739a7ae0e9
Change-Id: I520c14131ec1e12013f106c13cba00aac058ad83 Reviewed-on: http://gerrit.rockbox.org/391 Reviewed-by: Dominik Riebeling <Dominik.Riebeling@gmail.com>
121 lines
4.2 KiB
C
121 lines
4.2 KiB
C
/* This file is part of libmspack.
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* (C) 2003-2004 Stuart Caie.
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*
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* The deflate method was created by Phil Katz. MSZIP is equivalent to the
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* deflate method.
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*
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* libmspack is free software; you can redistribute it and/or modify it under
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* the terms of the GNU Lesser General Public License (LGPL) version 2.1
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*
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* For further details, see the file COPYING.LIB distributed with libmspack
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*/
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#ifndef MSPACK_MSZIP_H
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#define MSPACK_MSZIP_H 1
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* MSZIP (deflate) compression / (inflate) decompression definitions */
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#define MSZIP_FRAME_SIZE (32768) /* size of LZ history window */
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#define MSZIP_LITERAL_MAXSYMBOLS (288) /* literal/length huffman tree */
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#define MSZIP_LITERAL_TABLEBITS (9)
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#define MSZIP_DISTANCE_MAXSYMBOLS (32) /* distance huffman tree */
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#define MSZIP_DISTANCE_TABLEBITS (6)
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/* if there are less direct lookup entries than symbols, the longer
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* code pointers will be <= maxsymbols. This must not happen, or we
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* will decode entries badly */
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#if (1 << MSZIP_LITERAL_TABLEBITS) < (MSZIP_LITERAL_MAXSYMBOLS * 2)
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# define MSZIP_LITERAL_TABLESIZE (MSZIP_LITERAL_MAXSYMBOLS * 4)
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#else
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# define MSZIP_LITERAL_TABLESIZE ((1 << MSZIP_LITERAL_TABLEBITS) + \
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(MSZIP_LITERAL_MAXSYMBOLS * 2))
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#endif
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#if (1 << MSZIP_DISTANCE_TABLEBITS) < (MSZIP_DISTANCE_MAXSYMBOLS * 2)
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# define MSZIP_DISTANCE_TABLESIZE (MSZIP_DISTANCE_MAXSYMBOLS * 4)
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#else
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# define MSZIP_DISTANCE_TABLESIZE ((1 << MSZIP_DISTANCE_TABLEBITS) + \
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(MSZIP_DISTANCE_MAXSYMBOLS * 2))
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#endif
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struct mszipd_stream {
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struct mspack_system *sys; /* I/O routines */
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struct mspack_file *input; /* input file handle */
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struct mspack_file *output; /* output file handle */
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unsigned int window_posn; /* offset within window */
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/* inflate() will call this whenever the window should be emptied. */
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int (*flush_window)(struct mszipd_stream *, unsigned int);
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int error, repair_mode, bytes_output;
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/* I/O buffering */
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unsigned char *inbuf, *i_ptr, *i_end, *o_ptr, *o_end, input_end;
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unsigned int bit_buffer, bits_left, inbuf_size;
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/* huffman code lengths */
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unsigned char LITERAL_len[MSZIP_LITERAL_MAXSYMBOLS];
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unsigned char DISTANCE_len[MSZIP_DISTANCE_MAXSYMBOLS];
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/* huffman decoding tables */
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unsigned short LITERAL_table [MSZIP_LITERAL_TABLESIZE];
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unsigned short DISTANCE_table[MSZIP_DISTANCE_TABLESIZE];
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/* 32kb history window */
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unsigned char window[MSZIP_FRAME_SIZE];
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};
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/* allocates MS-ZIP decompression stream for decoding the given stream.
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*
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* - uses system->alloc() to allocate memory
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*
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* - returns NULL if not enough memory
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*
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* - input_buffer_size is how many bytes to use as an input bitstream buffer
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*
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* - if repair_mode is non-zero, errors in decompression will be skipped
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* and 'holes' left will be filled with zero bytes. This allows at least
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* a partial recovery of erroneous data.
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*/
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extern struct mszipd_stream *mszipd_init(struct mspack_system *system,
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struct mspack_file *input,
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struct mspack_file *output,
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int input_buffer_size,
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int repair_mode);
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/* decompresses, or decompresses more of, an MS-ZIP stream.
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*
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* - out_bytes of data will be decompressed and the function will return
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* with an MSPACK_ERR_OK return code.
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*
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* - decompressing will stop as soon as out_bytes is reached. if the true
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* amount of bytes decoded spills over that amount, they will be kept for
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* a later invocation of mszipd_decompress().
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*
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* - the output bytes will be passed to the system->write() function given in
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* mszipd_init(), using the output file handle given in mszipd_init(). More
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* than one call may be made to system->write()
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*
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* - MS-ZIP will read input bytes as necessary using the system->read()
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* function given in mszipd_init(), using the input file handle given in
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* mszipd_init(). This will continue until system->read() returns 0 bytes,
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* or an error.
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*/
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extern int mszipd_decompress(struct mszipd_stream *zip, off_t out_bytes);
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/* frees all stream associated with an MS-ZIP data stream
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*
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* - calls system->free() using the system pointer given in mszipd_init()
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*/
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void mszipd_free(struct mszipd_stream *zip);
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#ifdef __cplusplus
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}
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#endif
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#endif
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