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1041 lines
29 KiB
C
1041 lines
29 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* gunzip implementation for busybox
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*
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* Based on GNU gzip v1.2.4 Copyright (C) 1992-1993 Jean-loup Gailly.
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*
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* Originally adjusted for busybox by Sven Rudolph <sr1@inf.tu-dresden.de>
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* based on gzip sources
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*
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* Adjusted further by Erik Andersen <andersen@codepoet.org> to support
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* files as well as stdin/stdout, and to generally behave itself wrt
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* command line handling.
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*
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* General cleanup to better adhere to the style guide and make use of standard
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* busybox functions by Glenn McGrath <bug1@optushome.com.au>
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*
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* read_gz interface + associated hacking by Laurence Anderson
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*
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* gzip (GNU zip) -- compress files with zip algorithm and 'compress' interface
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* Copyright (C) 1992-1993 Jean-loup Gailly
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* The unzip code was written and put in the public domain by Mark Adler.
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* Portions of the lzw code are derived from the public domain 'compress'
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* written by Spencer Thomas, Joe Orost, James Woods, Jim McKie, Steve Davies,
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* Ken Turkowski, Dave Mack and Peter Jannesen.
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*
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* See the license_msg below and the file COPYING for the software license.
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* See the file algorithm.doc for the compression algorithms and file formats.
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*/
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#if 0
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static char *license_msg[] = {
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" Copyright (C) 1992-1993 Jean-loup Gailly",
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" This program is free software; you can redistribute it and/or modify",
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" it under the terms of the GNU General Public License as published by",
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" the Free Software Foundation; either version 2, or (at your option)",
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" any later version.",
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"",
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" This program is distributed in the hope that it will be useful,",
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" but WITHOUT ANY WARRANTY; without even the implied warranty of",
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" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the",
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" GNU General Public License for more details.",
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"",
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" You should have received a copy of the GNU General Public License",
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" along with this program; if not, write to the Free Software",
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" Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.",
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0
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};
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#endif
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include "config.h"
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#include "busybox.h"
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#include "unarchive.h"
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typedef struct huft_s {
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unsigned char e; /* number of extra bits or operation */
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unsigned char b; /* number of bits in this code or subcode */
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union {
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unsigned short n; /* literal, length base, or distance base */
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struct huft_s *t; /* pointer to next level of table */
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} v;
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} huft_t;
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static int gunzip_src_fd;
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unsigned int gunzip_bytes_out; /* number of output bytes */
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static unsigned int gunzip_outbuf_count; /* bytes in output buffer */
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/* gunzip_window size--must be a power of two, and
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* at least 32K for zip's deflate method */
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static const int gunzip_wsize = 0x8000;
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static unsigned char *gunzip_window;
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static unsigned int *gunzip_crc_table;
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unsigned int gunzip_crc;
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/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
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#define BMAX 16 /* maximum bit length of any code (16 for explode) */
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#define N_MAX 288 /* maximum number of codes in any set */
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/* bitbuffer */
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static unsigned int gunzip_bb; /* bit buffer */
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static unsigned char gunzip_bk; /* bits in bit buffer */
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/* These control the size of the bytebuffer */
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#define BYTEBUFFER_MAX 0x8000
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static unsigned char *bytebuffer = NULL;
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static unsigned int bytebuffer_offset = 0;
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static unsigned int bytebuffer_size = 0;
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static const unsigned short mask_bits[] = {
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0x0000, 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
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0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
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};
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/* Copy lengths for literal codes 257..285 */
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static const unsigned short cplens[] = {
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3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
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67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
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};
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/* note: see note #13 above about the 258 in this list. */
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/* Extra bits for literal codes 257..285 */
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static const unsigned char cplext[] = {
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0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5,
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5, 5, 5, 0, 99, 99
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}; /* 99==invalid */
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/* Copy offsets for distance codes 0..29 */
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static const unsigned short cpdist[] = {
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1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
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769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
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};
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/* Extra bits for distance codes */
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static const unsigned char cpdext[] = {
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0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
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11, 11, 12, 12, 13, 13
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};
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/* Tables for deflate from PKZIP's appnote.txt. */
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/* Order of the bit length code lengths */
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static const unsigned char border[] = {
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16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
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};
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static void fill_bytebuffer(void)
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{
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if (bytebuffer_offset >= bytebuffer_size) {
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/* Leave the first 4 bytes empty so we can always unwind the bitbuffer
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* to the front of the bytebuffer, leave 4 bytes free at end of tail
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* so we can easily top up buffer in check_trailer_gzip() */
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bytebuffer_size = 4 + bb_xread(gunzip_src_fd, &bytebuffer[4], BYTEBUFFER_MAX - 8);
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bytebuffer_offset = 4;
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}
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}
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static unsigned int fill_bitbuffer(unsigned int bitbuffer, unsigned int *current, const unsigned int required)
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{
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while (*current < required) {
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fill_bytebuffer();
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bitbuffer |= ((unsigned int) bytebuffer[bytebuffer_offset]) << *current;
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bytebuffer_offset++;
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*current += 8;
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}
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return(bitbuffer);
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}
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static void make_gunzip_crc_table(void)
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{
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const unsigned int poly = 0xedb88320; /* polynomial exclusive-or pattern */
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unsigned short i; /* counter for all possible eight bit values */
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/* initial shift register value */
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gunzip_crc = 0xffffffffL;
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gunzip_crc_table = (unsigned int *) malloc(256 * sizeof(unsigned int));
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/* Compute and print table of CRC's, five per line */
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for (i = 0; i < 256; i++) {
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unsigned int table_entry; /* crc shift register */
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unsigned char k; /* byte being shifted into crc apparatus */
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table_entry = i;
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/* The idea to initialize the register with the byte instead of
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* zero was stolen from Haruhiko Okumura's ar002
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*/
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for (k = 8; k; k--) {
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if (table_entry & 1) {
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table_entry = (table_entry >> 1) ^ poly;
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} else {
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table_entry >>= 1;
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}
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}
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gunzip_crc_table[i] = table_entry;
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}
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}
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/*
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* Free the malloc'ed tables built by huft_build(), which makes a linked
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* list of the tables it made, with the links in a dummy first entry of
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* each table.
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* t: table to free
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*/
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static int huft_free(huft_t * t)
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{
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huft_t *p;
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huft_t *q;
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/* Go through linked list, freeing from the malloced (t[-1]) address. */
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p = t;
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while (p != (huft_t *) NULL) {
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q = (--p)->v.t;
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free((char *) p);
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p = q;
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}
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return 0;
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}
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/* Given a list of code lengths and a maximum table size, make a set of
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* tables to decode that set of codes. Return zero on success, one if
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* the given code set is incomplete (the tables are still built in this
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* case), two if the input is invalid (all zero length codes or an
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* oversubscribed set of lengths), and three if not enough memory.
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*
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* b: code lengths in bits (all assumed <= BMAX)
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* n: number of codes (assumed <= N_MAX)
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* s: number of simple-valued codes (0..s-1)
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* d: list of base values for non-simple codes
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* e: list of extra bits for non-simple codes
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* t: result: starting table
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* m: maximum lookup bits, returns actual
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*/
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static int huft_build(unsigned int *b, const unsigned int n,
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const unsigned int s, const unsigned short *d,
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const unsigned char *e, huft_t ** t, int *m)
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{
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unsigned a; /* counter for codes of length k */
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unsigned c[BMAX + 1]; /* bit length count table */
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unsigned f; /* i repeats in table every f entries */
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int g; /* maximum code length */
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int h; /* table level */
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register unsigned i; /* counter, current code */
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register unsigned j; /* counter */
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register int k; /* number of bits in current code */
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int l; /* bits per table (returned in m) */
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register unsigned *p; /* pointer into c[], b[], or v[] */
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register huft_t *q; /* points to current table */
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huft_t r; /* table entry for structure assignment */
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huft_t *u[BMAX]; /* table stack */
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unsigned v[N_MAX]; /* values in order of bit length */
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register int w; /* bits before this table == (l * h) */
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unsigned x[BMAX + 1]; /* bit offsets, then code stack */
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unsigned *xp; /* pointer into x */
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int y; /* number of dummy codes added */
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unsigned z; /* number of entries in current table */
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/* Generate counts for each bit length */
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memset((void *) (c), 0, sizeof(c));
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p = b;
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i = n;
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do {
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c[*p]++; /* assume all entries <= BMAX */
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p++; /* Can't combine with above line (Solaris bug) */
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} while (--i);
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if (c[0] == n) { /* null input--all zero length codes */
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*t = (huft_t *) NULL;
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*m = 0;
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return 0;
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}
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/* Find minimum and maximum length, bound *m by those */
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l = *m;
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for (j = 1; j <= BMAX; j++) {
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if (c[j]) {
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break;
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}
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}
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k = j; /* minimum code length */
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if ((unsigned) l < j) {
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l = j;
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}
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for (i = BMAX; i; i--) {
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if (c[i]) {
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break;
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}
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}
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g = i; /* maximum code length */
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if ((unsigned) l > i) {
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l = i;
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}
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*m = l;
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/* Adjust last length count to fill out codes, if needed */
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for (y = 1 << j; j < i; j++, y <<= 1) {
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if ((y -= c[j]) < 0) {
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return 2; /* bad input: more codes than bits */
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}
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}
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if ((y -= c[i]) < 0) {
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return 2;
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}
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c[i] += y;
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/* Generate starting offsets into the value table for each length */
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x[1] = j = 0;
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p = c + 1;
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xp = x + 2;
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while (--i) { /* note that i == g from above */
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*xp++ = (j += *p++);
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}
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/* Make a table of values in order of bit lengths */
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p = b;
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i = 0;
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do {
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if ((j = *p++) != 0) {
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v[x[j]++] = i;
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}
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} while (++i < n);
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/* Generate the Huffman codes and for each, make the table entries */
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x[0] = i = 0; /* first Huffman code is zero */
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p = v; /* grab values in bit order */
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h = -1; /* no tables yet--level -1 */
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w = -l; /* bits decoded == (l * h) */
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u[0] = (huft_t *) NULL; /* just to keep compilers happy */
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q = (huft_t *) NULL; /* ditto */
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z = 0; /* ditto */
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/* go through the bit lengths (k already is bits in shortest code) */
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for (; k <= g; k++) {
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a = c[k];
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while (a--) {
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/* here i is the Huffman code of length k bits for value *p */
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/* make tables up to required level */
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while (k > w + l) {
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h++;
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w += l; /* previous table always l bits */
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/* compute minimum size table less than or equal to l bits */
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z = (z = g - w) > (unsigned) l ? l : z; /* upper limit on table size */
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if ((f = 1 << (j = k - w)) > a + 1) { /* try a k-w bit table *//* too few codes for k-w bit table */
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f -= a + 1; /* deduct codes from patterns left */
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xp = c + k;
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while (++j < z) { /* try smaller tables up to z bits */
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if ((f <<= 1) <= *++xp) {
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break; /* enough codes to use up j bits */
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}
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f -= *xp; /* else deduct codes from patterns */
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}
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}
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z = 1 << j; /* table entries for j-bit table */
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/* allocate and link in new table */
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q = (huft_t *) xmalloc((z + 1) * sizeof(huft_t));
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*t = q + 1; /* link to list for huft_free() */
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*(t = &(q->v.t)) = NULL;
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u[h] = ++q; /* table starts after link */
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/* connect to last table, if there is one */
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if (h) {
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x[h] = i; /* save pattern for backing up */
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r.b = (unsigned char) l; /* bits to dump before this table */
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r.e = (unsigned char) (16 + j); /* bits in this table */
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r.v.t = q; /* pointer to this table */
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j = i >> (w - l); /* (get around Turbo C bug) */
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u[h - 1][j] = r; /* connect to last table */
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}
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}
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/* set up table entry in r */
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r.b = (unsigned char) (k - w);
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if (p >= v + n) {
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r.e = 99; /* out of values--invalid code */
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} else if (*p < s) {
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r.e = (unsigned char) (*p < 256 ? 16 : 15); /* 256 is end-of-block code */
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r.v.n = (unsigned short) (*p); /* simple code is just the value */
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p++; /* one compiler does not like *p++ */
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} else {
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r.e = (unsigned char) e[*p - s]; /* non-simple--look up in lists */
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r.v.n = d[*p++ - s];
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}
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/* fill code-like entries with r */
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f = 1 << (k - w);
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for (j = i >> w; j < z; j += f) {
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q[j] = r;
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}
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/* backwards increment the k-bit code i */
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for (j = 1 << (k - 1); i & j; j >>= 1) {
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i ^= j;
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}
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i ^= j;
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/* backup over finished tables */
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while ((i & ((1 << w) - 1)) != x[h]) {
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h--; /* don't need to update q */
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w -= l;
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}
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}
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}
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/* Return true (1) if we were given an incomplete table */
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return y != 0 && g != 1;
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}
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/*
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* inflate (decompress) the codes in a deflated (compressed) block.
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* Return an error code or zero if it all goes ok.
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*
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* tl, td: literal/length and distance decoder tables
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* bl, bd: number of bits decoded by tl[] and td[]
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*/
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static int inflate_codes(huft_t * my_tl, huft_t * my_td, const unsigned int my_bl, const unsigned int my_bd, int setup)
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{
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static unsigned int e; /* table entry flag/number of extra bits */
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static unsigned int n, d; /* length and index for copy */
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static unsigned int w; /* current gunzip_window position */
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static huft_t *t; /* pointer to table entry */
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static unsigned int ml, md; /* masks for bl and bd bits */
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static unsigned int b; /* bit buffer */
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static unsigned int k; /* number of bits in bit buffer */
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static huft_t *tl, *td;
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static unsigned int bl, bd;
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static int resumeCopy = 0;
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if (setup) { // 1st time we are called, copy in variables
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tl = my_tl;
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td = my_td;
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bl = my_bl;
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bd = my_bd;
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/* make local copies of globals */
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b = gunzip_bb; /* initialize bit buffer */
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k = gunzip_bk;
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w = gunzip_outbuf_count; /* initialize gunzip_window position */
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/* inflate the coded data */
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ml = mask_bits[bl]; /* precompute masks for speed */
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md = mask_bits[bd];
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return 0; // Don't actually do anything the first time
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}
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if (resumeCopy) goto do_copy;
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while (1) { /* do until end of block */
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b = fill_bitbuffer(b, &k, bl);
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if ((e = (t = tl + ((unsigned) b & ml))->e) > 16)
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do {
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if (e == 99) {
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bb_error_msg_and_die("inflate_codes error 1");;
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}
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b >>= t->b;
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k -= t->b;
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e -= 16;
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b = fill_bitbuffer(b, &k, e);
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} while ((e =
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(t = t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
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b >>= t->b;
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k -= t->b;
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if (e == 16) { /* then it's a literal */
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gunzip_window[w++] = (unsigned char) t->v.n;
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if (w == gunzip_wsize) {
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gunzip_outbuf_count = (w);
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//flush_gunzip_window();
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w = 0;
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return 1; // We have a block to read
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}
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} else { /* it's an EOB or a length */
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|
|
/* exit if end of block */
|
|
if (e == 15) {
|
|
break;
|
|
}
|
|
|
|
/* get length of block to copy */
|
|
b = fill_bitbuffer(b, &k, e);
|
|
n = t->v.n + ((unsigned) b & mask_bits[e]);
|
|
b >>= e;
|
|
k -= e;
|
|
|
|
/* decode distance of block to copy */
|
|
b = fill_bitbuffer(b, &k, bd);
|
|
if ((e = (t = td + ((unsigned) b & md))->e) > 16)
|
|
do {
|
|
if (e == 99)
|
|
bb_error_msg_and_die("inflate_codes error 2");;
|
|
b >>= t->b;
|
|
k -= t->b;
|
|
e -= 16;
|
|
b = fill_bitbuffer(b, &k, e);
|
|
} while ((e =
|
|
(t =
|
|
t->v.t + ((unsigned) b & mask_bits[e]))->e) > 16);
|
|
b >>= t->b;
|
|
k -= t->b;
|
|
b = fill_bitbuffer(b, &k, e);
|
|
d = w - t->v.n - ((unsigned) b & mask_bits[e]);
|
|
b >>= e;
|
|
k -= e;
|
|
|
|
/* do the copy */
|
|
do_copy: do {
|
|
n -= (e =
|
|
(e =
|
|
gunzip_wsize - ((d &= gunzip_wsize - 1) > w ? d : w)) > n ? n : e);
|
|
/* copy to new buffer to prevent possible overwrite */
|
|
if (w - d >= e) { /* (this test assumes unsigned comparison) */
|
|
memcpy(gunzip_window + w, gunzip_window + d, e);
|
|
w += e;
|
|
d += e;
|
|
} else {
|
|
/* do it slow to avoid memcpy() overlap */
|
|
/* !NOMEMCPY */
|
|
do {
|
|
gunzip_window[w++] = gunzip_window[d++];
|
|
} while (--e);
|
|
}
|
|
if (w == gunzip_wsize) {
|
|
gunzip_outbuf_count = (w);
|
|
if (n) resumeCopy = 1;
|
|
else resumeCopy = 0;
|
|
//flush_gunzip_window();
|
|
w = 0;
|
|
return 1;
|
|
}
|
|
} while (n);
|
|
resumeCopy = 0;
|
|
}
|
|
}
|
|
|
|
/* restore the globals from the locals */
|
|
gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
|
|
gunzip_bb = b; /* restore global bit buffer */
|
|
gunzip_bk = k;
|
|
|
|
/* normally just after call to inflate_codes, but save code by putting it here */
|
|
/* free the decoding tables, return */
|
|
huft_free(tl);
|
|
huft_free(td);
|
|
|
|
/* done */
|
|
return 0;
|
|
}
|
|
|
|
static int inflate_stored(int my_n, int my_b_stored, int my_k_stored, int setup)
|
|
{
|
|
static int n, b_stored, k_stored, w;
|
|
if (setup) {
|
|
n = my_n;
|
|
b_stored = my_b_stored;
|
|
k_stored = my_k_stored;
|
|
w = gunzip_outbuf_count; /* initialize gunzip_window position */
|
|
return 0; // Don't do anything first time
|
|
}
|
|
|
|
/* read and output the compressed data */
|
|
while (n--) {
|
|
b_stored = fill_bitbuffer(b_stored, &k_stored, 8);
|
|
gunzip_window[w++] = (unsigned char) b_stored;
|
|
if (w == (unsigned int) gunzip_wsize) {
|
|
gunzip_outbuf_count = (w);
|
|
//flush_gunzip_window();
|
|
w = 0;
|
|
b_stored >>= 8;
|
|
k_stored -= 8;
|
|
return 1; // We have a block
|
|
}
|
|
b_stored >>= 8;
|
|
k_stored -= 8;
|
|
}
|
|
|
|
/* restore the globals from the locals */
|
|
gunzip_outbuf_count = w; /* restore global gunzip_window pointer */
|
|
gunzip_bb = b_stored; /* restore global bit buffer */
|
|
gunzip_bk = k_stored;
|
|
return 0; // Finished
|
|
}
|
|
|
|
/*
|
|
* decompress an inflated block
|
|
* e: last block flag
|
|
*
|
|
* GLOBAL VARIABLES: bb, kk,
|
|
*/
|
|
// Return values: -1 = inflate_stored, -2 = inflate_codes
|
|
static int inflate_block(int *e)
|
|
{
|
|
unsigned t; /* block type */
|
|
register unsigned int b; /* bit buffer */
|
|
unsigned int k; /* number of bits in bit buffer */
|
|
|
|
/* make local bit buffer */
|
|
|
|
b = gunzip_bb;
|
|
k = gunzip_bk;
|
|
|
|
/* read in last block bit */
|
|
b = fill_bitbuffer(b, &k, 1);
|
|
*e = (int) b & 1;
|
|
b >>= 1;
|
|
k -= 1;
|
|
|
|
/* read in block type */
|
|
b = fill_bitbuffer(b, &k, 2);
|
|
t = (unsigned) b & 3;
|
|
b >>= 2;
|
|
k -= 2;
|
|
|
|
/* restore the global bit buffer */
|
|
gunzip_bb = b;
|
|
gunzip_bk = k;
|
|
|
|
/* inflate that block type */
|
|
switch (t) {
|
|
case 0: /* Inflate stored */
|
|
{
|
|
unsigned int n; /* number of bytes in block */
|
|
unsigned int b_stored; /* bit buffer */
|
|
unsigned int k_stored; /* number of bits in bit buffer */
|
|
|
|
/* make local copies of globals */
|
|
b_stored = gunzip_bb; /* initialize bit buffer */
|
|
k_stored = gunzip_bk;
|
|
|
|
/* go to byte boundary */
|
|
n = k_stored & 7;
|
|
b_stored >>= n;
|
|
k_stored -= n;
|
|
|
|
/* get the length and its complement */
|
|
b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
|
|
n = ((unsigned) b_stored & 0xffff);
|
|
b_stored >>= 16;
|
|
k_stored -= 16;
|
|
|
|
b_stored = fill_bitbuffer(b_stored, &k_stored, 16);
|
|
if (n != (unsigned) ((~b_stored) & 0xffff)) {
|
|
return 1; /* error in compressed data */
|
|
}
|
|
b_stored >>= 16;
|
|
k_stored -= 16;
|
|
|
|
inflate_stored(n, b_stored, k_stored, 1); // Setup inflate_stored
|
|
return -1;
|
|
}
|
|
case 1: /* Inflate fixed
|
|
* decompress an inflated type 1 (fixed Huffman codes) block. We should
|
|
* either replace this with a custom decoder, or at least precompute the
|
|
* Huffman tables.
|
|
*/
|
|
{
|
|
int i; /* temporary variable */
|
|
huft_t *tl; /* literal/length code table */
|
|
huft_t *td; /* distance code table */
|
|
unsigned int bl; /* lookup bits for tl */
|
|
unsigned int bd; /* lookup bits for td */
|
|
unsigned int l[288]; /* length list for huft_build */
|
|
|
|
/* set up literal table */
|
|
for (i = 0; i < 144; i++) {
|
|
l[i] = 8;
|
|
}
|
|
for (; i < 256; i++) {
|
|
l[i] = 9;
|
|
}
|
|
for (; i < 280; i++) {
|
|
l[i] = 7;
|
|
}
|
|
for (; i < 288; i++) { /* make a complete, but wrong code set */
|
|
l[i] = 8;
|
|
}
|
|
bl = 7;
|
|
if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0) {
|
|
return i;
|
|
}
|
|
|
|
/* set up distance table */
|
|
for (i = 0; i < 30; i++) { /* make an incomplete code set */
|
|
l[i] = 5;
|
|
}
|
|
bd = 5;
|
|
if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1) {
|
|
huft_free(tl);
|
|
return i;
|
|
}
|
|
|
|
/* decompress until an end-of-block code */
|
|
inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
|
|
|
|
/* huft_free code moved into inflate_codes */
|
|
|
|
return -2;
|
|
}
|
|
case 2: /* Inflate dynamic */
|
|
{
|
|
const int dbits = 6; /* bits in base distance lookup table */
|
|
const int lbits = 9; /* bits in base literal/length lookup table */
|
|
|
|
huft_t *tl; /* literal/length code table */
|
|
huft_t *td; /* distance code table */
|
|
unsigned int i; /* temporary variables */
|
|
unsigned int j;
|
|
unsigned int l; /* last length */
|
|
unsigned int m; /* mask for bit lengths table */
|
|
unsigned int n; /* number of lengths to get */
|
|
unsigned int bl; /* lookup bits for tl */
|
|
unsigned int bd; /* lookup bits for td */
|
|
unsigned int nb; /* number of bit length codes */
|
|
unsigned int nl; /* number of literal/length codes */
|
|
unsigned int nd; /* number of distance codes */
|
|
|
|
unsigned int ll[286 + 30]; /* literal/length and distance code lengths */
|
|
unsigned int b_dynamic; /* bit buffer */
|
|
unsigned int k_dynamic; /* number of bits in bit buffer */
|
|
|
|
/* make local bit buffer */
|
|
b_dynamic = gunzip_bb;
|
|
k_dynamic = gunzip_bk;
|
|
|
|
/* read in table lengths */
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
|
|
nl = 257 + ((unsigned int) b_dynamic & 0x1f); /* number of literal/length codes */
|
|
|
|
b_dynamic >>= 5;
|
|
k_dynamic -= 5;
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 5);
|
|
nd = 1 + ((unsigned int) b_dynamic & 0x1f); /* number of distance codes */
|
|
|
|
b_dynamic >>= 5;
|
|
k_dynamic -= 5;
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 4);
|
|
nb = 4 + ((unsigned int) b_dynamic & 0xf); /* number of bit length codes */
|
|
|
|
b_dynamic >>= 4;
|
|
k_dynamic -= 4;
|
|
if (nl > 286 || nd > 30) {
|
|
return 1; /* bad lengths */
|
|
}
|
|
|
|
/* read in bit-length-code lengths */
|
|
for (j = 0; j < nb; j++) {
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
|
|
ll[border[j]] = (unsigned int) b_dynamic & 7;
|
|
b_dynamic >>= 3;
|
|
k_dynamic -= 3;
|
|
}
|
|
for (; j < 19; j++) {
|
|
ll[border[j]] = 0;
|
|
}
|
|
|
|
/* build decoding table for trees--single level, 7 bit lookup */
|
|
bl = 7;
|
|
i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl);
|
|
if (i != 0) {
|
|
if (i == 1) {
|
|
huft_free(tl);
|
|
}
|
|
return i; /* incomplete code set */
|
|
}
|
|
|
|
/* read in literal and distance code lengths */
|
|
n = nl + nd;
|
|
m = mask_bits[bl];
|
|
i = l = 0;
|
|
while ((unsigned int) i < n) {
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, (unsigned int)bl);
|
|
j = (td = tl + ((unsigned int) b_dynamic & m))->b;
|
|
b_dynamic >>= j;
|
|
k_dynamic -= j;
|
|
j = td->v.n;
|
|
if (j < 16) { /* length of code in bits (0..15) */
|
|
ll[i++] = l = j; /* save last length in l */
|
|
} else if (j == 16) { /* repeat last length 3 to 6 times */
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 2);
|
|
j = 3 + ((unsigned int) b_dynamic & 3);
|
|
b_dynamic >>= 2;
|
|
k_dynamic -= 2;
|
|
if ((unsigned int) i + j > n) {
|
|
return 1;
|
|
}
|
|
while (j--) {
|
|
ll[i++] = l;
|
|
}
|
|
} else if (j == 17) { /* 3 to 10 zero length codes */
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 3);
|
|
j = 3 + ((unsigned int) b_dynamic & 7);
|
|
b_dynamic >>= 3;
|
|
k_dynamic -= 3;
|
|
if ((unsigned int) i + j > n) {
|
|
return 1;
|
|
}
|
|
while (j--) {
|
|
ll[i++] = 0;
|
|
}
|
|
l = 0;
|
|
} else { /* j == 18: 11 to 138 zero length codes */
|
|
b_dynamic = fill_bitbuffer(b_dynamic, &k_dynamic, 7);
|
|
j = 11 + ((unsigned int) b_dynamic & 0x7f);
|
|
b_dynamic >>= 7;
|
|
k_dynamic -= 7;
|
|
if ((unsigned int) i + j > n) {
|
|
return 1;
|
|
}
|
|
while (j--) {
|
|
ll[i++] = 0;
|
|
}
|
|
l = 0;
|
|
}
|
|
}
|
|
|
|
/* free decoding table for trees */
|
|
huft_free(tl);
|
|
|
|
/* restore the global bit buffer */
|
|
gunzip_bb = b_dynamic;
|
|
gunzip_bk = k_dynamic;
|
|
|
|
/* build the decoding tables for literal/length and distance codes */
|
|
bl = lbits;
|
|
|
|
if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0) {
|
|
if (i == 1) {
|
|
bb_error_msg_and_die("Incomplete literal tree");
|
|
huft_free(tl);
|
|
}
|
|
return i; /* incomplete code set */
|
|
}
|
|
|
|
bd = dbits;
|
|
if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0) {
|
|
if (i == 1) {
|
|
bb_error_msg_and_die("incomplete distance tree");
|
|
huft_free(td);
|
|
}
|
|
huft_free(tl);
|
|
return i; /* incomplete code set */
|
|
}
|
|
|
|
/* decompress until an end-of-block code */
|
|
inflate_codes(tl, td, bl, bd, 1); // Setup inflate_codes
|
|
|
|
/* huft_free code moved into inflate_codes */
|
|
|
|
return -2;
|
|
}
|
|
default:
|
|
/* bad block type */
|
|
bb_error_msg_and_die("bad block type %d\n", t);
|
|
}
|
|
}
|
|
|
|
static void calculate_gunzip_crc(void)
|
|
{
|
|
int n;
|
|
for (n = 0; n < gunzip_outbuf_count; n++) {
|
|
gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8);
|
|
}
|
|
gunzip_bytes_out += gunzip_outbuf_count;
|
|
}
|
|
|
|
static int inflate_get_next_window(void)
|
|
{
|
|
static int needAnotherBlock = 1;
|
|
static int method = -1; // Method == -1 for stored, -2 for codes
|
|
static int e = 0;
|
|
|
|
gunzip_outbuf_count = 0;
|
|
|
|
while(1) {
|
|
int ret;
|
|
|
|
if (needAnotherBlock) {
|
|
if(e) {
|
|
calculate_gunzip_crc();
|
|
return 0;
|
|
} // Last block
|
|
method = inflate_block(&e);
|
|
needAnotherBlock = 0;
|
|
}
|
|
|
|
switch (method) {
|
|
case -1: ret = inflate_stored(0,0,0,0);
|
|
break;
|
|
case -2: ret = inflate_codes(0,0,0,0,0);
|
|
break;
|
|
default: bb_error_msg_and_die("inflate error %d", method);
|
|
}
|
|
|
|
if (ret == 1) {
|
|
calculate_gunzip_crc();
|
|
return 1; // More data left
|
|
} else needAnotherBlock = 1; // End of that block
|
|
}
|
|
/* Doesnt get here */
|
|
}
|
|
|
|
/*
|
|
* User functions
|
|
*
|
|
* read_gz, GZ_gzReadOpen, GZ_gzReadClose, inflate
|
|
*/
|
|
|
|
extern ssize_t read_gz(int fd, void *buf, size_t count)
|
|
{
|
|
static int morebytes = 0, finished = 0;
|
|
|
|
if (morebytes) {
|
|
int bytesRead = morebytes > count ? count : morebytes;
|
|
memcpy(buf, gunzip_window + (gunzip_outbuf_count - morebytes), bytesRead);
|
|
morebytes -= bytesRead;
|
|
return bytesRead;
|
|
} else if (finished) {
|
|
return 0;
|
|
} else if (count >= 0x8000) { // We can decompress direcly to the buffer, 32k at a time
|
|
// Could decompress to larger buffer, but it must be a power of 2, and calculating that is probably more expensive than the benefit
|
|
unsigned char *old_gunzip_window = gunzip_window; // Save old window
|
|
gunzip_window = buf;
|
|
if (inflate_get_next_window() == 0) finished = 1;
|
|
gunzip_window = old_gunzip_window; // Restore old window
|
|
return gunzip_outbuf_count;
|
|
} else { // Oh well, need to split up the gunzip_window
|
|
int bytesRead;
|
|
if (inflate_get_next_window() == 0) finished = 1;
|
|
morebytes = gunzip_outbuf_count;
|
|
bytesRead = morebytes > count ? count : morebytes;
|
|
memcpy(buf, gunzip_window, bytesRead);
|
|
morebytes -= bytesRead;
|
|
return bytesRead;
|
|
}
|
|
|
|
}
|
|
|
|
extern void GZ_gzReadOpen(int fd, void *unused, int nUnused)
|
|
{
|
|
typedef void (*sig_type) (int);
|
|
|
|
/* Allocate all global buffers (for DYN_ALLOC option) */
|
|
gunzip_window = xmalloc(gunzip_wsize);
|
|
gunzip_outbuf_count = 0;
|
|
gunzip_bytes_out = 0;
|
|
gunzip_src_fd = fd;
|
|
|
|
/* Input buffer */
|
|
bytebuffer = xmalloc(BYTEBUFFER_MAX);
|
|
|
|
/* initialize gunzip_window, bit buffer */
|
|
gunzip_bk = 0;
|
|
gunzip_bb = 0;
|
|
|
|
/* Create the crc table */
|
|
make_gunzip_crc_table();
|
|
}
|
|
|
|
extern void GZ_gzReadClose(void)
|
|
{
|
|
/* Cleanup */
|
|
free(gunzip_window);
|
|
free(gunzip_crc_table);
|
|
|
|
/* Store unused bytes in a global buffer so calling applets can access it */
|
|
if (gunzip_bk >= 8) {
|
|
/* Undo too much lookahead. The next read will be byte aligned
|
|
* so we can discard unused bits in the last meaningful byte. */
|
|
bytebuffer_offset--;
|
|
bytebuffer[bytebuffer_offset] = gunzip_bb & 0xff;
|
|
gunzip_bb >>= 8;
|
|
gunzip_bk -= 8;
|
|
}
|
|
}
|
|
|
|
/*extern int inflate(int in, int out) // Useful for testing read_gz
|
|
{
|
|
char buf[8192];
|
|
ssize_t nread, nwrote;
|
|
|
|
GZ_gzReadOpen(in, 0, 0);
|
|
while(1) { // Robbed from bb_copyfd.c
|
|
nread = read_gz(in, buf, sizeof(buf));
|
|
if (nread == 0) break; // no data to write
|
|
else if (nread == -1) {
|
|
bb_perror_msg("read");
|
|
return -1;
|
|
}
|
|
nwrote = bb_full_write(out, buf, nread);
|
|
if (nwrote == -1) {
|
|
bb_perror_msg("write");
|
|
return -1;
|
|
}
|
|
}
|
|
GZ_gzReadClose();
|
|
return 0;
|
|
}*/
|
|
|
|
extern int inflate(int in, int out)
|
|
{
|
|
ssize_t nwrote;
|
|
GZ_gzReadOpen(in, 0, 0);
|
|
while(1) {
|
|
int ret = inflate_get_next_window();
|
|
nwrote = bb_full_write(out, gunzip_window, gunzip_outbuf_count);
|
|
if (nwrote == -1) {
|
|
bb_perror_msg("write");
|
|
return -1;
|
|
}
|
|
if (ret == 0) break;
|
|
}
|
|
GZ_gzReadClose();
|
|
return 0;
|
|
}
|
|
|
|
extern void check_trailer_gzip(int src_fd)
|
|
{
|
|
unsigned int stored_crc = 0;
|
|
unsigned char count;
|
|
|
|
/* top up the input buffer with the rest of the trailer */
|
|
count = bytebuffer_size - bytebuffer_offset;
|
|
if (count < 8) {
|
|
bb_xread_all(src_fd, &bytebuffer[bytebuffer_size], 8 - count);
|
|
bytebuffer_size += 8 - count;
|
|
}
|
|
for (count = 0; count != 4; count++) {
|
|
stored_crc |= (bytebuffer[bytebuffer_offset] << (count * 8));
|
|
bytebuffer_offset++;
|
|
}
|
|
|
|
/* Validate decompression - crc */
|
|
if (stored_crc != (gunzip_crc ^ 0xffffffffL)) {
|
|
bb_error_msg_and_die("crc error");
|
|
}
|
|
|
|
/* Validate decompression - size */
|
|
if (gunzip_bytes_out !=
|
|
(bytebuffer[bytebuffer_offset] | (bytebuffer[bytebuffer_offset+1] << 8) |
|
|
(bytebuffer[bytebuffer_offset+2] << 16) | (bytebuffer[bytebuffer_offset+3] << 24))) {
|
|
bb_error_msg_and_die("Incorrect length, but crc is correct");
|
|
}
|
|
|
|
}
|