+++ /dev/null
-/***************************************************************************
- * lzx.c - LZX decompression routines *
- * ------------------- *
- * *
- * maintainer: Jed Wing <jedwin@ugcs.caltech.edu> *
- * source: modified lzx.c from cabextract v0.5 *
- * notes: This file was taken from cabextract v0.5, which was, *
- * itself, a modified version of the lzx decompression code *
- * from unlzx. *
- * *
- * platforms: In its current incarnation, this file has been tested on *
- * two different Linux platforms (one, redhat-based, with a *
- * 2.1.2 glibc and gcc 2.95.x, and the other, Debian, with *
- * 2.2.4 glibc and both gcc 2.95.4 and gcc 3.0.2). Both were *
- * Intel x86 compatible machines. *
- ***************************************************************************/
-
-/***************************************************************************
- *
- * Copyright(C) Stuart Caie
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library 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
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
- *
- ***************************************************************************/
-
-#include "precomp.h"
-
-/* sized types */
-typedef unsigned char UBYTE; /* 8 bits exactly */
-typedef unsigned short UWORD; /* 16 bits (or more) */
-
-/* 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) /* we allow length table decoding overruns */
-
-#define LZX_DECLARE_TABLE(tbl) \
- UWORD tbl##_table[(1<<LZX_##tbl##_TABLEBITS) + (LZX_##tbl##_MAXSYMBOLS<<1)];\
- UBYTE tbl##_len [LZX_##tbl##_MAXSYMBOLS + LZX_LENTABLE_SAFETY]
-
-struct LZXstate
-{
- UBYTE *window; /* the actual decoding window */
- ULONG window_size; /* window size (32Kb through 2Mb) */
- ULONG actual_size; /* window size when it was first allocated */
- ULONG window_posn; /* current offset within the window */
- ULONG R0, R1, R2; /* for the LRU offset system */
- UWORD main_elements; /* number of main tree elements */
- int header_read; /* have we started decoding at all yet? */
- UWORD block_type; /* type of this block */
- ULONG block_length; /* uncompressed length of this block */
- ULONG block_remaining; /* uncompressed bytes still left to decode */
- ULONG frames_read; /* the number of CFDATA blocks processed */
- LONG intel_filesize; /* magic header value used for transform */
- LONG intel_curpos; /* current offset in transform space */
- int intel_started; /* have we seen any translatable data yet? */
-
- LZX_DECLARE_TABLE(PRETREE);
- LZX_DECLARE_TABLE(MAINTREE);
- LZX_DECLARE_TABLE(LENGTH);
- LZX_DECLARE_TABLE(ALIGNED);
-};
-
-/* LZX decruncher */
-
-/* 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 uses what it calls 'position slots' to represent match offsets.
- * What this means is that a small 'position slot' number and a small
- * offset from that slot are encoded instead of one large offset for
- * every match.
- * - position_base is an index to the position slot bases
- * - extra_bits states how many bits of offset-from-base data is needed.
- */
-static const UBYTE extra_bits[51] = {
- 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
- 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14,
- 15, 15, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17,
- 17, 17, 17
-};
-
-static const ULONG position_base[51] = {
- 0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
- 256, 384, 512, 768, 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576, 32768, 49152,
- 65536, 98304, 131072, 196608, 262144, 393216, 524288, 655360, 786432, 917504, 1048576, 1179648, 1310720, 1441792, 1572864, 1703936,
- 1835008, 1966080, 2097152
-};
-
-struct LZXstate *LZXinit(int window)
-{
- struct LZXstate *pState=NULL;
- ULONG wndsize = 1 << window;
- int i, posn_slots;
-
- /* LZX supports window sizes of 2^15 (32Kb) through 2^21 (2Mb) */
- /* if a previously allocated window is big enough, keep it */
- if (window < 15 || window > 21) return NULL;
-
- /* allocate state and associated window */
- pState = HeapAlloc(GetProcessHeap(), 0, sizeof(struct LZXstate));
- if (!(pState->window = HeapAlloc(GetProcessHeap(), 0, wndsize)))
- {
- HeapFree(GetProcessHeap(), 0, pState);
- return NULL;
- }
- pState->actual_size = wndsize;
- pState->window_size = wndsize;
-
- /* calculate required position slots */
- if (window == 20) posn_slots = 42;
- else if (window == 21) posn_slots = 50;
- else posn_slots = window << 1;
-
- /** alternatively **/
- /* posn_slots=i=0; while (i < wndsize) i += 1 << extra_bits[posn_slots++]; */
-
- /* initialize other state */
- pState->R0 = pState->R1 = pState->R2 = 1;
- pState->main_elements = LZX_NUM_CHARS + (posn_slots << 3);
- pState->header_read = 0;
- pState->frames_read = 0;
- pState->block_remaining = 0;
- pState->block_type = LZX_BLOCKTYPE_INVALID;
- pState->intel_curpos = 0;
- pState->intel_started = 0;
- pState->window_posn = 0;
-
- /* initialise tables to 0 (because deltas will be applied to them) */
- for (i = 0; i < LZX_MAINTREE_MAXSYMBOLS; i++) pState->MAINTREE_len[i] = 0;
- for (i = 0; i < LZX_LENGTH_MAXSYMBOLS; i++) pState->LENGTH_len[i] = 0;
-
- return pState;
-}
-
-void LZXteardown(struct LZXstate *pState)
-{
- if (pState)
- {
- HeapFree(GetProcessHeap(), 0, pState->window);
- HeapFree(GetProcessHeap(), 0, pState);
- }
-}
-
-int LZXreset(struct LZXstate *pState)
-{
- int i;
-
- pState->R0 = pState->R1 = pState->R2 = 1;
- pState->header_read = 0;
- pState->frames_read = 0;
- pState->block_remaining = 0;
- pState->block_type = LZX_BLOCKTYPE_INVALID;
- pState->intel_curpos = 0;
- pState->intel_started = 0;
- pState->window_posn = 0;
-
- for (i = 0; i < LZX_MAINTREE_MAXSYMBOLS + LZX_LENTABLE_SAFETY; i++) pState->MAINTREE_len[i] = 0;
- for (i = 0; i < LZX_LENGTH_MAXSYMBOLS + LZX_LENTABLE_SAFETY; i++) pState->LENGTH_len[i] = 0;
-
- return DECR_OK;
-}
-
-
-/* Bitstream reading macros:
- *
- * INIT_BITSTREAM should be used first to set up the system
- * 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. This avoids having to mask any bits.
- * So we have to know the bit width of the bitbuffer variable. This is
- * sizeof(ULONG) * 8, also defined as ULONG_BITS
- */
-
-/* number of bits in ULONG. Note: This must be at multiple of 16, and at
- * least 32 for the bitbuffer code to work (ie, it must be able to ensure
- * up to 17 bits - that's adding 16 bits when there's one bit left, or
- * adding 32 bits when there are no bits left. The code should work fine
- * for machines where ULONG >= 32 bits.
- */
-#define ULONG_BITS (sizeof(ULONG)<<3)
-
-#define INIT_BITSTREAM do { bitsleft = 0; bitbuf = 0; } while (0)
-
-#define ENSURE_BITS(n) \
- while (bitsleft < (n)) { \
- bitbuf |= ((inpos[1]<<8)|inpos[0]) << (ULONG_BITS-16 - bitsleft); \
- bitsleft += 16; inpos+=2; \
- }
-
-#define PEEK_BITS(n) (bitbuf >> (ULONG_BITS - (n)))
-#define REMOVE_BITS(n) ((bitbuf <<= (n)), (bitsleft -= (n)))
-
-#define READ_BITS(v,n) do { \
- ENSURE_BITS(n); \
- (v) = PEEK_BITS(n); \
- REMOVE_BITS(n); \
-} while (0)
-
-
-/* Huffman macros */
-
-#define TABLEBITS(tbl) (LZX_##tbl##_TABLEBITS)
-#define MAXSYMBOLS(tbl) (LZX_##tbl##_MAXSYMBOLS)
-#define SYMTABLE(tbl) (pState->tbl##_table)
-#define LENTABLE(tbl) (pState->tbl##_len)
-
-/* BUILD_TABLE(tablename) builds a huffman lookup table from code lengths.
- * In reality, it just calls make_decode_table() with the appropriate
- * values - they're all fixed by some #defines anyway, so there's no point
- * writing each call out in full by hand.
- */
-#define BUILD_TABLE(tbl) \
- if (make_decode_table( \
- MAXSYMBOLS(tbl), TABLEBITS(tbl), LENTABLE(tbl), SYMTABLE(tbl) \
- )) { return DECR_ILLEGALDATA; }
-
-
-/* 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 { \
- ENSURE_BITS(16); \
- hufftbl = SYMTABLE(tbl); \
- if ((i = hufftbl[PEEK_BITS(TABLEBITS(tbl))]) >= MAXSYMBOLS(tbl)) { \
- j = 1 << (ULONG_BITS - TABLEBITS(tbl)); \
- do { \
- j >>= 1; i <<= 1; i |= (bitbuf & j) ? 1 : 0; \
- if (!j) { return DECR_ILLEGALDATA; } \
- } while ((i = hufftbl[i]) >= MAXSYMBOLS(tbl)); \
- } \
- j = LENTABLE(tbl)[(var) = i]; \
- REMOVE_BITS(j); \
-} while (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 { \
- lb.bb = bitbuf; lb.bl = bitsleft; lb.ip = inpos; \
- if (lzx_read_lens(pState, LENTABLE(tbl),(first),(last),&lb)) { \
- return DECR_ILLEGALDATA; \
- } \
- bitbuf = lb.bb; bitsleft = lb.bl; inpos = lb.ip; \
-} while (0)
-
-
-/* make_decode_table(nsyms, nbits, length[], table[])
- *
- * This function was coded by David Tritscher. It builds a fast huffman
- * decoding table out of just 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(ULONG nsyms, ULONG nbits, UBYTE *length, UWORD *table) {
- register UWORD sym;
- register ULONG leaf;
- register UBYTE bit_num = 1;
- ULONG fill;
- ULONG pos = 0; /* the current position in the decode table */
- ULONG table_mask = 1 << nbits;
- ULONG bit_mask = table_mask >> 1; /* don't do 0 length codes */
- ULONG next_symbol = bit_mask; /* base of allocation for long codes */
-
- /* fill entries for codes short enough for a direct mapping */
- while (bit_num <= nbits) {
- for (sym = 0; sym < nsyms; sym++) {
- if (length[sym] == bit_num) {
- leaf = pos;
-
- if((pos += bit_mask) > table_mask) return 1; /* table overrun */
-
- /* fill all possible lookups of this symbol with the symbol itself */
- fill = bit_mask;
- while (fill-- > 0) table[leaf++] = sym;
- }
- }
- bit_mask >>= 1;
- bit_num++;
- }
-
- /* if there are any codes longer than nbits */
- if (pos != table_mask) {
- /* clear the remainder of the table */
- for (sym = pos; sym < table_mask; sym++) table[sym] = 0;
-
- /* give ourselves room for codes to grow by up to 16 more bits */
- pos <<= 16;
- table_mask <<= 16;
- bit_mask = 1 << 15;
-
- while (bit_num <= 16) {
- for (sym = 0; sym < nsyms; sym++) {
- if (length[sym] == bit_num) {
- 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] == 0) {
- table[(next_symbol << 1)] = 0;
- table[(next_symbol << 1) + 1] = 0;
- 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;
- bit_num++;
- }
- }
-
- /* 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;
-}
-
-struct lzx_bits {
- ULONG bb;
- int bl;
- UBYTE *ip;
-};
-
-static int lzx_read_lens(struct LZXstate *pState, UBYTE *lens, ULONG first, ULONG last, struct lzx_bits *lb) {
- ULONG i,j, x,y;
- int z;
-
- register ULONG bitbuf = lb->bb;
- register int bitsleft = lb->bl;
- UBYTE *inpos = lb->ip;
- UWORD *hufftbl;
-
- for (x = 0; x < 20; x++) {
- READ_BITS(y, 4);
- LENTABLE(PRETREE)[x] = y;
- }
- BUILD_TABLE(PRETREE);
-
- for (x = first; x < last; ) {
- READ_HUFFSYM(PRETREE, z);
- if (z == 17) {
- READ_BITS(y, 4); y += 4;
- while (y--) lens[x++] = 0;
- }
- else if (z == 18) {
- READ_BITS(y, 5); y += 20;
- while (y--) lens[x++] = 0;
- }
- else if (z == 19) {
- 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 {
- z = lens[x] - z; if (z < 0) z += 17;
- lens[x++] = z;
- }
- }
-
- lb->bb = bitbuf;
- lb->bl = bitsleft;
- lb->ip = inpos;
- return 0;
-}
-
-int LZXdecompress(struct LZXstate *pState, unsigned char *inpos, unsigned char *outpos, int inlen, int outlen) {
- UBYTE *endinp = inpos + inlen;
- UBYTE *window = pState->window;
- UBYTE *runsrc, *rundest;
- UWORD *hufftbl; /* used in READ_HUFFSYM macro as chosen decoding table */
-
- ULONG window_posn = pState->window_posn;
- ULONG window_size = pState->window_size;
- ULONG R0 = pState->R0;
- ULONG R1 = pState->R1;
- ULONG R2 = pState->R2;
-
- register ULONG bitbuf;
- register int bitsleft;
- ULONG match_offset, i,j,k; /* ijk used in READ_HUFFSYM macro */
- struct lzx_bits lb; /* used in READ_LENGTHS macro */
-
- int togo = outlen, this_run, main_element, aligned_bits;
- int match_length, length_footer, extra, verbatim_bits;
- int copy_length;
-
- INIT_BITSTREAM;
-
- /* read header if necessary */
- if (!pState->header_read) {
- i = j = 0;
- READ_BITS(k, 1); if (k) { READ_BITS(i,16); READ_BITS(j,16); }
- pState->intel_filesize = (i << 16) | j; /* or 0 if not encoded */
- pState->header_read = 1;
- }
-
- /* main decoding loop */
- while (togo > 0) {
- /* last block finished, new block expected */
- if (pState->block_remaining == 0) {
- if (pState->block_type == LZX_BLOCKTYPE_UNCOMPRESSED) {
- if (pState->block_length & 1) inpos++; /* realign bitstream to word */
- INIT_BITSTREAM;
- }
-
- READ_BITS(pState->block_type, 3);
- READ_BITS(i, 16);
- READ_BITS(j, 8);
- pState->block_remaining = pState->block_length = (i << 8) | j;
-
- switch (pState->block_type) {
- case LZX_BLOCKTYPE_ALIGNED:
- for (i = 0; i < 8; i++) { READ_BITS(j, 3); LENTABLE(ALIGNED)[i] = j; }
- BUILD_TABLE(ALIGNED);
- /* rest of aligned header is same as verbatim */
-
- case LZX_BLOCKTYPE_VERBATIM:
- READ_LENGTHS(MAINTREE, 0, 256);
- READ_LENGTHS(MAINTREE, 256, pState->main_elements);
- BUILD_TABLE(MAINTREE);
- if (LENTABLE(MAINTREE)[0xE8] != 0) pState->intel_started = 1;
-
- READ_LENGTHS(LENGTH, 0, LZX_NUM_SECONDARY_LENGTHS);
- BUILD_TABLE(LENGTH);
- break;
-
- case LZX_BLOCKTYPE_UNCOMPRESSED:
- pState->intel_started = 1; /* because we can't assume otherwise */
- ENSURE_BITS(16); /* get up to 16 pad bits into the buffer */
- if (bitsleft > 16) inpos -= 2; /* and align the bitstream! */
- R0 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
- R1 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
- R2 = inpos[0]|(inpos[1]<<8)|(inpos[2]<<16)|(inpos[3]<<24);inpos+=4;
- break;
-
- default:
- return DECR_ILLEGALDATA;
- }
- }
-
- /* buffer exhaustion check */
- if (inpos > endinp) {
- /* it's possible to have a file where the next run is less than
- * 16 bits in size. In this case, the READ_HUFFSYM() macro used
- * in building the tables will exhaust the buffer, so we should
- * allow for this, but not allow those accidentally read bits to
- * be used (so we check that there are at least 16 bits
- * remaining - in this boundary case they aren't really part of
- * the compressed data)
- */
- if (inpos > (endinp+2) || bitsleft < 16) return DECR_ILLEGALDATA;
- }
-
- while ((this_run = pState->block_remaining) > 0 && togo > 0) {
- if (this_run > togo) this_run = togo;
- togo -= this_run;
- pState->block_remaining -= this_run;
-
- /* apply 2^x-1 mask */
- window_posn &= window_size - 1;
- /* runs can't straddle the window wraparound */
- if ((window_posn + this_run) > window_size)
- return DECR_DATAFORMAT;
-
- switch (pState->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;
-
- 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;
-
- match_offset = main_element >> 3;
-
- if (match_offset > 2) {
- /* not repeated offset */
- if (match_offset != 3) {
- extra = extra_bits[match_offset];
- READ_BITS(verbatim_bits, extra);
- match_offset = position_base[match_offset] - 2 + verbatim_bits;
- }
- else {
- match_offset = 1;
- }
-
- /* update repeated offset LRU queue */
- R2 = R1; R1 = R0; R0 = match_offset;
- }
- else if (match_offset == 0) {
- match_offset = R0;
- }
- else if (match_offset == 1) {
- match_offset = R1;
- R1 = R0; R0 = match_offset;
- }
- else /* match_offset == 2 */ {
- match_offset = R2;
- R2 = R0; R0 = match_offset;
- }
-
- rundest = window + window_posn;
- this_run -= match_length;
-
- /* copy any wrapped around source data */
- if (window_posn >= match_offset) {
- /* no wrap */
- runsrc = rundest - match_offset;
- } else {
- runsrc = rundest + (window_size - match_offset);
- copy_length = match_offset - window_posn;
- if (copy_length < match_length) {
- match_length -= copy_length;
- window_posn += copy_length;
- while (copy_length-- > 0) *rundest++ = *runsrc++;
- runsrc = window;
- }
- }
- window_posn += match_length;
-
- /* copy match data - no worries about destination wraps */
- while (match_length-- > 0) *rundest++ = *runsrc++;
-
- }
- }
- 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;
-
- 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;
-
- match_offset = main_element >> 3;
-
- if (match_offset > 2) {
- /* not repeated offset */
- 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 */ {
- /* ??? */
- match_offset = 1;
- }
-
- /* update repeated offset LRU queue */
- R2 = R1; R1 = R0; R0 = match_offset;
- }
- else if (match_offset == 0) {
- match_offset = R0;
- }
- else if (match_offset == 1) {
- match_offset = R1;
- R1 = R0; R0 = match_offset;
- }
- else /* match_offset == 2 */ {
- match_offset = R2;
- R2 = R0; R0 = match_offset;
- }
-
- rundest = window + window_posn;
- this_run -= match_length;
-
- /* copy any wrapped around source data */
- if (window_posn >= match_offset) {
- /* no wrap */
- runsrc = rundest - match_offset;
- } else {
- runsrc = rundest + (window_size - match_offset);
- copy_length = match_offset - window_posn;
- if (copy_length < match_length) {
- match_length -= copy_length;
- window_posn += copy_length;
- while (copy_length-- > 0) *rundest++ = *runsrc++;
- runsrc = window;
- }
- }
- window_posn += match_length;
-
- /* copy match data - no worries about destination wraps */
- while (match_length-- > 0) *rundest++ = *runsrc++;
-
- }
- }
- break;
-
- case LZX_BLOCKTYPE_UNCOMPRESSED:
- if ((inpos + this_run) > endinp) return DECR_ILLEGALDATA;
- memcpy(window + window_posn, inpos, (size_t) this_run);
- inpos += this_run; window_posn += this_run;
- break;
-
- default:
- return DECR_ILLEGALDATA; /* might as well */
- }
-
- }
- }
-
- if (togo != 0) return DECR_ILLEGALDATA;
- memcpy(outpos, window + ((!window_posn) ? window_size : window_posn) - outlen, (size_t) outlen);
-
- pState->window_posn = window_posn;
- pState->R0 = R0;
- pState->R1 = R1;
- pState->R2 = R2;
-
- /* intel E8 decoding */
- if ((pState->frames_read++ < 32768) && pState->intel_filesize != 0) {
- if (outlen <= 6 || !pState->intel_started) {
- pState->intel_curpos += outlen;
- }
- else {
- UBYTE *data = outpos;
- UBYTE *dataend = data + outlen - 10;
- LONG curpos = pState->intel_curpos;
- LONG filesize = pState->intel_filesize;
- LONG abs_off, rel_off;
-
- pState->intel_curpos = curpos + outlen;
-
- 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] = (UBYTE) rel_off;
- data[1] = (UBYTE) (rel_off >> 8);
- data[2] = (UBYTE) (rel_off >> 16);
- data[3] = (UBYTE) (rel_off >> 24);
- }
- data += 4;
- curpos += 5;
- }
- }
- }
- return DECR_OK;
-}
-
-#ifdef LZX_CHM_TESTDRIVER
-int main(int c, char **v)
-{
- FILE *fin, *fout;
- struct LZXstate state;
- UBYTE ibuf[16384];
- UBYTE obuf[32768];
- int ilen, olen;
- int status;
- int i;
- int count=0;
- int w = atoi(v[1]);
- LZXinit(&state, w);
- fout = fopen(v[2], "wb");
- for (i=3; i<c; i++)
- {
- fin = fopen(v[i], "rb");
- ilen = fread(ibuf, 1, 16384, fin);
- status = LZXdecompress(&state, ibuf, obuf, ilen, 32768);
- switch (status)
- {
- case DECR_OK:
- printf("ok\n");
- fwrite(obuf, 1, 32768, fout);
- break;
- case DECR_DATAFORMAT:
- printf("bad format\n");
- break;
- case DECR_ILLEGALDATA:
- printf("illegal data\n");
- break;
- case DECR_NOMEMORY:
- printf("no memory\n");
- break;
- default:
- break;
- }
- fclose(fin);
- if (++count == 2)
- {
- count = 0;
- LZXreset(&state);
- }
- }
- fclose(fout);
-}
-#endif
projects / reactos.git / blobdiff