linux/fs/ntfs3/lib/xpress_decompress.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * xpress_decompress.c - A decompressor for the XPRESS compression format
 * (Huffman variant), which can be used in "System Compressed" files.  This is
 * based on the code from wimlib.
 *
 * Copyright (C) 2015 Eric Biggers
 */

#include "decompress_common.h"
#include "lib.h"

#define XPRESS_NUM_SYMBOLS …
#define XPRESS_MAX_CODEWORD_LEN …
#define XPRESS_MIN_MATCH_LEN …

/* This value is chosen for fast decompression.  */
#define XPRESS_TABLEBITS …

/* Reusable heap-allocated memory for XPRESS decompression  */
struct xpress_decompressor { … };

/*
 * xpress_allocate_decompressor - Allocate an XPRESS decompressor
 *
 * Return the pointer to the decompressor on success, or return NULL and set
 * errno on failure.
 */
struct xpress_decompressor *xpress_allocate_decompressor(void)
{ … }

/*
 * xpress_decompress - Decompress a buffer of XPRESS-compressed data
 *
 * @decompressor:       A decompressor that was allocated with
 *			xpress_allocate_decompressor()
 * @compressed_data:	The buffer of data to decompress
 * @compressed_size:	Number of bytes of compressed data
 * @uncompressed_data:	The buffer in which to store the decompressed data
 * @uncompressed_size:	The number of bytes the data decompresses into
 *
 * Return 0 on success, or return -1 and set errno on failure.
 */
int xpress_decompress(struct xpress_decompressor *decompressor,
		      const void *compressed_data, size_t compressed_size,
		      void *uncompressed_data, size_t uncompressed_size)
{ … }

/*
 * xpress_free_decompressor - Free an XPRESS decompressor
 *
 * @decompressor:       A decompressor that was allocated with
 *			xpress_allocate_decompressor(), or NULL.
 */
void xpress_free_decompressor(struct xpress_decompressor *decompressor)
{ … }