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Switched LZX to C extension

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Marshall T. Vandegrift 2008-07-18 16:34:41 -04:00
parent f1aa90da36
commit 1e78860f4f
8 changed files with 3005 additions and 138 deletions
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138
src/calibre/ebooks/lit/lzxd.py
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import copy
# some constants defined by the LZX specification
MIN_MATCH = 2
MAX_MATCH = 257
NUM_CHARS = 256
BLOCKTYPE_INVALID = 0 # also blocktypes 4-7 invalid
BLOCKTYPE_VERBATIM = 1
BLOCKTYPE_ALIGNED = 2
BLOCKTYPE_UNCOMPRESSED = 3
PRETREE_NUM_ELEMENTS = 20
ALIGNED_NUM_ELEMENTS = 8 # aligned offset tree #elements
NUM_PRIMARY_LENGTHS = 7 # this one missing from spec!
NUM_SECONDARY_LENGTHS = 249 # length tree #elements
# LZX huffman defines: tweak tablebits as desired
PRETREE_MAXSYMBOLS = LZX_PRETREE_NUM_ELEMENTS
PRETREE_TABLEBITS = 6
MAINTREE_MAXSYMBOLS = LZX_NUM_CHARS + 50*8
MAINTREE_TABLEBITS = 12
LENGTH_MAXSYMBOLS = LZX_NUM_SECONDARY_LENGTHS+1
LENGTH_TABLEBITS = 12
ALIGNED_MAXSYMBOLS = LZX_ALIGNED_NUM_ELEMENTS
ALIGNED_TABLEBITS = 7
LENTABLE_SAFETY = 64 # table decoding overruns are allowed
FRAME_SIZE = 32768 # the size of a frame in LZX
class BitReader(object):
def __init__(self, data):
self.data, self.pos, self.nbits = \
data + "\x00\x00\x00\x00", 0, len(data) * 8
def peek(self, n):
r, g = 0, 0
while g < n:
r = (r << 8) | ord(self.data[(self.pos + g) >> 3])
g = g + 8 - ((self.pos + g) & 7)
return (r >> (g - n)) & ((1 << n) - 1)
def remove(self, n):
self.pos += n
return self.pos <= self.nbits
def left(self):
return self.nbits - self.pos
def read(self, n):
val = self.peek(n)
self.remove(n)
return val
class LzxError(Exception):
pass
POSITION_BASE = [0]*51
EXTRA_BITS = [0]*51
def _static_init():
j = 0
for i in xrange(0, 51, 2):
EXTRA_BITS[i] = j
EXTRA_BITS[i + 1] = j
if i != 0 or j < 17): j += 1
j = 0
for i in xrange(0, 51, 1):
POSITION_BASE[i] = j
j += 1 << extra_bits[i]
_static_init()
class LzxDecompressor(object):
def __init__(self, window_bits, reset_interval=0x7fff):
# LZX supports window sizes of 2^15 (32Kb) through 2^21 (2Mb)
if window_bits < 15 or window_bits > 21:
raise LzxError("Invalid window size")
self.window_size = 1 << window_bits
self.window_posn = 0
self.frame_posn = 0
self.frame = 0
self.reset_interval = reset_interval
self.intel_filesize = 0
self.intel_curpos = 0
# window bits: 15 16 17 18 19 20 21
# position slots: 30 32 34 36 38 42 50
self.posn_solts = 50 if window_bits == 21 \
else 42 if window_bits == 20 else window_bits << 1
self.intel_started = 0
self.input_end = 0
# huffman code lengths
self.PRETREE_len = [0] * (PRETREE_MAXSYMBOLS + LENTABLE_SAFETY)
self.MAINTREE_len = [0] * (MAINTREE_MAXSYMBOLS + LENTABLE_SAFETY)
self.LENGTH_len = [0] * (LENGTH_MAXSYMBOLS + LENTABLE_SAFETY)
self.ALIGNED_len = [0] * (ALIGNED_MAXSYMBOLS + LENTABLE_SAFETY)
# huffman decoding tables
self.PRETREE_table = \
[0] * ((1 << PRETREE_TABLEBITS) + (PRETREE_MAXSYMBOLS * 2))
self.MAINTREE_table = \
[0] * ((1 << MAINTREE_TABLEBITS) + (MAINTREE_MAXSYMBOLS * 2))
self.LENGTH_table = \
[0] * ((1 << LENGTH_TABLEBITS) + (LENGTH_MAXSYMBOLS * 2))
self.ALIGNED_table = \
[0] * ((1 << ALIGNED_TABLEBITS) + (ALIGNED_MAXSYMBOLS * 2))
self.o_buf = self.i_buf = ''
self._reset_state()
def _reset_state(self):
self.R0 = 1
self.R1 = 1
self.R2 = 1
self.header_read = 0
self.block_remaining = 0
self.block_type = BLOCKTYPE_INVALID
# initialise tables to 0 (because deltas will be applied to them)
for i in xrange(MAINTREE_MAXSYMBOLS): self.MAINTREE_len[i] = 0
for i in xrange(LENGTH_MAXSYMBOLS): self.LENGTH_len[i] = 0
def decompress(self, data, out_bytes):
return ''.join(self._decompress(data, out_bytes))
def _decompress(self, data, out_bytes):
# easy answers
if out_bytes < 0:
raise LzxError('Negative desired output bytes')
# Initialize input and output
input = BitReader(data)
output = []

5
src/calibre/utils/lzx-setup.py Normal file
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from distutils.core import setup, Extension
setup(name="lzx", version="1.0",
ext_modules=[Extension('lzx', sources=['lzx/lzxmodule.c', 'lzx/lzxd.c'],
include_dirs=['lzx'])])

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src/calibre/utils/lzx/lzx.h Normal file
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/* This file is part of libmspack.
* (C) 2003-2004 Stuart Caie.
*
* The LZX method was created by Jonathan Forbes and Tomi Poutanen, adapted
* by Microsoft Corporation.
*
* libmspack is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (LGPL) version 2.1
*
* For further details, see the file COPYING.LIB distributed with libmspack
*/
#include <sys/types.h>
#ifndef MSPACK_LZX_H
#define MSPACK_LZX_H 1
/* LZX compression / decompression definitions */
/* some constants defined by the LZX specification */
#define LZX_MIN_MATCH (2)
#define LZX_MAX_MATCH (257)
#define LZX_NUM_CHARS (256)
#define LZX_BLOCKTYPE_INVALID (0) /* also blocktypes 4-7 invalid */
#define LZX_BLOCKTYPE_VERBATIM (1)
#define LZX_BLOCKTYPE_ALIGNED (2)
#define LZX_BLOCKTYPE_UNCOMPRESSED (3)
#define LZX_PRETREE_NUM_ELEMENTS (20)
#define LZX_ALIGNED_NUM_ELEMENTS (8) /* aligned offset tree #elements */
#define LZX_NUM_PRIMARY_LENGTHS (7) /* this one missing from spec! */
#define LZX_NUM_SECONDARY_LENGTHS (249) /* length tree #elements */
/* LZX huffman defines: tweak tablebits as desired */
#define LZX_PRETREE_MAXSYMBOLS (LZX_PRETREE_NUM_ELEMENTS)
#define LZX_PRETREE_TABLEBITS (6)
#define LZX_MAINTREE_MAXSYMBOLS (LZX_NUM_CHARS + 50*8)
#define LZX_MAINTREE_TABLEBITS (12)
#define LZX_LENGTH_MAXSYMBOLS (LZX_NUM_SECONDARY_LENGTHS+1)
#define LZX_LENGTH_TABLEBITS (12)
#define LZX_ALIGNED_MAXSYMBOLS (LZX_ALIGNED_NUM_ELEMENTS)
#define LZX_ALIGNED_TABLEBITS (7)
#define LZX_LENTABLE_SAFETY (64) /* table decoding overruns are allowed */
#define LZX_FRAME_SIZE (32768) /* the size of a frame in LZX */
struct lzxd_stream {
struct mspack_system *sys; /* I/O routines */
struct mspack_file *input; /* input file handle */
struct mspack_file *output; /* output file handle */
off_t offset; /* number of bytes actually output */
off_t length; /* overall decompressed length of stream */
unsigned char *window; /* decoding window */
unsigned int window_size; /* window size */
unsigned int window_posn; /* decompression offset within window */
unsigned int frame_posn; /* current frame offset within in window */
unsigned int frame; /* the number of 32kb frames processed */
unsigned int reset_interval; /* which frame do we reset the compressor? */
unsigned int R0, R1, R2; /* for the LRU offset system */
unsigned int block_length; /* uncompressed length of this LZX block */
unsigned int block_remaining; /* uncompressed bytes still left to decode */
signed int intel_filesize; /* magic header value used for transform */
signed int intel_curpos; /* current offset in transform space */
unsigned char intel_started; /* has intel E8 decoding started? */
unsigned char block_type; /* type of the current block */
unsigned char header_read; /* have we started decoding at all yet? */
unsigned char posn_slots; /* how many posn slots in stream? */
unsigned char input_end; /* have we reached the end of input? */
int error;
/* I/O buffering */
unsigned char *inbuf, *i_ptr, *i_end, *o_ptr, *o_end;
unsigned int bit_buffer, bits_left, inbuf_size;
/* huffman code lengths */
unsigned char PRETREE_len [LZX_PRETREE_MAXSYMBOLS + LZX_LENTABLE_SAFETY];
unsigned char MAINTREE_len [LZX_MAINTREE_MAXSYMBOLS + LZX_LENTABLE_SAFETY];
unsigned char LENGTH_len [LZX_LENGTH_MAXSYMBOLS + LZX_LENTABLE_SAFETY];
unsigned char ALIGNED_len [LZX_ALIGNED_MAXSYMBOLS + LZX_LENTABLE_SAFETY];
/* huffman decoding tables */
unsigned short PRETREE_table [(1 << LZX_PRETREE_TABLEBITS) +
(LZX_PRETREE_MAXSYMBOLS * 2)];
unsigned short MAINTREE_table[(1 << LZX_MAINTREE_TABLEBITS) +
(LZX_MAINTREE_MAXSYMBOLS * 2)];
unsigned short LENGTH_table [(1 << LZX_LENGTH_TABLEBITS) +
(LZX_LENGTH_MAXSYMBOLS * 2)];
unsigned short ALIGNED_table [(1 << LZX_ALIGNED_TABLEBITS) +
(LZX_ALIGNED_MAXSYMBOLS * 2)];
/* this is used purely for doing the intel E8 transform */
unsigned char e8_buf[LZX_FRAME_SIZE];
};
/* allocates LZX decompression state for decoding the given stream.
*
* - returns NULL if window_bits is outwith the range 15 to 21 (inclusive).
*
* - uses system->alloc() to allocate memory
*
* - returns NULL if not enough memory
*
* - window_bits is the size of the LZX window, from 32Kb (15) to 2Mb (21).
*
* - reset_interval is how often the bitstream is reset, measured in
* multiples of 32Kb bytes output. For CAB LZX streams, this is always 0
* (does not occur).
*
* - input_buffer_size is how many bytes to use as an input bitstream buffer
*
* - output_length is the length in bytes of the entirely decompressed
* output stream, if known in advance. It is used to correctly perform
* the Intel E8 transformation, which must stop 6 bytes before the very
* end of the decompressed stream. It is not otherwise used or adhered
* to. If the full decompressed length is known in advance, set it here.
* If it is NOT known, use the value 0, and call lzxd_set_output_length()
* once it is known. If never set, 4 of the final 6 bytes of the output
* stream may be incorrect.
*/
extern struct lzxd_stream *lzxd_init(struct mspack_system *system,
struct mspack_file *input,
struct mspack_file *output,
int window_bits,
int reset_interval,
int input_buffer_size,
off_t output_length);
/* see description of output_length in lzxd_init() */
extern void lzxd_set_output_length(struct lzxd_stream *lzx,
off_t output_length);
/* decompresses, or decompresses more of, an LZX stream.
*
* - out_bytes of data will be decompressed and the function will return
* with an MSPACK_ERR_OK return code.
*
* - decompressing will stop as soon as out_bytes is reached. if the true
* amount of bytes decoded spills over that amount, they will be kept for
* a later invocation of lzxd_decompress().
*
* - the output bytes will be passed to the system->write() function given in
* lzxd_init(), using the output file handle given in lzxd_init(). More
* than one call may be made to system->write().
*
* - LZX will read input bytes as necessary using the system->read() function
* given in lzxd_init(), using the input file handle given in lzxd_init().
* This will continue until system->read() returns 0 bytes, or an error.
* input streams should convey an "end of input stream" by refusing to
* supply all the bytes that LZX asks for when they reach the end of the
* stream, rather than return an error code.
*
* - if an error code other than MSPACK_ERR_OK is returned, the stream should
* be considered unusable and lzxd_decompress() should not be called again
* on this stream.
*/
extern int lzxd_decompress(struct lzxd_stream *lzx, off_t out_bytes);
/* frees all state associated with an LZX data stream
*
* - calls system->free() using the system pointer given in lzxd_init()
*/
void lzxd_free(struct lzxd_stream *lzx);
#endif

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src/calibre/utils/lzx/lzxd.c Normal file
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/* This file is part of libmspack.
* (C) 2003-2004 Stuart Caie.
*
* The LZX method was created by Jonathan Forbes and Tomi Poutanen, adapted
* by Microsoft Corporation.
*
* libmspack is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (LGPL) version 2.1
*
* For further details, see the file COPYING.LIB distributed with libmspack
*/
/* LZX decompression implementation */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <mspack.h>
#include <system.h>
#include <lzx.h>
/* Microsoft's LZX document and their implementation of the
* com.ms.util.cab Java package do not concur.
*
* In the LZX document, there is a table showing the correlation between
* window size and the number of position slots. It states that the 1MB
* window = 40 slots and the 2MB window = 42 slots. In the implementation,
* 1MB = 42 slots, 2MB = 50 slots. The actual calculation is 'find the
* first slot whose position base is equal to or more than the required
* window size'. This would explain why other tables in the document refer
* to 50 slots rather than 42.
*
* The constant NUM_PRIMARY_LENGTHS used in the decompression pseudocode
* is not defined in the specification.
*
* The LZX document does not state the uncompressed block has an
* uncompressed length field. Where does this length field come from, so
* we can know how large the block is? The implementation has it as the 24
* bits following after the 3 blocktype bits, before the alignment
* padding.
*
* The LZX document states that aligned offset blocks have their aligned
* offset huffman tree AFTER the main and length trees. The implementation
* suggests that the aligned offset tree is BEFORE the main and length
* trees.
*
* The LZX document decoding algorithm states that, in an aligned offset
* block, if an extra_bits value is 1, 2 or 3, then that number of bits
* should be read and the result added to the match offset. This is
* correct for 1 and 2, but not 3, where just a huffman symbol (using the
* aligned tree) should be read.
*
* Regarding the E8 preprocessing, the LZX document states 'No translation
* may be performed on the last 6 bytes of the input block'. This is
* correct. However, the pseudocode provided checks for the *E8 leader*
* up to the last 6 bytes. If the leader appears between -10 and -7 bytes
* from the end, this would cause the next four bytes to be modified, at
* least one of which would be in the last 6 bytes, which is not allowed
* according to the spec.
*
* The specification states that the huffman trees must always contain at
* least one element. However, many CAB files contain blocks where the
* length tree is completely empty (because there are no matches), and
* this is expected to succeed.
*/
/* LZX decompressor input macros
*
* STORE_BITS stores bitstream state in lzxd_stream structure
* RESTORE_BITS restores bitstream state from lzxd_stream structure
* READ_BITS(var,n) takes N bits from the buffer and puts them in var
* ENSURE_BITS(n) ensures there are at least N bits in the bit buffer.
* PEEK_BITS(n) extracts without removing N bits from the bit buffer
* REMOVE_BITS(n) removes N bits from the bit buffer
*
* These bit access routines work by using the area beyond the MSB and the
* LSB as a free source of zeroes when shifting. This avoids having to
* mask any bits. So we have to know the bit width of the bit buffer
* variable.
*
* The bit buffer datatype should be at least 32 bits wide: it must be
* possible to ENSURE_BITS(16), so it must be possible to add 16 new bits
* to the bit buffer when the bit buffer already has 1 to 15 bits left.
*/
#if HAVE_LIMITS_H
# include <limits.h>
#endif
#ifndef CHAR_BIT
# define CHAR_BIT (8)
#endif
#define BITBUF_WIDTH (sizeof(bit_buffer) * CHAR_BIT)
#define STORE_BITS do { \
lzx->i_ptr = i_ptr; \
lzx->i_end = i_end; \
lzx->bit_buffer = bit_buffer; \
lzx->bits_left = bits_left; \
} while (0)
#define RESTORE_BITS do { \
i_ptr = lzx->i_ptr; \
i_end = lzx->i_end; \
bit_buffer = lzx->bit_buffer; \
bits_left = lzx->bits_left; \
} while (0)
#define ENSURE_BITS(nbits) \
while (bits_left < (nbits)) { \
if (i_ptr >= i_end) { \
if (lzxd_read_input(lzx)) return lzx->error; \
i_ptr = lzx->i_ptr; \
i_end = lzx->i_end; \
} \
bit_buffer |= ((i_ptr[1] << 8) | i_ptr[0]) \
<< (BITBUF_WIDTH - 16 - bits_left); \
bits_left += 16; \
i_ptr += 2; \
}
#define PEEK_BITS(nbits) (bit_buffer >> (BITBUF_WIDTH - (nbits)))
#define REMOVE_BITS(nbits) ((bit_buffer <<= (nbits)), (bits_left -= (nbits)))
#define READ_BITS(val, nbits) do { \
ENSURE_BITS(nbits); \
(val) = PEEK_BITS(nbits); \
REMOVE_BITS(nbits); \
} while (0)
static int lzxd_read_input(struct lzxd_stream *lzx) {
int read = lzx->sys->read(lzx->input, &lzx->inbuf[0], (int)lzx->inbuf_size);
if (read < 0) return lzx->error = MSPACK_ERR_READ;
/* huff decode's ENSURE_BYTES(16) might overrun the input stream, even
* if those bits aren't used, so fake 2 more bytes */
if (read == 0) {
if (lzx->input_end) {
D(("out of input bytes"))
return lzx->error = MSPACK_ERR_READ;
}
else {
read = 2;
lzx->inbuf[0] = lzx->inbuf[1] = 0;
lzx->input_end = 1;
}
}
lzx->i_ptr = &lzx->inbuf[0];
lzx->i_end = &lzx->inbuf[read];
return MSPACK_ERR_OK;
}
/* Huffman decoding macros */
/* READ_HUFFSYM(tablename, var) decodes one huffman symbol from the
* bitstream using the stated table and puts it in var.
*/
#define READ_HUFFSYM(tbl, var) do { \
/* huffman symbols can be up to 16 bits long */ \
ENSURE_BITS(16); \
/* immediate table lookup of [tablebits] bits of the code */ \
sym = lzx->tbl##_table[PEEK_BITS(LZX_##tbl##_TABLEBITS)]; \
/* is the symbol is longer than [tablebits] bits? (i=node index) */ \
if (sym >= LZX_##tbl##_MAXSYMBOLS) { \
/* decode remaining bits by tree traversal */ \
i = 1 << (BITBUF_WIDTH - LZX_##tbl##_TABLEBITS); \
do { \
/* one less bit. error if we run out of bits before decode */ \
i >>= 1; \
if (i == 0) { \
D(("out of bits in huffman decode")) \
return lzx->error = MSPACK_ERR_DECRUNCH; \
} \
/* double node index and add 0 (left branch) or 1 (right) */ \
sym <<= 1; sym |= (bit_buffer & i) ? 1 : 0; \
/* hop to next node index / decoded symbol */ \
sym = lzx->tbl##_table[sym]; \
/* while we are still in node indicies, not decoded symbols */ \
} while (sym >= LZX_##tbl##_MAXSYMBOLS); \
} \
/* result */ \
(var) = sym; \
/* look up the code length of that symbol and discard those bits */ \
i = lzx->tbl##_len[sym]; \
REMOVE_BITS(i); \
} while (0)
/* BUILD_TABLE(tbl) builds a huffman lookup table from code lengths */
#define BUILD_TABLE(tbl) \
if (make_decode_table(LZX_##tbl##_MAXSYMBOLS, LZX_##tbl##_TABLEBITS, \
&lzx->tbl##_len[0], &lzx->tbl##_table[0])) \
{ \
D(("failed to build %s table", #tbl)) \
return lzx->error = MSPACK_ERR_DECRUNCH; \
}
/* make_decode_table(nsyms, nbits, length[], table[])
*
* This function was coded by David Tritscher. It builds a fast huffman
* decoding table from a canonical huffman code lengths table.
*
* nsyms = total number of symbols in this huffman tree.
* nbits = any symbols with a code length of nbits or less can be decoded
* in one lookup of the table.
* length = A table to get code lengths from [0 to syms-1]
* table = The table to fill up with decoded symbols and pointers.
*
* Returns 0 for OK or 1 for error
*/
static int make_decode_table(unsigned int nsyms, unsigned int nbits,
unsigned char *length, unsigned short *table)
{
register unsigned short sym;
register unsigned int leaf, fill;
register unsigned char bit_num;
unsigned int pos = 0; /* the current position in the decode table */
unsigned int table_mask = 1 << nbits;
unsigned int bit_mask = table_mask >> 1; /* don't do 0 length codes */
unsigned int next_symbol = bit_mask; /* base of allocation for long codes */
/* fill entries for codes short enough for a direct mapping */
for (bit_num = 1; bit_num <= nbits; bit_num++) {
for (sym = 0; sym < nsyms; sym++) {
if (length[sym] != bit_num) continue;
leaf = pos;
if((pos += bit_mask) > table_mask) return 1; /* table overrun */
/* fill all possible lookups of this symbol with the symbol itself */
for (fill = bit_mask; fill-- > 0;) table[leaf++] = sym;
}
bit_mask >>= 1;
}
/* full table already? */
if (pos == table_mask) return 0;
/* clear the remainder of the table */
for (sym = pos; sym < table_mask; sym++) table[sym] = 0xFFFF;
/* allow codes to be up to nbits+16 long, instead of nbits */
pos <<= 16;
table_mask <<= 16;
bit_mask = 1 << 15;
for (bit_num = nbits+1; bit_num <= 16; bit_num++) {
for (sym = 0; sym < nsyms; sym++) {
if (length[sym] != bit_num) continue;
leaf = pos >> 16;
for (fill = 0; fill < bit_num - nbits; fill++) {
/* if this path hasn't been taken yet, 'allocate' two entries */
if (table[leaf] == 0xFFFF) {
table[(next_symbol << 1)] = 0xFFFF;
table[(next_symbol << 1) + 1] = 0xFFFF;
table[leaf] = next_symbol++;
}
/* follow the path and select either left or right for next bit */
leaf = table[leaf] << 1;
if ((pos >> (15-fill)) & 1) leaf++;
}
table[leaf] = sym;
if ((pos += bit_mask) > table_mask) return 1; /* table overflow */
}
bit_mask >>= 1;
}
/* full table? */
if (pos == table_mask) return 0;
/* either erroneous table, or all elements are 0 - let's find out. */
for (sym = 0; sym < nsyms; sym++) if (length[sym]) return 1;
return 0;
}
/* READ_LENGTHS(tablename, first, last) reads in code lengths for symbols
* first to last in the given table. The code lengths are stored in their
* own special LZX way.
*/
#define READ_LENGTHS(tbl, first, last) do { \
STORE_BITS; \
if (lzxd_read_lens(lzx, &lzx->tbl##_len[0], (first), \
(unsigned int)(last))) return lzx->error; \
RESTORE_BITS; \
} while (0)
static int lzxd_read_lens(struct lzxd_stream *lzx, unsigned char *lens,
unsigned int first, unsigned int last)
{
/* bit buffer and huffman symbol decode variables */
register unsigned int bit_buffer;
register int bits_left, i;
register unsigned short sym;
unsigned char *i_ptr, *i_end;
unsigned int x, y;
int z;
RESTORE_BITS;
/* read lengths for pretree (20 symbols, lengths stored in fixed 4 bits) */
for (x = 0; x < 20; x++) {
READ_BITS(y, 4);
lzx->PRETREE_len[x] = y;
}
BUILD_TABLE(PRETREE);
for (x = first; x < last; ) {
READ_HUFFSYM(PRETREE, z);
if (z == 17) {
/* code = 17, run of ([read 4 bits]+4) zeros */
READ_BITS(y, 4); y += 4;
while (y--) lens[x++] = 0;
}
else if (z == 18) {
/* code = 18, run of ([read 5 bits]+20) zeros */
READ_BITS(y, 5); y += 20;
while (y--) lens[x++] = 0;
}
else if (z == 19) {
/* code = 19, run of ([read 1 bit]+4) [read huffman symbol] */
READ_BITS(y, 1); y += 4;
READ_HUFFSYM(PRETREE, z);
z = lens[x] - z; if (z < 0) z += 17;
while (y--) lens[x++] = z;
}
else {
/* code = 0 to 16, delta current length entry */
z = lens[x] - z; if (z < 0) z += 17;
lens[x++] = z;
}
}
STORE_BITS;
return MSPACK_ERR_OK;
}
/* LZX static data tables:
*
* LZX uses 'position slots' to represent match offsets. For every match,
* a small 'position slot' number and a small offset from that slot are
* encoded instead of one large offset.
*
* position_base[] is an index to the position slot bases
*
* extra_bits[] states how many bits of offset-from-base data is needed.
*/
static unsigned int position_base[51];
static unsigned char extra_bits[51];
static void lzxd_static_init(void) {
int i, j;
for (i = 0, j = 0; i < 51; i += 2) {
extra_bits[i] = j; /* 0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7... */
extra_bits[i+1] = j;
if ((i != 0) && (j < 17)) j++; /* 0,0,1,2,3,4...15,16,17,17,17,17... */
}
for (i = 0, j = 0; i < 51; i++) {
position_base[i] = j; /* 0,1,2,3,4,6,8,12,16,24,32,... */
j += 1 << extra_bits[i]; /* 1,1,1,1,2,2,4,4,8,8,16,16,32,32,... */
}
}
static void lzxd_reset_state(struct lzxd_stream *lzx) {
int i;
lzx->R0 = 1;
lzx->R1 = 1;
lzx->R2 = 1;
lzx->header_read = 0;
lzx->block_remaining = 0;
lzx->block_type = LZX_BLOCKTYPE_INVALID;
/* initialise tables to 0 (because deltas will be applied to them) */
for (i = 0; i < LZX_MAINTREE_MAXSYMBOLS; i++) lzx->MAINTREE_len[i] = 0;
for (i = 0; i < LZX_LENGTH_MAXSYMBOLS; i++) lzx->LENGTH_len[i] = 0;
}
/*-------- main LZX code --------*/
struct lzxd_stream *lzxd_init(struct mspack_system *system,
struct mspack_file *input,
struct mspack_file *output,
int window_bits,
int reset_interval,
int input_buffer_size,
off_t output_length)
{
unsigned int window_size = 1 << window_bits;
struct lzxd_stream *lzx;
if (!system) return NULL;
/* LZX supports window sizes of 2^15 (32Kb) through 2^21 (2Mb) */
if (window_bits < 15 || window_bits > 21) return NULL;
input_buffer_size = (input_buffer_size + 1) & -2;
if (!input_buffer_size) return NULL;
/* initialise static data */
lzxd_static_init();
/* allocate decompression state */
if (!(lzx = system->alloc(system, sizeof(struct lzxd_stream)))) {
return NULL;
}
/* allocate decompression window and input buffer */
lzx->window = system->alloc(system, (size_t) window_size);
lzx->inbuf = system->alloc(system, (size_t) input_buffer_size);
if (!lzx->window || !lzx->inbuf) {
system->free(lzx->window);
system->free(lzx->inbuf);
system->free(lzx);
return NULL;
}
/* initialise decompression state */
lzx->sys = system;
lzx->input = input;
lzx->output = output;
lzx->offset = 0;
lzx->length = output_length;
lzx->inbuf_size = input_buffer_size;
lzx->window_size = 1 << window_bits;
lzx->window_posn = 0;
lzx->frame_posn = 0;
lzx->frame = 0;
lzx->reset_interval = reset_interval;
lzx->intel_filesize = 0;
lzx->intel_curpos = 0;
/* window bits: 15 16 17 18 19 20 21
* position slots: 30 32 34 36 38 42 50 */
lzx->posn_slots = ((window_bits == 21) ? 50 :
((window_bits == 20) ? 42 : (window_bits << 1)));
lzx->intel_started = 0;
lzx->input_end = 0;
lzx->error = MSPACK_ERR_OK;
lzx->i_ptr = lzx->i_end = &lzx->inbuf[0];
lzx->o_ptr = lzx->o_end = &lzx->e8_buf[0];
lzx->bit_buffer = lzx->bits_left = 0;
lzxd_reset_state(lzx);
return lzx;
}
void lzxd_set_output_length(struct lzxd_stream *lzx, off_t out_bytes) {
if (lzx) lzx->length = out_bytes;
}
int lzxd_decompress(struct lzxd_stream *lzx, off_t out_bytes) {
/* bitstream reading and huffman variables */
register unsigned int bit_buffer;
register int bits_left, i=0;
register unsigned short sym;
unsigned char *i_ptr, *i_end;
int match_length, length_footer, extra, verbatim_bits, bytes_todo;
int this_run, main_element, aligned_bits, j;
unsigned char *window, *runsrc, *rundest, buf[12];
unsigned int frame_size=0, end_frame, match_offset, window_posn;
unsigned int R0, R1, R2;
/* easy answers */
if (!lzx || (out_bytes < 0)) return MSPACK_ERR_ARGS;
if (lzx->error) return lzx->error;
/* flush out any stored-up bytes before we begin */
i = lzx->o_end - lzx->o_ptr;
if ((off_t) i > out_bytes) i = (int) out_bytes;
if (i) {
if (lzx->sys->write(lzx->output, lzx->o_ptr, i) != i) {
return lzx->error = MSPACK_ERR_WRITE;
}
lzx->o_ptr += i;
lzx->offset += i;
out_bytes -= i;
}
if (out_bytes == 0) return MSPACK_ERR_OK;
/* restore local state */
RESTORE_BITS;
window = lzx->window;
window_posn = lzx->window_posn;
R0 = lzx->R0;
R1 = lzx->R1;
R2 = lzx->R2;
end_frame = (unsigned int)((lzx->offset + out_bytes) / LZX_FRAME_SIZE) + 1;
while (lzx->frame < end_frame) {
/* have we reached the reset interval? (if there is one?) */
if (lzx->reset_interval && ((lzx->frame % lzx->reset_interval) == 0)) {
if (lzx->block_remaining) {
D(("%d bytes remaining at reset interval", lzx->block_remaining))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
/* re-read the intel header and reset the huffman lengths */
lzxd_reset_state(lzx);
}
/* read header if necessary */
if (!lzx->header_read) {
/* read 1 bit. if bit=0, intel filesize = 0.
* if bit=1, read intel filesize (32 bits) */
j = 0; READ_BITS(i, 1); if (i) { READ_BITS(i, 16); READ_BITS(j, 16); }
lzx->intel_filesize = (i << 16) | j;
lzx->header_read = 1;
}
/* calculate size of frame: all frames are 32k except the final frame
* which is 32kb or less. this can only be calculated when lzx->length
* has been filled in. */
frame_size = LZX_FRAME_SIZE;
if (lzx->length && (lzx->length - lzx->offset) < (off_t)frame_size) {
frame_size = lzx->length - lzx->offset;
}
/* decode until one more frame is available */
bytes_todo = lzx->frame_posn + frame_size - window_posn;
while (bytes_todo > 0) {
/* initialise new block, if one is needed */
if (lzx->block_remaining == 0) {
/* realign if previous block was an odd-sized UNCOMPRESSED block */
if ((lzx->block_type == LZX_BLOCKTYPE_UNCOMPRESSED) &&
(lzx->block_length & 1))
{
if (i_ptr == i_end) {
if (lzxd_read_input(lzx)) return lzx->error;
i_ptr = lzx->i_ptr;
i_end = lzx->i_end;
}
i_ptr++;
}
/* read block type (3 bits) and block length (24 bits) */
READ_BITS(lzx->block_type, 3);
READ_BITS(i, 16); READ_BITS(j, 8);
lzx->block_remaining = lzx->block_length = (i << 8) | j;
/*D(("new block t%d len %u", lzx->block_type, lzx->block_length))*/
/* read individual block headers */
switch (lzx->block_type) {
case LZX_BLOCKTYPE_ALIGNED:
/* read lengths of and build aligned huffman decoding tree */
for (i = 0; i < 8; i++) { READ_BITS(j, 3); lzx->ALIGNED_len[i] = j; }
BUILD_TABLE(ALIGNED);
/* no break -- rest of aligned header is same as verbatim */
case LZX_BLOCKTYPE_VERBATIM:
/* read lengths of and build main huffman decoding tree */
READ_LENGTHS(MAINTREE, 0, 256);
READ_LENGTHS(MAINTREE, 256, LZX_NUM_CHARS + (lzx->posn_slots << 3));
BUILD_TABLE(MAINTREE);
/* if the literal 0xE8 is anywhere in the block... */
if (lzx->MAINTREE_len[0xE8] != 0) lzx->intel_started = 1;
/* read lengths of and build lengths huffman decoding tree */
READ_LENGTHS(LENGTH, 0, LZX_NUM_SECONDARY_LENGTHS);
BUILD_TABLE(LENGTH);
break;
case LZX_BLOCKTYPE_UNCOMPRESSED:
/* because we can't assume otherwise */
lzx->intel_started = 1;
/* read 1-16 (not 0-15) bits to align to bytes */
ENSURE_BITS(16);
if (bits_left > 16) i_ptr -= 2;
bits_left = 0; bit_buffer = 0;
/* read 12 bytes of stored R0 / R1 / R2 values */
for (rundest = &buf[0], i = 0; i < 12; i++) {
if (i_ptr == i_end) {
if (lzxd_read_input(lzx)) return lzx->error;
i_ptr = lzx->i_ptr;
i_end = lzx->i_end;
}
*rundest++ = *i_ptr++;
}
R0 = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
R1 = buf[4] | (buf[5] << 8) | (buf[6] << 16) | (buf[7] << 24);
R2 = buf[8] | (buf[9] << 8) | (buf[10] << 16) | (buf[11] << 24);
break;
default:
D(("bad block type"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
}
/* decode more of the block:
* run = min(what's available, what's needed) */
this_run = lzx->block_remaining;
if (this_run > bytes_todo) this_run = bytes_todo;
/* assume we decode exactly this_run bytes, for now */
bytes_todo -= this_run;
lzx->block_remaining -= this_run;
/* decode at least this_run bytes */
switch (lzx->block_type) {
case LZX_BLOCKTYPE_VERBATIM:
while (this_run > 0) {
READ_HUFFSYM(MAINTREE, main_element);
if (main_element < LZX_NUM_CHARS) {
/* literal: 0 to LZX_NUM_CHARS-1 */
window[window_posn++] = main_element;
this_run--;
}
else {
/* match: LZX_NUM_CHARS + ((slot<<3) | length_header (3 bits)) */
main_element -= LZX_NUM_CHARS;
/* get match length */
match_length = main_element & LZX_NUM_PRIMARY_LENGTHS;
if (match_length == LZX_NUM_PRIMARY_LENGTHS) {
READ_HUFFSYM(LENGTH, length_footer);
match_length += length_footer;
}
match_length += LZX_MIN_MATCH;
/* get match offset */
switch ((match_offset = (main_element >> 3))) {
case 0: match_offset = R0; break;
case 1: match_offset = R1; R1=R0; R0 = match_offset; break;
case 2: match_offset = R2; R2=R0; R0 = match_offset; break;
case 3: match_offset = 1; R2=R1; R1=R0; R0 = match_offset; break;
default:
extra = extra_bits[match_offset];
READ_BITS(verbatim_bits, extra);
match_offset = position_base[match_offset] - 2 + verbatim_bits;
R2 = R1; R1 = R0; R0 = match_offset;
}
if ((window_posn + match_length) > lzx->window_size) {
D(("match ran over window wrap"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
/* copy match */
rundest = &window[window_posn];
i = match_length;
/* does match offset wrap the window? */
if (match_offset > window_posn) {
/* j = length from match offset to end of window */
j = match_offset - window_posn;
if (j > (int) lzx->window_size) {
D(("match offset beyond window boundaries"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
runsrc = &window[lzx->window_size - j];
if (j < i) {
/* if match goes over the window edge, do two copy runs */
i -= j; while (j-- > 0) *rundest++ = *runsrc++;
runsrc = window;
}
while (i-- > 0) *rundest++ = *runsrc++;
}
else {
runsrc = rundest - match_offset;
while (i-- > 0) *rundest++ = *runsrc++;
}
this_run -= match_length;
window_posn += match_length;
}
} /* while (this_run > 0) */
break;
case LZX_BLOCKTYPE_ALIGNED:
while (this_run > 0) {
READ_HUFFSYM(MAINTREE, main_element);
if (main_element < LZX_NUM_CHARS) {
/* literal: 0 to LZX_NUM_CHARS-1 */
window[window_posn++] = main_element;
this_run--;
}
else {
/* match: LZX_NUM_CHARS + ((slot<<3) | length_header (3 bits)) */
main_element -= LZX_NUM_CHARS;
/* get match length */
match_length = main_element & LZX_NUM_PRIMARY_LENGTHS;
if (match_length == LZX_NUM_PRIMARY_LENGTHS) {
READ_HUFFSYM(LENGTH, length_footer);
match_length += length_footer;
}
match_length += LZX_MIN_MATCH;
/* get match offset */
switch ((match_offset = (main_element >> 3))) {
case 0: match_offset = R0; break;
case 1: match_offset = R1; R1 = R0; R0 = match_offset; break;
case 2: match_offset = R2; R2 = R0; R0 = match_offset; break;
default:
extra = extra_bits[match_offset];
match_offset = position_base[match_offset] - 2;
if (extra > 3) {
/* verbatim and aligned bits */
extra -= 3;
READ_BITS(verbatim_bits, extra);
match_offset += (verbatim_bits << 3);
READ_HUFFSYM(ALIGNED, aligned_bits);
match_offset += aligned_bits;
}
else if (extra == 3) {
/* aligned bits only */
READ_HUFFSYM(ALIGNED, aligned_bits);
match_offset += aligned_bits;
}
else if (extra > 0) { /* extra==1, extra==2 */
/* verbatim bits only */
READ_BITS(verbatim_bits, extra);
match_offset += verbatim_bits;
}
else /* extra == 0 */ {
/* ??? not defined in LZX specification! */
match_offset = 1;
}
/* update repeated offset LRU queue */
R2 = R1; R1 = R0; R0 = match_offset;
}
if ((window_posn + match_length) > lzx->window_size) {
D(("match ran over window wrap"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
/* copy match */
rundest = &window[window_posn];
i = match_length;
/* does match offset wrap the window? */
if (match_offset > window_posn) {
/* j = length from match offset to end of window */
j = match_offset - window_posn;
if (j > (int) lzx->window_size) {
D(("match offset beyond window boundaries"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
runsrc = &window[lzx->window_size - j];
if (j < i) {
/* if match goes over the window edge, do two copy runs */
i -= j; while (j-- > 0) *rundest++ = *runsrc++;
runsrc = window;
}
while (i-- > 0) *rundest++ = *runsrc++;
}
else {
runsrc = rundest - match_offset;
while (i-- > 0) *rundest++ = *runsrc++;
}
this_run -= match_length;
window_posn += match_length;
}
} /* while (this_run > 0) */
break;
case LZX_BLOCKTYPE_UNCOMPRESSED:
/* as this_run is limited not to wrap a frame, this also means it
* won't wrap the window (as the window is a multiple of 32k) */
rundest = &window[window_posn];
window_posn += this_run;
while (this_run > 0) {
if ((i = i_end - i_ptr)) {
if (i > this_run) i = this_run;
lzx->sys->copy(i_ptr, rundest, (size_t) i);
rundest += i;
i_ptr += i;
this_run -= i;
}
else {
if (lzxd_read_input(lzx)) return lzx->error;
i_ptr = lzx->i_ptr;
i_end = lzx->i_end;
}
}
break;
default:
D(("Default Here."));
return lzx->error = MSPACK_ERR_DECRUNCH; /* might as well */
}
/* did the final match overrun our desired this_run length? */
if (this_run < 0) {
if ((unsigned int)(-this_run) > lzx->block_remaining) {
D(("overrun went past end of block by %d (%d remaining)",
-this_run, lzx->block_remaining ))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
lzx->block_remaining -= -this_run;
}
} /* while (bytes_todo > 0) */
/* streams don't extend over frame boundaries */
if ((window_posn - lzx->frame_posn) != frame_size) {
D(("decode beyond output frame limits! %d != %d",
window_posn - lzx->frame_posn, frame_size))
/* Ignored */
#if 0
return lzx->error = MSPACK_ERR_DECRUNCH;
#endif
}
/* re-align input bitstream */
if (bits_left > 0) ENSURE_BITS(16);
if (bits_left & 15) REMOVE_BITS(bits_left & 15);
/* check that we've used all of the previous frame first */
if (lzx->o_ptr != lzx->o_end) {
D(("%d avail bytes, new %d frame", lzx->o_end-lzx->o_ptr, frame_size))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
/* does this intel block _really_ need decoding? */
if (lzx->intel_started && lzx->intel_filesize &&
(lzx->frame <= 32768) && (frame_size > 10))
{
unsigned char *data = &lzx->e8_buf[0];
unsigned char *dataend = &lzx->e8_buf[frame_size - 10];
signed int curpos = lzx->intel_curpos;
signed int filesize = lzx->intel_filesize;
signed int abs_off, rel_off;
/* copy e8 block to the e8 buffer and tweak if needed */
lzx->o_ptr = data;
lzx->sys->copy(&lzx->window[lzx->frame_posn], data, frame_size);
while (data < dataend) {
if (*data++ != 0xE8) { curpos++; continue; }
abs_off = data[0] | (data[1]<<8) | (data[2]<<16) | (data[3]<<24);
if ((abs_off >= -curpos) && (abs_off < filesize)) {
rel_off = (abs_off >= 0) ? abs_off - curpos : abs_off + filesize;
data[0] = (unsigned char) rel_off;
data[1] = (unsigned char) (rel_off >> 8);
data[2] = (unsigned char) (rel_off >> 16);
data[3] = (unsigned char) (rel_off >> 24);
}
data += 4;
curpos += 5;
}
lzx->intel_curpos += frame_size;
}
else {
lzx->o_ptr = &lzx->window[lzx->frame_posn];
if (lzx->intel_filesize) lzx->intel_curpos += frame_size;
}
lzx->o_end = &lzx->o_ptr[frame_size];
/* write a frame */
i = (out_bytes < (off_t)frame_size) ? (unsigned int)out_bytes : frame_size;
if (lzx->sys->write(lzx->output, lzx->o_ptr, i) != i) {
return lzx->error = MSPACK_ERR_WRITE;
}
lzx->o_ptr += i;
lzx->offset += i;
out_bytes -= i;
/* advance frame start position */
lzx->frame_posn += frame_size;
lzx->frame++;
/* wrap window / frame position pointers */
if (window_posn == lzx->window_size) window_posn = 0;
if (lzx->frame_posn == lzx->window_size) lzx->frame_posn = 0;
} /* while (lzx->frame < end_frame) */
if (out_bytes) {
D(("bytes left to output"))
return lzx->error = MSPACK_ERR_DECRUNCH;
}
/* store local state */
STORE_BITS;
lzx->window_posn = window_posn;
lzx->R0 = R0;
lzx->R1 = R1;
lzx->R2 = R2;
return MSPACK_ERR_OK;
}
void lzxd_free(struct lzxd_stream *lzx) {
struct mspack_system *sys;
if (lzx) {
sys = lzx->sys;
sys->free(lzx->inbuf);
sys->free(lzx->window);
sys->free(lzx);
}
}

172
src/calibre/utils/lzx/lzxglue.c Normal file
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@ -0,0 +1,172 @@
/*--[lzxglue.c]----------------------------------------------------------------
| Copyright (C) 2004 DRS
|
| This file is part of the "openclit" library for processing .LIT files.
|
| "Openclit" is free software; you can redistribute it and/or modify
| it under the terms of the GNU General Public License as published by
| the Free Software Foundation; either version 2 of the License, or
| (at your option) any later version.
|
| This program 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 General Public License for more details.
|
| You should have received a copy of the GNU General Public License
| along with this program; if not, write to the Free Software
| Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
| The GNU General Public License may also be available at the following
| URL: http://www.gnu.org/licenses/gpl.html
*/
/* This provides a "glue" between Stuart Caie's libmspack library and the
* Openclit calls to the earlier LZX library.
*
* This way, I should be able to use the files unmodified.
*/
#include <stdio.h>
#include <stdlib.h>
#include "litlib.h"
#include "mspack.h"
#include "lzx.h"
typedef struct memory_file
{
unsigned int magic; /* 0xB5 */
void * buffer;
int total_bytes;
int current_bytes;
} memory_file;
void * glue_alloc(struct mspack_system *this, size_t bytes)
{
void * p;
p = (void *)malloc(bytes);
if (p == NULL) {
lit_error(ERR_R|ERR_LIBC,"Malloc(%d) failed!", bytes);
}
return p;
}
void glue_free(void * p)
{
free(p);
}
void glue_copy(void *src, void *dest, size_t bytes)
{
memcpy(dest, src, bytes);
}
struct mspack_file * glue_open(struct mspack_system *this, char *filename,
int mode)
{
lit_error(0,"MSPACK_OPEN unsupported!");
return NULL;
}
void glue_close(struct mspack_file * file) {
return;
}
int glue_read(struct mspack_file * file, void * buffer, int bytes)
{
memory_file * mem;
int remaining;
mem = (memory_file *)file;
if (mem->magic != 0xB5) return -1;
remaining = mem->total_bytes - mem->current_bytes;
if (!remaining) return 0;
if (bytes > remaining) bytes = remaining;
memcpy(buffer, (unsigned char *)mem->buffer+mem->current_bytes, bytes);
mem->current_bytes += bytes;
return bytes;
}
int glue_write(struct mspack_file * file, void * buffer, int bytes)
{
memory_file * mem;
int remaining;
mem = (memory_file *)file;
if (mem->magic != 0xB5) return -1;
remaining = mem->total_bytes - mem->current_bytes;
if (!remaining) return 0;
if (bytes > remaining) {
lit_error(0,"MSPACK_READ tried to write %d bytes, only %d left.",
bytes, remaining);
bytes = remaining;
}
memcpy((unsigned char *)mem->buffer+mem->current_bytes, buffer, bytes);
mem->current_bytes += bytes;
return bytes;
}
struct mspack_system lzxglue_system =
{
glue_open,
glue_close,
glue_read, /* Read */
glue_write, /* Write */
NULL, /* Seek */
NULL, /* Tell */
NULL, /* Message */
glue_alloc,
glue_free,
glue_copy,
NULL /* Termination */
};
int LZXwindow;
struct lzxd_stream * lzx_stream = NULL;
/* Can't really init here,don't know enough */
int LZXinit(int window)
{
LZXwindow = window;
lzx_stream = NULL;
return 0;
}
/* Doesn't exist. Oh well, reinitialize state every time anyway */
void LZXreset(void)
{
return;
}
int LZXdecompress(unsigned char *inbuf, unsigned char *outbuf,
unsigned int inlen, unsigned int outlen)
{
int err;
memory_file source;
memory_file dest;
source.magic = 0xB5;
source.buffer = inbuf;
source.current_bytes = 0;
source.total_bytes = inlen;
dest.magic = 0xB5;
dest.buffer = outbuf;
dest.current_bytes = 0;
dest.total_bytes = outlen;
lzx_stream = lzxd_init(&lzxglue_system, (struct mspack_file *)&source,
(struct mspack_file *)&dest, LZXwindow,
0x7fff /* Never reset, I do it */, 4096, outlen);
err = -1;
if (lzx_stream) err = lzxd_decompress(lzx_stream, outlen);
lzxd_free(lzx_stream);
lzx_stream = NULL;
return err;
}

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src/calibre/utils/lzx/lzxmodule.c Normal file
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#include <Python.h>
#include <mspack.h>
#include <lzx.h>
static char lzx_doc[] =
"Provide basic LZX decompression using the code from libmspack.";
static PyObject *LzxError = NULL;
typedef struct memory_file {
unsigned int magic; /* 0xB5 */
void * buffer;
int total_bytes;
int current_bytes;
} memory_file;
void *
glue_alloc(struct mspack_system *this, size_t bytes)
{
void *p = NULL;
p = (void *)malloc(bytes);
if (p == NULL) {
return (void *)PyErr_NoMemory();
}
return p;
}
void
glue_free(void *p)
{
free(p);
}
void
glue_copy(void *src, void *dest, size_t bytes)
{
memcpy(dest, src, bytes);
}
struct mspack_file *
glue_open(struct mspack_system *this, char *filename, int mode)
{
PyErr_SetString(LzxError, "MSPACK_OPEN unsupported");
return NULL;
}
void
glue_close(struct mspack_file *file)
{
return;
}
int
glue_read(struct mspack_file *file, void * buffer, int bytes)
{
memory_file *mem;
int remaining;
mem = (memory_file *)file;
if (mem->magic != 0xB5) return -1;
remaining = mem->total_bytes - mem->current_bytes;
if (!remaining) return 0;
if (bytes > remaining) bytes = remaining;
memcpy(buffer, (unsigned char *)mem->buffer + mem->current_bytes, bytes);
mem->current_bytes += bytes;
return bytes;
}
int
glue_write(struct mspack_file * file, void * buffer, int bytes)
{
memory_file *mem;
int remaining;
mem = (memory_file *)file;
if (mem->magic != 0xB5) return -1;
remaining = mem->total_bytes - mem->current_bytes;
if (!remaining) return 0;
if (bytes > remaining) {
PyErr_SetString(LzxError,
"MSPACK_WRITE tried to write beyond end of buffer");
bytes = remaining;
}
memcpy((unsigned char *)mem->buffer + mem->current_bytes, buffer, bytes);
mem->current_bytes += bytes;
return bytes;
}
struct mspack_system lzxglue_system = {
glue_open,
glue_close,
glue_read, /* Read */
glue_write, /* Write */
NULL, /* Seek */
NULL, /* Tell */
NULL, /* Message */
glue_alloc,
glue_free,
glue_copy,
NULL /* Termination */
};
int LZXwindow = 0;
struct lzxd_stream * lzx_stream = NULL;
/* Can't really init here, don't know enough */
static PyObject *
init(PyObject *self, PyObject *args)
{
int window = 0;
if (!PyArg_ParseTuple(args, "i", &window)) {
return NULL;
}
LZXwindow = window;
lzx_stream = NULL;
Py_RETURN_NONE;
}
/* Doesn't exist. Oh well, reinitialize state every time anyway */
static PyObject *
reset(PyObject *self, PyObject *args)
{
if (!PyArg_ParseTuple(args, "")) {
return NULL;
}
Py_RETURN_NONE;
}
//int LZXdecompress(unsigned char *inbuf, unsigned char *outbuf,
// unsigned int inlen, unsigned int outlen)
static PyObject *
decompress(PyObject *self, PyObject *args)
{
unsigned char *inbuf;
unsigned char *outbuf;
unsigned int inlen;
unsigned int outlen;
int err;
memory_file source;
memory_file dest;
PyObject *retval = NULL;
if (!PyArg_ParseTuple(args, "s#I", &inbuf, &inlen, &outlen)) {
return NULL;
}
retval = PyString_FromStringAndSize(NULL, outlen);
if (retval == NULL) {
return NULL;
}
outbuf = (unsigned char *)PyString_AS_STRING(retval);
source.magic = 0xB5;
source.buffer = inbuf;
source.current_bytes = 0;
source.total_bytes = inlen;
dest.magic = 0xB5;
dest.buffer = outbuf;
dest.current_bytes = 0;
dest.total_bytes = outlen;
lzx_stream = lzxd_init(&lzxglue_system, (struct mspack_file *)&source,
(struct mspack_file *)&dest, LZXwindow,
0x7fff /* Never reset, I do it */, 4096, outlen);
err = -1;
if (lzx_stream) err = lzxd_decompress(lzx_stream, outlen);
lzxd_free(lzx_stream);
lzx_stream = NULL;
if (err != MSPACK_ERR_OK) {
Py_DECREF(retval);
PyErr_SetString(LzxError, "LZX decompression failed");
}
return retval;
}
static PyMethodDef lzx_methods[] = {
{ "init", &init, METH_VARARGS, "Initialize the LZX decompressor" },
{ "reset", &reset, METH_VARARGS, "Reset the LZX decompressor" },
{ "decompress", &decompress, METH_VARARGS, "Run the LZX decompressor" },
{ NULL, NULL }
};
PyMODINIT_FUNC
initlzx(void)
{
PyObject *m;
m = Py_InitModule3("lzx", lzx_methods, lzx_doc);
if (m == NULL) return;
LzxError = PyErr_NewException("lzx.LzxError", NULL, NULL);
Py_INCREF(LzxError);
PyModule_AddObject(m, "LzxError", LzxError);
}

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src/calibre/utils/lzx/system.h Normal file
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/* This file is part of libmspack.
* (C) 2003-2004 Stuart Caie.
*
* libmspack is free software; you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License (LGPL) version 2.1
*
* For further details, see the file COPYING.LIB distributed with libmspack
*/
#ifndef MSPACK_SYSTEM_H
#define MSPACK_SYSTEM_H 1
#ifdef _MSC_VER
#define inline
#endif
#ifdef DEBUG
# include <stdio.h>
# define D(x) do { printf("%s:%d (%s) ",__FILE__, __LINE__, __FUNCTION__); \
printf x ; fputc('\n', stdout); fflush(stdout);} while (0);
#else
# define D(x)
#endif
/* endian-neutral reading of little-endian data */
#define __egi32(a,n) ( (((a)[n+3]) << 24) | (((a)[n+2]) << 16) | \
(((a)[n+1]) << 8) | ((a)[n+0]) )
#define EndGetI64(a) ((((unsigned long long int) __egi32(a,4)) << 32) | \
((unsigned int) __egi32(a,0)))
#define EndGetI32(a) __egi32(a,0)
#define EndGetI16(a) ((((a)[1])<<8)|((a)[0]))
/* endian-neutral reading of big-endian data */
#define EndGetM32(a) ((((a)[0])<<24)|(((a)[1])<<16)|(((a)[2])<<8)|((a)[3]))
#define EndGetM16(a) ((((a)[0])<<8)|((a)[1]))
extern struct mspack_system *mspack_default_system;
/* returns the length of a file opened for reading */
extern int mspack_sys_filelen(struct mspack_system *system,
struct mspack_file *file, off_t *length);
/* validates a system structure */
extern int mspack_valid_system(struct mspack_system *sys);
/* Can't redfine intrinsics in Microsoft Visual C */
#ifndef _MSC_VER
/* inline memcmp() */
static inline int memcmp(const void *s1, const void *s2, size_t n) {
unsigned char *c1 = (unsigned char *) s1;
unsigned char *c2 = (unsigned char *) s2;
if (n == 0) return 0;
while (--n && (*c1 == *c2)) c1++, c2++;
return *c1 - *c2;
}
/* inline strlen() */
static inline size_t strlen(const char *s) {
const char *e = s;
while (*e) e++;
return e - s;
}
#endif
#endif