);
/* Read compressor options to the input file.
Returns zero on success, -1 on failure.
Internally prints error messages to stderr. */
int (*read_options)(compressor_t *cmp, int fd);
/*
Compress or uncompress a chunk of data.
Returns the number of bytes written to the output buffer, -1 on
failure or 0 if the output buffer was too small.
The compressor also returns 0 if the compressed result ends
up larger than the original input.
Internally prints compressor specific error messages to stderr.
*/
ssize_t (*do_block)(compressor_t *cmp, const uint8_t *in, size_t size,
uint8_t *out, size_t outsize);
void (*destroy)(compressor_t *stream);
};
bool compressor_exists(E_SQFS_COMPRESSOR id);
/* block_size is the configured block size for the SquashFS image. Needed
by some compressors to set internal defaults. */
compressor_t *compressor_create(E_SQFS_COMPRESSOR id, bool compress,
size_t block_size);
#endif /* COMPRESS_H */
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