commit bcf78a20978d76f64b7cd46d1a4d7a79a578c77b Author: Mark Adler Date: Fri Sep 9 22:36:31 2011 -0700 zlib 0.71 diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 00000000..40fc89f9 --- /dev/null +++ b/ChangeLog @@ -0,0 +1,51 @@ + ChangeLog file for zlib + +Changes in 0.71 (14 April 95) +- Fixed more MSDOS compilation problems :( There is still a bug with + TurboC large model. + +Changes in 0.7 (14 April 95) +- Added full inflate support. +- Simplified the crc32() interface. The pre- and post-conditioning + (one's complement) is now done inside crc32(). WARNING: this is + incompatible with previous versions; see zlib.h for the new usage. + +Changes in 0.61 (12 April 95) +- workaround for a bug in TurboC. example and minigzip now work on MSDOS. + +Changes in 0.6 (11 April 95) +- added minigzip.c +- added gzdopen to reopen a file descriptor as gzFile +- added transparent reading of non-gziped files in gzread. +- fixed bug in gzread (don't read crc as data) +- fixed bug in destroy (gzio.c) (don't return Z_STREAM_END for gzclose). +- don't allocate big arrays in the stack (for MSDOS) +- fix some MSDOS compilation problems + +Changes in 0.5: +- do real compression in deflate.c. Z_PARTIAL_FLUSH is supported but + not yet Z_FULL_FLUSH. +- support decompression but only in a single step (forced Z_FINISH) +- added opaque object for zalloc and zfree. +- added deflateReset and inflateReset +- added a variable zlib_version for consistency checking. +- renamed the 'filter' parameter of deflateInit2 as 'strategy'. + Added Z_FILTERED and Z_HUFFMAN_ONLY constants. + +Changes in 0.4: +- avoid "zip" everywhere, use zlib instead of ziplib. +- suppress Z_BLOCK_FLUSH, interpret Z_PARTIAL_FLUSH as block flush + if compression method == 8. +- added adler32 and crc32 +- renamed deflateOptions as deflateInit2, call one or the other but not both +- added the method parameter for deflateInit2. +- added inflateInit2 +- simplied considerably deflateInit and inflateInit by not supporting + user-provided history buffer. This is supported only in deflateInit2 + and inflateInit2. + +Changes in 0.3: +- prefix all macro names with Z_ +- use Z_FINISH instead of deflateEnd to finish compression. +- added Z_HUFFMAN_ONLY +- added gzerror() diff --git a/Makefile b/Makefile new file mode 100644 index 00000000..478920a1 --- /dev/null +++ b/Makefile @@ -0,0 +1,59 @@ +CC=cc +CFLAGS=-O +#CFLAGS=-g -DDEBUG +LDFLAGS=-L. -lgz + +RANLIB=ranlib + +OBJS = adler32.o compress.o crc32.o gzio.o uncompr.o deflate.o trees.o \ + zutil.o inflate.o infblock.o inftrees.o infcodes.o infutil.o + +TEST_OBJS = example.o minigzip.o inftest.o + +all: example minigzip inftest + +test: all + ./example + echo hello world | ./minigzip | ./minigzip -d + +libgz.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +example: example.o libgz.a + $(CC) $(CFLAGS) -o $@ example.o $(LDFLAGS) + +minigzip: minigzip.o libgz.a + $(CC) $(CFLAGS) -o $@ minigzip.o $(LDFLAGS) + +inftest: inftest.o libgz.a + $(CC) $(CFLAGS) -o $@ inftest.o $(LDFLAGS) + +clean: + rm -f *.o example minigzip inftest libgz.a foo.gz + +zip: + zip -ul9 zlib README ChangeLog Makefile *.[ch] + +tgz: + cd ..; tar cfz zlib/zlib.tgz zlib/README zlib/ChangeLog zlib/Makefile \ + zlib/*.[ch] + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +adler32.o: zutil.h zlib.h zconf.h +compress.o: zlib.h zconf.h +crc32.o: zutil.h zlib.h zconf.h +deflate.o: deflate.h zutil.h zlib.h zconf.h +example.o: zlib.h zconf.h +gzio.o: zutil.h zlib.h zconf.h +infblock.o: zutil.h zlib.h zconf.h infblock.h inftrees.h infcodes.h infutil.h +infcodes.o: zutil.h zlib.h zconf.h inftrees.h infutil.h infcodes.h +inflate.o: zutil.h zlib.h zconf.h infblock.h +inftest.o: zutil.h zlib.h zconf.h +inftrees.o: zutil.h zlib.h zconf.h inftrees.h +infutil.o: zutil.h zlib.h zconf.h inftrees.h infutil.h +minigzip.o: zlib.h zconf.h +trees.o: deflate.h zutil.h zlib.h zconf.h +uncompr.o: zlib.h zconf.h +zutil.o: zutil.h zlib.h zconf.h diff --git a/README b/README new file mode 100644 index 00000000..5c424025 --- /dev/null +++ b/README @@ -0,0 +1,57 @@ +zlib 0.71 is a beta version of a general purpose compression library. + +The data format used by the zlib library is described in the +file zlib-3.1.doc, deflate-1.1.doc and gzip-4.1.doc, available +in ftp.uu.net:/pub/archiving/zip/doc. + +All functions of the compression library are documented in the file +zlib.h. A usage example of the library is given in the file example.c +which also tests that the library is working correctly. +To compile all files and run the test program, just type: make test + +The changes made in version 0.71 are documented in the file ChangeLog. +The main changes since 0.5 are: +- added full inflate support +- added minigzip.c +- added gzdopen to reopen a file descriptor as gzFile +- added transparent reading of non-gziped files in gzread. +- fix some MSDOS problems. example and minigzip now work on MSDOS. +- Simplified the crc32() interface. The pre- and post-conditioning + (one's complement) is now done inside crc32(). WARNING: this is + incompatible with previous versions; see zlib.h for the new usage. + +On MSDOS, this version works in large and small model with MSC; in +small model only with TurboC (bug being investigated). For both +compilers, small model compression works only for small values of +MEM_LEVEL and WBITS (see zutil.h), and requires -DUSE_CALLOC. + + + Copyright (C) 1995 Jean-loup Gailly and Mark Adler + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. + + Jean-loup Gailly Mark Adler + gzip@prep.ai.mit.edu madler@cco.caltech.edu + +If you use the zlib library in a product, we would appreciate *not* +receiving lengthy legal documents to sign. The sources are provided +for free but without warranty of any kind. The library has been +entirely written by Jean-loup Gailly and Mark Adler; it does not +include third-party code. + +If you redistribute modified sources, we would appreciate that you include +in the file ChangeLog history information documenting your changes. diff --git a/adler32.c b/adler32.c new file mode 100644 index 00000000..0b2b820e --- /dev/null +++ b/adler32.c @@ -0,0 +1,46 @@ +/* adler32.c -- compute the Adler-32 checksum of a data stream + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: adler32.c,v 1.5 1995/04/14 14:49:51 jloup Exp $ */ + +#include "zutil.h" + +#define BASE 65521 /* largest prime smaller than 65536 */ +#define NMAX 5552 +/* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */ + +#define DO1(buf) {s1 += *buf++; s2 += s1;} +#define DO2(buf) DO1(buf); DO1(buf); +#define DO4(buf) DO2(buf); DO2(buf); +#define DO8(buf) DO4(buf); DO4(buf); +#define DO16(buf) DO8(buf); DO8(buf); + +/* ========================================================================= */ +uLong adler32(adler, buf, len) + uLong adler; + Byte *buf; + uInt len; +{ + unsigned long s1 = adler & 0xffff; + unsigned long s2 = (adler >> 16) & 0xffff; + int k; + + if (buf == Z_NULL) return 1L; + + while (len > 0) { + k = len < NMAX ? len : NMAX; + len -= k; + while (k >= 16) { + DO16(buf); + k -= 16; + } + if (k != 0) do { + DO1(buf); + } while (--k); + s1 %= BASE; + s2 %= BASE; + } + return (s2 << 16) | s1; +} diff --git a/compress.c b/compress.c new file mode 100644 index 00000000..8edcb2ae --- /dev/null +++ b/compress.c @@ -0,0 +1,55 @@ +/* compress.c -- compress a memory buffer + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: compress.c,v 1.4 1995/04/10 15:52:04 jloup Exp $ */ + +#include "zlib.h" + +/* =========================================================================== + Compresses the source buffer into the destination buffer. sourceLen is + the byte length of the source buffer. Upon entry, destLen is the total + size of the destination buffer, which must be at least 0.1% larger than + sourceLen plus 8 bytes. Upon exit, destLen is the actual size of the + compressed buffer. + This function can be used to compress a whole file at once if the + input file is mmap'ed. + compress returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_BUF_ERROR if there was not enough room in the output + buffer. +*/ +int compress (dest, destLen, source, sourceLen) + Byte *dest; + uLong *destLen; + Byte *source; + uLong sourceLen; +{ + z_stream stream; + int err; + + stream.next_in = source; + stream.avail_in = (uInt)sourceLen; + /* Check for source > 64K on 16-bit machine: */ + if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; + + stream.next_out = dest; + stream.avail_out = (uInt)*destLen; + if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; + + stream.zalloc = (alloc_func)0; + stream.zfree = (free_func)0; + + err = deflateInit(&stream, Z_DEFAULT_COMPRESSION); + if (err != Z_OK) return err; + + err = deflate(&stream, Z_FINISH); + if (err != Z_OK) { + deflateEnd(&stream); + return err; + } + *destLen = stream.total_out; + + err = deflateEnd(&stream); + return err; +} diff --git a/crc32.c b/crc32.c new file mode 100644 index 00000000..e8d385fc --- /dev/null +++ b/crc32.c @@ -0,0 +1,103 @@ +/* crc32.c -- compute the CRC-32 of a data stream + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: crc32.c,v 1.4 1995/04/14 14:55:12 jloup Exp $ */ + +#include "zlib.h" + +extern uLong crc_table[]; /* crc table, defined below */ + +/* ========================================================================= */ +uLong crc32(crc, buf, len) + uLong crc; + Byte *buf; + uInt len; +{ + if (buf == Z_NULL) return 0L; + crc = crc ^ 0xffffffffL; + if (len) do { + crc = crc_table[((int)crc ^ (*buf++)) & 0xff] ^ (crc >> 8); + } while (--len); + return crc ^ 0xffffffffL; +} + +/* ========================================================================= + * Make the crc table. This function is needed only if you want to compute + * the table dynamically. + */ +#ifdef DYNAMIC_CRC_TABLE + +void make_crc_table() +{ + uLong c; + int n, k; + + for (n = 0; n < 256; n++) + { + c = (uLong)n; + for (k = 0; k < 8; k++) + c = c & 1 ? 0xedb88320L ^ (c >> 1) : c >> 1; + crc_table[n] = c; + } +} +#endif + +/* ======================================================================== + * Table of CRC-32's of all single-byte values (made by make_crc_table) + */ +uLong crc_table[] = { + 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, + 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, + 0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, + 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, + 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, + 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, + 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, + 0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, + 0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, + 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL, + 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L, + 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, + 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, + 0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, + 0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, + 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L, + 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL, + 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, + 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, + 0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, + 0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, + 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L, + 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L, + 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, + 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, + 0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, + 0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L, + 0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L, + 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L, + 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, + 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, + 0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, + 0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, + 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL, + 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL, + 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, + 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, + 0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, + 0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, + 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L, + 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL, + 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, + 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, + 0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, + 0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, + 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L, + 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L, + 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, + 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, + 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, + 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, + 0x2d02ef8dL +}; diff --git a/deflate.c b/deflate.c new file mode 100644 index 00000000..2409f07b --- /dev/null +++ b/deflate.c @@ -0,0 +1,932 @@ +/* deflate.c -- compress data using the deflation algorithm + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* + * ALGORITHM + * + * The "deflation" process depends on being able to identify portions + * of the input text which are identical to earlier input (within a + * sliding window trailing behind the input currently being processed). + * + * The most straightforward technique turns out to be the fastest for + * most input files: try all possible matches and select the longest. + * The key feature of this algorithm is that insertions into the string + * dictionary are very simple and thus fast, and deletions are avoided + * completely. Insertions are performed at each input character, whereas + * string matches are performed only when the previous match ends. So it + * is preferable to spend more time in matches to allow very fast string + * insertions and avoid deletions. The matching algorithm for small + * strings is inspired from that of Rabin & Karp. A brute force approach + * is used to find longer strings when a small match has been found. + * A similar algorithm is used in comic (by Jan-Mark Wams) and freeze + * (by Leonid Broukhis). + * A previous version of this file used a more sophisticated algorithm + * (by Fiala and Greene) which is guaranteed to run in linear amortized + * time, but has a larger average cost, uses more memory and is patented. + * However the F&G algorithm may be faster for some highly redundant + * files if the parameter max_chain_length (described below) is too large. + * + * ACKNOWLEDGEMENTS + * + * The idea of lazy evaluation of matches is due to Jan-Mark Wams, and + * I found it in 'freeze' written by Leonid Broukhis. + * Thanks to many people for bug reports and testing. + * + * REFERENCES + * + * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". + * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc + * + * A description of the Rabin and Karp algorithm is given in the book + * "Algorithms" by R. Sedgewick, Addison-Wesley, p252. + * + * Fiala,E.R., and Greene,D.H. + * Data Compression with Finite Windows, Comm.ACM, 32,4 (1989) 490-595 + * + */ + +/* $Id: deflate.c,v 1.3 1995/04/10 16:03:45 jloup Exp $ */ + +#include "deflate.h" + +char copyright[] = " deflate Copyright 1995 Jean-loup Gailly "; +/* + If you use the zlib library in a product, an acknowledgment is welcome + in the documentation of your product. If for some reason you cannot + include such an acknowledgment, I would appreciate that you keep this + copyright string in the executable of your product. + */ + +#define NIL 0 +/* Tail of hash chains */ + +#ifndef TOO_FAR +# define TOO_FAR 4096 +#endif +/* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ + +#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) +/* Minimum amount of lookahead, except at the end of the input file. + * See deflate.c for comments about the MIN_MATCH+1. + */ + +/* Values for max_lazy_match, good_match and max_chain_length, depending on + * the desired pack level (0..9). The values given below have been tuned to + * exclude worst case performance for pathological files. Better values may be + * found for specific files. + */ + +typedef struct config_s { + ush good_length; /* reduce lazy search above this match length */ + ush max_lazy; /* do not perform lazy search above this match length */ + ush nice_length; /* quit search above this match length */ + ush max_chain; +} config; + +local config configuration_table[10] = { +/* good lazy nice chain */ +/* 0 */ {0, 0, 0, 0}, /* store only */ +/* 1 */ {4, 4, 8, 4}, /* maximum speed, no lazy matches */ +/* 2 */ {4, 5, 16, 8}, +/* 3 */ {4, 6, 32, 32}, + +/* 4 */ {4, 4, 16, 16}, /* lazy matches */ +/* 5 */ {8, 16, 32, 32}, +/* 6 */ {8, 16, 128, 128}, +/* 7 */ {8, 32, 128, 256}, +/* 8 */ {32, 128, 258, 1024}, +/* 9 */ {32, 258, 258, 4096}}; /* maximum compression */ + +/* Note: the deflate() code requires max_lazy >= MIN_MATCH and max_chain >= 4 + * For deflate_fast() (levels <= 3) good is ignored and lazy has a different + * meaning. + */ + +#define EQUAL 0 +/* result of memcmp for equal strings */ + +struct static_tree_desc_s {int dummy;}; /* for buggy compilers */ + +/* =========================================================================== + * Prototypes for local functions. + */ + +local void fill_window __P((deflate_state *s)); +local int deflate_fast __P((deflate_state *s, int flush)); +local int deflate_slow __P((deflate_state *s, int flush)); +local void lm_init __P((deflate_state *s)); + +local int longest_match __P((deflate_state *s, IPos cur_match)); +#ifdef ASMV + void match_init __P((void)); /* asm code initialization */ +#endif + +#ifdef DEBUG +local void check_match __P((deflate_state *s, IPos start, IPos match, + int length)); +#endif + + +/* =========================================================================== + * Update a hash value with the given input byte + * IN assertion: all calls to to UPDATE_HASH are made with consecutive + * input characters, so that a running hash key can be computed from the + * previous key instead of complete recalculation each time. + */ +#define UPDATE_HASH(s,h,c) (h = (((h)<hash_shift) ^ (c)) & s->hash_mask) + +/* =========================================================================== + * Insert string str in the dictionary and set match_head to the previous head + * of the hash chain (the most recent string with same hash key). Return + * the previous length of the hash chain. + * IN assertion: all calls to to INSERT_STRING are made with consecutive + * input characters and the first MIN_MATCH bytes of str are valid + * (except for the last MIN_MATCH-1 bytes of the input file). + */ +#define INSERT_STRING(s, str, match_head) \ + (UPDATE_HASH(s, s->ins_h, s->window[(str) + MIN_MATCH-1]), \ + s->prev[(str) & s->w_mask] = match_head = s->head[s->ins_h], \ + s->head[s->ins_h] = (str)) + +/* ========================================================================= */ +int deflateInit (strm, level) + z_stream *strm; + int level; +{ + return deflateInit2 (strm, level, DEFLATED, WBITS, MEM_LEVEL, 0); + /* To do: ignore strm->next_in if we use it as window */ +} + +/* ========================================================================= */ +int deflateInit2 (strm, level, method, windowBits, memLevel, strategy) + z_stream *strm; + int level; + int method; + int windowBits; + int memLevel; + int strategy; +{ + deflate_state *s; + int noheader = 0; + + if (strm == Z_NULL) return Z_STREAM_ERROR; + + strm->msg = Z_NULL; + if (strm->zalloc == Z_NULL) strm->zalloc = zcalloc; + if (strm->zfree == Z_NULL) strm->zfree = zcfree; + + if (level == Z_DEFAULT_COMPRESSION) level = 6; + + if (windowBits < 0) { /* undocumented feature: suppress zlib header */ + noheader = 1; + windowBits = -windowBits; + } + if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method != DEFLATED || + windowBits < 8 || windowBits > 15 || level < 1 || level > 9) { + return Z_STREAM_ERROR; + } + s = (deflate_state *) ZALLOC(strm, 1, sizeof(deflate_state)); + if (s == Z_NULL) return Z_MEM_ERROR; + strm->state = (struct internal_state *)s; + s->strm = strm; + + s->noheader = noheader; + s->w_bits = windowBits; + s->w_size = 1 << s->w_bits; + + s->hash_bits = memLevel + 7; + s->hash_size = 1 << s->hash_bits; + s->hash_shift = ((s->hash_bits+MIN_MATCH-1)/MIN_MATCH); + + s->window = (Byte*) ZALLOC(strm, s->w_size, 2*sizeof(Byte)); + s->prev = (Pos*) ZALLOC(strm, s->w_size, sizeof(Pos)); + s->head = (Pos*) ZALLOC(strm, s->hash_size, sizeof(Pos)); + + s->lit_bufsize = 1 << (memLevel + 6); /* 16K elements by default */ + + s->pending_buf = (uch*) ZALLOC(strm, s->lit_bufsize, 2*sizeof(ush)); + + if (s->window == Z_NULL || s->prev == Z_NULL || s->head == Z_NULL || + s->pending_buf == Z_NULL) { + strm->msg = z_errmsg[1-Z_MEM_ERROR]; + deflateEnd (strm); + return Z_MEM_ERROR; + } + s->d_buf = (ush*) &(s->pending_buf[s->lit_bufsize]); + s->l_buf = (uch*) &(s->pending_buf[3*s->lit_bufsize]); + /* We overlay pending_buf and d_buf+l_buf. This works since the average + * output size for (length,distance) codes is <= 32 bits (worst case + * is 15+15+13=33). + */ + + s->level = level; + s->strategy = strategy; + s->method = method; + + return deflateReset(strm); +} + +/* ========================================================================= */ +int deflateReset (strm) + z_stream *strm; +{ + deflate_state *s; + + if (strm == Z_NULL || strm->state == Z_NULL || + strm->zalloc == Z_NULL || strm->zfree == Z_NULL) return Z_STREAM_ERROR; + + strm->total_in = strm->total_out = 0; + strm->msg = Z_NULL; /* use zfree if we ever allocate msg dynamically */ + strm->data_type = Z_UNKNOWN; + + s = (deflate_state *)strm->state; + s->pending = 0; + s->pending_out = s->pending_buf; + + s->status = s->noheader ? BUSY_STATE : INIT_STATE; + s->adler = 1; + + ct_init(s); + lm_init(s); + + return Z_OK; +} + +/* ========================================================================= + * Put a short the pending_out buffer. The 16-bit value is put in MSB order. + * IN assertion: the stream state is correct and there is enough room in + * the pending_out buffer. + */ +local void putShortMSB (s, b) + deflate_state *s; + uInt b; +{ + put_byte(s, b >> 8); + put_byte(s, b & 0xff); +} + +/* ========================================================================= + * Flush as much pending output as possible. + */ +local void flush_pending(strm) + z_stream *strm; +{ + unsigned len = strm->state->pending; + + if (len > strm->avail_out) len = strm->avail_out; + if (len == 0) return; + + zmemcpy(strm->next_out, strm->state->pending_out, len); + strm->next_out += len; + strm->state->pending_out += len; + strm->total_out += len; + strm->avail_out -= len; + strm->state->pending -= len; + if (strm->state->pending == 0) { + strm->state->pending_out = strm->state->pending_buf; + } +} + +/* ========================================================================= */ +int deflate (strm, flush) + z_stream *strm; + int flush; +{ + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; + + if (strm->next_out == Z_NULL || strm->next_in == Z_NULL) { + ERR_RETURN(strm, Z_STREAM_ERROR); + } + if (strm->avail_out == 0) ERR_RETURN(strm, Z_BUF_ERROR); + + strm->state->strm = strm; /* just in case */ + + /* Write the zlib header */ + if (strm->state->status == INIT_STATE) { + + uInt header = (DEFLATED + ((strm->state->w_bits-8)<<4)) << 8; + uInt level_flags = (strm->state->level-1) >> 1; + + if (level_flags > 3) level_flags = 3; + header |= (level_flags << 6); + header += 31 - (header % 31); + + strm->state->status = BUSY_STATE; + putShortMSB(strm->state, header); + } + + /* Flush as much pending output as possible */ + if (strm->state->pending != 0) { + flush_pending(strm); + if (strm->avail_out == 0) return Z_OK; + } + + /* User must not provide more input after the first FINISH: */ + if (strm->state->status == FINISH_STATE && strm->avail_in != 0) { + ERR_RETURN(strm, Z_BUF_ERROR); + } + + /* Start a new block or continue the current one. + */ + if (strm->avail_in != 0 || + (flush == Z_FINISH && strm->state->status != FINISH_STATE)) { + + if (flush == Z_FINISH) { + strm->state->status = FINISH_STATE; + } + if (strm->state->level <= 3) { + if (deflate_fast(strm->state, flush)) return Z_OK; + } else { + if (deflate_slow(strm->state, flush)) return Z_OK; + } + } + Assert(strm->avail_out > 0, "bug2"); + + if (flush != Z_FINISH || strm->state->noheader) return Z_OK; + + /* Write the zlib trailer (adler32) */ + putShortMSB(strm->state, strm->state->adler >> 16); + putShortMSB(strm->state, strm->state->adler & 0xffff); + flush_pending(strm); + /* If avail_out is zero, the application will call deflate again + * to flush the rest. + */ + strm->state->noheader = 1; /* write the trailer only once! */ + return Z_OK; +} + +/* ========================================================================= */ +int deflateEnd (strm) + z_stream *strm; +{ + if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR; + + TRY_FREE(strm, strm->state->window); + TRY_FREE(strm, strm->state->prev); + TRY_FREE(strm, strm->state->head); + TRY_FREE(strm, strm->state->pending_buf); + + ZFREE(strm, strm->state); + strm->state = Z_NULL; + + return Z_OK; +} + +/* ========================================================================= */ +int deflateCopy (dest, source) + z_stream *dest; + z_stream *source; +{ + if (source == Z_NULL || dest == Z_NULL || source->state == Z_NULL) { + return Z_STREAM_ERROR; + } + *dest = *source; + return Z_STREAM_ERROR; /* to be implemented */ +#if 0 + dest->state = (struct internal_state *) + (*dest->zalloc)(1, sizeof(deflate_state)); + if (dest->state == Z_NULL) return Z_MEM_ERROR; + + *(dest->state) = *(source->state); + return Z_OK; +#endif +} + +/* =========================================================================== + * Read a new buffer from the current input stream, update the adler32 + * and total number of bytes read. + */ +local int read_buf(strm, buf, size) + z_stream *strm; + char *buf; + unsigned size; +{ + unsigned len = strm->avail_in; + + if (len > size) len = size; + if (len == 0) return 0; + + strm->avail_in -= len; + + if (!strm->state->noheader) { + strm->state->adler = adler32(strm->state->adler, strm->next_in, len); + } + zmemcpy(buf, strm->next_in, len); + strm->next_in += len; + strm->total_in += len; + + return (int)len; +} + +/* =========================================================================== + * Initialize the "longest match" routines for a new zlib stream + */ +local void lm_init (s) + deflate_state *s; +{ + register unsigned j; + + s->window_size = (ulg)2L*s->w_size; + + + /* Initialize the hash table (avoiding 64K overflow for 16 bit systems). + * prev[] will be initialized on the fly. + */ + s->head[s->hash_size-1] = NIL; + zmemzero((char*)s->head, (unsigned)(s->hash_size-1)*sizeof(*s->head)); + + /* Set the default configuration parameters: + */ + s->max_lazy_match = configuration_table[s->level].max_lazy; + s->good_match = configuration_table[s->level].good_length; + s->nice_match = configuration_table[s->level].nice_length; + s->max_chain_length = configuration_table[s->level].max_chain; + + s->strstart = 0; + s->block_start = 0L; + s->lookahead = 0; + s->match_length = MIN_MATCH-1; + s->match_available = 0; +#ifdef ASMV + match_init(); /* initialize the asm code */ +#endif + + s->ins_h = 0; + for (j=0; jins_h, s->window[j]); + /* If lookahead < MIN_MATCH, ins_h is garbage, but this is + * not important since only literal bytes will be emitted. + */ +} + +/* =========================================================================== + * Set match_start to the longest match starting at the given string and + * return its length. Matches shorter or equal to prev_length are discarded, + * in which case the result is equal to prev_length and match_start is + * garbage. + * IN assertions: cur_match is the head of the hash chain for the current + * string (strstart) and its distance is <= MAX_DIST, and prev_length >= 1 + */ +#ifndef ASMV +/* For 80x86 and 680x0, an optimized version will be provided in match.asm or + * match.S. The code will be functionally equivalent. + */ +local int longest_match(s, cur_match) + deflate_state *s; + IPos cur_match; /* current match */ +{ + unsigned chain_length = s->max_chain_length;/* max hash chain length */ + register Byte *scan = s->window + s->strstart; /* current string */ + register Byte *match; /* matched string */ + register int len; /* length of current match */ + int best_len = s->prev_length; /* best match length so far */ + IPos limit = s->strstart > (IPos)MAX_DIST(s) ? + s->strstart - (IPos)MAX_DIST(s) : NIL; + /* Stop when cur_match becomes <= limit. To simplify the code, + * we prevent matches with the string of window index 0. + */ + +#ifdef UNALIGNED_OK + /* Compare two bytes at a time. Note: this is not always beneficial. + * Try with and without -DUNALIGNED_OK to check. + */ + register Byte *strend = s->window + s->strstart + MAX_MATCH - 1; + register ush scan_start = *(ush*)scan; + register ush scan_end = *(ush*)(scan+best_len-1); +#else + register Byte *strend = s->window + s->strstart + MAX_MATCH; + register Byte scan_end1 = scan[best_len-1]; + register Byte scan_end = scan[best_len]; +#endif + + /* The code is optimized for HASH_BITS >= 8 and MAX_MATCH-2 multiple of 16. + * It is easy to get rid of this optimization if necessary. + */ + Assert(s->hash_bits >= 8 && MAX_MATCH == 258, "Code too clever"); + + /* Do not waste too much time if we already have a good match: */ + if (s->prev_length >= s->good_match) { + chain_length >>= 2; + } + Assert(s->strstart <= s->window_size-MIN_LOOKAHEAD, "need lookahead"); + + do { + Assert(cur_match < s->strstart, "no future"); + match = s->window + cur_match; + + /* Skip to next match if the match length cannot increase + * or if the match length is less than 2: + */ +#if (defined(UNALIGNED_OK) && MAX_MATCH == 258) + /* This code assumes sizeof(unsigned short) == 2. Do not use + * UNALIGNED_OK if your compiler uses a different size. + */ + if (*(ush*)(match+best_len-1) != scan_end || + *(ush*)match != scan_start) continue; + + /* It is not necessary to compare scan[2] and match[2] since they are + * always equal when the other bytes match, given that the hash keys + * are equal and that HASH_BITS >= 8. Compare 2 bytes at a time at + * strstart+3, +5, ... up to strstart+257. We check for insufficient + * lookahead only every 4th comparison; the 128th check will be made + * at strstart+257. If MAX_MATCH-2 is not a multiple of 8, it is + * necessary to put more guard bytes at the end of the window, or + * to check more often for insufficient lookahead. + */ + scan++, match++; + do { + } while (*(ush*)(scan+=2) == *(ush*)(match+=2) && + *(ush*)(scan+=2) == *(ush*)(match+=2) && + *(ush*)(scan+=2) == *(ush*)(match+=2) && + *(ush*)(scan+=2) == *(ush*)(match+=2) && + scan < strend); + /* The funny "do {}" generates better code on most compilers */ + + /* Here, scan <= window+strstart+257 */ + Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); + if (*scan == *match) scan++; + + len = (MAX_MATCH - 1) - (int)(strend-scan); + scan = strend - (MAX_MATCH-1); + +#else /* UNALIGNED_OK */ + + if (match[best_len] != scan_end || + match[best_len-1] != scan_end1 || + *match != *scan || + *++match != scan[1]) continue; + + /* The check at best_len-1 can be removed because it will be made + * again later. (This heuristic is not always a win.) + * It is not necessary to compare scan[2] and match[2] since they + * are always equal when the other bytes match, given that + * the hash keys are equal and that HASH_BITS >= 8. + */ + scan += 2, match++; + + /* We check for insufficient lookahead only every 8th comparison; + * the 256th check will be made at strstart+258. + */ + do { + } while (*++scan == *++match && *++scan == *++match && + *++scan == *++match && *++scan == *++match && + *++scan == *++match && *++scan == *++match && + *++scan == *++match && *++scan == *++match && + scan < strend); + + Assert(scan <= s->window+(unsigned)(s->window_size-1), "wild scan"); + + len = MAX_MATCH - (int)(strend - scan); + scan = strend - MAX_MATCH; + +#endif /* UNALIGNED_OK */ + + if (len > best_len) { + s->match_start = cur_match; + best_len = len; + if (len >= s->nice_match) break; +#ifdef UNALIGNED_OK + scan_end = *(ush*)(scan+best_len-1); +#else + scan_end1 = scan[best_len-1]; + scan_end = scan[best_len]; +#endif + } + } while ((cur_match = s->prev[cur_match & s->w_mask]) > limit + && --chain_length != 0); + + return best_len; +} +#endif /* ASMV */ + +#ifdef DEBUG +/* =========================================================================== + * Check that the match at match_start is indeed a match. + */ +local void check_match(s, start, match, length) + deflate_state *s; + IPos start, match; + int length; +{ + /* check that the match is indeed a match */ + if (memcmp((char*)s->window + match, + (char*)s->window + start, length) != EQUAL) { + fprintf(stderr, + " start %d, match %d, length %d\n", + start, match, length); + z_error("invalid match"); + } + if (verbose > 1) { + fprintf(stderr,"\\[%d,%d]", start-match, length); + do { putc(s->window[start++], stderr); } while (--length != 0); + } +} +#else +# define check_match(s, start, match, length) +#endif + +/* =========================================================================== + * Fill the window when the lookahead becomes insufficient. + * Updates strstart and lookahead. + * + * IN assertion: lookahead < MIN_LOOKAHEAD + * OUT assertions: strstart <= window_size-MIN_LOOKAHEAD + * At least one byte has been read, or avail_in == 0; reads are + * performed for at least two bytes (required for the zip translate_eol + * option -- not supported here). + */ +local void fill_window(s) + deflate_state *s; +{ + register unsigned n, m; + unsigned more; /* Amount of free space at the end of the window. */ + + do { + more = (unsigned)(s->window_size -(ulg)s->lookahead -(ulg)s->strstart); + + /* Deal with !@#$% 64K limit: */ + if (more == 0 && s->strstart == 0 && s->lookahead == 0) { + more = s->w_size; + } else if (more == (unsigned)(-1)) { + /* Very unlikely, but possible on 16 bit machine if strstart == 0 + * and lookahead == 1 (input done one byte at time) + */ + more--; + + /* If the window is almost full and there is insufficient lookahead, + * move the upper half to the lower one to make room in the upper half. + */ + } else if (s->strstart >= s->w_size+MAX_DIST(s)) { + + /* By the IN assertion, the window is not empty so we can't confuse + * more == 0 with more == 64K on a 16 bit machine. + */ + memcpy((char*)s->window, (char*)s->window+s->w_size, + (unsigned)s->w_size); + s->match_start -= s->w_size; + s->strstart -= s->w_size; /* we now have strstart >= MAX_DIST */ + + s->block_start -= (long) s->w_size; + + for (n = 0; n < s->hash_size; n++) { + m = s->head[n]; + s->head[n] = (Pos)(m >= s->w_size ? m-s->w_size : NIL); + } + for (n = 0; n < s->w_size; n++) { + m = s->prev[n]; + s->prev[n] = (Pos)(m >= s->w_size ? m-s->w_size : NIL); + /* If n is not on any hash chain, prev[n] is garbage but + * its value will never be used. + */ + } + more += s->w_size; + } + if (s->strm->avail_in == 0) return; + + /* If there was no sliding: + * strstart <= WSIZE+MAX_DIST-1 && lookahead <= MIN_LOOKAHEAD - 1 && + * more == window_size - lookahead - strstart + * => more >= window_size - (MIN_LOOKAHEAD-1 + WSIZE + MAX_DIST-1) + * => more >= window_size - 2*WSIZE + 2 + * In the BIG_MEM or MMAP case (not yet supported), + * window_size == input_size + MIN_LOOKAHEAD && + * strstart + s->lookahead <= input_size => more >= MIN_LOOKAHEAD. + * Otherwise, window_size == 2*WSIZE so more >= 2. + * If there was sliding, more >= WSIZE. So in all cases, more >= 2. + */ + Assert(more >= 2, "more < 2"); + + n = read_buf(s->strm, (char*)s->window + s->strstart + s->lookahead, + more); + s->lookahead += n; + + } while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0); +} + +/* =========================================================================== + * Flush the current block, with given end-of-file flag. + * IN assertion: strstart is set to the end of the current match. + */ +#define FLUSH_BLOCK_ONLY(s, eof) { \ + ct_flush_block(s, (s->block_start >= 0L ? \ + (char*)&s->window[(unsigned)s->block_start] : \ + (char*)Z_NULL), (long)s->strstart - s->block_start, (eof)); \ + s->block_start = s->strstart; \ + flush_pending(s->strm); \ +} + +/* Same but force premature exit if necessary. */ +#define FLUSH_BLOCK(s, eof) { \ + FLUSH_BLOCK_ONLY(s, eof); \ + if (s->strm->avail_out == 0) return 1; \ +} + +/* =========================================================================== + * Compress as much as possible from the input stream, return true if + * processing was terminated prematurely (no more input or output space). + * This function does not perform lazy evaluationof matches and inserts + * new strings in the dictionary only for unmatched strings or for short + * matches. It is used only for the fast compression options. + */ +local int deflate_fast(s, flush) + deflate_state *s; + int flush; +{ + IPos hash_head; /* head of the hash chain */ + int bflush; /* set if current block must be flushed */ + + s->prev_length = MIN_MATCH-1; + + for (;;) { + /* Make sure that we always have enough lookahead, except + * at the end of the input file. We need MAX_MATCH bytes + * for the next match, plus MIN_MATCH bytes to insert the + * string following the next match. + */ + if (s->lookahead < MIN_LOOKAHEAD) { + fill_window(s); + if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; + + if (s->lookahead == 0) break; /* flush the current block */ + } + + /* Insert the string window[strstart .. strstart+2] in the + * dictionary, and set hash_head to the head of the hash chain: + */ + INSERT_STRING(s, s->strstart, hash_head); + + /* Find the longest match, discarding those <= prev_length. + * At this point we have always match_length < MIN_MATCH + */ + if (hash_head != NIL && s->strstart - hash_head <= MAX_DIST(s)) { + /* To simplify the code, we prevent matches with the string + * of window index 0 (in particular we have to avoid a match + * of the string with itself at the start of the input file). + */ + if (s->strategy != Z_HUFFMAN_ONLY) { + s->match_length = longest_match (s, hash_head); + } + /* longest_match() sets match_start */ + + if (s->match_length > s->lookahead) s->match_length = s->lookahead; + } + if (s->match_length >= MIN_MATCH) { + check_match(s, s->strstart, s->match_start, s->match_length); + + bflush = ct_tally(s, s->strstart - s->match_start, + s->match_length - MIN_MATCH); + + s->lookahead -= s->match_length; + + /* Insert new strings in the hash table only if the match length + * is not too large. This saves time but degrades compression. + */ + if (s->match_length <= s->max_insert_length) { + s->match_length--; /* string at strstart already in hash table */ + do { + s->strstart++; + INSERT_STRING(s, s->strstart, hash_head); + /* strstart never exceeds WSIZE-MAX_MATCH, so there are + * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH + * these bytes are garbage, but it does not matter since + * the next lookahead bytes will be emitted as literals. + */ + } while (--s->match_length != 0); + s->strstart++; + } else { + s->strstart += s->match_length; + s->match_length = 0; + s->ins_h = s->window[s->strstart]; + UPDATE_HASH(s, s->ins_h, s->window[s->strstart+1]); +#if MIN_MATCH != 3 + Call UPDATE_HASH() MIN_MATCH-3 more times +#endif + } + } else { + /* No match, output a literal byte */ + Tracevv((stderr,"%c", s->window[s->strstart])); + bflush = ct_tally (s, 0, s->window[s->strstart]); + s->lookahead--; + s->strstart++; + } + if (bflush) FLUSH_BLOCK(s, 0); + } + FLUSH_BLOCK(s, flush == Z_FINISH); + return 0; /* normal exit */ +} + +/* =========================================================================== + * Same as above, but achieves better compression. We use a lazy + * evaluation for matches: a match is finally adopted only if there is + * no better match at the next window position. + */ +local int deflate_slow(s, flush) + deflate_state *s; + int flush; +{ + IPos hash_head; /* head of hash chain */ + int bflush; /* set if current block must be flushed */ + + /* Process the input block. */ + for (;;) { + /* Make sure that we always have enough lookahead, except + * at the end of the input file. We need MAX_MATCH bytes + * for the next match, plus MIN_MATCH bytes to insert the + * string following the next match. + */ + if (s->lookahead < MIN_LOOKAHEAD) { + fill_window(s); + if (s->lookahead < MIN_LOOKAHEAD && flush == Z_NO_FLUSH) return 1; + + if (s->lookahead == 0) break; /* flush the current block */ + } + + /* Insert the string window[strstart .. strstart+2] in the + * dictionary, and set hash_head to the head of the hash chain: + */ + INSERT_STRING(s, s->strstart, hash_head); + + /* Find the longest match, discarding those <= prev_length. + */ + s->prev_length = s->match_length, s->prev_match = s->match_start; + s->match_length = MIN_MATCH-1; + + if (hash_head != NIL && s->prev_length < s->max_lazy_match && + s->strstart - hash_head <= MAX_DIST(s)) { + /* To simplify the code, we prevent matches with the string + * of window index 0 (in particular we have to avoid a match + * of the string with itself at the start of the input file). + */ + if (s->strategy != Z_HUFFMAN_ONLY) { + s->match_length = longest_match (s, hash_head); + } + /* longest_match() sets match_start */ + if (s->match_length > s->lookahead) s->match_length = s->lookahead; + + if (s->match_length <= 5 && (s->strategy == Z_FILTERED || + (s->match_length == MIN_MATCH && + s->strstart - s->match_start > TOO_FAR))) { + + /* If prev_match is also MIN_MATCH, match_start is garbage + * but we will ignore the current match anyway. + */ + s->match_length = MIN_MATCH-1; + } + } + /* If there was a match at the previous step and the current + * match is not better, output the previous match: + */ + if (s->prev_length >= MIN_MATCH && s->match_length <= s->prev_length) { + + check_match(s, s->strstart-1, s->prev_match, s->prev_length); + + bflush = ct_tally(s, s->strstart -1 - s->prev_match, + s->prev_length - MIN_MATCH); + + /* Insert in hash table all strings up to the end of the match. + * strstart-1 and strstart are already inserted. + */ + s->lookahead -= s->prev_length-1; + s->prev_length -= 2; + do { + s->strstart++; + INSERT_STRING(s, s->strstart, hash_head); + /* strstart never exceeds WSIZE-MAX_MATCH, so there are + * always MIN_MATCH bytes ahead. If lookahead < MIN_MATCH + * these bytes are garbage, but it does not matter since the + * next lookahead bytes will always be emitted as literals. + */ + } while (--s->prev_length != 0); + s->match_available = 0; + s->match_length = MIN_MATCH-1; + s->strstart++; + + if (bflush) FLUSH_BLOCK(s, 0); + + } else if (s->match_available) { + /* If there was no match at the previous position, output a + * single literal. If there was a match but the current match + * is longer, truncate the previous match to a single literal. + */ + Tracevv((stderr,"%c", s->window[s->strstart-1])); + if (ct_tally (s, 0, s->window[s->strstart-1])) { + FLUSH_BLOCK_ONLY(s, 0); + } + s->strstart++; + s->lookahead--; + if (s->strm->avail_out == 0) return 1; + } else { + /* There is no previous match to compare with, wait for + * the next step to decide. + */ + s->match_available = 1; + s->strstart++; + s->lookahead--; + } + } + if (s->match_available) ct_tally (s, 0, s->window[s->strstart-1]); + + FLUSH_BLOCK(s, flush == Z_FINISH); + return 0; +} diff --git a/deflate.h b/deflate.h new file mode 100644 index 00000000..740c25a4 --- /dev/null +++ b/deflate.h @@ -0,0 +1,270 @@ +/* deflate.h -- internal compression state + * Copyright (C) 1995 Jean-loup Gailly + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +/* $Id: deflate.h,v 1.3 1995/04/14 12:39:45 jloup Exp $ */ + +#include "zutil.h" + +/* =========================================================================== + * Internal compression state. + */ + +/* Data type */ +#define BINARY 0 +#define ASCII 1 +#define UNKNOWN 2 + +#define LENGTH_CODES 29 +/* number of length codes, not counting the special END_BLOCK code */ + +#define LITERALS 256 +/* number of literal bytes 0..255 */ + +#define L_CODES (LITERALS+1+LENGTH_CODES) +/* number of Literal or Length codes, including the END_BLOCK code */ + +#define D_CODES 30 +/* number of distance codes */ + +#define BL_CODES 19 +/* number of codes used to transfer the bit lengths */ + +#define HEAP_SIZE (2*L_CODES+1) +/* maximum heap size */ + +#define MAX_BITS 15 +/* All codes must not exceed MAX_BITS bits */ + +#define INIT_STATE 42 +#define BUSY_STATE 113 +#define FINISH_STATE 666 +/* Stream status */ + + +/* Data structure describing a single value and its code string. */ +typedef struct ct_data_s { + union { + ush freq; /* frequency count */ + ush code; /* bit string */ + } fc; + union { + ush dad; /* father node in Huffman tree */ + ush len; /* length of bit string */ + } dl; +} ct_data; + +#define Freq fc.freq +#define Code fc.code +#define Dad dl.dad +#define Len dl.len + +typedef struct static_tree_desc_s static_tree_desc; + +typedef struct tree_desc_s { + ct_data *dyn_tree; /* the dynamic tree */ + int max_code; /* largest code with non zero frequency */ + static_tree_desc *stat_desc; /* the corresponding static tree */ +} tree_desc; + +typedef ush Pos; +typedef unsigned IPos; +/* A Pos is an index in the character window. We use short instead of int to + * save space in the various tables. IPos is used only for parameter passing. + */ + +typedef struct internal_state { + z_stream *strm; /* pointer back to this zlib stream */ + int status; /* as the name implies */ + Byte *pending_buf; /* output still pending */ + Byte *pending_out; /* next pending byte to output to the stream */ + int pending; /* nb of bytes in the pending buffer */ + uLong adler; /* adler32 of uncompressed data */ + int noheader; /* suppress zlib header and adler32 */ + Byte data_type; /* UNKNOWN, BINARY or ASCII */ + Byte method; /* STORED (for zip only) or DEFLATED */ + + /* used by deflate.c: */ + + uInt w_size; /* LZ77 window size (32K by default) */ + uInt w_bits; /* log2(w_size) (8..16) */ + uInt w_mask; /* w_size - 1 */ + + Byte *window; + /* Sliding window. Input bytes are read into the second half of the window, + * and move to the first half later to keep a dictionary of at least wSize + * bytes. With this organization, matches are limited to a distance of + * wSize-MAX_MATCH bytes, but this ensures that IO is always + * performed with a length multiple of the block size. Also, it limits + * the window size to 64K, which is quite useful on MSDOS. + * To do: use the user input buffer as sliding window. + */ + + ulg window_size; + /* Actual size of window: 2*wSize, except when the user input buffer + * is directly used as sliding window. + */ + + Pos *prev; + /* Link to older string with same hash index. To limit the size of this + * array to 64K, this link is maintained only for the last 32K strings. + * An index in this array is thus a window index modulo 32K. + */ + + Pos *head; /* Heads of the hash chains or NIL. */ + + uInt ins_h; /* hash index of string to be inserted */ + uInt hash_size; /* number of elements in hash table */ + uInt hash_bits; /* log2(hash_size) */ + uInt hash_mask; /* hash_size-1 */ + + uInt hash_shift; + /* Number of bits by which ins_h must be shifted at each input + * step. It must be such that after MIN_MATCH steps, the oldest + * byte no longer takes part in the hash key, that is: + * hash_shift * MIN_MATCH >= hash_bits + */ + + long block_start; + /* Window position at the beginning of the current output block. Gets + * negative when the window is moved backwards. + */ + + uInt match_length; /* length of best match */ + IPos prev_match; /* previous match */ + int match_available; /* set if previous match exists */ + uInt strstart; /* start of string to insert */ + uInt match_start; /* start of matching string */ + uInt lookahead; /* number of valid bytes ahead in window */ + + uInt prev_length; + /* Length of the best match at previous step. Matches not greater than this + * are discarded. This is used in the lazy match evaluation. + */ + + uInt max_chain_length; + /* To speed up deflation, hash chains are never searched beyond this + * length. A higher limit improves compression ratio but degrades the + * speed. + */ + + uInt max_lazy_match; + /* Attempt to find a better match only when the current match is strictly + * smaller than this value. This mechanism is used only for compression + * levels >= 4. + */ +# define max_insert_length max_lazy_match + /* Insert new strings in the hash table only if the match length is not + * greater than this length. This saves time but degrades compression. + * max_insert_length is used only for compression levels <= 3. + */ + + int level; /* compression level (1..9) */ + int strategy; /* favor or force Huffman coding*/ + + uInt good_match; + /* Use a faster search when the previous match is longer than this */ + + int nice_match; /* Stop searching when current match exceeds this */ + + /* used by trees.c: */ + + ct_data dyn_ltree[HEAP_SIZE]; /* literal and length tree */ + ct_data dyn_dtree[2*D_CODES+1]; /* distance tree */ + ct_data bl_tree[2*BL_CODES+1]; /* Huffman tree for the bit lengths */ + + tree_desc l_desc; /* descriptor for literal tree */ + tree_desc d_desc; /* descriptor for distance tree */ + tree_desc bl_desc; /* descriptor for bit length tree */ + + ush bl_count[MAX_BITS+1]; + /* number of codes at each bit length for an optimal tree */ + + int heap[2*L_CODES+1]; /* heap used to build the Huffman trees */ + int heap_len; /* number of elements in the heap */ + int heap_max; /* element of largest frequency */ + /* The sons of heap[n] are heap[2*n] and heap[2*n+1]. heap[0] is not used. + * The same heap array is used to build all trees. + */ + + uch depth[2*L_CODES+1]; + /* Depth of each subtree used as tie breaker for trees of equal frequency + */ + + uch *l_buf; /* buffer for literals or lengths */ + + uInt lit_bufsize; + /* Size of match buffer for literals/lengths. There are 4 reasons for + * limiting lit_bufsize to 64K: + * - frequencies can be kept in 16 bit counters + * - if compression is not successful for the first block, all input + * data is still in the window so we can still emit a stored block even + * when input comes from standard input. (This can also be done for + * all blocks if lit_bufsize is not greater than 32K.) + * - if compression is not successful for a file smaller than 64K, we can + * even emit a stored file instead of a stored block (saving 5 bytes). + * This is applicable only for zip (not gzip or zlib). + * - creating new Huffman trees less frequently may not provide fast + * adaptation to changes in the input data statistics. (Take for + * example a binary file with poorly compressible code followed by + * a highly compressible string table.) Smaller buffer sizes give + * fast adaptation but have of course the overhead of transmitting + * trees more frequently. + * - I can't count above 4 + */ + + uInt last_lit; /* running index in l_buf */ + + ush *d_buf; + /* Buffer for distances. To simplify the code, d_buf and l_buf have + * the same number of elements. To use different lengths, an extra flag + * array would be necessary. + */ + + ulg opt_len; /* bit length of current block with optimal trees */ + ulg static_len; /* bit length of current block with static trees */ + ulg compressed_len; /* total bit length of compressed file */ + uInt matches; /* number of string matches in current block */ + +#ifdef DEBUG + ulg bits_sent; /* bit length of the compressed data */ +#endif + + ush bi_buf; + /* Output buffer. bits are inserted starting at the bottom (least + * significant bits). + */ + int bi_valid; + /* Number of valid bits in bi_buf. All bits above the last valid bit + * are always zero. + */ + +} deflate_state; + + +/* Output a byte on the stream. + * IN assertion: there is enough room in pending_buf. + */ +#define put_byte(s, c) {s->pending_buf[s->pending++] = (c);} + + +#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1) +/* Minimum amount of lookahead, except at the end of the input file. + * See deflate.c for comments about the MIN_MATCH+1. + */ + +#define MAX_DIST(s) ((s)->w_size-MIN_LOOKAHEAD) +/* In order to simplify the code, particularly on 16 bit machines, match + * distances are limited to MAX_DIST instead of WSIZE. + */ + + /* in trees.c */ +void ct_init __P((deflate_state *s)); +int ct_tally __P((deflate_state *s, int dist, int lc)); +ulg ct_flush_block __P((deflate_state *s, char *buf, ulg stored_len, int eof)); diff --git a/example.c b/example.c new file mode 100644 index 00000000..ea1a9eb9 --- /dev/null +++ b/example.c @@ -0,0 +1,201 @@ +/* example.c -- usage example of the zlib compression library + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: example.c,v 1.4 1995/04/14 13:32:49 jloup Exp $ */ + +#include +#include "zlib.h" + +#define BUFLEN 4096 + +#define local static +/* For MSDOS and other systems with limitation on stack size. For Unix, + #define local + works also. + */ + +#define CHECK_ERR(err, msg) { \ + if (err != Z_OK) { \ + fprintf(stderr, "%s error: %d\n", msg, err); \ + exit(1); \ + } \ +} + +char *hello = "hello world"; + +/* =========================================================================== + * Test compress() and uncompress() + */ +void test_compress() +{ + local Byte compr[BUFLEN]; + uLong comprLen = sizeof(compr); + local Byte uncompr[BUFLEN]; + uLong uncomprLen = sizeof(uncompr); + int err; + uLong len = strlen(hello)+1; + + err = compress(compr, &comprLen, hello, len); + CHECK_ERR(err, "compress"); + + strcpy(uncompr, "garbage"); + + err = uncompress(uncompr, &uncomprLen, compr, comprLen); + CHECK_ERR(err, "uncompress"); + + if (strcmp(uncompr, hello)) { + fprintf(stderr, "bad uncompress\n"); + } else { + printf("uncompress(): %s\n", uncompr); + } +} + +/* =========================================================================== + * Test read/write of .gz files + */ +void test_gzio(out, in) + char *out; /* output file */ + char *in; /* input file */ +{ + local Byte uncompr[BUFLEN]; + uLong uncomprLen = sizeof(uncompr); + int err; + int len = strlen(hello)+1; + gzFile file; + + file = gzopen(out, "wb"); + if (file == NULL) { + fprintf(stderr, "gzopen error\n"); + exit(1); + } + + if (gzwrite(file, hello, len) != len) { + fprintf(stderr, "gzwrite err: %s\n", gzerror(file, &err)); + } + gzclose(file); + + file = gzopen(in, "rb"); + if (file == NULL) { + fprintf(stderr, "gzopen error\n"); + } + strcpy(uncompr, "garbage"); + + uncomprLen = gzread(file, uncompr, uncomprLen); + if (uncomprLen != len) { + fprintf(stderr, "gzread err: %s\n", gzerror(file, &err)); + } + gzclose(file); + + if (strcmp(uncompr, hello)) { + fprintf(stderr, "bad gzread\n"); + } else { + printf("gzread(): %s\n", uncompr); + } +} + +/* =========================================================================== + * Test deflate() with small buffers, return the compressed length. + */ +uLong test_deflate(compr) + Byte compr[]; +{ + z_stream c_stream; /* compression stream */ + int err; + int len = strlen(hello)+1; + + c_stream.zalloc = (alloc_func)0; + c_stream.zfree = (free_func)0; + + err = deflateInit(&c_stream, Z_DEFAULT_COMPRESSION); + CHECK_ERR(err, "deflateInit"); + + c_stream.next_in = (Byte*)hello; + c_stream.next_out = compr; + + while (c_stream.total_in != len) { + c_stream.avail_in = c_stream.avail_out = 1; /* force small buffers */ + err = deflate(&c_stream, Z_NO_FLUSH); + CHECK_ERR(err, "deflate"); + } + /* Finish the stream, still forcing small buffers: */ + do { + c_stream.avail_out = 1; + err = deflate(&c_stream, Z_FINISH); + CHECK_ERR(err, "deflate"); + } while (c_stream.avail_out == 0); + + err = deflateEnd(&c_stream); + CHECK_ERR(err, "deflateEnd"); + + return c_stream.total_out; +} + +/* =========================================================================== + * Test inflate() with small buffers + */ +void test_inflate(compr) + Byte compr[]; +{ + local Byte uncompr[BUFLEN]; + int err; + z_stream d_stream; /* decompression stream */ + + strcpy(uncompr, "garbage"); + + d_stream.zalloc = (alloc_func)0; + d_stream.zfree = (free_func)0; + + err = inflateInit(&d_stream); + CHECK_ERR(err, "inflateInit"); + + d_stream.next_in = compr; + d_stream.next_out = uncompr; + + for (;;) { + d_stream.avail_in = d_stream.avail_out = 1; /* force small buffers */ + err = inflate(&d_stream, Z_NO_FLUSH); + if (err == Z_STREAM_END) break; + CHECK_ERR(err, "inflate"); + } + + err = inflateEnd(&d_stream); + CHECK_ERR(err, "inflateEnd"); + + if (strcmp(uncompr, hello)) { + fprintf(stderr, "bad inflate\n"); + } else { + printf("inflate(): %s\n", uncompr); + } +} + +/* =========================================================================== + * Usage: example [output.gz [input.gz]] + */ + +void main(argc, argv) + int argc; + char *argv[]; +{ + local Byte compr[BUFLEN]; + uLong comprLen; + + if (zlib_version[0] != ZLIB_VERSION[0]) { + fprintf(stderr, "incompatible zlib version\n"); + exit(1); + + } else if (strcmp(zlib_version, ZLIB_VERSION) != 0) { + fprintf(stderr, "warning: different zlib version\n"); + } + test_compress(); + + test_gzio((argc > 1 ? argv[1] : "foo.gz"), + (argc > 2 ? argv[2] : "foo.gz")); + + comprLen = test_deflate(compr); + + test_inflate(compr); + + exit(0); +} diff --git a/gzio.c b/gzio.c new file mode 100644 index 00000000..b488e96a --- /dev/null +++ b/gzio.c @@ -0,0 +1,459 @@ +/* gzio.c -- IO on .gz files + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: gzio.c,v 1.4 1995/04/14 14:50:52 jloup Exp $ */ + +#include + +#include "zutil.h" + +struct internal_state {int dummy;}; /* for buggy compilers */ + +#define Z_BUFSIZE 4096 + +#define ALLOC(size) zcalloc((voidp)0, 1, size) +#define TRYFREE(p) {if (p) zcfree((voidp)0, p);} + +#define GZ_MAGIC_1 0x1f +#define GZ_MAGIC_2 0x8b + +/* gzip flag byte */ +#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */ +#define HEAD_CRC 0x02 /* bit 1 set: header CRC present */ +#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ +#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ +#define COMMENT 0x10 /* bit 4 set: file comment present */ +#define RESERVED 0xE0 /* bits 5..7: reserved */ + +#ifndef SEEK_CUR +# define SEEK_CUR 1 +#endif + +typedef struct gz_stream { + z_stream stream; + int z_err; /* error code for last stream operation */ + int z_eof; /* set if end of input file */ + FILE *file; /* .gz file */ + Byte *inbuf; /* input buffer */ + Byte *outbuf; /* output buffer */ + uLong crc; /* crc32 of uncompressed data */ + char *msg; /* error message */ + char *path; /* path name for debugging only */ + int transparent; /* 1 if input file is not a .gz file */ + char mode; /* 'w' or 'r' */ +} gz_stream; + + +/* =========================================================================== + * Cleanup then free the given gz_stream. Return a zlib error code. + */ +local int destroy (s) + gz_stream *s; +{ + int err = Z_OK; + + if (!s) return Z_STREAM_ERROR; + + TRYFREE(s->inbuf); + TRYFREE(s->outbuf); + TRYFREE(s->path); + TRYFREE(s->msg); + + if (s->stream.state != NULL) { + if (s->mode == 'w') { + err = deflateEnd(&(s->stream)); + } else if (s->mode == 'r') { + err = inflateEnd(&(s->stream)); + } + } + if (s->file != NULL && fclose(s->file)) { + err = Z_ERRNO; + } + zcfree((voidp)0, s); + return s->z_err < 0 ? s->z_err : err; +} + +/* =========================================================================== + Opens a gzip (.gz) file for reading or writing. The mode parameter + is as in fopen ("rb" or "wb"). The file is given either by file descritor + or path name (if fd == -1). + gz_open return NULL if the file could not be opened or if there was + insufficient memory to allocate the (de)compression state; errno + can be checked to distinguish the two cases (if errno is zero, the + zlib error is Z_MEM_ERROR). +*/ +local gzFile gz_open (path, mode, fd) + char *path; + char *mode; + int fd; +{ + int err; + char *p = mode; + gz_stream *s = (gz_stream *)ALLOC(sizeof(gz_stream)); + + if (!s) return Z_NULL; + + s->stream.zalloc = (alloc_func)0; + s->stream.zfree = (free_func)0; + s->stream.next_in = s->inbuf = Z_NULL; + s->stream.next_out = s->outbuf = Z_NULL; + s->stream.avail_in = s->stream.avail_out = 0; + s->file = NULL; + s->z_err = Z_OK; + s->z_eof = 0; + s->crc = crc32(0L, Z_NULL, 0); + s->msg = NULL; + s->transparent = 0; + + s->path = (char*)ALLOC(strlen(path)+1); + if (s->path == NULL) { + return destroy(s), (gzFile)Z_NULL; + } + strcpy(s->path, path); /* do this early for debugging */ + + s->mode = '\0'; + do { + if (*p == 'r') s->mode = 'r'; + if (*p == 'w') s->mode = 'w'; + } while (*p++); + if (s->mode == '\0') return destroy(s), (gzFile)Z_NULL; + + if (s->mode == 'w') { + err = deflateInit2(&(s->stream), Z_DEFAULT_COMPRESSION, + DEFLATED, -WBITS, MEM_LEVEL, 0); + /* windowBits is passed < 0 to suppress zlib header */ + + s->stream.next_out = s->outbuf = ALLOC(Z_BUFSIZE); + + if (err != Z_OK || s->outbuf == Z_NULL) { + return destroy(s), (gzFile)Z_NULL; + } + } else { + err = inflateInit2(&(s->stream), -WBITS); + s->stream.next_in = s->inbuf = ALLOC(Z_BUFSIZE); + + if (err != Z_OK || s->inbuf == Z_NULL) { + return destroy(s), (gzFile)Z_NULL; + } + } + s->stream.avail_out = Z_BUFSIZE; + + errno = 0; + s->file = fd < 0 ? FOPEN(path, mode) : fdopen(fd, mode); + + if (s->file == NULL) { + return destroy(s), (gzFile)Z_NULL; + } + if (s->mode == 'w') { + /* Write a very simple .gz header: + */ + fprintf(s->file, "%c%c%c%c%c%c%c%c%c%c", GZ_MAGIC_1, GZ_MAGIC_2, + DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/, 0 /*xflags*/, OS_CODE); + } else { + /* Check and skip the header: + */ + Byte c1 = 0, c2 = 0; + Byte method = 0; + Byte flags = 0; + Byte xflags = 0; + Byte time[4]; + Byte osCode; + int c; + + s->stream.avail_in = fread(s->inbuf, 1, 2, s->file); + if (s->stream.avail_in != 2 || s->inbuf[0] != GZ_MAGIC_1 + || s->inbuf[1] != GZ_MAGIC_2) { + s->transparent = 1; + return (gzFile)s; + } + s->stream.avail_in = 0; + fscanf(s->file,"%c%c%4c%c%c", &method, &flags, time, &xflags, &osCode); + + if (method != DEFLATED || feof(s->file) || (flags & RESERVED) != 0) { + s->z_err = Z_DATA_ERROR; + return (gzFile)s; + } + if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */ + long len; + fscanf(s->file, "%c%c", &c1, &c2); + len = c1 + ((long)c2<<8); + fseek(s->file, len, SEEK_CUR); + } + if ((flags & ORIG_NAME) != 0) { /* skip the original file name */ + while ((c = getc(s->file)) != 0 && c != EOF) ; + } + if ((flags & COMMENT) != 0) { /* skip the .gz file comment */ + while ((c = getc(s->file)) != 0 && c != EOF) ; + } + if ((flags & HEAD_CRC) != 0) { /* skip the header crc */ + fscanf(s->file, "%c%c", &c1, &c2); + } + if (feof(s->file)) { + s->z_err = Z_DATA_ERROR; + } + } + return (gzFile)s; +} + +/* =========================================================================== + Opens a gzip (.gz) file for reading or writing. +*/ +gzFile gzopen (path, mode) + char *path; + char *mode; +{ + return gz_open (path, mode, -1); +} + +/* =========================================================================== + Associate a gzFile with the file descriptor fd. +*/ +gzFile gzdopen (fd, mode) + int fd; + char *mode; +{ + char name[20]; + sprintf(name, "_fd:%d_", fd); /* for debugging */ + + return gz_open (name, mode, fd); +} + +/* =========================================================================== + Reads the given number of uncompressed bytes from the compressed file. + gzread returns the number of bytes actually read (0 for end of file). +*/ +int gzread (file, buf, len) + gzFile file; + voidp buf; + unsigned len; +{ + gz_stream *s = (gz_stream*)file; + + if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR; + + if (s->transparent) { + unsigned n = 0; + /* Copy the first two (non-magic) bytes if not done already */ + while (s->stream.avail_in > 0 && len > 0) { + *((Byte*)buf)++ = *s->stream.next_in++; + s->stream.avail_in--; + len--; n++; + } + if (len == 0) return n; + return n + fread(buf, 1, len, s->file); + } + if (s->z_err == Z_DATA_ERROR) return -1; /* bad .gz file */ + if (s->z_err == Z_STREAM_END) return 0; /* don't read crc as data */ + + s->stream.next_out = buf; + s->stream.avail_out = len; + + while (s->stream.avail_out != 0) { + + if (s->stream.avail_in == 0 && !s->z_eof) { + + errno = 0; + s->stream.avail_in = + fread(s->inbuf, 1, Z_BUFSIZE, s->file); + if (s->stream.avail_in == 0) { + s->z_eof = 1; + } else if (s->stream.avail_in == (uInt)EOF) { + s->stream.avail_in = 0; + s->z_eof = 1; + s->z_err = Z_ERRNO; + break; + } + s->stream.next_in = s->inbuf; + } + s->z_err = inflate(&(s->stream), Z_NO_FLUSH); + + if (s->z_err == Z_STREAM_END || + s->z_err != Z_OK || s->z_eof) break; + } + len -= s->stream.avail_out; + s->crc = crc32(s->crc, buf, len); + return len; +} + +/* =========================================================================== + Writes the given number of uncompressed bytes into the compressed file. + gzwrite returns the number of bytes actually written (0 in case of error). +*/ +int gzwrite (file, buf, len) + gzFile file; + voidp buf; + unsigned len; +{ + gz_stream *s = (gz_stream*)file; + + if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; + + s->stream.next_in = buf; + s->stream.avail_in = len; + + while (s->stream.avail_in != 0) { + + if (s->stream.avail_out == 0) { + + s->stream.next_out = s->outbuf; + if (fwrite(s->outbuf, 1, Z_BUFSIZE, s->file) != Z_BUFSIZE) { + s->z_err = Z_ERRNO; + break; + } + s->stream.avail_out = Z_BUFSIZE; + } + s->z_err = deflate(&(s->stream), Z_NO_FLUSH); + + if (s->z_err != Z_OK) break; + } + s->crc = crc32(s->crc, buf, len); + + return len - s->stream.avail_in; +} + +/* =========================================================================== + Flushes all pending output into the compressed file. The parameter + flush is as in the deflate() function. + gzflush should be called only when strictly necessary because it can + degrade compression. +*/ +int gzflush (file, flush) + gzFile file; + int flush; +{ + uInt len; + int done = 0; + gz_stream *s = (gz_stream*)file; + + if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR; + + s->stream.avail_in = 0; /* should be zero already anyway */ + + for (;;) { + len = Z_BUFSIZE - s->stream.avail_out; + + if (len != 0) { + if (fwrite(s->outbuf, 1, len, s->file) != len) { + s->z_err = Z_ERRNO; + break; + } + s->stream.next_out = s->outbuf; + s->stream.avail_out = Z_BUFSIZE; + } + if (done) break; + s->z_err = deflate(&(s->stream), flush); + + if (s->z_err != Z_OK) break; + + /* deflate has finished flushing only when it hasn't used up + * all the available space in the output buffer: + */ + done = (s->stream.avail_out != 0); + } + return s->z_err; +} + +/* =========================================================================== + Outputs a long in LSB order to the given file +*/ +local void putLong (file, x) + FILE *file; + uLong x; +{ + int n; + for (n = 0; n < 4; n++) { + fputc(x & 0xff, file); + x >>= 8; + } +} + +/* =========================================================================== + Reads a long in LSB order from the given buffer +*/ +local uLong getLong (buf) + Byte *buf; +{ + uLong x = 0; + Byte *p = buf+4; + + do { + x <<= 8; + x |= *--p; + } while (p != buf); + return x; +} + +/* =========================================================================== + Flushes all pending output if necessary, closes the compressed file + and deallocates all the (de)compression state. +*/ +int gzclose (file) + gzFile file; +{ + uInt n; + gz_stream *s = (gz_stream*)file; + + if (s == NULL) return Z_STREAM_ERROR; + + if (s->mode == 'w') { + gzflush (file, Z_FINISH); + putLong (s->file, s->crc); + putLong (s->file, s->stream.total_in); + + } else if (s->mode == 'r' && s->z_err == Z_STREAM_END) { + + /* slide CRC and original size if they are at the end of inbuf */ + if ((n = s->stream.avail_in) < 8 && !s->z_eof) { + Byte *p = s->inbuf; + Byte *q = s->stream.next_in; + while (n--) { *p++ = *q++; }; + + n = s->stream.avail_in; + n += fread(p, 1, 8, s->file); + s->stream.next_in = s->inbuf; + } + /* check CRC and original size */ + if (n < 8 || + getLong(s->stream.next_in) != s->crc || + getLong(s->stream.next_in + 4) != s->stream.total_out) { + + s->z_err = Z_DATA_ERROR; + } + } + return destroy(file); +} + +/* =========================================================================== + Returns the error message for the last error which occured on the + given compressed file. errnum is set to zlib error number. If an + error occured in the file system and not in the compression library, + errnum is set to Z_ERRNO and the application may consult errno + to get the exact error code. +*/ +char* gzerror (file, errnum) + gzFile file; + int *errnum; +{ + char *m; + gz_stream *s = (gz_stream*)file; + + if (s == NULL) { + *errnum = Z_STREAM_ERROR; + return z_errmsg[1-Z_STREAM_ERROR]; + } + *errnum = s->z_err; + if (*errnum == Z_OK) return ""; + + m = *errnum == Z_ERRNO ? zstrerror(errno) : s->stream.msg; + + if (m == NULL || *m == '\0') m = z_errmsg[1-s->z_err]; + + TRYFREE(s->msg); + s->msg = (char*)ALLOC(strlen(s->path) + strlen(m) + 3); + strcpy(s->msg, s->path); + strcat(s->msg, ": "); + strcat(s->msg, m); + return s->msg; +} diff --git a/infblock.c b/infblock.c new file mode 100644 index 00000000..3a582809 --- /dev/null +++ b/infblock.c @@ -0,0 +1,324 @@ +/* infblock.c -- interpret and process block types to last block + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "infblock.h" +#include "inftrees.h" +#include "infcodes.h" +#include "infutil.h" + +struct inflate_codes_state {int dummy;}; /* for buggy compilers */ + +/* Table for deflate from PKZIP's appnote.txt. */ +local uInt border[] = { /* Order of the bit length code lengths */ + 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; + +/* + Notes beyond the 1.93a appnote.txt: + + 1. Distance pointers never point before the beginning of the output + stream. + 2. Distance pointers can point back across blocks, up to 32k away. + 3. There is an implied maximum of 7 bits for the bit length table and + 15 bits for the actual data. + 4. If only one code exists, then it is encoded using one bit. (Zero + would be more efficient, but perhaps a little confusing.) If two + codes exist, they are coded using one bit each (0 and 1). + 5. There is no way of sending zero distance codes--a dummy must be + sent if there are none. (History: a pre 2.0 version of PKZIP would + store blocks with no distance codes, but this was discovered to be + too harsh a criterion.) Valid only for 1.93a. 2.04c does allow + zero distance codes, which is sent as one code of zero bits in + length. + 6. There are up to 286 literal/length codes. Code 256 represents the + end-of-block. Note however that the static length tree defines + 288 codes just to fill out the Huffman codes. Codes 286 and 287 + cannot be used though, since there is no length base or extra bits + defined for them. Similarily, there are up to 30 distance codes. + However, static trees define 32 codes (all 5 bits) to fill out the + Huffman codes, but the last two had better not show up in the data. + 7. Unzip can check dynamic Huffman blocks for complete code sets. + The exception is that a single code would not be complete (see #4). + 8. The five bits following the block type is really the number of + literal codes sent minus 257. + 9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits + (1+6+6). Therefore, to output three times the length, you output + three codes (1+1+1), whereas to output four times the same length, + you only need two codes (1+3). Hmm. + 10. In the tree reconstruction algorithm, Code = Code + Increment + only if BitLength(i) is not zero. (Pretty obvious.) + 11. Correction: 4 Bits: # of Bit Length codes - 4 (4 - 19) + 12. Note: length code 284 can represent 227-258, but length code 285 + really is 258. The last length deserves its own, short code + since it gets used a lot in very redundant files. The length + 258 is special since 258 - 3 (the min match length) is 255. + 13. The literal/length and distance code bit lengths are read as a + single stream of lengths. It is possible (and advantageous) for + a repeat code (16, 17, or 18) to go across the boundary between + the two sets of lengths. + */ + +struct inflate_blocks_state *inflate_blocks_new(z,wsize) +z_stream *z; +uInt wsize; +{ + struct inflate_blocks_state *s; + + if ((s = (struct inflate_blocks_state *)ZALLOC + (z,1,sizeof(struct inflate_blocks_state))) == Z_NULL) + return s; + if ((s->window = (Byte *)ZALLOC(z,1,wsize)) == Z_NULL) + { + ZFREE(z, s); + return Z_NULL; + } + s->mode = TYPE; + s->bitk = 0; + s->read = s->write = s->window; + s->end = s->window + wsize; + s->check = 1; + return s; +} + + +int inflate_blocks(s, z, r) +struct inflate_blocks_state *s; +z_stream *z; +int r; +{ + uInt t; /* temporary storage */ + uLong b; /* bit buffer */ + uInt k; /* bits in bit buffer */ + Byte *p; /* input data pointer */ + uInt n; /* bytes available there */ + Byte *q; /* output window write pointer */ + uInt m; /* bytes to end of window or read pointer */ + + /* copy input/output information to locals (UPDATE macro restores) */ + LOAD + + /* process input based on current state */ + while (1) switch (s->mode) + { + case TYPE: + NEEDBITS(3) + t = (uInt)b & 7; + s->last = t & 1; + switch (t >> 1) + { + case 0: /* stored */ + DUMPBITS(3) + t = k & 7; /* go to byte boundary */ + DUMPBITS(t) + s->mode = LENS; /* get length of stored block */ + break; + case 1: /* fixed */ + { + uInt bl, bd; + inflate_huft *tl, *td; + + inflate_trees_fixed(&bl, &bd, &tl, &td); + s->sub.codes = inflate_codes_new(bl, bd, tl, td, z); + if (s->sub.codes == Z_NULL) + { + r = Z_MEM_ERROR; + LEAVE + } + } + DUMPBITS(3) + s->mode = CODES; + break; + case 2: /* dynamic */ + DUMPBITS(3) + s->mode = TABLE; + break; + case 3: /* illegal */ + DUMPBITS(3) + s->mode = ERROR; + z->msg = "invalid block type"; + r = Z_DATA_ERROR; + LEAVE + } + break; + case LENS: + NEEDBITS(32) + if ((~b) >> 16 != (b & 0xffff)) + { + s->mode = ERROR; + z->msg = "invalid stored block lengths"; + r = Z_DATA_ERROR; + LEAVE + } + k = 0; /* dump bits */ + s->sub.left = (uInt)b & 0xffff; + s->mode = s->sub.left ? STORED : TYPE; + break; + case STORED: + do { + NEEDBYTE + NEEDOUT + OUTBYTE(NEXTBYTE) + } while (--s->sub.left); + s->mode = s->last ? DRY : TYPE; + break; + case TABLE: + NEEDBITS(14) + s->sub.trees.table = t = (uInt)b & 0x3fff; +#ifndef PKZIP_BUG_WORKAROUND + if ((t & 0x1f) > 29 || ((t >> 5) & 0x1f) > 29) + { + s->mode = ERROR; + z->msg = "too many length or distance symbols"; + r = Z_DATA_ERROR; + LEAVE + } +#endif + t = 258 + (t & 0x1f) + ((t >> 5) & 0x1f); + if (t < 19) + t = 19; + if ((s->sub.trees.blens = (uInt*)ZALLOC(z, t, sizeof(uInt))) == Z_NULL) + { + r = Z_MEM_ERROR; + LEAVE + } + DUMPBITS(14) + s->sub.trees.index = 0; + s->mode = BTREE; + case BTREE: + while (s->sub.trees.index < 4 + (s->sub.trees.table >> 10)) + { + NEEDBITS(3) + s->sub.trees.blens[border[s->sub.trees.index++]] = (uInt)b & 7; + DUMPBITS(3) + } + while (s->sub.trees.index < 19) + s->sub.trees.blens[border[s->sub.trees.index++]] = 0; + s->sub.trees.bb = 7; + t = inflate_trees_bits(s->sub.trees.blens, &s->sub.trees.bb, + &s->sub.trees.tb, z); + if (t != Z_OK) + { + r = t; + if (r == Z_DATA_ERROR) + s->mode = ERROR; + LEAVE + } + s->sub.trees.index = 0; + s->mode = DTREE; + case DTREE: + while (t = s->sub.trees.table, + s->sub.trees.index < 258 + (t & 0x1f) + ((t >> 5) & 0x1f)) + { + inflate_huft *h; + uInt i, j, c; + + t = s->sub.trees.bb; + NEEDBITS(t) + h = s->sub.trees.tb + ((uInt)b & inflate_mask[t]); + t = h->word.what.Bits; + c = h->more.Base; + if (c < 16) + { + DUMPBITS(t) + s->sub.trees.blens[s->sub.trees.index++] = c; + } + else /* c == 16..18 */ + { + i = c == 18 ? 7 : c - 14; + j = c == 18 ? 11 : 3; + NEEDBITS(t + i) + DUMPBITS(t) + j += (uInt)b & inflate_mask[i]; + DUMPBITS(i) + i = s->sub.trees.index; + t = s->sub.trees.table; + if (i + j > 258 + (t & 0x1f) + ((t >> 5) & 0x1f) || + (c == 16 && i < 1)) + { + s->mode = ERROR; + z->msg = "invalid bit length repeat"; + r = Z_DATA_ERROR; + LEAVE + } + c = c == 16 ? s->sub.trees.blens[i - 1] : 0; + do { + s->sub.trees.blens[i++] = c; + } while (--j); + s->sub.trees.index = i; + } + } + inflate_trees_free(s->sub.trees.tb, z); + s->sub.trees.tb = Z_NULL; + { + uInt bl, bd; + inflate_huft *tl, *td; + struct inflate_codes_state *c; + + bl = 9; + bd = 6; + t = s->sub.trees.table; + t = inflate_trees_dynamic(257 + (t & 0x1f), 1 + ((t >> 5) & 0x1f), + s->sub.trees.blens, &bl, &bd, &tl, &td, z); + if (t != Z_OK) + { + if (t == (uInt)Z_DATA_ERROR) + s->mode = ERROR; + r = t; + LEAVE + } + if ((c = inflate_codes_new(bl, bd, tl, td, z)) == Z_NULL) + { + inflate_trees_free(td, z); + inflate_trees_free(tl, z); + r = Z_MEM_ERROR; + LEAVE + } + ZFREE(z, s->sub.trees.blens); + s->sub.codes = c; + } + s->mode = CODES; + case CODES: + UPDATE + if ((r = inflate_codes(s, z, r)) != Z_STREAM_END) + return inflate_flush(s, z, r); + r = Z_OK; + inflate_codes_free(s->sub.codes, z); + LOAD + s->mode = s->last ? DRY : TYPE; + break; + case DRY: + FLUSH + if (s->read != s->write) + LEAVE + s->mode = DONE; + case DONE: + r = Z_STREAM_END; + LEAVE + case ERROR: + r = Z_DATA_ERROR; + LEAVE + default: + r = Z_STREAM_ERROR; + LEAVE + } +} + + +int inflate_blocks_free(s, z, c, e) +struct inflate_blocks_state *s; +z_stream *z; +uLong *c; +int *e; +{ + *e = s->bitk > 7 ? (s->bitb >> (s->bitk & 7)) & 0xff : -1; + *c = s->check; + if (s->mode == BTREE || s->mode == DTREE) + ZFREE(z, s->sub.trees.blens); + if (s->mode == CODES) + inflate_codes_free(s->sub.codes, z); + ZFREE(z, s->window); + ZFREE(z, s); + return Z_OK; +} diff --git a/infblock.h b/infblock.h new file mode 100644 index 00000000..f70c471f --- /dev/null +++ b/infblock.h @@ -0,0 +1,26 @@ +/* infblock.h -- header to use infblock.c + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +struct inflate_blocks_state; + +extern struct inflate_blocks_state * inflate_blocks_new __P(( + z_stream *, + uInt)); /* window size */ + +extern int inflate_blocks __P(( + struct inflate_blocks_state *, + z_stream *, + int)); /* initial return code */ + +extern int inflate_blocks_free __P(( + struct inflate_blocks_state *, + z_stream *, + uLong *, /* check value on output */ + int *)); /* possible leftover byte to return */ diff --git a/infcodes.c b/infcodes.c new file mode 100644 index 00000000..ffae26d4 --- /dev/null +++ b/infcodes.c @@ -0,0 +1,217 @@ +/* infcodes.c -- process literals and length/distance pairs + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "inftrees.h" +#include "infutil.h" +#include "infcodes.h" + +/* simplify the use of the inflate_huft type with some defines */ +#define base more.Base +#define next more.Next +#define exop word.what.Exop +#define bits word.what.Bits + +/* inflate codes private state */ +struct inflate_codes_state { + + /* mode */ + enum { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ + START, /* x: set up for LEN */ + LEN, /* i: get length/literal/eob next */ + LENEXT, /* i: getting length extra (have base) */ + DIST, /* i: get distance next */ + DISTEXT, /* i: getting distance extra */ + COPY, /* o: copying bytes in window, waiting for space */ + LIT, /* o: got literal, waiting for output space */ + WASH, /* o: got eob, possibly still output waiting */ + END, /* x: got eob and all data flushed */ + BAD} /* x: got error */ + mode; /* current inflate_codes mode */ + + /* mode dependent information */ + uInt len; + union { + struct { + inflate_huft *tree; /* pointer into tree */ + uInt need; /* bits needed */ + } code; /* if LEN or DIST, where in tree */ + uInt lit; /* if LIT, literal */ + struct { + uInt get; /* bits to get for extra */ + uInt dist; /* distance back to copy from */ + } copy; /* if EXT or COPY, where and how much */ + } sub; /* submode */ + + /* mode independent information */ + Byte lbits; /* ltree bits decoded per branch */ + Byte dbits; /* dtree bits decoder per branch */ + inflate_huft *ltree; /* literal/length/eob tree */ + inflate_huft *dtree; /* distance tree */ + +}; + + +struct inflate_codes_state *inflate_codes_new(bl, bd, tl, td, z) +uInt bl, bd; +inflate_huft *tl, *td; +z_stream *z; +{ + struct inflate_codes_state *c; + + if ((c = (struct inflate_codes_state *) + ZALLOC(z,1,sizeof(struct inflate_codes_state))) != Z_NULL) + { + c->mode = START; + c->lbits = (Byte)bl; + c->dbits = (Byte)bd; + c->ltree = tl; + c->dtree = td; + } + return c; +} + + +int inflate_codes(s, z, r) +struct inflate_blocks_state *s; +z_stream *z; +int r; +{ + uInt j; /* temporary storage */ + inflate_huft *t; /* temporary pointer */ + int e; /* extra bits or operation */ + uLong b; /* bit buffer */ + uInt k; /* bits in bit buffer */ + Byte *p; /* input data pointer */ + uInt n; /* bytes available there */ + Byte *q; /* output window write pointer */ + uInt m; /* bytes to end of window or read pointer */ + Byte *f; /* pointer to copy strings from */ + struct inflate_codes_state *c = s->sub.codes; /* codes state */ + + /* copy input/output information to locals (UPDATE macro restores) */ + LOAD + + /* process input and output based on current state */ + while (1) switch (c->mode) + { /* waiting for "i:"=input, "o:"=output, "x:"=nothing */ + case START: /* x: set up for LEN */ + /* %%% check for avail in and out to do fast loop %%% */ + c->sub.code.need = c->lbits; + c->sub.code.tree = c->ltree; + c->mode = LEN; + case LEN: /* i: get length/literal/eob next */ + j = c->sub.code.need; + NEEDBITS(j) + t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); + DUMPBITS(t->bits) + if ((e = (int)(t->exop)) < 0) + { + if (e == -128) /* invalid code */ + { + c->mode = BAD; + z->msg = "invalid huffman code"; + r = Z_DATA_ERROR; + LEAVE + } + e = -e; + if (e & 64) /* end of block */ + { + c->mode = END; + break; + } + c->sub.code.need = e; + c->sub.code.tree = t->next; + break; + } + if (e & 16) /* literal */ + { + c->sub.lit = t->base; + c->mode = LIT; + break; + } + c->sub.copy.get = e; + c->len = t->base; + c->mode = LENEXT; + case LENEXT: /* i: getting length extra (have base) */ + j = c->sub.copy.get; + NEEDBITS(j) + c->len += (uInt)b & inflate_mask[j]; + DUMPBITS(j) + c->sub.code.need = c->dbits; + c->sub.code.tree = c->dtree; + c->mode = DIST; + case DIST: /* i: get distance next */ + j = c->sub.code.need; + NEEDBITS(j) + t = c->sub.code.tree + ((uInt)b & inflate_mask[j]); + DUMPBITS(t->bits) + if ((e = (int)(t->exop)) < 0) + { + if (e == -128) + { + c->mode = BAD; + z->msg = "invalid huffman code"; + r = Z_DATA_ERROR; + LEAVE + } + c->sub.code.need = -e; + c->sub.code.tree = t->next; + break; + } + c->sub.copy.dist = t->base; + c->sub.copy.get = e; + c->mode = DISTEXT; + case DISTEXT: /* i: getting distance extra */ + j = c->sub.copy.get; + NEEDBITS(j) + c->sub.copy.dist += (uInt)b & inflate_mask[j]; + DUMPBITS(j) + c->mode = COPY; + case COPY: /* o: copying bytes in window, waiting for space */ + f = q - s->window < c->sub.copy.dist ? + s->end - (c->sub.copy.dist - (q - s->window)) : + q - c->sub.copy.dist; + while (c->len) + { + NEEDOUT + OUTBYTE(*f++) + if (f == s->end) + f = s->window; + c->len--; + } + c->mode = START; + break; + case LIT: /* o: got literal, waiting for output space */ + NEEDOUT + OUTBYTE(c->sub.lit) + c->mode = START; + break; + case WASH: /* o: got eob, possibly more output */ + FLUSH + if (s->read != s->write) + LEAVE + c->mode = END; + case END: + r = Z_STREAM_END; + LEAVE + case BAD: /* x: got error */ + r = Z_DATA_ERROR; + LEAVE + default: + r = Z_STREAM_ERROR; + LEAVE + } +} + + +void inflate_codes_free(c, z) +struct inflate_codes_state *c; +z_stream *z; +{ + inflate_trees_free(c->dtree, z); + inflate_trees_free(c->ltree, z); + ZFREE(z, c); +} diff --git a/infcodes.h b/infcodes.h new file mode 100644 index 00000000..af99cd12 --- /dev/null +++ b/infcodes.h @@ -0,0 +1,25 @@ +/* infcodes.h -- header to use infcodes.c + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +struct inflate_codes_state; + +extern struct inflate_codes_state *inflate_codes_new __P(( + uInt, uInt, + inflate_huft *, inflate_huft *, + z_stream *)); + +extern int inflate_codes __P(( + struct inflate_blocks_state *, + z_stream *, + int)); + +extern void inflate_codes_free __P(( + struct inflate_codes_state *, + z_stream *)); diff --git a/inflate.c b/inflate.c new file mode 100644 index 00000000..478f46d0 --- /dev/null +++ b/inflate.c @@ -0,0 +1,221 @@ +/* inflate.c -- zlib interface to inflate modules + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "infblock.h" + +struct inflate_blocks_state {int dummy;}; /* for buggy compilers */ + +/* inflate private state */ +struct internal_state { + + /* mode */ + enum { + METHOD, /* waiting for method byte */ + FLAG, /* waiting for flag byte */ + START, /* make new blocks state */ + BLOCKS, /* decompressing blocks */ + CHECK4, /* four check bytes to go */ + CHECK3, /* three check bytes to go */ + CHECK2, /* two check bytes to go */ + CHECK1, /* one check byte to go */ + DONE, /* finished check, done */ + ERROR} /* got an error--stay here */ + mode; /* current inflate mode */ + + int no_header; + uInt w_size; /* LZ77 window size (32K by default) */ + uInt w_bits; /* log2(w_size) (8..16) */ + + /* mode dependent information */ + union { + uInt method; /* if FLAGS, method byte */ + struct inflate_blocks_state + *blocks; /* if BLOCKS, current state */ + struct { + uLong was; /* computed check value */ + uLong need; /* stream check value */ + } check; /* if CHECK, check values to compare */ + } sub; /* submode */ +}; + + +int inflateInit (strm) +z_stream *strm; +{ + return inflateInit2(strm, WBITS); +} + +int inflateInit2(z, windowBits) +z_stream *z; +int windowBits; +{ + if (z == Z_NULL) + return Z_STREAM_ERROR; + if (z->zalloc == Z_NULL) z->zalloc = zcalloc; + if (z->zfree == Z_NULL) z->zfree = zcfree; + z->total_in = z->total_out = 0; + z->msg = Z_NULL; + if ((z->state = (struct internal_state *) + ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL) + return Z_MEM_ERROR; + z->state->mode = METHOD; + + z->state->no_header = 0; + if (windowBits < 0) { /* undocumented feature: no zlib header */ + windowBits = - windowBits; + z->state->no_header = 1; + z->state->sub.method = DEFLATED; + z->state->mode = START; + } + if (windowBits < 8 || windowBits > 15) { + inflateEnd(z); + return Z_STREAM_ERROR; + } + z->state->w_bits = windowBits; + z->state->w_size = 1<avail_in--,z->total_in++,*z->next_in++) + +int inflate(z, f) +z_stream *z; +int f; +{ + int r; + uInt b; + uLong c; + + if (z == Z_NULL || z->next_in == Z_NULL) + return Z_STREAM_ERROR; + r = Z_BUF_ERROR; + while (1) switch (z->state->mode) + { + case METHOD: + if (z->avail_in == 0) return r; r = Z_OK; + if (((z->state->sub.method = NEXTBYTE) & 0xf != DEFLATED)) + { + z->state->mode = ERROR; + z->msg = "unknown compression method"; + return Z_DATA_ERROR; + } + if ((z->state->sub.method >> 4) > z->state->w_bits) + { + z->state->mode = ERROR; + z->msg = "invalid window size"; + return Z_DATA_ERROR; + } + z->state->mode = FLAG; + case FLAG: + if (z->avail_in == 0) return r; r = Z_OK; + if ((b = NEXTBYTE) & 0x20) + { + z->state->mode = ERROR; + z->msg = "invalid reserved bit"; + return Z_DATA_ERROR; + } + if (((z->state->sub.method << 8) + b) % 31) + { + z->state->mode = ERROR; + z->msg = "incorrect header check"; + return Z_DATA_ERROR; + } + z->state->mode = START; + case START: + if ((z->state->sub.blocks = inflate_blocks_new(z,z->state->w_size)) + == Z_NULL) + return Z_MEM_ERROR; + z->state->mode = BLOCKS; + case BLOCKS: + if ((r = inflate_blocks(z->state->sub.blocks, z, r)) != Z_STREAM_END) + return r; + inflate_blocks_free(z->state->sub.blocks, z, &c, &r); + if (z->state->no_header) { + z->state->mode = DONE; + return Z_STREAM_END; + } + z->state->sub.check.was = c; + if (r != -1) + { + z->state->sub.check.need = (uLong)r << 24; + z->state->mode = CHECK3; + r = Z_OK; + break; + } + r = Z_OK; + z->state->mode = CHECK4; + case CHECK4: + if (z->avail_in == 0) return r; r = Z_OK; + z->state->sub.check.need = (uLong)NEXTBYTE << 24; + z->state->mode = CHECK3; + case CHECK3: + if (z->avail_in == 0) return r; r = Z_OK; + z->state->sub.check.need += (uLong)NEXTBYTE << 16; + z->state->mode = CHECK2; + case CHECK2: + if (z->avail_in == 0) return r; r = Z_OK; + z->state->sub.check.need += (uLong)NEXTBYTE << 8; + z->state->mode = CHECK1; + case CHECK1: + if (z->avail_in == 0) return r; r = Z_OK; + z->state->sub.check.need += (uLong)NEXTBYTE; + if (z->state->sub.check.was != z->state->sub.check.need) + { + z->state->mode = ERROR; + z->msg = "incorrect data check"; + return Z_DATA_ERROR; + } + z->state->mode = DONE; + case DONE: + return Z_STREAM_END; + case ERROR: + return Z_DATA_ERROR; + default: + return Z_STREAM_ERROR; + } +} + + +int inflateEnd(z) +z_stream *z; +{ + uLong c; + int e; + + if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL) + return Z_STREAM_ERROR; + if (z->state->mode == BLOCKS) + inflate_blocks_free(z->state->sub.blocks, z, &c, &e); + ZFREE(z, z->state); + z->state = Z_NULL; + return Z_OK; +} + + +/* inflateSync not implemented yet--this just consumes input */ +int inflateSync(z) +z_stream *z; +{ + if (z == Z_NULL) return Z_STREAM_ERROR; + if (z->avail_in == 0) return Z_BUF_ERROR; + do { + z->total_in++; + } while (--z->avail_in); + return Z_DATA_ERROR; +} + + +/* inflateReset not fully implemented yet--this frees and reallocates */ +int inflateReset(z) +z_stream *z; +{ + int r; + + if ((r = inflateEnd(z)) != Z_OK) + return r; + return inflateInit(z); +} diff --git a/inflate.h b/inflate.h new file mode 100644 index 00000000..843224f4 --- /dev/null +++ b/inflate.h @@ -0,0 +1,22 @@ +/* temporary kludge assuming single pass decompression */ + +/* $Id: inflate.h,v 1.2 1995/04/11 14:47:32 jloup Exp $ */ + +#include + +#define NEXTBYTE \ + (istrm->total_in++, istrm->avail_in-- == 0 ? \ + (z_error("too small"), 0) : *istrm->next_in++) + +#define FLUSH(n) { \ + if (istrm->avail_out < n) z_error("too big"); \ + istrm->avail_out -= n; \ + memcpy(istrm->next_out, slide, n); \ + istrm->next_out += n; \ + istrm->total_out += n; \ +} +#define WSIZE istrm->state->w_size +#define slide istrm->state->window +#define memzero(a,s) memset((a),0,(s)) +#define inflate z_inflate +#define qflag 1 diff --git a/inftest.c b/inftest.c new file mode 100644 index 00000000..7dc29079 --- /dev/null +++ b/inftest.c @@ -0,0 +1,67 @@ +#include +#include +#include "zutil.h" + +/* This test is in honor of Ed Hamrick who suggested that the interface + to inflate be a byte at a time--this implements that, and is, of course, + monumentally slow. It has the virtue though of stressing the push-pull + interface for testing purposes. */ + +void main() +{ + int a, r; + char c; + z_stream z; + + z.zalloc = Z_NULL; + z.zfree = Z_NULL; + r = inflateInit(&z); + if (r != Z_OK) + fprintf(stderr, "init error: %s\n", z_errmsg[1 - r]); + while ((a = getchar()) != EOF) + { + /* feed one byte of input */ + z.avail_out = 0; + c = (char)a; + z.next_in = (Byte*)&c; + z.avail_in = 1; + r = inflate(&z, 0); + if (r == Z_STREAM_END) + break; + if (r != Z_OK) + { + fprintf(stderr, "inflate error: %s\n", z_errmsg[1 - r]); + break; + } + if (z.avail_in != 0) + { + fprintf(stderr, "inflate didn't eat byte and didn't say buf err!\n"); + break; + } + + /* empty output one byte at a time */ + while (1) + { + z.next_out = (Byte*)&c; + z.avail_out = 1; + r = inflate(&z, 0); + if (r == Z_STREAM_END) + break; + if (r != Z_OK && r != Z_BUF_ERROR) + { + fprintf(stderr, "inflate error: %s\n", z_errmsg[1 - r]); + break; + } + if (z.avail_out == 0) + putchar(c); + else + break; + } + if (r != Z_OK && r != Z_BUF_ERROR) + break; + } + inflateEnd(&z); + fprintf(stderr, "%d bytes in, %d bytes out\n", z.total_in, z.total_out); + if (z.msg != NULL) + fprintf(stderr, "msg is <%s>\n", z.msg); +} diff --git a/inftrees.c b/inftrees.c new file mode 100644 index 00000000..4b00e3ce --- /dev/null +++ b/inftrees.c @@ -0,0 +1,471 @@ +/* inftrees.c -- generate Huffman trees for efficient decoding + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "inftrees.h" + +struct internal_state {int dummy;}; /* for buggy compilers */ + +/* simplify the use of the inflate_huft type with some defines */ +#define base more.Base +#define next more.Next +#define exop word.what.Exop +#define bits word.what.Bits + + +local int huft_build __P(( + uInt *, /* code lengths in bits */ + uInt, /* number of codes */ + uInt, /* number of "simple" codes */ + uInt *, /* list of base values for non-simple codes */ + uInt *, /* list of extra bits for non-simple codes */ + inflate_huft **, /* result: starting table */ + uInt *, /* maximum lookup bits (returns actual) */ + z_stream *)); /* for zalloc function */ + +local voidp falloc __P(( + voidp, /* opaque pointer (not used) */ + uInt, /* number of items */ + uInt)); /* size of item */ + +local void ffree __P(( + voidp q, /* opaque pointer (not used) */ + voidp p)); /* what to free (not used) */ + +/* Tables for deflate from PKZIP's appnote.txt. */ +local uInt cplens[] = { /* Copy lengths for literal codes 257..285 */ + 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, + 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0}; + /* actually lengths - 2; also see note #13 above about 258 */ +local uInt cplext[] = { /* Extra bits for literal codes 257..285 */ + 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, 5, 5, 5, 0, 128, 128}; /* 128==invalid */ +local uInt cpdist[] = { /* Copy offsets for distance codes 0..29 */ + 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, + 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, + 8193, 12289, 16385, 24577}; +local uInt cpdext[] = { /* Extra bits for distance codes */ + 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}; + +/* + Huffman code decoding is performed using a multi-level table lookup. + The fastest way to decode is to simply build a lookup table whose + size is determined by the longest code. However, the time it takes + to build this table can also be a factor if the data being decoded + is not very long. The most common codes are necessarily the + shortest codes, so those codes dominate the decoding time, and hence + the speed. The idea is you can have a shorter table that decodes the + shorter, more probable codes, and then point to subsidiary tables for + the longer codes. The time it costs to decode the longer codes is + then traded against the time it takes to make longer tables. + + This results of this trade are in the variables lbits and dbits + below. lbits is the number of bits the first level table for literal/ + length codes can decode in one step, and dbits is the same thing for + the distance codes. Subsequent tables are also less than or equal to + those sizes. These values may be adjusted either when all of the + codes are shorter than that, in which case the longest code length in + bits is used, or when the shortest code is *longer* than the requested + table size, in which case the length of the shortest code in bits is + used. + + There are two different values for the two tables, since they code a + different number of possibilities each. The literal/length table + codes 286 possible values, or in a flat code, a little over eight + bits. The distance table codes 30 possible values, or a little less + than five bits, flat. The optimum values for speed end up being + about one bit more than those, so lbits is 8+1 and dbits is 5+1. + The optimum values may differ though from machine to machine, and + possibly even between compilers. Your mileage may vary. + */ + + +/* If BMAX needs to be larger than 16, then h and x[] should be uLong. */ +#define BMAX 15 /* maximum bit length of any code */ +#define N_MAX 288 /* maximum number of codes in any set */ + +#ifdef DEBUG + uInt inflate_hufts; +#endif + +local int huft_build(b, n, s, d, e, t, m, zs) +uInt *b; /* code lengths in bits (all assumed <= BMAX) */ +uInt n; /* number of codes (assumed <= N_MAX) */ +uInt s; /* number of simple-valued codes (0..s-1) */ +uInt *d; /* list of base values for non-simple codes */ +uInt *e; /* list of extra bits for non-simple codes */ +inflate_huft **t; /* result: starting table */ +uInt *m; /* maximum lookup bits, returns actual */ +z_stream *zs; /* for zalloc function */ +/* Given a list of code lengths and a maximum table size, make a set of + tables to decode that set of codes. Return Z_OK on success, Z_BUF_ERROR + if the given code set is incomplete (the tables are still built in this + case), Z_DATA_ERROR if the input is invalid (all zero length codes or an + over-subscribed set of lengths), or Z_MEM_ERROR if not enough memory. */ +{ + uInt a; /* counter for codes of length k */ + uInt c[BMAX+1]; /* bit length count table */ + uInt f; /* i repeats in table every f entries */ + int g; /* maximum code length */ + int h; /* table level */ + register uInt i; /* counter, current code */ + register uInt j; /* counter */ + register int k; /* number of bits in current code */ + int l; /* bits per table (returned in m) */ + register uInt *p; /* pointer into c[], b[], or v[] */ + register inflate_huft *q; /* points to current table */ + inflate_huft r; /* table entry for structure assignment */ + inflate_huft *u[BMAX]; /* table stack */ + uInt v[N_MAX]; /* values in order of bit length */ + register int w; /* bits before this table == (l * h) */ + uInt x[BMAX+1]; /* bit offsets, then code stack */ + uInt *xp; /* pointer into x */ + int y; /* number of dummy codes added */ + uInt z; /* number of entries in current table */ + + + /* Generate counts for each bit length */ + p = c; +#define C0 *p++ = 0; +#define C2 C0 C0 C0 C0 +#define C4 C2 C2 C2 C2 + C4 /* clear c[]--assume BMAX+1 is 16 */ + p = b; i = n; + do { + c[*p++]++; /* assume all entries <= BMAX */ + } while (--i); + if (c[0] == n) /* null input--all zero length codes */ + { + *t = (inflate_huft *)Z_NULL; + *m = 0; + return Z_OK; + } + + + /* Find minimum and maximum length, bound *m by those */ + l = *m; + for (j = 1; j <= BMAX; j++) + if (c[j]) + break; + k = j; /* minimum code length */ + if ((uInt)l < j) + l = j; + for (i = BMAX; i; i--) + if (c[i]) + break; + g = i; /* maximum code length */ + if ((uInt)l > i) + l = i; + *m = l; + + + /* Adjust last length count to fill out codes, if needed */ + for (y = 1 << j; j < i; j++, y <<= 1) + if ((y -= c[j]) < 0) + return Z_DATA_ERROR; + if ((y -= c[i]) < 0) + return Z_DATA_ERROR; + c[i] += y; + + + /* Generate starting offsets into the value table for each length */ + x[1] = j = 0; + p = c + 1; xp = x + 2; + while (--i) { /* note that i == g from above */ + *xp++ = (j += *p++); + } + + + /* Make a table of values in order of bit lengths */ + p = b; i = 0; + do { + if ((j = *p++) != 0) + v[x[j]++] = i; + } while (++i < n); + + + /* Generate the Huffman codes and for each, make the table entries */ + x[0] = i = 0; /* first Huffman code is zero */ + p = v; /* grab values in bit order */ + h = -1; /* no tables yet--level -1 */ + w = -l; /* bits decoded == (l * h) */ + u[0] = (inflate_huft *)Z_NULL; /* just to keep compilers happy */ + q = (inflate_huft *)Z_NULL; /* ditto */ + z = 0; /* ditto */ + + /* go through the bit lengths (k already is bits in shortest code) */ + for (; k <= g; k++) + { + a = c[k]; + while (a--) + { + /* here i is the Huffman code of length k bits for value *p */ + /* make tables up to required level */ + while (k > w + l) + { + h++; + w += l; /* previous table always l bits */ + + /* compute minimum size table less than or equal to l bits */ + z = (z = g - w) > (uInt)l ? l : z; /* table size upper limit */ + if ((f = 1 << (j = k - w)) > a + 1) /* try a k-w bit table */ + { /* too few codes for k-w bit table */ + f -= a + 1; /* deduct codes from patterns left */ + xp = c + k; + if (j < z) + while (++j < z) /* try smaller tables up to z bits */ + { + if ((f <<= 1) <= *++xp) + break; /* enough codes to use up j bits */ + f -= *xp; /* else deduct codes from patterns */ + } + } + z = 1 << j; /* table entries for j-bit table */ + + /* allocate and link in new table */ + if ((q = (inflate_huft *)ZALLOC + (zs,z + 1,sizeof(inflate_huft))) == Z_NULL) + { + if (h) + inflate_trees_free(u[0], zs); + return Z_MEM_ERROR; /* not enough memory */ + } +#ifdef DEBUG + inflate_hufts += z + 1; +#endif + *t = q + 1; /* link to list for huft_free() */ + *(t = &(q->next)) = (inflate_huft *)Z_NULL; + u[h] = ++q; /* table starts after link */ + + /* connect to last table, if there is one */ + if (h) + { + x[h] = i; /* save pattern for backing up */ + r.bits = (char)l; /* bits to dump before this table */ + r.exop = (char)(-j); /* bits in this table */ + r.next = q; /* pointer to this table */ + j = i >> (w - l); /* (get around Turbo C bug) */ + u[h-1][j] = r; /* connect to last table */ + } + } + + /* set up table entry in r */ + r.bits = (char)(k - w); + if (p >= v + n) + r.exop = -128; /* out of values--invalid code */ + else if (*p < s) + { + r.exop = (char)(*p < 256 ? 16 : -64); /* 256 is end-of-block code */ + r.base = *p++; /* simple code is just the value */ + } + else + { + r.exop = (char)e[*p - s]; /* non-simple--look up in lists */ + r.base = d[*p++ - s]; + } + + /* fill code-like entries with r */ + f = 1 << (k - w); + for (j = i >> w; j < z; j += f) + q[j] = r; + + /* backwards increment the k-bit code i */ + for (j = 1 << (k - 1); i & j; j >>= 1) + i ^= j; + i ^= j; + + /* backup over finished tables */ + while ((i & ((1 << w) - 1)) != x[h]) + { + h--; /* don't need to update q */ + w -= l; + } + } + } + + + /* Return Z_BUF_ERROR if we were given an incomplete table */ + return y != 0 && g != 1 ? Z_BUF_ERROR : Z_OK; +} + + +int inflate_trees_bits(c, bb, tb, z) +uInt *c; /* 19 code lengths */ +uInt *bb; /* bits tree desired/actual depth */ +inflate_huft **tb; /* bits tree result */ +z_stream *z; /* for zfree function */ +{ + int r; + + r = huft_build(c, 19, 19, (uInt*)Z_NULL, (uInt*)Z_NULL, tb, bb, z); + if (r == Z_DATA_ERROR) + z->msg = "oversubscribed dynamic bit lengths tree"; + else if (r == Z_BUF_ERROR) + { + inflate_trees_free(*tb, z); + z->msg = "incomplete dynamic bit lengths tree"; + r = Z_DATA_ERROR; + } + return r; +} + + +int inflate_trees_dynamic(nl, nd, c, bl, bd, tl, td, z) +uInt nl; /* number of literal/length codes */ +uInt nd; /* number of distance codes */ +uInt *c; /* that many (total) code lengths */ +uInt *bl; /* literal desired/actual bit depth */ +uInt *bd; /* distance desired/actual bit depth */ +inflate_huft **tl; /* literal/length tree result */ +inflate_huft **td; /* distance tree result */ +z_stream *z; /* for zfree function */ +{ + int r; + + /* build literal/length tree */ + if ((r = huft_build(c, nl, 257, cplens, cplext, tl, bl, z)) != Z_OK) + { + if (r == Z_DATA_ERROR) + z->msg = "oversubscribed literal/length tree"; + else if (r == Z_BUF_ERROR) + { + inflate_trees_free(*tl, z); + z->msg = "incomplete literal/length tree"; + r = Z_DATA_ERROR; + } + return r; + } + + /* build distance tree */ + if ((r = huft_build(c + nl, nd, 0, cpdist, cpdext, td, bd, z)) != Z_OK) + { + if (r == Z_DATA_ERROR) + z->msg = "oversubscribed literal/length tree"; + else if (r == Z_BUF_ERROR) { +#ifdef PKZIP_BUG_WORKAROUND + r = Z_OK; + } +#else + inflate_trees_free(*td, z); + z->msg = "incomplete literal/length tree"; + r = Z_DATA_ERROR; + } + inflate_trees_free(*tl, z); + return r; +#endif + } + + /* done */ + return Z_OK; +} + + +/* build fixed tables only once--keep them here */ +local int fixed_lock = 0; +local int fixed_built = 0; +#define FIXEDH 530 /* number of hufts used by fixed tables */ +local uInt fixed_left = FIXEDH; +local inflate_huft fixed_mem[FIXEDH]; +local uInt fixed_bl; +local uInt fixed_bd; +local inflate_huft *fixed_tl; +local inflate_huft *fixed_td; + + +local voidp falloc(q, n, s) +voidp q; /* opaque pointer (not used) */ +uInt n; /* number of items */ +uInt s; /* size of item */ +{ + Assert(s == sizeof(inflate_huft) && n <= fixed_left, + "inflate_trees falloc overflow"); + fixed_left -= n; + return (voidp)(fixed_mem + fixed_left); +} + + +local void ffree(q, p) +voidp q; +voidp p; +{ + Assert(0, "inflate_trees ffree called!"); +} + + +int inflate_trees_fixed(bl, bd, tl, td) +uInt *bl; /* literal desired/actual bit depth */ +uInt *bd; /* distance desired/actual bit depth */ +inflate_huft **tl; /* literal/length tree result */ +inflate_huft **td; /* distance tree result */ +{ + /* build fixed tables if not built already--lock out other instances */ + while (++fixed_lock > 1) + fixed_lock--; + if (!fixed_built) + { + int k; /* temporary variable */ + unsigned c[288]; /* length list for huft_build */ + z_stream z; /* for falloc function */ + + /* set up fake z_stream for memory routines */ + z.zalloc = falloc; + z.zfree = ffree; + z.opaque = Z_NULL; + + /* literal table */ + for (k = 0; k < 144; k++) + c[k] = 8; + for (; k < 256; k++) + c[k] = 9; + for (; k < 280; k++) + c[k] = 7; + for (; k < 288; k++) + c[k] = 8; + fixed_bl = 7; + huft_build(c, 288, 257, cplens, cplext, &fixed_tl, &fixed_bl, &z); + + /* distance table */ + for (k = 0; k < 30; k++) + c[k] = 5; + fixed_bd = 5; + huft_build(c, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd, &z); + + /* done */ + fixed_built = 1; + } + fixed_lock--; + *bl = fixed_bl; + *bd = fixed_bd; + *tl = fixed_tl; + *td = fixed_td; + return Z_OK; +} + + +int inflate_trees_free(t, z) +inflate_huft *t; /* table to free */ +z_stream *z; /* for zfree function */ +/* Free the malloc'ed tables built by huft_build(), which makes a linked + list of the tables it made, with the links in a dummy first entry of + each table. */ +{ + register inflate_huft *p, *q; + + /* Don't free fixed trees */ + if (t >= fixed_mem && t <= fixed_mem + FIXEDH) + return Z_OK; + + /* Go through linked list, freeing from the malloced (t[-1]) address. */ + p = t; + while (p != Z_NULL) + { + q = (--p)->next; + ZFREE(z,p); + p = q; + } + return Z_OK; +} diff --git a/inftrees.h b/inftrees.h new file mode 100644 index 00000000..6001a4e4 --- /dev/null +++ b/inftrees.h @@ -0,0 +1,62 @@ +/* inftrees.h -- header to use inftrees.c + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +/* Huffman code lookup table entry--this entry is four bytes for machines + that have 16-bit pointers (e.g. PC's in the small or medium model). + Valid extra bits (exop) are 0..13. exop == -64 is EOB (end of block), + exop == 16 means that v is a literal, exop < 0 means that v is a pointer + to the next table, which codes -exop bits, and lastly exop == -128 + indicates an unused code. If a code with exop == -128 is looked up, + this implies an error in the data. */ + +typedef struct inflate_huft_s inflate_huft; +struct inflate_huft_s { + union { + struct { + char Exop; /* number of extra bits or operation */ + char Bits; /* number of bits in this code or subcode */ + } what; + Byte *pad; /* pad structure to a power of 2 (4 bytes for */ + } word; /* 16-bit, 8 bytes for 32-bit machines) */ + union { + uInt Base; /* literal, length base, or distance base */ + inflate_huft *Next; /* pointer to next level of table */ + } more; +}; + +#ifdef DEBUG + extern uInt inflate_hufts; +#endif + +extern int inflate_trees_bits __P(( + uInt *, /* 19 code lengths */ + uInt *, /* bits tree desired/actual depth */ + inflate_huft **, /* bits tree result */ + z_stream *)); /* for zalloc, zfree functions */ + +extern int inflate_trees_dynamic __P(( + uInt, /* number of literal/length codes */ + uInt, /* number of distance codes */ + uInt *, /* that many (total) code lengths */ + uInt *, /* literal desired/actual bit depth */ + uInt *, /* distance desired/actual bit depth */ + inflate_huft **, /* literal/length tree result */ + inflate_huft **, /* distance tree result */ + z_stream *)); /* for zalloc, zfree functions */ + +extern int inflate_trees_fixed __P(( + uInt *, /* literal desired/actual bit depth */ + uInt *, /* distance desired/actual bit depth */ + inflate_huft **, /* literal/length tree result */ + inflate_huft **)); /* distance tree result */ + +extern int inflate_trees_free __P(( + inflate_huft *, /* tables to free */ + z_stream *)); /* for zfree function */ diff --git a/infutil.c b/infutil.c new file mode 100644 index 00000000..92d115fd --- /dev/null +++ b/infutil.c @@ -0,0 +1,76 @@ +/* inflate_util.c -- data and routines common to blocks and codes + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +#include "zutil.h" +#include "inftrees.h" +#include "infutil.h" + +struct inflate_codes_state {int dummy;}; /* for buggy compilers */ + +/* And'ing with mask[n] masks the lower n bits */ +uInt inflate_mask[] = { + 0x0000, + 0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff, + 0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff +}; + + +/* copy as much as possible from the sliding window to the output area */ +int inflate_flush(s, z, r) +struct inflate_blocks_state *s; +z_stream *z; +int r; +{ + uInt n; + Byte *p, *q; + + /* local copies of source and destination pointers */ + p = z->next_out; + q = s->read; + + /* compute number of bytes to copy as far as end of window */ + n = (q <= s->write ? s->write : s->end) - q; + if (n > z->avail_out) n = z->avail_out; + if (n && r == Z_BUF_ERROR) r = Z_OK; + + /* update counters */ + z->avail_out -= n; + z->total_out += n; + + /* update check information */ + s->check = adler32(s->check, q, n); + + /* copy as far as end of window */ + while (n--) *p++ = *q++; + + /* see if more to copy at beginning of window */ + if (q == s->end) + { + /* wrap source pointer */ + q = s->window; + + /* compute bytes to copy */ + n = s->write - q; + if (n > z->avail_out) n = z->avail_out; + if (n && r == Z_BUF_ERROR) r = Z_OK; + + /* update counters */ + z->avail_out -= n; + z->total_out += n; + + /* update check information */ + s->check = adler32(s->check, q, n); + + /* copy */ + while (n--) *p++ = *q++; + } + + /* update pointers */ + z->next_out = p; + s->read = q; + + /* done */ + return r; +} diff --git a/infutil.h b/infutil.h new file mode 100644 index 00000000..af073728 --- /dev/null +++ b/infutil.h @@ -0,0 +1,86 @@ +/* infutil.h -- types and macros common to blocks and codes + * Copyright (C) 1995 Mark Adler + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +/* inflate blocks semi-private state */ +struct inflate_blocks_state { + + /* mode */ + enum { + TYPE, /* get type bits (3, including end bit) */ + LENS, /* get lengths for stored */ + STORED, /* processing stored block */ + TABLE, /* get table lengths */ + BTREE, /* get bit lengths tree for a dynamic block */ + DTREE, /* get length, distance trees for a dynamic block */ + CODES, /* processing fixed or dynamic block */ + DRY, /* output remaining window bytes */ + DONE, /* finished last block, done */ + ERROR} /* got a data error--stuck here */ + mode; /* current inflate_block mode */ + + /* mode dependent information */ + union { + uInt left; /* if STORED, bytes left to copy */ + struct { + uInt table; /* table lengths (14 bits) */ + uInt index; /* index into blens (or border) */ + uInt *blens; /* bit lengths of codes */ + uInt bb; /* bit length tree depth */ + inflate_huft *tb; /* bit length decoding tree */ + } trees; /* if DTREE, decoding info for trees */ + struct inflate_codes_state + *codes; /* if CODES, current state */ + } sub; /* submode */ + uInt last; /* true if this block is the last block */ + + /* mode independent information */ + uInt bitk; /* bits in bit buffer */ + uLong bitb; /* bit buffer */ + Byte *window; /* sliding window */ + Byte *end; /* one byte after sliding window */ + Byte *read; /* window read pointer */ + Byte *write; /* window write pointer */ + uLong check; /* check on output */ + +}; + +/* defines for inflate input/output */ +/* update pointers and return */ +#define UPDBITS {s->bitb=b;s->bitk=k;} +#define UPDIN {z->avail_in=n;z->total_in+=p-z->next_in;z->next_in=p;} +#define UPDOUT {s->write=q;} +#define UPDATE {UPDBITS UPDIN UPDOUT} +#define LEAVE {UPDATE return inflate_flush(s,z,r);} +/* get bytes and bits */ +#define LOADIN {p=z->next_in;n=z->avail_in;b=s->bitb;k=s->bitk;} +#define NEEDBYTE {if(n)r=Z_OK;else LEAVE} +#define NEXTBYTE (n--,*p++) +#define NEEDBITS(j) {while(k<(j)){NEEDBYTE;b|=((uLong)NEXTBYTE)<>=(j);k-=(j);} +/* output bytes */ +#define WAVAIL (qread?s->read-q-1:s->end-q) +#define LOADOUT {q=s->write;m=WAVAIL;} +#define WRAP {if(q==s->end&&s->read!=s->window){q=s->window;m=WAVAIL;}} +#define FLUSH {UPDOUT r=inflate_flush(s,z,r); LOADOUT} +#define NEEDOUT {if(m==0){WRAP if(m==0){FLUSH WRAP if(m==0) LEAVE}}r=Z_OK;} +#define OUTBYTE(a) {*q++=(Byte)(a);m--;} +/* load local pointers */ +#define LOAD {LOADIN LOADOUT} + +/* masks for lower bits */ +extern uInt inflate_mask[]; + +/* copy as much as possible from the sliding window to the output area */ +extern int inflate_flush __P(( + struct inflate_blocks_state *, + z_stream *, + int)); + +struct internal_state {int dummy;}; /* for buggy compilers */ diff --git a/minigzip.c b/minigzip.c new file mode 100644 index 00000000..688b3a1b --- /dev/null +++ b/minigzip.c @@ -0,0 +1,210 @@ +/* minigzip.c -- simulate gzip using the zlib compression library + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* + * minigzip is a minimal implementation of the gzip utility. This is + * only an example of using zlib and isn't meant to replace the + * full-featured gzip. No attempt is made to deal with file systems + * limiting names to 14 or 8+3 characters, etc... Error checking is + * very limited. So use minigzip only for testing; use gzip for the + * real thing. On MSDOS, use only on file names without extension + * or in pipe mode. + */ + +/* $Id: minigzip.c,v 1.1 1995/04/14 13:35:59 jloup Exp $ */ + +#include +#include "zlib.h" + +#ifdef MSDOS +# include +# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) +#else +# define SET_BINARY_MODE(file) +#endif + +#define BUFLEN 4096 +#define MAX_NAME_LEN 1024 + +#define local static +/* For MSDOS and other systems with limitation on stack size. For Unix, + #define local + works also. + */ + +char *prog; + +/* =========================================================================== + * Display error message and exit + */ +void error(msg) + char *msg; +{ + fprintf(stderr, "%s: %s\n", prog, msg); + exit(1); +} + +/* =========================================================================== + * Compress input to output then close both files. + */ +void gz_compress(in, out) + FILE *in; + gzFile out; +{ + local char buf[BUFLEN]; + int len; + int err; + + for (;;) { + len = fread(buf, 1, sizeof(buf), in); + if (ferror(in)) { + perror("fread"); + exit(1); + } + if (len == 0) break; + + if (gzwrite(out, buf, len) != len) error(gzerror(out, &err)); + } + fclose(in); + if (gzclose(out) != Z_OK) error("failed gzclose"); +} + +/* =========================================================================== + * Uncompress input to output then close both files. + */ +void gz_uncompress(in, out) + gzFile in; + FILE *out; +{ + local char buf[BUFLEN]; + int len; + int err; + + for (;;) { + len = gzread(in, buf, sizeof(buf)); + if (len < 0) error (gzerror(in, &err)); + if (len == 0) break; + + if (fwrite(buf, 1, len, out) != len) error("failed fwrite"); + } + if (fclose(out)) error("failed fclose"); + + if (gzclose(in) != Z_OK) error("failed gzclose"); +} + + +/* =========================================================================== + * Compress the given file: create a corresponding .gz file and remove the + * original. + */ +void file_compress(file) + char *file; +{ + local char outfile[MAX_NAME_LEN]; + FILE *in; + gzFile out; + + strcpy(outfile, file); + strcat(outfile, ".gz"); + + in = fopen(file, "rb"); + if (in == NULL) { + perror(file); + exit(1); + } + out = gzopen(outfile, "wb"); + if (out == NULL) { + fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile); + exit(1); + } + gz_compress(in, out); + + unlink(file); +} + + +/* =========================================================================== + * Uncompress the given file and remove the original. + */ +void file_uncompress(file) + char *file; +{ + local char buf[MAX_NAME_LEN]; + char *infile, *outfile; + FILE *out; + gzFile in; + int len = strlen(file); + + strcpy(buf, file); + + if (len > 3 && strcmp(file+len-3, ".gz") == 0) { + infile = file; + outfile = buf; + outfile[len-3] = '\0'; + } else { + outfile = file; + infile = buf; + strcat(infile, ".gz"); + } + in = gzopen(infile, "rb"); + if (in == NULL) { + fprintf(stderr, "%s: can't gzopen %s\n", prog, infile); + exit(1); + } + out = fopen(outfile, "wb"); + if (out == NULL) { + perror(file); + exit(1); + } + + gz_uncompress(in, out); + + unlink(infile); +} + + +/* =========================================================================== + * Usage: minigzip [-d] [files...] + */ + +void main(argc, argv) + int argc; + char *argv[]; +{ + int uncompr = 0; + gzFile file; + + prog = argv[0]; + argc--, argv++; + + if (argc > 0) { + uncompr = (strcmp(*argv, "-d") == 0); + if (uncompr) { + argc--, argv++; + } + } + if (argc == 0) { + SET_BINARY_MODE(stdin); + SET_BINARY_MODE(stdout); + if (uncompr) { + file = gzdopen(fileno(stdin), "rb"); + if (file == NULL) error("can't gzdopen stdin"); + gz_uncompress(file, stdout); + } else { + file = gzdopen(fileno(stdout), "wb"); + if (file == NULL) error("can't gzdopen stdout"); + gz_compress(stdin, file); + } + } else { + do { + if (uncompr) { + file_uncompress(*argv); + } else { + file_compress(*argv); + } + } while (argv++, --argc); + } + exit(0); +} diff --git a/trees.c b/trees.c new file mode 100644 index 00000000..79cab9f8 --- /dev/null +++ b/trees.c @@ -0,0 +1,1048 @@ +/* trees.c -- output deflated data using Huffman coding + * Copyright (C) 1995 Jean-loup Gailly + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* + * ALGORITHM + * + * The "deflation" process uses several Huffman trees. The more + * common source values are represented by shorter bit sequences. + * + * Each code tree is stored in a compressed form which is itself + * a Huffman encoding of the lengths of all the code strings (in + * ascending order by source values). The actual code strings are + * reconstructed from the lengths in the inflate process, as described + * in the deflate specification. + * + * REFERENCES + * + * Deutsch, L.P.,"'Deflate' Compressed Data Format Specification". + * Available in ftp.uu.net:/pub/archiving/zip/doc/deflate-1.1.doc + * + * Storer, James A. + * Data Compression: Methods and Theory, pp. 49-50. + * Computer Science Press, 1988. ISBN 0-7167-8156-5. + * + * Sedgewick, R. + * Algorithms, p290. + * Addison-Wesley, 1983. ISBN 0-201-06672-6. + */ + +/* $Id: trees.c,v 1.2 1995/04/10 16:21:44 jloup Exp $ */ + +#include "deflate.h" + +#ifdef DEBUG +# include +#endif + +/* =========================================================================== + * Constants + */ + +#define MAX_BL_BITS 7 +/* Bit length codes must not exceed MAX_BL_BITS bits */ + +#define END_BLOCK 256 +/* end of block literal code */ + +#define REP_3_6 16 +/* repeat previous bit length 3-6 times (2 bits of repeat count) */ + +#define REPZ_3_10 17 +/* repeat a zero length 3-10 times (3 bits of repeat count) */ + +#define REPZ_11_138 18 +/* repeat a zero length 11-138 times (7 bits of repeat count) */ + +local int extra_lbits[LENGTH_CODES] /* extra bits for each length code */ + = {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,0}; + +local int extra_dbits[D_CODES] /* extra bits for each distance code */ + = {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}; + +local int extra_blbits[BL_CODES]/* extra bits for each bit length code */ + = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,2,3,7}; + +local uch bl_order[BL_CODES] + = {16,17,18,0,8,7,9,6,10,5,11,4,12,3,13,2,14,1,15}; +/* The lengths of the bit length codes are sent in order of decreasing + * probability, to avoid transmitting the lengths for unused bit length codes. + */ + +#define Buf_size (8 * 2*sizeof(char)) +/* Number of bits used within bi_buf. (bi_buf might be implemented on + * more than 16 bits on some systems.) + */ + +/* =========================================================================== + * Local data. These are initialized only once. + * To do: initialize at compile time to be completely reentrant. ??? + */ + +local ct_data static_ltree[L_CODES+2]; +/* The static literal tree. Since the bit lengths are imposed, there is no + * need for the L_CODES extra codes used during heap construction. However + * The codes 286 and 287 are needed to build a canonical tree (see ct_init + * below). + */ + +local ct_data static_dtree[D_CODES]; +/* The static distance tree. (Actually a trivial tree since all codes use + * 5 bits.) + */ + +local uch dist_code[512]; +/* distance codes. The first 256 values correspond to the distances + * 3 .. 258, the last 256 values correspond to the top 8 bits of + * the 15 bit distances. + */ + +local uch length_code[MAX_MATCH-MIN_MATCH+1]; +/* length code for each normalized match length (0 == MIN_MATCH) */ + +local int base_length[LENGTH_CODES]; +/* First normalized length for each code (0 = MIN_MATCH) */ + +local int base_dist[D_CODES]; +/* First normalized distance for each code (0 = distance of 1) */ + +struct static_tree_desc_s { + ct_data *static_tree; /* static tree or NULL */ + int *extra_bits; /* extra bits for each code or NULL */ + int extra_base; /* base index for extra_bits */ + int elems; /* max number of elements in the tree */ + int max_length; /* max bit length for the codes */ +}; + +local static_tree_desc static_l_desc = +{static_ltree, extra_lbits, LITERALS+1, L_CODES, MAX_BITS}; + +local static_tree_desc static_d_desc = +{static_dtree, extra_dbits, 0, D_CODES, MAX_BITS}; + +local static_tree_desc static_bl_desc = +{(ct_data *)0, extra_blbits, 0, BL_CODES, MAX_BL_BITS}; + +/* =========================================================================== + * Local (static) routines in this file. + */ + +local void ct_static_init __P((void)); +local void init_block __P((deflate_state *s)); +local void pqdownheap __P((deflate_state *s, ct_data *tree, int k)); +local void gen_bitlen __P((deflate_state *s, tree_desc *desc)); +local void gen_codes __P((ct_data *tree, int max_code, ush bl_count[])); +local void build_tree __P((deflate_state *s, tree_desc *desc)); +local void scan_tree __P((deflate_state *s, ct_data *tree, int max_code)); +local void send_tree __P((deflate_state *s, ct_data *tree, int max_code)); +local int build_bl_tree __P((deflate_state *s)); +local void send_all_trees __P((deflate_state *s, int lcodes, int dcodes, + int blcodes)); +local void compress_block __P((deflate_state *s, ct_data *ltree, + ct_data *dtree)); +local void set_data_type __P((deflate_state *s)); +local void send_bits __P((deflate_state *s, int value, int length)); +local unsigned bi_reverse __P((unsigned value, int length)); +local void bi_windup __P((deflate_state *s)); +local void copy_block __P((deflate_state *s, char *buf, unsigned len, + int header)); + +#ifndef DEBUG +# define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len) + /* Send a code of the given tree. c and tree must not have side effects */ + +#else /* DEBUG */ +# define send_code(s, c, tree) \ + { if (verbose>1) fprintf(stderr,"\ncd %3d ",(c)); \ + send_bits(s, tree[c].Code, tree[c].Len); } +#endif + +#define d_code(dist) \ + ((dist) < 256 ? dist_code[dist] : dist_code[256+((dist)>>7)]) +/* Mapping from a distance to a distance code. dist is the distance - 1 and + * must not have side effects. dist_code[256] and dist_code[257] are never + * used. + */ + +#define MAX(a,b) (a >= b ? a : b) +/* the arguments must not have side effects */ + +/* =========================================================================== + * Initialize the various 'constant' tables. + * To do: do this at compile time. + */ +local void ct_static_init() +{ + int n; /* iterates over tree elements */ + int bits; /* bit counter */ + int length; /* length value */ + int code; /* code value */ + int dist; /* distance index */ + ush bl_count[MAX_BITS+1]; + /* number of codes at each bit length for an optimal tree */ + + /* Initialize the mapping length (0..255) -> length code (0..28) */ + length = 0; + for (code = 0; code < LENGTH_CODES-1; code++) { + base_length[code] = length; + for (n = 0; n < (1< dist code (0..29) */ + dist = 0; + for (code = 0 ; code < 16; code++) { + base_dist[code] = dist; + for (n = 0; n < (1<>= 7; /* from now on, all distances are divided by 128 */ + for ( ; code < D_CODES; code++) { + base_dist[code] = dist << 7; + for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) { + dist_code[256 + dist++] = (uch)code; + } + } + Assert (dist == 256, "ct_static_init: 256+dist != 512"); + + /* Construct the codes of the static literal tree */ + for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0; + n = 0; + while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++; + while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++; + while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++; + while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++; + /* Codes 286 and 287 do not exist, but we must include them in the + * tree construction to get a canonical Huffman tree (longest code + * all ones) + */ + gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count); + + /* The static distance tree is trivial: */ + for (n = 0; n < D_CODES; n++) { + static_dtree[n].Len = 5; + static_dtree[n].Code = bi_reverse(n, 5); + } +} + +/* =========================================================================== + * Initialize the tree data structures for a new zlib stream. + */ +void ct_init(s) + deflate_state *s; +{ + if (static_dtree[0].Len == 0) { + ct_static_init(); /* To do: at compile time */ + } + + s->compressed_len = 0L; + + s->l_desc.dyn_tree = s->dyn_ltree; + s->l_desc.stat_desc = &static_l_desc; + + s->d_desc.dyn_tree = s->dyn_dtree; + s->d_desc.stat_desc = &static_d_desc; + + s->bl_desc.dyn_tree = s->bl_tree; + s->bl_desc.stat_desc = &static_bl_desc; + + s->bi_buf = 0; + s->bi_valid = 0; +#ifdef DEBUG + s->bits_sent = 0L; +#endif + + /* Initialize the first block of the first file: */ + init_block(s); +} + +/* =========================================================================== + * Initialize a new block. + */ +local void init_block(s) + deflate_state *s; +{ + int n; /* iterates over tree elements */ + + /* Initialize the trees. */ + for (n = 0; n < L_CODES; n++) s->dyn_ltree[n].Freq = 0; + for (n = 0; n < D_CODES; n++) s->dyn_dtree[n].Freq = 0; + for (n = 0; n < BL_CODES; n++) s->bl_tree[n].Freq = 0; + + s->dyn_ltree[END_BLOCK].Freq = 1; + s->opt_len = s->static_len = 0L; + s->last_lit = s->matches = 0; +} + +#define SMALLEST 1 +/* Index within the heap array of least frequent node in the Huffman tree */ + + +/* =========================================================================== + * Remove the smallest element from the heap and recreate the heap with + * one less element. Updates heap and heap_len. + */ +#define pqremove(s, tree, top) \ +{\ + top = s->heap[SMALLEST]; \ + s->heap[SMALLEST] = s->heap[s->heap_len--]; \ + pqdownheap(s, tree, SMALLEST); \ +} + +/* =========================================================================== + * Compares to subtrees, using the tree depth as tie breaker when + * the subtrees have equal frequency. This minimizes the worst case length. + */ +#define smaller(tree, n, m, depth) \ + (tree[n].Freq < tree[m].Freq || \ + (tree[n].Freq == tree[m].Freq && depth[n] <= depth[m])) + +/* =========================================================================== + * Restore the heap property by moving down the tree starting at node k, + * exchanging a node with the smallest of its two sons if necessary, stopping + * when the heap property is re-established (each father smaller than its + * two sons). + */ +local void pqdownheap(s, tree, k) + deflate_state *s; + ct_data *tree; /* the tree to restore */ + int k; /* node to move down */ +{ + int v = s->heap[k]; + int j = k << 1; /* left son of k */ + while (j <= s->heap_len) { + /* Set j to the smallest of the two sons: */ + if (j < s->heap_len && + smaller(tree, s->heap[j+1], s->heap[j], s->depth)) { + j++; + } + /* Exit if v is smaller than both sons */ + if (smaller(tree, v, s->heap[j], s->depth)) break; + + /* Exchange v with the smallest son */ + s->heap[k] = s->heap[j]; k = j; + + /* And continue down the tree, setting j to the left son of k */ + j <<= 1; + } + s->heap[k] = v; +} + +/* =========================================================================== + * Compute the optimal bit lengths for a tree and update the total bit length + * for the current block. + * IN assertion: the fields freq and dad are set, heap[heap_max] and + * above are the tree nodes sorted by increasing frequency. + * OUT assertions: the field len is set to the optimal bit length, the + * array bl_count contains the frequencies for each bit length. + * The length opt_len is updated; static_len is also updated if stree is + * not null. + */ +local void gen_bitlen(s, desc) + deflate_state *s; + tree_desc *desc; /* the tree descriptor */ +{ + ct_data *tree = desc->dyn_tree; + int max_code = desc->max_code; + ct_data *stree = desc->stat_desc->static_tree; + int *extra = desc->stat_desc->extra_bits; + int base = desc->stat_desc->extra_base; + int max_length = desc->stat_desc->max_length; + int h; /* heap index */ + int n, m; /* iterate over the tree elements */ + int bits; /* bit length */ + int xbits; /* extra bits */ + ush f; /* frequency */ + int overflow = 0; /* number of elements with bit length too large */ + + for (bits = 0; bits <= MAX_BITS; bits++) s->bl_count[bits] = 0; + + /* In a first pass, compute the optimal bit lengths (which may + * overflow in the case of the bit length tree). + */ + tree[s->heap[s->heap_max]].Len = 0; /* root of the heap */ + + for (h = s->heap_max+1; h < HEAP_SIZE; h++) { + n = s->heap[h]; + bits = tree[tree[n].Dad].Len + 1; + if (bits > max_length) bits = max_length, overflow++; + tree[n].Len = (ush)bits; + /* We overwrite tree[n].Dad which is no longer needed */ + + if (n > max_code) continue; /* not a leaf node */ + + s->bl_count[bits]++; + xbits = 0; + if (n >= base) xbits = extra[n-base]; + f = tree[n].Freq; + s->opt_len += (ulg)f * (bits + xbits); + if (stree) s->static_len += (ulg)f * (stree[n].Len + xbits); + } + if (overflow == 0) return; + + Trace((stderr,"\nbit length overflow\n")); + /* This happens for example on obj2 and pic of the Calgary corpus */ + + /* Find the first bit length which could increase: */ + do { + bits = max_length-1; + while (s->bl_count[bits] == 0) bits--; + s->bl_count[bits]--; /* move one leaf down the tree */ + s->bl_count[bits+1] += 2; /* move one overflow item as its brother */ + s->bl_count[max_length]--; + /* The brother of the overflow item also moves one step up, + * but this does not affect bl_count[max_length] + */ + overflow -= 2; + } while (overflow > 0); + + /* Now recompute all bit lengths, scanning in increasing frequency. + * h is still equal to HEAP_SIZE. (It is simpler to reconstruct all + * lengths instead of fixing only the wrong ones. This idea is taken + * from 'ar' written by Haruhiko Okumura.) + */ + for (bits = max_length; bits != 0; bits--) { + n = s->bl_count[bits]; + while (n != 0) { + m = s->heap[--h]; + if (m > max_code) continue; + if (tree[m].Len != (unsigned) bits) { + Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits)); + s->opt_len += ((long)bits - (long)tree[m].Len) + *(long)tree[m].Freq; + tree[m].Len = (ush)bits; + } + n--; + } + } +} + +/* =========================================================================== + * Generate the codes for a given tree and bit counts (which need not be + * optimal). + * IN assertion: the array bl_count contains the bit length statistics for + * the given tree and the field len is set for all tree elements. + * OUT assertion: the field code is set for all tree elements of non + * zero code length. + */ +local void gen_codes (tree, max_code, bl_count) + ct_data *tree; /* the tree to decorate */ + int max_code; /* largest code with non zero frequency */ + ush bl_count[]; /* number of codes at each bit length */ +{ + ush next_code[MAX_BITS+1]; /* next code value for each bit length */ + ush code = 0; /* running code value */ + int bits; /* bit index */ + int n; /* code index */ + + /* The distribution counts are first used to generate the code values + * without bit reversal. + */ + for (bits = 1; bits <= MAX_BITS; bits++) { + next_code[bits] = code = (code + bl_count[bits-1]) << 1; + } + /* Check that the bit counts in bl_count are consistent. The last code + * must be all ones. + */ + Assert (code + bl_count[MAX_BITS]-1 == (1<dyn_tree; + ct_data *stree = desc->stat_desc->static_tree; + int elems = desc->stat_desc->elems; + int n, m; /* iterate over heap elements */ + int max_code = -1; /* largest code with non zero frequency */ + int node = elems; /* next internal node of the tree */ + int new; /* new node being created */ + + /* Construct the initial heap, with least frequent element in + * heap[SMALLEST]. The sons of heap[n] are heap[2*n] and heap[2*n+1]. + * heap[0] is not used. + */ + s->heap_len = 0, s->heap_max = HEAP_SIZE; + + for (n = 0; n < elems; n++) { + if (tree[n].Freq != 0) { + s->heap[++(s->heap_len)] = max_code = n; + s->depth[n] = 0; + } else { + tree[n].Len = 0; + } + } + + /* The pkzip format requires that at least one distance code exists, + * and that at least one bit should be sent even if there is only one + * possible code. So to avoid special checks later on we force at least + * two codes of non zero frequency. + */ + while (s->heap_len < 2) { + new = s->heap[++(s->heap_len)] = (max_code < 2 ? ++max_code : 0); + tree[new].Freq = 1; + s->depth[new] = 0; + s->opt_len--; if (stree) s->static_len -= stree[new].Len; + /* new is 0 or 1 so it does not have extra bits */ + } + desc->max_code = max_code; + + /* The elements heap[heap_len/2+1 .. heap_len] are leaves of the tree, + * establish sub-heaps of increasing lengths: + */ + for (n = s->heap_len/2; n >= 1; n--) pqdownheap(s, tree, n); + + /* Construct the Huffman tree by repeatedly combining the least two + * frequent nodes. + */ + do { + pqremove(s, tree, n); /* n = node of least frequency */ + m = s->heap[SMALLEST]; /* m = node of next least frequency */ + + s->heap[--(s->heap_max)] = n; /* keep the nodes sorted by frequency */ + s->heap[--(s->heap_max)] = m; + + /* Create a new node father of n and m */ + tree[node].Freq = tree[n].Freq + tree[m].Freq; + s->depth[node] = (uch) (MAX(s->depth[n], s->depth[m]) + 1); + tree[n].Dad = tree[m].Dad = (ush)node; +#ifdef DUMP_BL_TREE + if (tree == s->bl_tree) { + fprintf(stderr,"\nnode %d(%d), sons %d(%d) %d(%d)", + node, tree[node].Freq, n, tree[n].Freq, m, tree[m].Freq); + } +#endif + /* and insert the new node in the heap */ + s->heap[SMALLEST] = node++; + pqdownheap(s, tree, SMALLEST); + + } while (s->heap_len >= 2); + + s->heap[--(s->heap_max)] = s->heap[SMALLEST]; + + /* At this point, the fields freq and dad are set. We can now + * generate the bit lengths. + */ + gen_bitlen(s, (tree_desc *)desc); + + /* The field len is now set, we can generate the bit codes */ + gen_codes ((ct_data *)tree, max_code, s->bl_count); +} + +/* =========================================================================== + * Scan a literal or distance tree to determine the frequencies of the codes + * in the bit length tree. + */ +local void scan_tree (s, tree, max_code) + deflate_state *s; + ct_data *tree; /* the tree to be scanned */ + int max_code; /* and its largest code of non zero frequency */ +{ + int n; /* iterates over all tree elements */ + int prevlen = -1; /* last emitted length */ + int curlen; /* length of current code */ + int nextlen = tree[0].Len; /* length of next code */ + int count = 0; /* repeat count of the current code */ + int max_count = 7; /* max repeat count */ + int min_count = 4; /* min repeat count */ + + if (nextlen == 0) max_count = 138, min_count = 3; + tree[max_code+1].Len = (ush)0xffff; /* guard */ + + for (n = 0; n <= max_code; n++) { + curlen = nextlen; nextlen = tree[n+1].Len; + if (++count < max_count && curlen == nextlen) { + continue; + } else if (count < min_count) { + s->bl_tree[curlen].Freq += count; + } else if (curlen != 0) { + if (curlen != prevlen) s->bl_tree[curlen].Freq++; + s->bl_tree[REP_3_6].Freq++; + } else if (count <= 10) { + s->bl_tree[REPZ_3_10].Freq++; + } else { + s->bl_tree[REPZ_11_138].Freq++; + } + count = 0; prevlen = curlen; + if (nextlen == 0) { + max_count = 138, min_count = 3; + } else if (curlen == nextlen) { + max_count = 6, min_count = 3; + } else { + max_count = 7, min_count = 4; + } + } +} + +/* =========================================================================== + * Send a literal or distance tree in compressed form, using the codes in + * bl_tree. + */ +local void send_tree (s, tree, max_code) + deflate_state *s; + ct_data *tree; /* the tree to be scanned */ + int max_code; /* and its largest code of non zero frequency */ +{ + int n; /* iterates over all tree elements */ + int prevlen = -1; /* last emitted length */ + int curlen; /* length of current code */ + int nextlen = tree[0].Len; /* length of next code */ + int count = 0; /* repeat count of the current code */ + int max_count = 7; /* max repeat count */ + int min_count = 4; /* min repeat count */ + + /* tree[max_code+1].Len = -1; */ /* guard already set */ + if (nextlen == 0) max_count = 138, min_count = 3; + + for (n = 0; n <= max_code; n++) { + curlen = nextlen; nextlen = tree[n+1].Len; + if (++count < max_count && curlen == nextlen) { + continue; + } else if (count < min_count) { + do { send_code(s, curlen, s->bl_tree); } while (--count != 0); + + } else if (curlen != 0) { + if (curlen != prevlen) { + send_code(s, curlen, s->bl_tree); count--; + } + Assert(count >= 3 && count <= 6, " 3_6?"); + send_code(s, REP_3_6, s->bl_tree); send_bits(s, count-3, 2); + + } else if (count <= 10) { + send_code(s, REPZ_3_10, s->bl_tree); send_bits(s, count-3, 3); + + } else { + send_code(s, REPZ_11_138, s->bl_tree); send_bits(s, count-11, 7); + } + count = 0; prevlen = curlen; + if (nextlen == 0) { + max_count = 138, min_count = 3; + } else if (curlen == nextlen) { + max_count = 6, min_count = 3; + } else { + max_count = 7, min_count = 4; + } + } +} + +/* =========================================================================== + * Construct the Huffman tree for the bit lengths and return the index in + * bl_order of the last bit length code to send. + */ +local int build_bl_tree(s) + deflate_state *s; +{ + int max_blindex; /* index of last bit length code of non zero freq */ + + /* Determine the bit length frequencies for literal and distance trees */ + scan_tree(s, (ct_data *)s->dyn_ltree, s->l_desc.max_code); + scan_tree(s, (ct_data *)s->dyn_dtree, s->d_desc.max_code); + + /* Build the bit length tree: */ + build_tree(s, (tree_desc *)(&(s->bl_desc))); + /* opt_len now includes the length of the tree representations, except + * the lengths of the bit lengths codes and the 5+5+4 bits for the counts. + */ + + /* Determine the number of bit length codes to send. The pkzip format + * requires that at least 4 bit length codes be sent. (appnote.txt says + * 3 but the actual value used is 4.) + */ + for (max_blindex = BL_CODES-1; max_blindex >= 3; max_blindex--) { + if (s->bl_tree[bl_order[max_blindex]].Len != 0) break; + } + /* Update opt_len to include the bit length tree and counts */ + s->opt_len += 3*(max_blindex+1) + 5+5+4; + Tracev((stderr, "\ndyn trees: dyn %ld, stat %ld", + s->opt_len, s->static_len)); + + return max_blindex; +} + +/* =========================================================================== + * Send the header for a block using dynamic Huffman trees: the counts, the + * lengths of the bit length codes, the literal tree and the distance tree. + * IN assertion: lcodes >= 257, dcodes >= 1, blcodes >= 4. + */ +local void send_all_trees(s, lcodes, dcodes, blcodes) + deflate_state *s; + int lcodes, dcodes, blcodes; /* number of codes for each tree */ +{ + int rank; /* index in bl_order */ + + Assert (lcodes >= 257 && dcodes >= 1 && blcodes >= 4, "not enough codes"); + Assert (lcodes <= L_CODES && dcodes <= D_CODES && blcodes <= BL_CODES, + "too many codes"); + Tracev((stderr, "\nbl counts: ")); + send_bits(s, lcodes-257, 5); /* not +255 as stated in appnote.txt */ + send_bits(s, dcodes-1, 5); + send_bits(s, blcodes-4, 4); /* not -3 as stated in appnote.txt */ + for (rank = 0; rank < blcodes; rank++) { + Tracev((stderr, "\nbl code %2d ", bl_order[rank])); + send_bits(s, s->bl_tree[bl_order[rank]].Len, 3); + } + Tracev((stderr, "\nbl tree: sent %ld", s->bits_sent)); + + send_tree(s, (ct_data *)s->dyn_ltree, lcodes-1); /* literal tree */ + Tracev((stderr, "\nlit tree: sent %ld", s->bits_sent)); + + send_tree(s, (ct_data *)s->dyn_dtree, dcodes-1); /* distance tree */ + Tracev((stderr, "\ndist tree: sent %ld", s->bits_sent)); +} + +/* =========================================================================== + * Determine the best encoding for the current block: dynamic trees, static + * trees or store, and output the encoded block to the zip file. This function + * returns the total compressed length for the file so far. + */ +ulg ct_flush_block(s, buf, stored_len, eof) + deflate_state *s; + char *buf; /* input block, or NULL if too old */ + ulg stored_len; /* length of input block */ + int eof; /* true if this is the last block for a file */ +{ + ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ + int max_blindex; /* index of last bit length code of non zero freq */ + + /* Check if the file is ascii or binary */ + if (s->data_type == UNKNOWN) set_data_type(s); + + /* Construct the literal and distance trees */ + build_tree(s, (tree_desc *)(&(s->l_desc))); + Tracev((stderr, "\nlit data: dyn %ld, stat %ld", s->opt_len, + s->static_len)); + + build_tree(s, (tree_desc *)(&(s->d_desc))); + Tracev((stderr, "\ndist data: dyn %ld, stat %ld", s->opt_len, + s->static_len)); + /* At this point, opt_len and static_len are the total bit lengths of + * the compressed block data, excluding the tree representations. + */ + + /* Build the bit length tree for the above two trees, and get the index + * in bl_order of the last bit length code to send. + */ + max_blindex = build_bl_tree(s); + + /* Determine the best encoding. Compute first the block length in bytes */ + opt_lenb = (s->opt_len+3+7)>>3; + static_lenb = (s->static_len+3+7)>>3; + + Tracev((stderr, "\nopt %lu(%lu) stat %lu(%lu) stored %lu lit %u ", + opt_lenb, s->opt_len, static_lenb, s->static_len, stored_len, + s->last_lit)); + + if (static_lenb <= opt_lenb) opt_lenb = static_lenb; + + /* If compression failed and this is the first and last block, + * and if the .zip file can be seeked (to rewrite the local header), + * the whole file is transformed into a stored file: + */ +#ifdef STORED_FILE_OK +# ifdef FORCE_METHOD + if (level == 1 && eof && compressed_len == 0L) { /* force stored file */ +# else + if (stored_len <= opt_lenb && eof && s->compressed_len==0L && seekable()) { +# endif + /* Since LIT_BUFSIZE <= 2*WSIZE, the input data must be there: */ + if (buf == (char*)0) error ("block vanished"); + + copy_block(buf, (unsigned)stored_len, 0); /* without header */ + s->compressed_len = stored_len << 3; + s->method = STORED; + } else +#endif /* STORED_FILE_OK */ + +#ifdef FORCE_METHOD + if (level == 2 && buf != (char*)0) { /* force stored block */ +#else + if (stored_len+4 <= opt_lenb && buf != (char*)0) { + /* 4: two words for the lengths */ +#endif + /* The test buf != NULL is only necessary if LIT_BUFSIZE > WSIZE. + * Otherwise we can't have processed more than WSIZE input bytes since + * the last block flush, because compression would have been + * successful. If LIT_BUFSIZE <= WSIZE, it is never too late to + * transform a block into a stored block. + */ + send_bits(s, (STORED_BLOCK<<1)+eof, 3); /* send block type */ + s->compressed_len = (s->compressed_len + 3 + 7) & ~7L; + s->compressed_len += (stored_len + 4) << 3; + + copy_block(s, buf, (unsigned)stored_len, 1); /* with header */ + +#ifdef FORCE_METHOD + } else if (level == 3) { /* force static trees */ +#else + } else if (static_lenb == opt_lenb) { +#endif + send_bits(s, (STATIC_TREES<<1)+eof, 3); + compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree); + s->compressed_len += 3 + s->static_len; + } else { + send_bits(s, (DYN_TREES<<1)+eof, 3); + send_all_trees(s, s->l_desc.max_code+1, s->d_desc.max_code+1, + max_blindex+1); + compress_block(s, (ct_data *)s->dyn_ltree, (ct_data *)s->dyn_dtree); + s->compressed_len += 3 + s->opt_len; + } + Assert (s->compressed_len == s->bits_sent, "bad compressed size"); + init_block(s); + + if (eof) { + bi_windup(s); + s->compressed_len += 7; /* align on byte boundary */ + } + Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3, + s->compressed_len-7*eof)); + + return s->compressed_len >> 3; +} + +/* =========================================================================== + * Save the match info and tally the frequency counts. Return true if + * the current block must be flushed. + */ +int ct_tally (s, dist, lc) + deflate_state *s; + int dist; /* distance of matched string */ + int lc; /* match length-MIN_MATCH or unmatched char (if dist==0) */ +{ + s->d_buf[s->last_lit] = (ush)dist; + s->l_buf[s->last_lit++] = (uch)lc; + if (dist == 0) { + /* lc is the unmatched char */ + s->dyn_ltree[lc].Freq++; + } else { + s->matches++; + /* Here, lc is the match length - MIN_MATCH */ + dist--; /* dist = match distance - 1 */ + Assert((ush)dist < (ush)MAX_DIST(s) && + (ush)lc <= (ush)(MAX_MATCH-MIN_MATCH) && + (ush)d_code(dist) < (ush)D_CODES, "ct_tally: bad match"); + + s->dyn_ltree[length_code[lc]+LITERALS+1].Freq++; + s->dyn_dtree[d_code(dist)].Freq++; + } + + /* Try to guess if it is profitable to stop the current block here */ + if (s->level > 2 && (s->last_lit & 0xfff) == 0) { + /* Compute an upper bound for the compressed length */ + ulg out_length = (ulg)s->last_lit*8L; + ulg in_length = (ulg)s->strstart - s->block_start; + int dcode; + for (dcode = 0; dcode < D_CODES; dcode++) { + out_length += (ulg)s->dyn_dtree[dcode].Freq * + (5L+extra_dbits[dcode]); + } + out_length >>= 3; + Tracev((stderr,"\nlast_lit %u, in %ld, out ~%ld(%ld%%) ", + s->last_lit, in_length, out_length, + 100L - out_length*100L/in_length)); + if (s->matches < s->last_lit/2 && out_length < in_length/2) return 1; + } + return (s->last_lit == s->lit_bufsize-1); + /* We avoid equality with lit_bufsize because of wraparound at 64K + * on 16 bit machines and because stored blocks are restricted to + * 64K-1 bytes. + */ +} + +/* =========================================================================== + * Send the block data compressed using the given Huffman trees + */ +local void compress_block(s, ltree, dtree) + deflate_state *s; + ct_data *ltree; /* literal tree */ + ct_data *dtree; /* distance tree */ +{ + unsigned dist; /* distance of matched string */ + int lc; /* match length or unmatched char (if dist == 0) */ + unsigned lx = 0; /* running index in l_buf */ + unsigned code; /* the code to send */ + int extra; /* number of extra bits to send */ + + if (s->last_lit != 0) do { + dist = s->d_buf[lx]; + lc = s->l_buf[lx++]; + if (dist == 0) { + send_code(s, lc, ltree); /* send a literal byte */ + Tracecv(isgraph(lc), (stderr," '%c' ", lc)); + } else { + /* Here, lc is the match length - MIN_MATCH */ + code = length_code[lc]; + send_code(s, code+LITERALS+1, ltree); /* send the length code */ + extra = extra_lbits[code]; + if (extra != 0) { + lc -= base_length[code]; + send_bits(s, lc, extra); /* send the extra length bits */ + } + dist--; /* dist is now the match distance - 1 */ + code = d_code(dist); + Assert (code < D_CODES, "bad d_code"); + + send_code(s, code, dtree); /* send the distance code */ + extra = extra_dbits[code]; + if (extra != 0) { + dist -= base_dist[code]; + send_bits(s, dist, extra); /* send the extra distance bits */ + } + } /* literal or match pair ? */ + + /* Check that the overlay between pending_buf and d_buf+l_buf is ok: */ + Assert(s->pending < s->lit_bufsize + 2*lx, "pendingBuf overflow"); + + } while (lx < s->last_lit); + + send_code(s, END_BLOCK, ltree); +} + +/* =========================================================================== + * Set the data type to ASCII or BINARY, using a crude approximation: + * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise. + * IN assertion: the fields freq of dyn_ltree are set and the total of all + * frequencies does not exceed 64K (to fit in an int on 16 bit machines). + */ +local void set_data_type(s) + deflate_state *s; +{ + int n = 0; + unsigned ascii_freq = 0; + unsigned bin_freq = 0; + while (n < 7) bin_freq += s->dyn_ltree[n++].Freq; + while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq; + while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq; + s->data_type = bin_freq > (ascii_freq >> 2) ? BINARY : ASCII; +} + +/* =========================================================================== + * Output a short LSB first on the stream. + * IN assertion: there is enough room in pendingBuf. + */ +#define put_short(s, w) { \ + put_byte(s, (uch)((w) & 0xff)); \ + put_byte(s, (uch)((ush)(w) >> 8)); \ +} + +/* =========================================================================== + * Send a value on a given number of bits. + * IN assertion: length <= 16 and value fits in length bits. + */ +local void send_bits(s, value, length) + deflate_state *s; + int value; /* value to send */ + int length; /* number of bits */ +{ +#ifdef DEBUG + Tracev((stderr," l %2d v %4x ", length, value)); + Assert(length > 0 && length <= 15, "invalid length"); + s->bits_sent += (ulg)length; +#endif + /* If not enough room in bi_buf, use (valid) bits from bi_buf and + * (16 - bi_valid) bits from value, leaving (width - (16-bi_valid)) + * unused bits in value. + */ + if (s->bi_valid > (int)Buf_size - length) { + s->bi_buf |= (value << s->bi_valid); + put_short(s, s->bi_buf); + s->bi_buf = (ush)value >> (Buf_size - s->bi_valid); + s->bi_valid += length - Buf_size; + } else { + s->bi_buf |= value << s->bi_valid; + s->bi_valid += length; + } +} + +/* =========================================================================== + * Reverse the first len bits of a code, using straightforward code (a faster + * method would use a table) + * IN assertion: 1 <= len <= 15 + */ +local unsigned bi_reverse(code, len) + unsigned code; /* the value to invert */ + int len; /* its bit length */ +{ + register unsigned res = 0; + do { + res |= code & 1; + code >>= 1, res <<= 1; + } while (--len > 0); + return res >> 1; +} + +/* =========================================================================== + * Write out any remaining bits in an incomplete byte. + */ +local void bi_windup(s) + deflate_state *s; +{ + if (s->bi_valid > 8) { + put_short(s, s->bi_buf); + } else if (s->bi_valid > 0) { + put_byte(s, s->bi_buf); + } + s->bi_buf = 0; + s->bi_valid = 0; +#ifdef DEBUG + s->bits_sent = (s->bits_sent+7) & ~7; +#endif +} + +/* =========================================================================== + * Copy a stored block, storing first the length and its + * one's complement if requested. + */ +local void copy_block(s, buf, len, header) + deflate_state *s; + char *buf; /* the input data */ + unsigned len; /* its length */ + int header; /* true if block header must be written */ +{ + bi_windup(s); /* align on byte boundary */ + + if (header) { + put_short(s, (ush)len); + put_short(s, (ush)~len); +#ifdef DEBUG + s->bits_sent += 2*16; +#endif + } +#ifdef DEBUG + s->bits_sent += (ulg)len<<3; +#endif + while (len--) { + put_byte(s, *buf++); + } +} diff --git a/uncompr.c b/uncompr.c new file mode 100644 index 00000000..4c8b3af0 --- /dev/null +++ b/uncompr.c @@ -0,0 +1,58 @@ +/* uncompr.c -- decompress a memory buffer + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: uncompr.c,v 1.4 1995/04/10 16:22:22 jloup Exp $ */ + +#include "zlib.h" + +/* =========================================================================== + Decompresses the source buffer into the destination buffer. sourceLen is + the byte length of the source buffer. Upon entry, destLen is the total + size of the destination buffer, which must be large enough to hold the + entire uncompressed data. (The size of the uncompressed data must have + been saved previously by the compressor and transmitted to the decompressor + by some mechanism outside the scope of this compression library.) + Upon exit, destLen is the actual size of the compressed buffer. + This function can be used to decompress a whole file at once if the + input file is mmap'ed. + + uncompress returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_BUF_ERROR if there was not enough room in the output + buffer, or Z_DATA_ERROR if the input data was corrupted. +*/ +int uncompress (dest, destLen, source, sourceLen) + Byte *dest; + uLong *destLen; + Byte *source; + uLong sourceLen; +{ + z_stream stream; + int err; + + stream.next_in = source; + stream.avail_in = (uInt)sourceLen; + /* Check for source > 64K on 16-bit machine: */ + if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; + + stream.next_out = dest; + stream.avail_out = (uInt)*destLen; + if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; + + stream.zalloc = (alloc_func)0; + stream.zfree = (free_func)0; + + err = inflateInit(&stream); + if (err != Z_OK) return err; + + err = inflate(&stream, Z_FINISH); + if (err != Z_STREAM_END) { + inflateEnd(&stream); + return err; + } + *destLen = stream.total_out; + + err = inflateEnd(&stream); + return err; +} diff --git a/zconf.h b/zconf.h new file mode 100644 index 00000000..29496d72 --- /dev/null +++ b/zconf.h @@ -0,0 +1,66 @@ +/* zconf.h -- configuration of the zlib compression library + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* $Id: zconf.h,v 1.7 1995/04/12 20:42:28 jloup Exp $ */ + +#ifndef _ZCONF_H +#define _ZCONF_H + +/* + The library does not install any signal handler. It is recommended to + add at least a handler for SIGSEGV when decompressing; the library checks + the consistency of the input data whenever possible but may go nuts + for some forms of corrupted input. + */ + +/* + * Compile with -DMAXSEG_64K if the alloc function cannot allocate more + * than 64k bytes at a time (needed on systems with 16-bit int). + */ +#if defined(_GNUC__) && !defined(__32BIT__) +# define __32BIT__ +#endif +#if defined(__MSDOS__) && !defined(MSDOS) +# define MSDOS +#endif +#if defined(MSDOS) && !defined(__32BIT__) +# define MAXSEG_64K +#endif + +#ifdef MAXSEG_64K +# define MAX_MEM_LEVEL 8 +#else +# define MAX_MEM_LEVEL 9 +#endif + + /* Type declarations */ + +#ifndef __P /* function prototypes */ +# if defined(__STDC__) || defined(MSDOS) +# define __P(args) args +# else +# define __P(args) () +# endif +#endif + +#ifndef Byte + typedef unsigned char Byte; /* 8 bits */ +#endif +#ifndef uInt + typedef unsigned int uInt; /* may be 16 or 32 bits */ +#endif +#ifndef uLong + typedef unsigned long uLong; /* 32 bits or more */ +#endif +#ifndef voidp +# if defined(__STDC__) || defined(MSDOS) + typedef void *voidp; +# else + typedef Byte *voidp; +# endif +#endif + +#endif /* _ZCONF_H */ + diff --git a/zlib.h b/zlib.h new file mode 100644 index 00000000..d1f2ca96 --- /dev/null +++ b/zlib.h @@ -0,0 +1,604 @@ +/* zlib.h -- interface of the 'zlib' general purpose compression library + version 0.7 April 14th, 1995. + + Copyright (C) 1995 Jean-loup Gailly and Mark Adler + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. + + Jean-loup Gailly Mark Adler + gzip@prep.ai.mit.edu madler@cco.caltech.edu + */ + +#ifndef _ZLIB_H +#define _ZLIB_H + +#include "zconf.h" + +#define ZLIB_VERSION "0.7" + +/* + The 'zlib' compression library provides in-memory compression and + decompression functions, including integrity checks of the uncompressed + data. This version of the library supports only one compression method + (deflation) but other algorithms may be added later and will have the same + stream interface. + + For compression the application must provide the output buffer and + may optionally provide the input buffer for optimization. For decompression, + the application must provide the input buffer and may optionally provide + the output buffer for optimization. + + Compression can be done in a single step if the buffers are large + enough (for example if an input file is mmap'ed), or can be done by + repeated calls of the compression function. In the latter case, the + application must provide more input and/or consume the output + (providing more output space) before each call. +*/ + +typedef voidp (*alloc_func) __P((voidp opaque, uInt items, uInt size)); +typedef void (*free_func) __P((voidp opaque, voidp address)); + +struct internal_state; + +typedef struct z_stream_s { + Byte *next_in; /* next input byte */ + uInt avail_in; /* number of bytes available at next_in */ + uLong total_in; /* total nb of input bytes read so far */ + + Byte *next_out; /* next output byte should be put there */ + uInt avail_out; /* remaining free space at next_out */ + uLong total_out; /* total nb of bytes output so far */ + + char *msg; /* last error message, NULL if no error */ + struct internal_state *state; /* not visible by applications */ + + alloc_func zalloc; /* used to allocate the internal state */ + free_func zfree; /* used to free the internal state */ + voidp opaque; /* private data object passed to zalloc and zfree */ + + Byte data_type; /* best guess about the data type: ascii or binary */ + +} z_stream; + +/* + The application must update next_in and avail_in when avail_in has + dropped to zero. It must update next_out and avail_out when avail_out + has dropped to zero. The application must initialize zalloc, zfree and + opaque before calling the init function. All other fields are set by the + compression library and must not be updated by the application. + + The opaque value provided by the application will be passed as first + parameter for calls of zalloc and zfree. This can be useful for custom + memory management. The compression library attaches no meaning to the + opaque value. + + zalloc must return Z_NULL if there is not enough memory for the object. + On 16-bit systems, the functions zalloc and zfree must be able to allocate + exactly 65536 bytes, but will not be require to allocate more than this + if the symbol MAXSEG_64K is defined (see zconf.h). + + The fields total_in and total_out can be used for statistics or + progress reports. After compression, total_in holds the total size of + the uncompressed data and may be saved for use in the decompressor + (particularly if the decompressor wants to decompress everything in + a single step). +*/ + + /* constants */ + +#define Z_NO_FLUSH 0 +#define Z_PARTIAL_FLUSH 1 +#define Z_FULL_FLUSH 2 +#define Z_FINISH 4 +/* See deflate() below for the usage of these constants */ + +#define Z_OK 0 +#define Z_STREAM_END 1 +#define Z_ERRNO (-1) +#define Z_STREAM_ERROR (-2) +#define Z_DATA_ERROR (-3) +#define Z_MEM_ERROR (-4) +#define Z_BUF_ERROR (-5) +/* error codes for the compression/decompression functions */ + +#define Z_BEST_SPEED 1 +#define Z_BEST_COMPRESSION 9 +#define Z_DEFAULT_COMPRESSION (-1) +/* compression levels */ + +#define Z_FILTERED 1 +#define Z_HUFFMAN_ONLY 2 +#define Z_DEFAULT_STRATEGY 0 + +#define Z_BINARY 0 +#define Z_ASCII 1 +#define Z_UNKNOWN 2 +/* Used to set the data_type field */ + +#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ + +extern char *zlib_version; +/* The application can compare zlib_version and ZLIB_VERSION for consistency. + If the first character differs, the library code actually used is + not compatible with the zlib.h header file used by the application. + */ + + /* basic functions */ + +extern int deflateInit __P((z_stream *strm, int level)); +/* + Initializes the internal stream state for compression. The fields + zalloc, zfree and opaque must be initialized before by the caller. + If zalloc and zfree are set to Z_NULL, deflateInit updates them to + use default allocation functions. + + The compression level must be Z_DEFAULT_COMPRESSION, or between 1 and 9: + 1 gives best speed, 9 gives best compression. Z_DEFAULT_COMPRESSION requests + a default compromise between speed and compression (currently equivalent + to level 6). + + deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_STREAM_ERROR if the stream state was inconsistent (such + as zalloc being NULL). msg is set to null if there is no error message. + deflateInit does not perform any compression: this will be done by + deflate(). */ + + +extern int deflate __P((z_stream *strm, int flush)); +/* + Performs one or both of the following actions: + + - Compress more input starting at next_in and update next_in and avail_in + accordingly. If not all input can be processed (because there is not + enough room in the output buffer), next_in is updated and processing + will resume at this point for the next call of deflate(). + + - Provide more output starting at next_out and update next_out and avail_out + accordingly. This action is forced if the parameter flush is non zero. + Forcing flush frequently degrades the compression ratio, so this parameter + should be set only when necessary (in interactive applications). + Some output may be provided even if flush is not set. + + Before the call of deflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming + more output, and updating avail_in or avail_out accordingly. + The application can consume the compressed output when the output + buffer is full (avail_out == 0), or after each call of deflate(). + + If the parameter flush is set to Z_PARTIAL_FLUSH, the current compression + block is byte aligned and flushed to the output buffer so that the + decompressor can get all input data available so far; if the compression + method is 8 (deflate without partial flush capability), the current block + is terminated. If flush is set to Z_FULL_FLUSH, the compression block is + terminated, a special marker is output and the compression dictionary is + discarded; this is useful to allow the decompressor to synchronize if one + compressed block has been damaged. + Flushing degrades compression and so should be used only when necessary. + Using Z_FULL_FLUSH too often can seriously degrade the compression. + + If the parameter flush is set to Z_FINISH, all pending input is + processed and all pending output is flushed. The next operation on this + stream must be another call of deflate with Z_FINISH but no more input data + (unchanged avail_in) if this call returned with avail_out equal to zero, + or a call of deflateEnd to deallocate the compression state. Z_FINISH can + be used immediately after deflateInit if all the compression is to be + done in a single step. In this case, avail_out must be at least 0.1% + larger than avail_in plus 8 bytes. + + deflate() may update strm->data_type if it can make a good guess about + the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered + binary. This field is only for information purposes and does not affect + the compression algorithm in any manner. + + deflate() return Z_OK if some progress has been made (more input processed + or more output produced), Z_STREAM_ERROR if the stream state was + inconsistent (for example if next_in or next_out was NULL), Z_BUF_ERROR if + no progress is possible or if there was not enough room in the output buffer + when Z_FINISH is used. +*/ + + +extern int deflateEnd __P((z_stream *strm)); +/* + All dynamically allocated data structures for this stream are freed. + This function discards any unprocessed input and does not flush any + pending output. + + deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the + stream state was inconsistent. In the error case, msg may be set + but then points to a static string (which must not be deallocated). +*/ + + +extern int inflateInit __P((z_stream *strm)); +/* + Initializes the internal stream state for decompression. The fields + zalloc and zfree must be initialized before by the caller. If zalloc and + zfree are set to Z_NULL, deflateInit updates them to use default allocation + functions. + + inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not + enough memory, Z_STREAM_ERROR if the stream state was inconsistent (such + as zalloc being NULL). msg is set to null if there is no error message. + inflateInit does not perform any decompression: this will be done by + inflate(). +*/ + + +extern int inflate __P((z_stream *strm, int flush)); +/* + Performs one or both of the following actions: + + - Decompress more input starting at next_in and update next_in and avail_in + accordingly. If not all input can be processed (because there is not + enough room in the output buffer), next_in is updated and processing + will resume at this point for the next call of inflate(). + + - Provide more output starting at next_out and update next_out and avail_out + accordingly. inflate() always provides as much output as possible + (until no more input data or no more space in the output buffer). + + Before the call of inflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming + more output, and updating the next_* and avail_* values accordingly. + The application can consume the uncompressed output when the output + buffer is full (avail_out == 0), or after each call of inflate(). + + If the parameter flush is set to Z_PARTIAL_FLUSH, inflate flushes as much + output as possible to the output buffer. The flushing behavior of inflate is + not specified for values of the flush paramater other than Z_PARTIAL_FLUSH + and Z_FINISH, but the current implementation actually flushes as much output + as possible anyway. + + inflate() should normally be called until it returns Z_STREAM_END or an + error. However if all decompression is to be performed in a single step + (a single call of inflate), the parameter flush should be set to + Z_FINISH. In this case all pending input is processed and all pending + output is flushed; avail_out must be large enough to hold all the + uncompressed data. (The size of the uncompressed data may have been saved + by the compressor for this purpose.) The next operation on this stream must + be inflateEnd to deallocate the decompression state. + + inflate() returns Z_OK if some progress has been made (more input + processed or more output produced), Z_STREAM_END if the end of the + compressed data has been reached, Z_DATA_ERROR if the input data was + corrupted, Z_STREAM_ERROR if the stream structure was inconsistent (for + example if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough + memory, Z_BUF_ERROR if no progress is possible or if there was not enough + room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR case, + the application may then call inflateSync to look for a good compression + block. +*/ + + +extern int inflateEnd __P((z_stream *strm)); +/* + All dynamically allocated data structures for this stream are freed. + This function discards any unprocessed input and does not flush any + pending output. + + inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state + was inconsistent. In the error case, msg may be set but then points to a + static string (which must not be deallocated). +*/ + + /* advanced functions */ + +/* + The following functions are needed only in some special applications. +*/ + +extern int deflateInit2 __P((z_stream *strm, + int level, + int method, + int windowBits, + int memLevel, + int strategy)); +/* + This is another version of deflateInit with more compression options. The + fields next_in, zalloc and zfree must be initialized before by the caller. + + The method parameter is the compression method. It must be 8 in this + version of the library. (Method 9 will allow a 64K history buffer and + partial block flushes.) + + The windowBits parameter is the base two logarithm of the window size + (the size of the history buffer). It should be in the range 8..15 for this + version of the library (the value 16 will be allowed soon). Larger values + of this parameter result in better compression at the expense of memory + usage. The default value is 15 if deflateInit is used instead. + + The memLevel parameter specifies how much memory should be allocated + for the internal compression state. memLevel=1 uses minimum memory but + is slow and reduces compression ratio; memLevel=9 uses maximum memory + for optimal speed. The default value is 8. + + The strategy parameter is used to tune the compression algorithm. Use + the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data + produced by a filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman + encoding only (no string match). Filtered data consists mostly of small + values with a somewhat random distribution. In this case, the + compression algorithm is tuned to compress them better. The strategy + parameter only affects the compression ratio but not the correctness of + the compressed output even if it is not set appropriately. + + If next_in is not null, the library will use this buffer to hold also + some history information; the buffer must either hold the entire input + data, or have at least (1< + +#include "zutil.h" + +char *zlib_version = ZLIB_VERSION; + +char *z_errmsg[] = { +"stream end", /* Z_STREAM_END 1 */ +"", /* Z_OK 0 */ +"file error", /* Z_ERRNO (-1) */ +"stream error", /* Z_STREAM_ERROR (-2) */ +"data error", /* Z_DATA_ERROR (-3) */ +"insufficient memory", /* Z_MEM_ERROR (-4) */ +"buffer error", /* Z_BUF_ERROR (-5) */ +""}; + + +void z_error (m) + char *m; +{ + fprintf(stderr, "%s\n", m); + exit(1); +} + +#ifndef HAVE_MEMCPY + +void zmemcpy(dest, source, len) + Byte* dest; + Byte* source; + uInt len; +{ + if (len == 0) return; + do { + *dest++ = *source++; /* ??? to be unrolled */ + } while (--len != 0); +} + +void zmemzero(dest, len) + Byte* dest; + uInt len; +{ + if (len == 0) return; + do { + *dest++ = 0; /* ??? to be unrolled */ + } while (--len != 0); +} +#endif + +#if defined(MSDOS) && !defined(USE_CALLOC) +# ifdef __TURBOC__ + +/* Turbo C malloc() does not allow dynamic allocation of 64K bytes + * and farmalloc(64K) returns a pointer with an offset of 8, so we + * must fix the pointer. Warning: the pointer must be put back to its + * original form in order to free it, use zcfree(). + */ + +#define MAX_PTR 10 +/* 10*64K = 640K */ + +local int next_ptr = 0; + +typedef struct ptr_table_s { + voidp org_ptr; + voidp new_ptr; +} ptr_table; + +local ptr_table table[MAX_PTR]; +/* This table is used to remember the original form of pointers + * to large buffers (64K). Such pointers are normalized with a zero offset. + * Since MSDOS is not a preemptive multitasking OS, this table is not + * protected from concurrent access. This hack doesn't work anyway on + * a protected system like OS/2. Use Microsoft C instead. + */ + +voidp zcalloc (voidp opaque, unsigned items, unsigned size) +{ + voidp buf; + ulg bsize = (ulg)items*size; + + if (bsize < 65536L) { + buf = farmalloc(bsize); + if (*(ush*)&buf != 0) return buf; + } else { + buf = farmalloc(bsize + 16L); + } + if (buf == NULL || next_ptr >= MAX_PTR) return NULL; + table[next_ptr].org_ptr = buf; + + /* Normalize the pointer to seg:0 */ + *((ush*)&buf+1) += ((ush)((uch*)buf-0) + 15) >> 4; + *(ush*)&buf = 0; + table[next_ptr++].new_ptr = buf; + return buf; +} + +void zcfree (voidp opaque, voidp ptr) +{ + int n; + if (*(ush*)&ptr != 0) { /* object < 64K */ + farfree(ptr); + return; + } + /* Find the original pointer */ + for (n = 0; n < next_ptr; n++) { + if (ptr != table[n].new_ptr) continue; + + farfree(table[n].org_ptr); + while (++n < next_ptr) { + table[n-1] = table[n]; + } + next_ptr--; + return; + } + z_error("zcfree: ptr not found"); +} + +# else /* MSC */ + +#if (!defined(_MSC_VER) || (_MSC_VER < 600)) +# define _halloc halloc +# define _hfree hfree +#endif + +voidp zcalloc (voidp opaque, unsigned items, unsigned size) +{ + return _halloc((long)items, size); +} + +void zcfree (voidp opaque, voidp ptr) +{ + return _hfree(ptr); +} + +# endif /* __TURBOC__ ? */ + +#else /* !MSDOS */ + +extern voidp calloc __P((uInt items, uInt size)); +extern void free __P((voidp ptr)); + +voidp zcalloc (opaque, items, size) + voidp opaque; + unsigned items; + unsigned size; +{ + return calloc(items, size); +} + +void zcfree (opaque, ptr) + voidp opaque; + voidp ptr; +{ + free(ptr); +} + +#endif /* MSDOS */ diff --git a/zutil.h b/zutil.h new file mode 100644 index 00000000..a1108e62 --- /dev/null +++ b/zutil.h @@ -0,0 +1,166 @@ +/* zutil.h -- internal interface and configuration of the compression library + * Copyright (C) 1995 Jean-loup Gailly. + * For conditions of distribution and use, see copyright notice in zlib.h + */ + +/* WARNING: this file should *not* be used by applications. It is + part of the implementation of the compression library and is + subject to change. Applications should only use zlib.h. + */ + +/* $Id: zutil.h,v 1.4 1995/04/14 10:22:17 jloup Exp $ */ + +#ifndef _Z_UTIL_H +#define _Z_UTIL_H + +#include "zlib.h" + +#ifdef MSDOS +# include +#else + extern int errno; +#endif + +#ifndef local +# define local static +#endif +/* compile with -Dlocal if your debugger can't find static symbols */ + +typedef unsigned char uch; +typedef unsigned short ush; +typedef unsigned long ulg; + +extern char *z_errmsg[]; /* indexed by 1-zlib_error */ + +#define ERR_RETURN(strm,err) return (strm->msg=z_errmsg[1-err], err) +/* To be used only when the state is known to be valid */ + + /* common constants */ + +#define DEFLATED 8 + +#ifndef WBITS +# define WBITS 15 /* 32K window */ +#endif + +#ifndef MEM_LEVEL +# define MEM_LEVEL 8 +#endif + +#define STORED_BLOCK 0 +#define STATIC_TREES 1 +#define DYN_TREES 2 +/* The three kinds of block type */ + +#define MIN_MATCH 3 +#define MAX_MATCH 258 +/* The minimum and maximum match lengths */ + + /* target dependencies */ + +#ifdef MSDOS +# define OS_CODE 0x00 +# ifdef __TURBOC__ +# include +# define exit(n) _exit(n) +# else /* MSC */ +# include +# endif +#endif + +#ifdef OS2 +# define OS_CODE 0x06 +#endif + +#ifdef WIN32 /* Windows NT */ +# define OS_CODE 0x0b +#endif + +#if defined(VAXC) || defined(VMS) +# define OS_CODE 0x02 +# define FOPEN(name, mode) \ + fopen((name), (mode), "mbc=60", "ctx=stm", "rfm=fix", "mrs=512") +#endif + +#ifdef AMIGA +# define OS_CODE 0x01 +#endif + +#if defined(ATARI) || defined(atarist) +# define OS_CODE 0x05 +#endif + +#ifdef MACOS +# define OS_CODE 0x07 +#endif + +#ifdef __50SERIES /* Prime/PRIMOS */ +# define OS_CODE 0x0F +#endif + +#ifdef TOPS20 +# define OS_CODE 0x0a +#endif + + /* Common defaults */ + +#ifndef OS_CODE +# define OS_CODE 0x03 /* assume Unix */ +#endif + +#ifndef FOPEN +# define FOPEN(name, mode) fopen((name), (mode)) +#endif + + /* functions */ + +#ifdef HAVE_STRERROR + extern char *strerror __P((int)); +# define zstrerror(errnum) strerror(errnum) +#else +# define zstrerror(errnum) "" +#endif + +#if defined(__STDC__) && !defined(HAVE_MEMCPY) +# define HAVE_MEMCPY +#endif +#ifdef HAVE_MEMCPY +# define zmemcpy memcpy +# define zmemzero(dest, len) memset(dest, 0, len) +#else + extern void zmemcpy __P((Byte* dest, Byte* source, uInt len)); + extern void zmemzero __P((Byte* dest, uInt len)); +#endif + +/* Diagnostic functions */ +#ifdef DEBUG +# include +# ifndef verbose +# define verbose 0 +# endif +# define Assert(cond,msg) {if(!(cond)) z_error(msg);} +# define Trace(x) fprintf x +# define Tracev(x) {if (verbose) fprintf x ;} +# define Tracevv(x) {if (verbose>1) fprintf x ;} +# define Tracec(c,x) {if (verbose && (c)) fprintf x ;} +# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;} +#else +# define Assert(cond,msg) +# define Trace(x) +# define Tracev(x) +# define Tracevv(x) +# define Tracec(c,x) +# define Tracecv(c,x) +#endif + + +extern void z_error __P((char *m)); + +voidp zcalloc __P((voidp opaque, unsigned items, unsigned size)); +void zcfree __P((voidp opaque, voidp ptr)); + +#define ZALLOC(strm, items, size) (*strm->zalloc)(strm->opaque, items, size) +#define ZFREE(strm, addr) (*strm->zfree) (strm->opaque, (voidp)addr) +#define TRY_FREE(s, p) {if (p) ZFREE(s, p);} + +#endif /* _Z_UTIL_H */