Index: trunk/minix/lib/zlib-1.2.3/examples/README.examples =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/README.examples (revision 9) +++ (revision ) @@ -1,42 +1,0 @@ -This directory contains examples of the use of zlib. - -fitblk.c - compress just enough input to nearly fill a requested output size - - zlib isn't designed to do this, but fitblk does it anyway - -gun.c - uncompress a gzip file - - illustrates the use of inflateBack() for high speed file-to-file - decompression using call-back functions - - is approximately twice as fast as gzip -d - - also provides Unix uncompress functionality, again twice as fast - -gzappend.c - append to a gzip file - - illustrates the use of the Z_BLOCK flush parameter for inflate() - - illustrates the use of deflatePrime() to start at any bit - -gzjoin.c - join gzip files without recalculating the crc or recompressing - - illustrates the use of the Z_BLOCK flush parameter for inflate() - - illustrates the use of crc32_combine() - -gzlog.c -gzlog.h - efficiently maintain a message log file in gzip format - - illustrates use of raw deflate and Z_SYNC_FLUSH - - illustrates use of gzip header extra field - -zlib_how.html - painfully comprehensive description of zpipe.c (see below) - - describes in excruciating detail the use of deflate() and inflate() - -zpipe.c - reads and writes zlib streams from stdin to stdout - - illustrates the proper use of deflate() and inflate() - - deeply commented in zlib_how.html (see above) - -zran.c - index a zlib or gzip stream and randomly access it - - illustrates the use of Z_BLOCK, inflatePrime(), and - inflateSetDictionary() to provide random access Index: trunk/minix/lib/zlib-1.2.3/examples/fitblk.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/fitblk.c (revision 9) +++ (revision ) @@ -1,233 +1,0 @@ -/* fitblk.c: example of fitting compressed output to a specified size - Not copyrighted -- provided to the public domain - Version 1.1 25 November 2004 Mark Adler */ - -/* Version history: - 1.0 24 Nov 2004 First version - 1.1 25 Nov 2004 Change deflateInit2() to deflateInit() - Use fixed-size, stack-allocated raw buffers - Simplify code moving compression to subroutines - Use assert() for internal errors - Add detailed description of approach - */ - -/* Approach to just fitting a requested compressed size: - - fitblk performs three compression passes on a portion of the input - data in order to determine how much of that input will compress to - nearly the requested output block size. The first pass generates - enough deflate blocks to produce output to fill the requested - output size plus a specfied excess amount (see the EXCESS define - below). The last deflate block may go quite a bit past that, but - is discarded. The second pass decompresses and recompresses just - the compressed data that fit in the requested plus excess sized - buffer. The deflate process is terminated after that amount of - input, which is less than the amount consumed on the first pass. - The last deflate block of the result will be of a comparable size - to the final product, so that the header for that deflate block and - the compression ratio for that block will be about the same as in - the final product. The third compression pass decompresses the - result of the second step, but only the compressed data up to the - requested size minus an amount to allow the compressed stream to - complete (see the MARGIN define below). That will result in a - final compressed stream whose length is less than or equal to the - requested size. Assuming sufficient input and a requested size - greater than a few hundred bytes, the shortfall will typically be - less than ten bytes. - - If the input is short enough that the first compression completes - before filling the requested output size, then that compressed - stream is return with no recompression. - - EXCESS is chosen to be just greater than the shortfall seen in a - two pass approach similar to the above. That shortfall is due to - the last deflate block compressing more efficiently with a smaller - header on the second pass. EXCESS is set to be large enough so - that there is enough uncompressed data for the second pass to fill - out the requested size, and small enough so that the final deflate - block of the second pass will be close in size to the final deflate - block of the third and final pass. MARGIN is chosen to be just - large enough to assure that the final compression has enough room - to complete in all cases. - */ - -#include -#include -#include -#include "zlib.h" - -#define local static - -/* print nastygram and leave */ -local void quit(char *why) -{ - fprintf(stderr, "fitblk abort: %s\n", why); - exit(1); -} - -#define RAWLEN 4096 /* intermediate uncompressed buffer size */ - -/* compress from file to def until provided buffer is full or end of - input reached; return last deflate() return value, or Z_ERRNO if - there was read error on the file */ -local int partcompress(FILE *in, z_streamp def) -{ - int ret, flush; - unsigned char raw[RAWLEN]; - - flush = Z_NO_FLUSH; - do { - def->avail_in = fread(raw, 1, RAWLEN, in); - if (ferror(in)) - return Z_ERRNO; - def->next_in = raw; - if (feof(in)) - flush = Z_FINISH; - ret = deflate(def, flush); - assert(ret != Z_STREAM_ERROR); - } while (def->avail_out != 0 && flush == Z_NO_FLUSH); - return ret; -} - -/* recompress from inf's input to def's output; the input for inf and - the output for def are set in those structures before calling; - return last deflate() return value, or Z_MEM_ERROR if inflate() - was not able to allocate enough memory when it needed to */ -local int recompress(z_streamp inf, z_streamp def) -{ - int ret, flush; - unsigned char raw[RAWLEN]; - - flush = Z_NO_FLUSH; - do { - /* decompress */ - inf->avail_out = RAWLEN; - inf->next_out = raw; - ret = inflate(inf, Z_NO_FLUSH); - assert(ret != Z_STREAM_ERROR && ret != Z_DATA_ERROR && - ret != Z_NEED_DICT); - if (ret == Z_MEM_ERROR) - return ret; - - /* compress what was decompresed until done or no room */ - def->avail_in = RAWLEN - inf->avail_out; - def->next_in = raw; - if (inf->avail_out != 0) - flush = Z_FINISH; - ret = deflate(def, flush); - assert(ret != Z_STREAM_ERROR); - } while (ret != Z_STREAM_END && def->avail_out != 0); - return ret; -} - -#define EXCESS 256 /* empirically determined stream overage */ -#define MARGIN 8 /* amount to back off for completion */ - -/* compress from stdin to fixed-size block on stdout */ -int main(int argc, char **argv) -{ - int ret; /* return code */ - unsigned size; /* requested fixed output block size */ - unsigned have; /* bytes written by deflate() call */ - unsigned char *blk; /* intermediate and final stream */ - unsigned char *tmp; /* close to desired size stream */ - z_stream def, inf; /* zlib deflate and inflate states */ - - /* get requested output size */ - if (argc != 2) - quit("need one argument: size of output block"); - ret = strtol(argv[1], argv + 1, 10); - if (argv[1][0] != 0) - quit("argument must be a number"); - if (ret < 8) /* 8 is minimum zlib stream size */ - quit("need positive size of 8 or greater"); - size = (unsigned)ret; - - /* allocate memory for buffers and compression engine */ - blk = malloc(size + EXCESS); - def.zalloc = Z_NULL; - def.zfree = Z_NULL; - def.opaque = Z_NULL; - ret = deflateInit(&def, Z_DEFAULT_COMPRESSION); - if (ret != Z_OK || blk == NULL) - quit("out of memory"); - - /* compress from stdin until output full, or no more input */ - def.avail_out = size + EXCESS; - def.next_out = blk; - ret = partcompress(stdin, &def); - if (ret == Z_ERRNO) - quit("error reading input"); - - /* if it all fit, then size was undersubscribed -- done! */ - if (ret == Z_STREAM_END && def.avail_out >= EXCESS) { - /* write block to stdout */ - have = size + EXCESS - def.avail_out; - if (fwrite(blk, 1, have, stdout) != have || ferror(stdout)) - quit("error writing output"); - - /* clean up and print results to stderr */ - ret = deflateEnd(&def); - assert(ret != Z_STREAM_ERROR); - free(blk); - fprintf(stderr, - "%u bytes unused out of %u requested (all input)\n", - size - have, size); - return 0; - } - - /* it didn't all fit -- set up for recompression */ - inf.zalloc = Z_NULL; - inf.zfree = Z_NULL; - inf.opaque = Z_NULL; - inf.avail_in = 0; - inf.next_in = Z_NULL; - ret = inflateInit(&inf); - tmp = malloc(size + EXCESS); - if (ret != Z_OK || tmp == NULL) - quit("out of memory"); - ret = deflateReset(&def); - assert(ret != Z_STREAM_ERROR); - - /* do first recompression close to the right amount */ - inf.avail_in = size + EXCESS; - inf.next_in = blk; - def.avail_out = size + EXCESS; - def.next_out = tmp; - ret = recompress(&inf, &def); - if (ret == Z_MEM_ERROR) - quit("out of memory"); - - /* set up for next reocmpression */ - ret = inflateReset(&inf); - assert(ret != Z_STREAM_ERROR); - ret = deflateReset(&def); - assert(ret != Z_STREAM_ERROR); - - /* do second and final recompression (third compression) */ - inf.avail_in = size - MARGIN; /* assure stream will complete */ - inf.next_in = tmp; - def.avail_out = size; - def.next_out = blk; - ret = recompress(&inf, &def); - if (ret == Z_MEM_ERROR) - quit("out of memory"); - assert(ret == Z_STREAM_END); /* otherwise MARGIN too small */ - - /* done -- write block to stdout */ - have = size - def.avail_out; - if (fwrite(blk, 1, have, stdout) != have || ferror(stdout)) - quit("error writing output"); - - /* clean up and print results to stderr */ - free(tmp); - ret = inflateEnd(&inf); - assert(ret != Z_STREAM_ERROR); - ret = deflateEnd(&def); - assert(ret != Z_STREAM_ERROR); - free(blk); - fprintf(stderr, - "%u bytes unused out of %u requested (%lu input)\n", - size - have, size, def.total_in); - return 0; -} Index: trunk/minix/lib/zlib-1.2.3/examples/gun.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/gun.c (revision 9) +++ (revision ) @@ -1,693 +1,0 @@ -/* gun.c -- simple gunzip to give an example of the use of inflateBack() - * Copyright (C) 2003, 2005 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - Version 1.3 12 June 2005 Mark Adler */ - -/* Version history: - 1.0 16 Feb 2003 First version for testing of inflateBack() - 1.1 21 Feb 2005 Decompress concatenated gzip streams - Remove use of "this" variable (C++ keyword) - Fix return value for in() - Improve allocation failure checking - Add typecasting for void * structures - Add -h option for command version and usage - Add a bunch of comments - 1.2 20 Mar 2005 Add Unix compress (LZW) decompression - Copy file attributes from input file to output file - 1.3 12 Jun 2005 Add casts for error messages [Oberhumer] - */ - -/* - gun [ -t ] [ name ... ] - - decompresses the data in the named gzip files. If no arguments are given, - gun will decompress from stdin to stdout. The names must end in .gz, -gz, - .z, -z, _z, or .Z. The uncompressed data will be written to a file name - with the suffix stripped. On success, the original file is deleted. On - failure, the output file is deleted. For most failures, the command will - continue to process the remaining names on the command line. A memory - allocation failure will abort the command. If -t is specified, then the - listed files or stdin will be tested as gzip files for integrity (without - checking for a proper suffix), no output will be written, and no files - will be deleted. - - Like gzip, gun allows concatenated gzip streams and will decompress them, - writing all of the uncompressed data to the output. Unlike gzip, gun allows - an empty file on input, and will produce no error writing an empty output - file. - - gun will also decompress files made by Unix compress, which uses LZW - compression. These files are automatically detected by virtue of their - magic header bytes. Since the end of Unix compress stream is marked by the - end-of-file, they cannot be concantenated. If a Unix compress stream is - encountered in an input file, it is the last stream in that file. - - Like gunzip and uncompress, the file attributes of the orignal compressed - file are maintained in the final uncompressed file, to the extent that the - user permissions allow it. - - On my Mac OS X PowerPC G4, gun is almost twice as fast as gunzip (version - 1.2.4) is on the same file, when gun is linked with zlib 1.2.2. Also the - LZW decompression provided by gun is about twice as fast as the standard - Unix uncompress command. - */ - -/* external functions and related types and constants */ -#include /* fprintf() */ -#include /* malloc(), free() */ -#include /* strerror(), strcmp(), strlen(), memcpy() */ -#include /* errno */ -#include /* open() */ -#include /* read(), write(), close(), chown(), unlink() */ -#include -#include /* stat(), chmod() */ -#include /* utime() */ -#include "zlib.h" /* inflateBackInit(), inflateBack(), */ - /* inflateBackEnd(), crc32() */ - -/* function declaration */ -#define local static - -/* buffer constants */ -#define SIZE 32768U /* input and output buffer sizes */ -#define PIECE 16384 /* limits i/o chunks for 16-bit int case */ - -/* structure for infback() to pass to input function in() -- it maintains the - input file and a buffer of size SIZE */ -struct ind { - int infile; - unsigned char *inbuf; -}; - -/* Load input buffer, assumed to be empty, and return bytes loaded and a - pointer to them. read() is called until the buffer is full, or until it - returns end-of-file or error. Return 0 on error. */ -local unsigned in(void *in_desc, unsigned char **buf) -{ - int ret; - unsigned len; - unsigned char *next; - struct ind *me = (struct ind *)in_desc; - - next = me->inbuf; - *buf = next; - len = 0; - do { - ret = PIECE; - if ((unsigned)ret > SIZE - len) - ret = (int)(SIZE - len); - ret = (int)read(me->infile, next, ret); - if (ret == -1) { - len = 0; - break; - } - next += ret; - len += ret; - } while (ret != 0 && len < SIZE); - return len; -} - -/* structure for infback() to pass to output function out() -- it maintains the - output file, a running CRC-32 check on the output and the total number of - bytes output, both for checking against the gzip trailer. (The length in - the gzip trailer is stored modulo 2^32, so it's ok if a long is 32 bits and - the output is greater than 4 GB.) */ -struct outd { - int outfile; - int check; /* true if checking crc and total */ - unsigned long crc; - unsigned long total; -}; - -/* Write output buffer and update the CRC-32 and total bytes written. write() - is called until all of the output is written or an error is encountered. - On success out() returns 0. For a write failure, out() returns 1. If the - output file descriptor is -1, then nothing is written. - */ -local int out(void *out_desc, unsigned char *buf, unsigned len) -{ - int ret; - struct outd *me = (struct outd *)out_desc; - - if (me->check) { - me->crc = crc32(me->crc, buf, len); - me->total += len; - } - if (me->outfile != -1) - do { - ret = PIECE; - if ((unsigned)ret > len) - ret = (int)len; - ret = (int)write(me->outfile, buf, ret); - if (ret == -1) - return 1; - buf += ret; - len -= ret; - } while (len != 0); - return 0; -} - -/* next input byte macro for use inside lunpipe() and gunpipe() */ -#define NEXT() (have ? 0 : (have = in(indp, &next)), \ - last = have ? (have--, (int)(*next++)) : -1) - -/* memory for gunpipe() and lunpipe() -- - the first 256 entries of prefix[] and suffix[] are never used, could - have offset the index, but it's faster to waste the memory */ -unsigned char inbuf[SIZE]; /* input buffer */ -unsigned char outbuf[SIZE]; /* output buffer */ -unsigned short prefix[65536]; /* index to LZW prefix string */ -unsigned char suffix[65536]; /* one-character LZW suffix */ -unsigned char match[65280 + 2]; /* buffer for reversed match or gzip - 32K sliding window */ - -/* throw out what's left in the current bits byte buffer (this is a vestigial - aspect of the compressed data format derived from an implementation that - made use of a special VAX machine instruction!) */ -#define FLUSHCODE() \ - do { \ - left = 0; \ - rem = 0; \ - if (chunk > have) { \ - chunk -= have; \ - have = 0; \ - if (NEXT() == -1) \ - break; \ - chunk--; \ - if (chunk > have) { \ - chunk = have = 0; \ - break; \ - } \ - } \ - have -= chunk; \ - next += chunk; \ - chunk = 0; \ - } while (0) - -/* Decompress a compress (LZW) file from indp to outfile. The compress magic - header (two bytes) has already been read and verified. There are have bytes - of buffered input at next. strm is used for passing error information back - to gunpipe(). - - lunpipe() will return Z_OK on success, Z_BUF_ERROR for an unexpected end of - file, read error, or write error (a write error indicated by strm->next_in - not equal to Z_NULL), or Z_DATA_ERROR for invalid input. - */ -local int lunpipe(unsigned have, unsigned char *next, struct ind *indp, - int outfile, z_stream *strm) -{ - int last; /* last byte read by NEXT(), or -1 if EOF */ - int chunk; /* bytes left in current chunk */ - int left; /* bits left in rem */ - unsigned rem; /* unused bits from input */ - int bits; /* current bits per code */ - unsigned code; /* code, table traversal index */ - unsigned mask; /* mask for current bits codes */ - int max; /* maximum bits per code for this stream */ - int flags; /* compress flags, then block compress flag */ - unsigned end; /* last valid entry in prefix/suffix tables */ - unsigned temp; /* current code */ - unsigned prev; /* previous code */ - unsigned final; /* last character written for previous code */ - unsigned stack; /* next position for reversed string */ - unsigned outcnt; /* bytes in output buffer */ - struct outd outd; /* output structure */ - - /* set up output */ - outd.outfile = outfile; - outd.check = 0; - - /* process remainder of compress header -- a flags byte */ - flags = NEXT(); - if (last == -1) - return Z_BUF_ERROR; - if (flags & 0x60) { - strm->msg = (char *)"unknown lzw flags set"; - return Z_DATA_ERROR; - } - max = flags & 0x1f; - if (max < 9 || max > 16) { - strm->msg = (char *)"lzw bits out of range"; - return Z_DATA_ERROR; - } - if (max == 9) /* 9 doesn't really mean 9 */ - max = 10; - flags &= 0x80; /* true if block compress */ - - /* clear table */ - bits = 9; - mask = 0x1ff; - end = flags ? 256 : 255; - - /* set up: get first 9-bit code, which is the first decompressed byte, but - don't create a table entry until the next code */ - if (NEXT() == -1) /* no compressed data is ok */ - return Z_OK; - final = prev = (unsigned)last; /* low 8 bits of code */ - if (NEXT() == -1) /* missing a bit */ - return Z_BUF_ERROR; - if (last & 1) { /* code must be < 256 */ - strm->msg = (char *)"invalid lzw code"; - return Z_DATA_ERROR; - } - rem = (unsigned)last >> 1; /* remaining 7 bits */ - left = 7; - chunk = bits - 2; /* 7 bytes left in this chunk */ - outbuf[0] = (unsigned char)final; /* write first decompressed byte */ - outcnt = 1; - - /* decode codes */ - stack = 0; - for (;;) { - /* if the table will be full after this, increment the code size */ - if (end >= mask && bits < max) { - FLUSHCODE(); - bits++; - mask <<= 1; - mask++; - } - - /* get a code of length bits */ - if (chunk == 0) /* decrement chunk modulo bits */ - chunk = bits; - code = rem; /* low bits of code */ - if (NEXT() == -1) { /* EOF is end of compressed data */ - /* write remaining buffered output */ - if (outcnt && out(&outd, outbuf, outcnt)) { - strm->next_in = outbuf; /* signal write error */ - return Z_BUF_ERROR; - } - return Z_OK; - } - code += (unsigned)last << left; /* middle (or high) bits of code */ - left += 8; - chunk--; - if (bits > left) { /* need more bits */ - if (NEXT() == -1) /* can't end in middle of code */ - return Z_BUF_ERROR; - code += (unsigned)last << left; /* high bits of code */ - left += 8; - chunk--; - } - code &= mask; /* mask to current code length */ - left -= bits; /* number of unused bits */ - rem = (unsigned)last >> (8 - left); /* unused bits from last byte */ - - /* process clear code (256) */ - if (code == 256 && flags) { - FLUSHCODE(); - bits = 9; /* initialize bits and mask */ - mask = 0x1ff; - end = 255; /* empty table */ - continue; /* get next code */ - } - - /* special code to reuse last match */ - temp = code; /* save the current code */ - if (code > end) { - /* Be picky on the allowed code here, and make sure that the code - we drop through (prev) will be a valid index so that random - input does not cause an exception. The code != end + 1 check is - empirically derived, and not checked in the original uncompress - code. If this ever causes a problem, that check could be safely - removed. Leaving this check in greatly improves gun's ability - to detect random or corrupted input after a compress header. - In any case, the prev > end check must be retained. */ - if (code != end + 1 || prev > end) { - strm->msg = (char *)"invalid lzw code"; - return Z_DATA_ERROR; - } - match[stack++] = (unsigned char)final; - code = prev; - } - - /* walk through linked list to generate output in reverse order */ - while (code >= 256) { - match[stack++] = suffix[code]; - code = prefix[code]; - } - match[stack++] = (unsigned char)code; - final = code; - - /* link new table entry */ - if (end < mask) { - end++; - prefix[end] = (unsigned short)prev; - suffix[end] = (unsigned char)final; - } - - /* set previous code for next iteration */ - prev = temp; - - /* write output in forward order */ - while (stack > SIZE - outcnt) { - while (outcnt < SIZE) - outbuf[outcnt++] = match[--stack]; - if (out(&outd, outbuf, outcnt)) { - strm->next_in = outbuf; /* signal write error */ - return Z_BUF_ERROR; - } - outcnt = 0; - } - do { - outbuf[outcnt++] = match[--stack]; - } while (stack); - - /* loop for next code with final and prev as the last match, rem and - left provide the first 0..7 bits of the next code, end is the last - valid table entry */ - } -} - -/* Decompress a gzip file from infile to outfile. strm is assumed to have been - successfully initialized with inflateBackInit(). The input file may consist - of a series of gzip streams, in which case all of them will be decompressed - to the output file. If outfile is -1, then the gzip stream(s) integrity is - checked and nothing is written. - - The return value is a zlib error code: Z_MEM_ERROR if out of memory, - Z_DATA_ERROR if the header or the compressed data is invalid, or if the - trailer CRC-32 check or length doesn't match, Z_BUF_ERROR if the input ends - prematurely or a write error occurs, or Z_ERRNO if junk (not a another gzip - stream) follows a valid gzip stream. - */ -local int gunpipe(z_stream *strm, int infile, int outfile) -{ - int ret, first, last; - unsigned have, flags, len; - unsigned char *next; - struct ind ind, *indp; - struct outd outd; - - /* setup input buffer */ - ind.infile = infile; - ind.inbuf = inbuf; - indp = &ind; - - /* decompress concatenated gzip streams */ - have = 0; /* no input data read in yet */ - first = 1; /* looking for first gzip header */ - strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */ - for (;;) { - /* look for the two magic header bytes for a gzip stream */ - if (NEXT() == -1) { - ret = Z_OK; - break; /* empty gzip stream is ok */ - } - if (last != 31 || (NEXT() != 139 && last != 157)) { - strm->msg = (char *)"incorrect header check"; - ret = first ? Z_DATA_ERROR : Z_ERRNO; - break; /* not a gzip or compress header */ - } - first = 0; /* next non-header is junk */ - - /* process a compress (LZW) file -- can't be concatenated after this */ - if (last == 157) { - ret = lunpipe(have, next, indp, outfile, strm); - break; - } - - /* process remainder of gzip header */ - ret = Z_BUF_ERROR; - if (NEXT() != 8) { /* only deflate method allowed */ - if (last == -1) break; - strm->msg = (char *)"unknown compression method"; - ret = Z_DATA_ERROR; - break; - } - flags = NEXT(); /* header flags */ - NEXT(); /* discard mod time, xflgs, os */ - NEXT(); - NEXT(); - NEXT(); - NEXT(); - NEXT(); - if (last == -1) break; - if (flags & 0xe0) { - strm->msg = (char *)"unknown header flags set"; - ret = Z_DATA_ERROR; - break; - } - if (flags & 4) { /* extra field */ - len = NEXT(); - len += (unsigned)(NEXT()) << 8; - if (last == -1) break; - while (len > have) { - len -= have; - have = 0; - if (NEXT() == -1) break; - len--; - } - if (last == -1) break; - have -= len; - next += len; - } - if (flags & 8) /* file name */ - while (NEXT() != 0 && last != -1) - ; - if (flags & 16) /* comment */ - while (NEXT() != 0 && last != -1) - ; - if (flags & 2) { /* header crc */ - NEXT(); - NEXT(); - } - if (last == -1) break; - - /* set up output */ - outd.outfile = outfile; - outd.check = 1; - outd.crc = crc32(0L, Z_NULL, 0); - outd.total = 0; - - /* decompress data to output */ - strm->next_in = next; - strm->avail_in = have; - ret = inflateBack(strm, in, indp, out, &outd); - if (ret != Z_STREAM_END) break; - next = strm->next_in; - have = strm->avail_in; - strm->next_in = Z_NULL; /* so Z_BUF_ERROR means EOF */ - - /* check trailer */ - ret = Z_BUF_ERROR; - if (NEXT() != (outd.crc & 0xff) || - NEXT() != ((outd.crc >> 8) & 0xff) || - NEXT() != ((outd.crc >> 16) & 0xff) || - NEXT() != ((outd.crc >> 24) & 0xff)) { - /* crc error */ - if (last != -1) { - strm->msg = (char *)"incorrect data check"; - ret = Z_DATA_ERROR; - } - break; - } - if (NEXT() != (outd.total & 0xff) || - NEXT() != ((outd.total >> 8) & 0xff) || - NEXT() != ((outd.total >> 16) & 0xff) || - NEXT() != ((outd.total >> 24) & 0xff)) { - /* length error */ - if (last != -1) { - strm->msg = (char *)"incorrect length check"; - ret = Z_DATA_ERROR; - } - break; - } - - /* go back and look for another gzip stream */ - } - - /* clean up and return */ - return ret; -} - -/* Copy file attributes, from -> to, as best we can. This is best effort, so - no errors are reported. The mode bits, including suid, sgid, and the sticky - bit are copied (if allowed), the owner's user id and group id are copied - (again if allowed), and the access and modify times are copied. */ -local void copymeta(char *from, char *to) -{ - struct stat was; - struct utimbuf when; - - /* get all of from's Unix meta data, return if not a regular file */ - if (stat(from, &was) != 0 || (was.st_mode & S_IFMT) != S_IFREG) - return; - - /* set to's mode bits, ignore errors */ - (void)chmod(to, was.st_mode & 07777); - - /* copy owner's user and group, ignore errors */ - (void)chown(to, was.st_uid, was.st_gid); - - /* copy access and modify times, ignore errors */ - when.actime = was.st_atime; - when.modtime = was.st_mtime; - (void)utime(to, &when); -} - -/* Decompress the file inname to the file outnname, of if test is true, just - decompress without writing and check the gzip trailer for integrity. If - inname is NULL or an empty string, read from stdin. If outname is NULL or - an empty string, write to stdout. strm is a pre-initialized inflateBack - structure. When appropriate, copy the file attributes from inname to - outname. - - gunzip() returns 1 if there is an out-of-memory error or an unexpected - return code from gunpipe(). Otherwise it returns 0. - */ -local int gunzip(z_stream *strm, char *inname, char *outname, int test) -{ - int ret; - int infile, outfile; - - /* open files */ - if (inname == NULL || *inname == 0) { - inname = "-"; - infile = 0; /* stdin */ - } - else { - infile = open(inname, O_RDONLY, 0); - if (infile == -1) { - fprintf(stderr, "gun cannot open %s\n", inname); - return 0; - } - } - if (test) - outfile = -1; - else if (outname == NULL || *outname == 0) { - outname = "-"; - outfile = 1; /* stdout */ - } - else { - outfile = open(outname, O_CREAT | O_TRUNC | O_WRONLY, 0666); - if (outfile == -1) { - close(infile); - fprintf(stderr, "gun cannot create %s\n", outname); - return 0; - } - } - errno = 0; - - /* decompress */ - ret = gunpipe(strm, infile, outfile); - if (outfile > 2) close(outfile); - if (infile > 2) close(infile); - - /* interpret result */ - switch (ret) { - case Z_OK: - case Z_ERRNO: - if (infile > 2 && outfile > 2) { - copymeta(inname, outname); /* copy attributes */ - unlink(inname); - } - if (ret == Z_ERRNO) - fprintf(stderr, "gun warning: trailing garbage ignored in %s\n", - inname); - break; - case Z_DATA_ERROR: - if (outfile > 2) unlink(outname); - fprintf(stderr, "gun data error on %s: %s\n", inname, strm->msg); - break; - case Z_MEM_ERROR: - if (outfile > 2) unlink(outname); - fprintf(stderr, "gun out of memory error--aborting\n"); - return 1; - case Z_BUF_ERROR: - if (outfile > 2) unlink(outname); - if (strm->next_in != Z_NULL) { - fprintf(stderr, "gun write error on %s: %s\n", - outname, strerror(errno)); - } - else if (errno) { - fprintf(stderr, "gun read error on %s: %s\n", - inname, strerror(errno)); - } - else { - fprintf(stderr, "gun unexpected end of file on %s\n", - inname); - } - break; - default: - if (outfile > 2) unlink(outname); - fprintf(stderr, "gun internal error--aborting\n"); - return 1; - } - return 0; -} - -/* Process the gun command line arguments. See the command syntax near the - beginning of this source file. */ -int main(int argc, char **argv) -{ - int ret, len, test; - char *outname; - unsigned char *window; - z_stream strm; - - /* initialize inflateBack state for repeated use */ - window = match; /* reuse LZW match buffer */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - ret = inflateBackInit(&strm, 15, window); - if (ret != Z_OK) { - fprintf(stderr, "gun out of memory error--aborting\n"); - return 1; - } - - /* decompress each file to the same name with the suffix removed */ - argc--; - argv++; - test = 0; - if (argc && strcmp(*argv, "-h") == 0) { - fprintf(stderr, "gun 1.3 (12 Jun 2005)\n"); - fprintf(stderr, "Copyright (c) 2005 Mark Adler\n"); - fprintf(stderr, "usage: gun [-t] [file1.gz [file2.Z ...]]\n"); - return 0; - } - if (argc && strcmp(*argv, "-t") == 0) { - test = 1; - argc--; - argv++; - } - if (argc) - do { - if (test) - outname = NULL; - else { - len = (int)strlen(*argv); - if (strcmp(*argv + len - 3, ".gz") == 0 || - strcmp(*argv + len - 3, "-gz") == 0) - len -= 3; - else if (strcmp(*argv + len - 2, ".z") == 0 || - strcmp(*argv + len - 2, "-z") == 0 || - strcmp(*argv + len - 2, "_z") == 0 || - strcmp(*argv + len - 2, ".Z") == 0) - len -= 2; - else { - fprintf(stderr, "gun error: no gz type on %s--skipping\n", - *argv); - continue; - } - outname = malloc(len + 1); - if (outname == NULL) { - fprintf(stderr, "gun out of memory error--aborting\n"); - ret = 1; - break; - } - memcpy(outname, *argv, len); - outname[len] = 0; - } - ret = gunzip(&strm, *argv, outname, test); - if (outname != NULL) free(outname); - if (ret) break; - } while (argv++, --argc); - else - ret = gunzip(&strm, NULL, NULL, test); - - /* clean up */ - inflateBackEnd(&strm); - return ret; -} Index: trunk/minix/lib/zlib-1.2.3/examples/gzappend.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/gzappend.c (revision 9) +++ (revision ) @@ -1,500 +1,0 @@ -/* gzappend -- command to append to a gzip file - - Copyright (C) 2003 Mark Adler, all rights reserved - version 1.1, 4 Nov 2003 - - This software is provided 'as-is', without any express or implied - warranty. In no event will the author 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. - - Mark Adler madler@alumni.caltech.edu - */ - -/* - * Change history: - * - * 1.0 19 Oct 2003 - First version - * 1.1 4 Nov 2003 - Expand and clarify some comments and notes - * - Add version and copyright to help - * - Send help to stdout instead of stderr - * - Add some preemptive typecasts - * - Add L to constants in lseek() calls - * - Remove some debugging information in error messages - * - Use new data_type definition for zlib 1.2.1 - * - Simplfy and unify file operations - * - Finish off gzip file in gztack() - * - Use deflatePrime() instead of adding empty blocks - * - Keep gzip file clean on appended file read errors - * - Use in-place rotate instead of auxiliary buffer - * (Why you ask? Because it was fun to write!) - */ - -/* - gzappend takes a gzip file and appends to it, compressing files from the - command line or data from stdin. The gzip file is written to directly, to - avoid copying that file, in case it's large. Note that this results in the - unfriendly behavior that if gzappend fails, the gzip file is corrupted. - - This program was written to illustrate the use of the new Z_BLOCK option of - zlib 1.2.x's inflate() function. This option returns from inflate() at each - block boundary to facilitate locating and modifying the last block bit at - the start of the final deflate block. Also whether using Z_BLOCK or not, - another required feature of zlib 1.2.x is that inflate() now provides the - number of unusued bits in the last input byte used. gzappend will not work - with versions of zlib earlier than 1.2.1. - - gzappend first decompresses the gzip file internally, discarding all but - the last 32K of uncompressed data, and noting the location of the last block - bit and the number of unused bits in the last byte of the compressed data. - The gzip trailer containing the CRC-32 and length of the uncompressed data - is verified. This trailer will be later overwritten. - - Then the last block bit is cleared by seeking back in the file and rewriting - the byte that contains it. Seeking forward, the last byte of the compressed - data is saved along with the number of unused bits to initialize deflate. - - A deflate process is initialized, using the last 32K of the uncompressed - data from the gzip file to initialize the dictionary. If the total - uncompressed data was less than 32K, then all of it is used to initialize - the dictionary. The deflate output bit buffer is also initialized with the - last bits from the original deflate stream. From here on, the data to - append is simply compressed using deflate, and written to the gzip file. - When that is complete, the new CRC-32 and uncompressed length are written - as the trailer of the gzip file. - */ - -#include -#include -#include -#include -#include -#include "zlib.h" - -#define local static -#define LGCHUNK 14 -#define CHUNK (1U << LGCHUNK) -#define DSIZE 32768U - -/* print an error message and terminate with extreme prejudice */ -local void bye(char *msg1, char *msg2) -{ - fprintf(stderr, "gzappend error: %s%s\n", msg1, msg2); - exit(1); -} - -/* return the greatest common divisor of a and b using Euclid's algorithm, - modified to be fast when one argument much greater than the other, and - coded to avoid unnecessary swapping */ -local unsigned gcd(unsigned a, unsigned b) -{ - unsigned c; - - while (a && b) - if (a > b) { - c = b; - while (a - c >= c) - c <<= 1; - a -= c; - } - else { - c = a; - while (b - c >= c) - c <<= 1; - b -= c; - } - return a + b; -} - -/* rotate list[0..len-1] left by rot positions, in place */ -local void rotate(unsigned char *list, unsigned len, unsigned rot) -{ - unsigned char tmp; - unsigned cycles; - unsigned char *start, *last, *to, *from; - - /* normalize rot and handle degenerate cases */ - if (len < 2) return; - if (rot >= len) rot %= len; - if (rot == 0) return; - - /* pointer to last entry in list */ - last = list + (len - 1); - - /* do simple left shift by one */ - if (rot == 1) { - tmp = *list; - memcpy(list, list + 1, len - 1); - *last = tmp; - return; - } - - /* do simple right shift by one */ - if (rot == len - 1) { - tmp = *last; - memmove(list + 1, list, len - 1); - *list = tmp; - return; - } - - /* otherwise do rotate as a set of cycles in place */ - cycles = gcd(len, rot); /* number of cycles */ - do { - start = from = list + cycles; /* start index is arbitrary */ - tmp = *from; /* save entry to be overwritten */ - for (;;) { - to = from; /* next step in cycle */ - from += rot; /* go right rot positions */ - if (from > last) from -= len; /* (pointer better not wrap) */ - if (from == start) break; /* all but one shifted */ - *to = *from; /* shift left */ - } - *to = tmp; /* complete the circle */ - } while (--cycles); -} - -/* structure for gzip file read operations */ -typedef struct { - int fd; /* file descriptor */ - int size; /* 1 << size is bytes in buf */ - unsigned left; /* bytes available at next */ - unsigned char *buf; /* buffer */ - unsigned char *next; /* next byte in buffer */ - char *name; /* file name for error messages */ -} file; - -/* reload buffer */ -local int readin(file *in) -{ - int len; - - len = read(in->fd, in->buf, 1 << in->size); - if (len == -1) bye("error reading ", in->name); - in->left = (unsigned)len; - in->next = in->buf; - return len; -} - -/* read from file in, exit if end-of-file */ -local int readmore(file *in) -{ - if (readin(in) == 0) bye("unexpected end of ", in->name); - return 0; -} - -#define read1(in) (in->left == 0 ? readmore(in) : 0, \ - in->left--, *(in->next)++) - -/* skip over n bytes of in */ -local void skip(file *in, unsigned n) -{ - unsigned bypass; - - if (n > in->left) { - n -= in->left; - bypass = n & ~((1U << in->size) - 1); - if (bypass) { - if (lseek(in->fd, (off_t)bypass, SEEK_CUR) == -1) - bye("seeking ", in->name); - n -= bypass; - } - readmore(in); - if (n > in->left) - bye("unexpected end of ", in->name); - } - in->left -= n; - in->next += n; -} - -/* read a four-byte unsigned integer, little-endian, from in */ -unsigned long read4(file *in) -{ - unsigned long val; - - val = read1(in); - val += (unsigned)read1(in) << 8; - val += (unsigned long)read1(in) << 16; - val += (unsigned long)read1(in) << 24; - return val; -} - -/* skip over gzip header */ -local void gzheader(file *in) -{ - int flags; - unsigned n; - - if (read1(in) != 31 || read1(in) != 139) bye(in->name, " not a gzip file"); - if (read1(in) != 8) bye("unknown compression method in", in->name); - flags = read1(in); - if (flags & 0xe0) bye("unknown header flags set in", in->name); - skip(in, 6); - if (flags & 4) { - n = read1(in); - n += (unsigned)(read1(in)) << 8; - skip(in, n); - } - if (flags & 8) while (read1(in) != 0) ; - if (flags & 16) while (read1(in) != 0) ; - if (flags & 2) skip(in, 2); -} - -/* decompress gzip file "name", return strm with a deflate stream ready to - continue compression of the data in the gzip file, and return a file - descriptor pointing to where to write the compressed data -- the deflate - stream is initialized to compress using level "level" */ -local int gzscan(char *name, z_stream *strm, int level) -{ - int ret, lastbit, left, full; - unsigned have; - unsigned long crc, tot; - unsigned char *window; - off_t lastoff, end; - file gz; - - /* open gzip file */ - gz.name = name; - gz.fd = open(name, O_RDWR, 0); - if (gz.fd == -1) bye("cannot open ", name); - gz.buf = malloc(CHUNK); - if (gz.buf == NULL) bye("out of memory", ""); - gz.size = LGCHUNK; - gz.left = 0; - - /* skip gzip header */ - gzheader(&gz); - - /* prepare to decompress */ - window = malloc(DSIZE); - if (window == NULL) bye("out of memory", ""); - strm->zalloc = Z_NULL; - strm->zfree = Z_NULL; - strm->opaque = Z_NULL; - ret = inflateInit2(strm, -15); - if (ret != Z_OK) bye("out of memory", " or library mismatch"); - - /* decompress the deflate stream, saving append information */ - lastbit = 0; - lastoff = lseek(gz.fd, 0L, SEEK_CUR) - gz.left; - left = 0; - strm->avail_in = gz.left; - strm->next_in = gz.next; - crc = crc32(0L, Z_NULL, 0); - have = full = 0; - do { - /* if needed, get more input */ - if (strm->avail_in == 0) { - readmore(&gz); - strm->avail_in = gz.left; - strm->next_in = gz.next; - } - - /* set up output to next available section of sliding window */ - strm->avail_out = DSIZE - have; - strm->next_out = window + have; - - /* inflate and check for errors */ - ret = inflate(strm, Z_BLOCK); - if (ret == Z_STREAM_ERROR) bye("internal stream error!", ""); - if (ret == Z_MEM_ERROR) bye("out of memory", ""); - if (ret == Z_DATA_ERROR) - bye("invalid compressed data--format violated in", name); - - /* update crc and sliding window pointer */ - crc = crc32(crc, window + have, DSIZE - have - strm->avail_out); - if (strm->avail_out) - have = DSIZE - strm->avail_out; - else { - have = 0; - full = 1; - } - - /* process end of block */ - if (strm->data_type & 128) { - if (strm->data_type & 64) - left = strm->data_type & 0x1f; - else { - lastbit = strm->data_type & 0x1f; - lastoff = lseek(gz.fd, 0L, SEEK_CUR) - strm->avail_in; - } - } - } while (ret != Z_STREAM_END); - inflateEnd(strm); - gz.left = strm->avail_in; - gz.next = strm->next_in; - - /* save the location of the end of the compressed data */ - end = lseek(gz.fd, 0L, SEEK_CUR) - gz.left; - - /* check gzip trailer and save total for deflate */ - if (crc != read4(&gz)) - bye("invalid compressed data--crc mismatch in ", name); - tot = strm->total_out; - if ((tot & 0xffffffffUL) != read4(&gz)) - bye("invalid compressed data--length mismatch in", name); - - /* if not at end of file, warn */ - if (gz.left || readin(&gz)) - fprintf(stderr, - "gzappend warning: junk at end of gzip file overwritten\n"); - - /* clear last block bit */ - lseek(gz.fd, lastoff - (lastbit != 0), SEEK_SET); - if (read(gz.fd, gz.buf, 1) != 1) bye("reading after seek on ", name); - *gz.buf = (unsigned char)(*gz.buf ^ (1 << ((8 - lastbit) & 7))); - lseek(gz.fd, -1L, SEEK_CUR); - if (write(gz.fd, gz.buf, 1) != 1) bye("writing after seek to ", name); - - /* if window wrapped, build dictionary from window by rotating */ - if (full) { - rotate(window, DSIZE, have); - have = DSIZE; - } - - /* set up deflate stream with window, crc, total_in, and leftover bits */ - ret = deflateInit2(strm, level, Z_DEFLATED, -15, 8, Z_DEFAULT_STRATEGY); - if (ret != Z_OK) bye("out of memory", ""); - deflateSetDictionary(strm, window, have); - strm->adler = crc; - strm->total_in = tot; - if (left) { - lseek(gz.fd, --end, SEEK_SET); - if (read(gz.fd, gz.buf, 1) != 1) bye("reading after seek on ", name); - deflatePrime(strm, 8 - left, *gz.buf); - } - lseek(gz.fd, end, SEEK_SET); - - /* clean up and return */ - free(window); - free(gz.buf); - return gz.fd; -} - -/* append file "name" to gzip file gd using deflate stream strm -- if last - is true, then finish off the deflate stream at the end */ -local void gztack(char *name, int gd, z_stream *strm, int last) -{ - int fd, len, ret; - unsigned left; - unsigned char *in, *out; - - /* open file to compress and append */ - fd = 0; - if (name != NULL) { - fd = open(name, O_RDONLY, 0); - if (fd == -1) - fprintf(stderr, "gzappend warning: %s not found, skipping ...\n", - name); - } - - /* allocate buffers */ - in = fd == -1 ? NULL : malloc(CHUNK); - out = malloc(CHUNK); - if (out == NULL) bye("out of memory", ""); - - /* compress input file and append to gzip file */ - do { - /* get more input */ - len = fd == -1 ? 0 : read(fd, in, CHUNK); - if (len == -1) { - fprintf(stderr, - "gzappend warning: error reading %s, skipping rest ...\n", - name); - len = 0; - } - strm->avail_in = (unsigned)len; - strm->next_in = in; - if (len) strm->adler = crc32(strm->adler, in, (unsigned)len); - - /* compress and write all available output */ - do { - strm->avail_out = CHUNK; - strm->next_out = out; - ret = deflate(strm, last && len == 0 ? Z_FINISH : Z_NO_FLUSH); - left = CHUNK - strm->avail_out; - while (left) { - len = write(gd, out + CHUNK - strm->avail_out - left, left); - if (len == -1) bye("writing gzip file", ""); - left -= (unsigned)len; - } - } while (strm->avail_out == 0 && ret != Z_STREAM_END); - } while (len != 0); - - /* write trailer after last entry */ - if (last) { - deflateEnd(strm); - out[0] = (unsigned char)(strm->adler); - out[1] = (unsigned char)(strm->adler >> 8); - out[2] = (unsigned char)(strm->adler >> 16); - out[3] = (unsigned char)(strm->adler >> 24); - out[4] = (unsigned char)(strm->total_in); - out[5] = (unsigned char)(strm->total_in >> 8); - out[6] = (unsigned char)(strm->total_in >> 16); - out[7] = (unsigned char)(strm->total_in >> 24); - len = 8; - do { - ret = write(gd, out + 8 - len, len); - if (ret == -1) bye("writing gzip file", ""); - len -= ret; - } while (len); - close(gd); - } - - /* clean up and return */ - free(out); - if (in != NULL) free(in); - if (fd > 0) close(fd); -} - -/* process the compression level option if present, scan the gzip file, and - append the specified files, or append the data from stdin if no other file - names are provided on the command line -- the gzip file must be writable - and seekable */ -int main(int argc, char **argv) -{ - int gd, level; - z_stream strm; - - /* ignore command name */ - argv++; - - /* provide usage if no arguments */ - if (*argv == NULL) { - printf("gzappend 1.1 (4 Nov 2003) Copyright (C) 2003 Mark Adler\n"); - printf( - "usage: gzappend [-level] file.gz [ addthis [ andthis ... ]]\n"); - return 0; - } - - /* set compression level */ - level = Z_DEFAULT_COMPRESSION; - if (argv[0][0] == '-') { - if (argv[0][1] < '0' || argv[0][1] > '9' || argv[0][2] != 0) - bye("invalid compression level", ""); - level = argv[0][1] - '0'; - if (*++argv == NULL) bye("no gzip file name after options", ""); - } - - /* prepare to append to gzip file */ - gd = gzscan(*argv++, &strm, level); - - /* append files on command line, or from stdin if none */ - if (*argv == NULL) - gztack(NULL, gd, &strm, 1); - else - do { - gztack(*argv, gd, &strm, argv[1] == NULL); - } while (*++argv != NULL); - return 0; -} Index: trunk/minix/lib/zlib-1.2.3/examples/gzjoin.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/gzjoin.c (revision 9) +++ (revision ) @@ -1,448 +1,0 @@ -/* gzjoin -- command to join gzip files into one gzip file - - Copyright (C) 2004 Mark Adler, all rights reserved - version 1.0, 11 Dec 2004 - - This software is provided 'as-is', without any express or implied - warranty. In no event will the author 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. - - Mark Adler madler@alumni.caltech.edu - */ - -/* - * Change history: - * - * 1.0 11 Dec 2004 - First version - * 1.1 12 Jun 2005 - Changed ssize_t to long for portability - */ - -/* - gzjoin takes one or more gzip files on the command line and writes out a - single gzip file that will uncompress to the concatenation of the - uncompressed data from the individual gzip files. gzjoin does this without - having to recompress any of the data and without having to calculate a new - crc32 for the concatenated uncompressed data. gzjoin does however have to - decompress all of the input data in order to find the bits in the compressed - data that need to be modified to concatenate the streams. - - gzjoin does not do an integrity check on the input gzip files other than - checking the gzip header and decompressing the compressed data. They are - otherwise assumed to be complete and correct. - - Each joint between gzip files removes at least 18 bytes of previous trailer - and subsequent header, and inserts an average of about three bytes to the - compressed data in order to connect the streams. The output gzip file - has a minimal ten-byte gzip header with no file name or modification time. - - This program was written to illustrate the use of the Z_BLOCK option of - inflate() and the crc32_combine() function. gzjoin will not compile with - versions of zlib earlier than 1.2.3. - */ - -#include /* fputs(), fprintf(), fwrite(), putc() */ -#include /* exit(), malloc(), free() */ -#include /* open() */ -#include /* close(), read(), lseek() */ -#include "zlib.h" - /* crc32(), crc32_combine(), inflateInit2(), inflate(), inflateEnd() */ - -#define local static - -/* exit with an error (return a value to allow use in an expression) */ -local int bail(char *why1, char *why2) -{ - fprintf(stderr, "gzjoin error: %s%s, output incomplete\n", why1, why2); - exit(1); - return 0; -} - -/* -- simple buffered file input with access to the buffer -- */ - -#define CHUNK 32768 /* must be a power of two and fit in unsigned */ - -/* bin buffered input file type */ -typedef struct { - char *name; /* name of file for error messages */ - int fd; /* file descriptor */ - unsigned left; /* bytes remaining at next */ - unsigned char *next; /* next byte to read */ - unsigned char *buf; /* allocated buffer of length CHUNK */ -} bin; - -/* close a buffered file and free allocated memory */ -local void bclose(bin *in) -{ - if (in != NULL) { - if (in->fd != -1) - close(in->fd); - if (in->buf != NULL) - free(in->buf); - free(in); - } -} - -/* open a buffered file for input, return a pointer to type bin, or NULL on - failure */ -local bin *bopen(char *name) -{ - bin *in; - - in = malloc(sizeof(bin)); - if (in == NULL) - return NULL; - in->buf = malloc(CHUNK); - in->fd = open(name, O_RDONLY, 0); - if (in->buf == NULL || in->fd == -1) { - bclose(in); - return NULL; - } - in->left = 0; - in->next = in->buf; - in->name = name; - return in; -} - -/* load buffer from file, return -1 on read error, 0 or 1 on success, with - 1 indicating that end-of-file was reached */ -local int bload(bin *in) -{ - long len; - - if (in == NULL) - return -1; - if (in->left != 0) - return 0; - in->next = in->buf; - do { - len = (long)read(in->fd, in->buf + in->left, CHUNK - in->left); - if (len < 0) - return -1; - in->left += (unsigned)len; - } while (len != 0 && in->left < CHUNK); - return len == 0 ? 1 : 0; -} - -/* get a byte from the file, bail if end of file */ -#define bget(in) (in->left ? 0 : bload(in), \ - in->left ? (in->left--, *(in->next)++) : \ - bail("unexpected end of file on ", in->name)) - -/* get a four-byte little-endian unsigned integer from file */ -local unsigned long bget4(bin *in) -{ - unsigned long val; - - val = bget(in); - val += (unsigned long)(bget(in)) << 8; - val += (unsigned long)(bget(in)) << 16; - val += (unsigned long)(bget(in)) << 24; - return val; -} - -/* skip bytes in file */ -local void bskip(bin *in, unsigned skip) -{ - /* check pointer */ - if (in == NULL) - return; - - /* easy case -- skip bytes in buffer */ - if (skip <= in->left) { - in->left -= skip; - in->next += skip; - return; - } - - /* skip what's in buffer, discard buffer contents */ - skip -= in->left; - in->left = 0; - - /* seek past multiples of CHUNK bytes */ - if (skip > CHUNK) { - unsigned left; - - left = skip & (CHUNK - 1); - if (left == 0) { - /* exact number of chunks: seek all the way minus one byte to check - for end-of-file with a read */ - lseek(in->fd, skip - 1, SEEK_CUR); - if (read(in->fd, in->buf, 1) != 1) - bail("unexpected end of file on ", in->name); - return; - } - - /* skip the integral chunks, update skip with remainder */ - lseek(in->fd, skip - left, SEEK_CUR); - skip = left; - } - - /* read more input and skip remainder */ - bload(in); - if (skip > in->left) - bail("unexpected end of file on ", in->name); - in->left -= skip; - in->next += skip; -} - -/* -- end of buffered input functions -- */ - -/* skip the gzip header from file in */ -local void gzhead(bin *in) -{ - int flags; - - /* verify gzip magic header and compression method */ - if (bget(in) != 0x1f || bget(in) != 0x8b || bget(in) != 8) - bail(in->name, " is not a valid gzip file"); - - /* get and verify flags */ - flags = bget(in); - if ((flags & 0xe0) != 0) - bail("unknown reserved bits set in ", in->name); - - /* skip modification time, extra flags, and os */ - bskip(in, 6); - - /* skip extra field if present */ - if (flags & 4) { - unsigned len; - - len = bget(in); - len += (unsigned)(bget(in)) << 8; - bskip(in, len); - } - - /* skip file name if present */ - if (flags & 8) - while (bget(in) != 0) - ; - - /* skip comment if present */ - if (flags & 16) - while (bget(in) != 0) - ; - - /* skip header crc if present */ - if (flags & 2) - bskip(in, 2); -} - -/* write a four-byte little-endian unsigned integer to out */ -local void put4(unsigned long val, FILE *out) -{ - putc(val & 0xff, out); - putc((val >> 8) & 0xff, out); - putc((val >> 16) & 0xff, out); - putc((val >> 24) & 0xff, out); -} - -/* Load up zlib stream from buffered input, bail if end of file */ -local void zpull(z_streamp strm, bin *in) -{ - if (in->left == 0) - bload(in); - if (in->left == 0) - bail("unexpected end of file on ", in->name); - strm->avail_in = in->left; - strm->next_in = in->next; -} - -/* Write header for gzip file to out and initialize trailer. */ -local void gzinit(unsigned long *crc, unsigned long *tot, FILE *out) -{ - fwrite("\x1f\x8b\x08\0\0\0\0\0\0\xff", 1, 10, out); - *crc = crc32(0L, Z_NULL, 0); - *tot = 0; -} - -/* Copy the compressed data from name, zeroing the last block bit of the last - block if clr is true, and adding empty blocks as needed to get to a byte - boundary. If clr is false, then the last block becomes the last block of - the output, and the gzip trailer is written. crc and tot maintains the - crc and length (modulo 2^32) of the output for the trailer. The resulting - gzip file is written to out. gzinit() must be called before the first call - of gzcopy() to write the gzip header and to initialize crc and tot. */ -local void gzcopy(char *name, int clr, unsigned long *crc, unsigned long *tot, - FILE *out) -{ - int ret; /* return value from zlib functions */ - int pos; /* where the "last block" bit is in byte */ - int last; /* true if processing the last block */ - bin *in; /* buffered input file */ - unsigned char *start; /* start of compressed data in buffer */ - unsigned char *junk; /* buffer for uncompressed data -- discarded */ - z_off_t len; /* length of uncompressed data (support > 4 GB) */ - z_stream strm; /* zlib inflate stream */ - - /* open gzip file and skip header */ - in = bopen(name); - if (in == NULL) - bail("could not open ", name); - gzhead(in); - - /* allocate buffer for uncompressed data and initialize raw inflate - stream */ - junk = malloc(CHUNK); - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - strm.avail_in = 0; - strm.next_in = Z_NULL; - ret = inflateInit2(&strm, -15); - if (junk == NULL || ret != Z_OK) - bail("out of memory", ""); - - /* inflate and copy compressed data, clear last-block bit if requested */ - len = 0; - zpull(&strm, in); - start = strm.next_in; - last = start[0] & 1; - if (last && clr) - start[0] &= ~1; - strm.avail_out = 0; - for (;;) { - /* if input used and output done, write used input and get more */ - if (strm.avail_in == 0 && strm.avail_out != 0) { - fwrite(start, 1, strm.next_in - start, out); - start = in->buf; - in->left = 0; - zpull(&strm, in); - } - - /* decompress -- return early when end-of-block reached */ - strm.avail_out = CHUNK; - strm.next_out = junk; - ret = inflate(&strm, Z_BLOCK); - switch (ret) { - case Z_MEM_ERROR: - bail("out of memory", ""); - case Z_DATA_ERROR: - bail("invalid compressed data in ", in->name); - } - - /* update length of uncompressed data */ - len += CHUNK - strm.avail_out; - - /* check for block boundary (only get this when block copied out) */ - if (strm.data_type & 128) { - /* if that was the last block, then done */ - if (last) - break; - - /* number of unused bits in last byte */ - pos = strm.data_type & 7; - - /* find the next last-block bit */ - if (pos != 0) { - /* next last-block bit is in last used byte */ - pos = 0x100 >> pos; - last = strm.next_in[-1] & pos; - if (last && clr) - strm.next_in[-1] &= ~pos; - } - else { - /* next last-block bit is in next unused byte */ - if (strm.avail_in == 0) { - /* don't have that byte yet -- get it */ - fwrite(start, 1, strm.next_in - start, out); - start = in->buf; - in->left = 0; - zpull(&strm, in); - } - last = strm.next_in[0] & 1; - if (last && clr) - strm.next_in[0] &= ~1; - } - } - } - - /* update buffer with unused input */ - in->left = strm.avail_in; - in->next = strm.next_in; - - /* copy used input, write empty blocks to get to byte boundary */ - pos = strm.data_type & 7; - fwrite(start, 1, in->next - start - 1, out); - last = in->next[-1]; - if (pos == 0 || !clr) - /* already at byte boundary, or last file: write last byte */ - putc(last, out); - else { - /* append empty blocks to last byte */ - last &= ((0x100 >> pos) - 1); /* assure unused bits are zero */ - if (pos & 1) { - /* odd -- append an empty stored block */ - putc(last, out); - if (pos == 1) - putc(0, out); /* two more bits in block header */ - fwrite("\0\0\xff\xff", 1, 4, out); - } - else { - /* even -- append 1, 2, or 3 empty fixed blocks */ - switch (pos) { - case 6: - putc(last | 8, out); - last = 0; - case 4: - putc(last | 0x20, out); - last = 0; - case 2: - putc(last | 0x80, out); - putc(0, out); - } - } - } - - /* update crc and tot */ - *crc = crc32_combine(*crc, bget4(in), len); - *tot += (unsigned long)len; - - /* clean up */ - inflateEnd(&strm); - free(junk); - bclose(in); - - /* write trailer if this is the last gzip file */ - if (!clr) { - put4(*crc, out); - put4(*tot, out); - } -} - -/* join the gzip files on the command line, write result to stdout */ -int main(int argc, char **argv) -{ - unsigned long crc, tot; /* running crc and total uncompressed length */ - - /* skip command name */ - argc--; - argv++; - - /* show usage if no arguments */ - if (argc == 0) { - fputs("gzjoin usage: gzjoin f1.gz [f2.gz [f3.gz ...]] > fjoin.gz\n", - stderr); - return 0; - } - - /* join gzip files on command line and write to stdout */ - gzinit(&crc, &tot, stdout); - while (argc--) - gzcopy(*argv++, argc, &crc, &tot, stdout); - - /* done */ - return 0; -} Index: trunk/minix/lib/zlib-1.2.3/examples/gzlog.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/gzlog.c (revision 9) +++ (revision ) @@ -1,413 +1,0 @@ -/* - * gzlog.c - * Copyright (C) 2004 Mark Adler - * For conditions of distribution and use, see copyright notice in gzlog.h - * version 1.0, 26 Nov 2004 - * - */ - -#include /* memcmp() */ -#include /* malloc(), free(), NULL */ -#include /* size_t, off_t */ -#include /* read(), close(), sleep(), ftruncate(), */ - /* lseek() */ -#include /* open() */ -#include /* flock() */ -#include "zlib.h" /* deflateInit2(), deflate(), deflateEnd() */ - -#include "gzlog.h" /* interface */ -#define local static - -/* log object structure */ -typedef struct { - int id; /* object identifier */ - int fd; /* log file descriptor */ - off_t extra; /* offset of extra "ap" subfield */ - off_t mark_off; /* offset of marked data */ - off_t last_off; /* offset of last block */ - unsigned long crc; /* uncompressed crc */ - unsigned long len; /* uncompressed length (modulo 2^32) */ - unsigned stored; /* length of current stored block */ -} gz_log; - -#define GZLOGID 19334 /* gz_log object identifier */ - -#define LOCK_RETRY 1 /* retry lock once a second */ -#define LOCK_PATIENCE 1200 /* try about twenty minutes before forcing */ - -/* acquire a lock on a file */ -local int lock(int fd) -{ - int patience; - - /* try to lock every LOCK_RETRY seconds for LOCK_PATIENCE seconds */ - patience = LOCK_PATIENCE; - do { - if (flock(fd, LOCK_EX + LOCK_NB) == 0) - return 0; - (void)sleep(LOCK_RETRY); - patience -= LOCK_RETRY; - } while (patience > 0); - - /* we've run out of patience -- give up */ - return -1; -} - -/* release lock */ -local void unlock(int fd) -{ - (void)flock(fd, LOCK_UN); -} - -/* release a log object */ -local void log_clean(gz_log *log) -{ - unlock(log->fd); - (void)close(log->fd); - free(log); -} - -/* read an unsigned long from a byte buffer little-endian */ -local unsigned long make_ulg(unsigned char *buf) -{ - int n; - unsigned long val; - - val = (unsigned long)(*buf++); - for (n = 8; n < 32; n += 8) - val += (unsigned long)(*buf++) << n; - return val; -} - -/* read an off_t from a byte buffer little-endian */ -local off_t make_off(unsigned char *buf) -{ - int n; - off_t val; - - val = (off_t)(*buf++); - for (n = 8; n < 64; n += 8) - val += (off_t)(*buf++) << n; - return val; -} - -/* write an unsigned long little-endian to byte buffer */ -local void dice_ulg(unsigned long val, unsigned char *buf) -{ - int n; - - for (n = 0; n < 4; n++) { - *buf++ = val & 0xff; - val >>= 8; - } -} - -/* write an off_t little-endian to byte buffer */ -local void dice_off(off_t val, unsigned char *buf) -{ - int n; - - for (n = 0; n < 8; n++) { - *buf++ = val & 0xff; - val >>= 8; - } -} - -/* initial, empty gzip file for appending */ -local char empty_gz[] = { - 0x1f, 0x8b, /* magic gzip id */ - 8, /* compression method is deflate */ - 4, /* there is an extra field */ - 0, 0, 0, 0, /* no modification time provided */ - 0, 0xff, /* no extra flags, no OS */ - 20, 0, 'a', 'p', 16, 0, /* extra field with "ap" subfield */ - 32, 0, 0, 0, 0, 0, 0, 0, /* offset of uncompressed data */ - 32, 0, 0, 0, 0, 0, 0, 0, /* offset of last block */ - 1, 0, 0, 0xff, 0xff, /* empty stored block (last) */ - 0, 0, 0, 0, /* crc */ - 0, 0, 0, 0 /* uncompressed length */ -}; - -/* initialize a log object with locking */ -void *gzlog_open(char *path) -{ - unsigned xlen; - unsigned char temp[20]; - unsigned sub_len; - int good; - gz_log *log; - - /* allocate log structure */ - log = malloc(sizeof(gz_log)); - if (log == NULL) - return NULL; - log->id = GZLOGID; - - /* open file, creating it if necessary, and locking it */ - log->fd = open(path, O_RDWR | O_CREAT, 0600); - if (log->fd < 0) { - free(log); - return NULL; - } - if (lock(log->fd)) { - close(log->fd); - free(log); - return NULL; - } - - /* if file is empty, write new gzip stream */ - if (lseek(log->fd, 0, SEEK_END) == 0) { - if (write(log->fd, empty_gz, sizeof(empty_gz)) != sizeof(empty_gz)) { - log_clean(log); - return NULL; - } - } - - /* check gzip header */ - (void)lseek(log->fd, 0, SEEK_SET); - if (read(log->fd, temp, 12) != 12 || temp[0] != 0x1f || - temp[1] != 0x8b || temp[2] != 8 || (temp[3] & 4) == 0) { - log_clean(log); - return NULL; - } - - /* process extra field to find "ap" sub-field */ - xlen = temp[10] + (temp[11] << 8); - good = 0; - while (xlen) { - if (xlen < 4 || read(log->fd, temp, 4) != 4) - break; - sub_len = temp[2]; - sub_len += temp[3] << 8; - xlen -= 4; - if (memcmp(temp, "ap", 2) == 0 && sub_len == 16) { - good = 1; - break; - } - if (xlen < sub_len) - break; - (void)lseek(log->fd, sub_len, SEEK_CUR); - xlen -= sub_len; - } - if (!good) { - log_clean(log); - return NULL; - } - - /* read in "ap" sub-field */ - log->extra = lseek(log->fd, 0, SEEK_CUR); - if (read(log->fd, temp, 16) != 16) { - log_clean(log); - return NULL; - } - log->mark_off = make_off(temp); - log->last_off = make_off(temp + 8); - - /* get crc, length of gzip file */ - (void)lseek(log->fd, log->last_off, SEEK_SET); - if (read(log->fd, temp, 13) != 13 || - memcmp(temp, "\001\000\000\377\377", 5) != 0) { - log_clean(log); - return NULL; - } - log->crc = make_ulg(temp + 5); - log->len = make_ulg(temp + 9); - - /* set up to write over empty last block */ - (void)lseek(log->fd, log->last_off + 5, SEEK_SET); - log->stored = 0; - return (void *)log; -} - -/* maximum amount to put in a stored block before starting a new one */ -#define MAX_BLOCK 16384 - -/* write a block to a log object */ -int gzlog_write(void *obj, char *data, size_t len) -{ - size_t some; - unsigned char temp[5]; - gz_log *log; - - /* check object */ - log = (gz_log *)obj; - if (log == NULL || log->id != GZLOGID) - return 1; - - /* write stored blocks until all of the input is written */ - do { - some = MAX_BLOCK - log->stored; - if (some > len) - some = len; - if (write(log->fd, data, some) != some) - return 1; - log->crc = crc32(log->crc, data, some); - log->len += some; - len -= some; - data += some; - log->stored += some; - - /* if the stored block is full, end it and start another */ - if (log->stored == MAX_BLOCK) { - (void)lseek(log->fd, log->last_off, SEEK_SET); - temp[0] = 0; - dice_ulg(log->stored + ((unsigned long)(~log->stored) << 16), - temp + 1); - if (write(log->fd, temp, 5) != 5) - return 1; - log->last_off = lseek(log->fd, log->stored, SEEK_CUR); - (void)lseek(log->fd, 5, SEEK_CUR); - log->stored = 0; - } - } while (len); - return 0; -} - -/* recompress the remaining stored deflate data in place */ -local int recomp(gz_log *log) -{ - z_stream strm; - size_t len, max; - unsigned char *in; - unsigned char *out; - unsigned char temp[16]; - - /* allocate space and read it all in (it's around 1 MB) */ - len = log->last_off - log->mark_off; - max = len + (len >> 12) + (len >> 14) + 11; - out = malloc(max); - if (out == NULL) - return 1; - in = malloc(len); - if (in == NULL) { - free(out); - return 1; - } - (void)lseek(log->fd, log->mark_off, SEEK_SET); - if (read(log->fd, in, len) != len) { - free(in); - free(out); - return 1; - } - - /* recompress in memory, decoding stored data as we go */ - /* note: this assumes that unsigned is four bytes or more */ - /* consider not making that assumption */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - if (deflateInit2(&strm, Z_BEST_COMPRESSION, Z_DEFLATED, -15, 8, - Z_DEFAULT_STRATEGY) != Z_OK) { - free(in); - free(out); - return 1; - } - strm.next_in = in; - strm.avail_out = max; - strm.next_out = out; - while (len >= 5) { - if (strm.next_in[0] != 0) - break; - strm.avail_in = strm.next_in[1] + (strm.next_in[2] << 8); - strm.next_in += 5; - len -= 5; - if (strm.avail_in != 0) { - if (len < strm.avail_in) - break; - len -= strm.avail_in; - (void)deflate(&strm, Z_NO_FLUSH); - if (strm.avail_in != 0 || strm.avail_out == 0) - break; - } - } - (void)deflate(&strm, Z_SYNC_FLUSH); - (void)deflateEnd(&strm); - free(in); - if (len != 0 || strm.avail_out == 0) { - free(out); - return 1; - } - - /* overwrite stored data with compressed data */ - (void)lseek(log->fd, log->mark_off, SEEK_SET); - len = max - strm.avail_out; - if (write(log->fd, out, len) != len) { - free(out); - return 1; - } - free(out); - - /* write last empty block, crc, and length */ - log->mark_off = log->last_off = lseek(log->fd, 0, SEEK_CUR); - temp[0] = 1; - dice_ulg(0xffffL << 16, temp + 1); - dice_ulg(log->crc, temp + 5); - dice_ulg(log->len, temp + 9); - if (write(log->fd, temp, 13) != 13) - return 1; - - /* truncate file to discard remaining stored data and old trailer */ - ftruncate(log->fd, lseek(log->fd, 0, SEEK_CUR)); - - /* update extra field to point to new last empty block */ - (void)lseek(log->fd, log->extra, SEEK_SET); - dice_off(log->mark_off, temp); - dice_off(log->last_off, temp + 8); - if (write(log->fd, temp, 16) != 16) - return 1; - return 0; -} - -/* maximum accumulation of stored blocks before compressing */ -#define MAX_STORED 1048576 - -/* close log object */ -int gzlog_close(void *obj) -{ - unsigned char temp[8]; - gz_log *log; - - /* check object */ - log = (gz_log *)obj; - if (log == NULL || log->id != GZLOGID) - return 1; - - /* go to start of most recent block being written */ - (void)lseek(log->fd, log->last_off, SEEK_SET); - - /* if some stuff was put there, update block */ - if (log->stored) { - temp[0] = 0; - dice_ulg(log->stored + ((unsigned long)(~log->stored) << 16), - temp + 1); - if (write(log->fd, temp, 5) != 5) - return 1; - log->last_off = lseek(log->fd, log->stored, SEEK_CUR); - } - - /* write last block (empty) */ - if (write(log->fd, "\001\000\000\377\377", 5) != 5) - return 1; - - /* write updated crc and uncompressed length */ - dice_ulg(log->crc, temp); - dice_ulg(log->len, temp + 4); - if (write(log->fd, temp, 8) != 8) - return 1; - - /* put offset of that last block in gzip extra block */ - (void)lseek(log->fd, log->extra + 8, SEEK_SET); - dice_off(log->last_off, temp); - if (write(log->fd, temp, 8) != 8) - return 1; - - /* if more than 1 MB stored, then time to compress it */ - if (log->last_off - log->mark_off > MAX_STORED) { - if (recomp(log)) - return 1; - } - - /* unlock and close file */ - log_clean(log); - return 0; -} Index: trunk/minix/lib/zlib-1.2.3/examples/gzlog.h =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/gzlog.h (revision 9) +++ (revision ) @@ -1,58 +1,0 @@ -/* gzlog.h - Copyright (C) 2004 Mark Adler, all rights reserved - version 1.0, 26 Nov 2004 - - This software is provided 'as-is', without any express or implied - warranty. In no event will the author 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. - - Mark Adler madler@alumni.caltech.edu - */ - -/* - The gzlog object allows writing short messages to a gzipped log file, - opening the log file locked for small bursts, and then closing it. The log - object works by appending stored data to the gzip file until 1 MB has been - accumulated. At that time, the stored data is compressed, and replaces the - uncompressed data in the file. The log file is truncated to its new size at - that time. After closing, the log file is always valid gzip file that can - decompressed to recover what was written. - - A gzip header "extra" field contains two file offsets for appending. The - first points to just after the last compressed data. The second points to - the last stored block in the deflate stream, which is empty. All of the - data between those pointers is uncompressed. - */ - -/* Open a gzlog object, creating the log file if it does not exist. Return - NULL on error. Note that gzlog_open() could take a long time to return if - there is difficulty in locking the file. */ -void *gzlog_open(char *path); - -/* Write to a gzlog object. Return non-zero on error. This function will - simply write data to the file uncompressed. Compression of the data - will not occur until gzlog_close() is called. It is expected that - gzlog_write() is used for a short message, and then gzlog_close() is - called. If a large amount of data is to be written, then the application - should write no more than 1 MB at a time with gzlog_write() before - calling gzlog_close() and then gzlog_open() again. */ -int gzlog_write(void *log, char *data, size_t len); - -/* Close a gzlog object. Return non-zero on error. The log file is locked - until this function is called. This function will compress stored data - at the end of the gzip file if at least 1 MB has been accumulated. Note - that the file will not be a valid gzip file until this function completes. - */ -int gzlog_close(void *log); Index: trunk/minix/lib/zlib-1.2.3/examples/zlib_how.html =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/zlib_how.html (revision 9) +++ (revision ) @@ -1,523 +1,0 @@ - - - - -zlib Usage Example - - - -

zlib Usage Example

-We often get questions about how the deflate() and inflate() functions should be used. -Users wonder when they should provide more input, when they should use more output, -what to do with a Z_BUF_ERROR, how to make sure the process terminates properly, and -so on. So for those who have read zlib.h (a few times), and -would like further edification, below is an annotated example in C of simple routines to compress and decompress -from an input file to an output file using deflate() and inflate() respectively. The -annotations are interspersed between lines of the code. So please read between the lines. -We hope this helps explain some of the intricacies of zlib. -

-Without further adieu, here is the program zpipe.c: -


-/* zpipe.c: example of proper use of zlib's inflate() and deflate()
-   Not copyrighted -- provided to the public domain
-   Version 1.2  9 November 2004  Mark Adler */
-
-/* Version history:
-   1.0  30 Oct 2004  First version
-   1.1   8 Nov 2004  Add void casting for unused return values
-                     Use switch statement for inflate() return values
-   1.2   9 Nov 2004  Add assertions to document zlib guarantees
- */
-
-We now include the header files for the required definitions. From -stdio.h we use fopen(), fread(), fwrite(), -feof(), ferror(), and fclose() for file i/o, and -fputs() for error messages. From string.h we use -strcmp() for command line argument processing. -From assert.h we use the assert() macro. -From zlib.h -we use the basic compression functions deflateInit(), -deflate(), and deflateEnd(), and the basic decompression -functions inflateInit(), inflate(), and -inflateEnd(). -

-#include <stdio.h>
-#include <string.h>
-#include <assert.h>
-#include "zlib.h"
-
-CHUNK is simply the buffer size for feeding data to and pulling data -from the zlib routines. Larger buffer sizes would be more efficient, -especially for inflate(). If the memory is available, buffers sizes -on the order of 128K or 256K bytes should be used. -

-#define CHUNK 16384
-
-The def() routine compresses data from an input file to an output file. The output data -will be in the zlib format, which is different from the gzip or zip -formats. The zlib format has a very small header of only two bytes to identify it as -a zlib stream and to provide decoding information, and a four-byte trailer with a fast -check value to verify the integrity of the uncompressed data after decoding. -

-/* Compress from file source to file dest until EOF on source.
-   def() returns Z_OK on success, Z_MEM_ERROR if memory could not be
-   allocated for processing, Z_STREAM_ERROR if an invalid compression
-   level is supplied, Z_VERSION_ERROR if the version of zlib.h and the
-   version of the library linked do not match, or Z_ERRNO if there is
-   an error reading or writing the files. */
-int def(FILE *source, FILE *dest, int level)
-{
-
-Here are the local variables for def(). ret will be used for zlib -return codes. flush will keep track of the current flushing state for deflate(), -which is either no flushing, or flush to completion after the end of the input file is reached. -have is the amount of data returned from deflate(). The strm structure -is used to pass information to and from the zlib routines, and to maintain the -deflate() state. in and out are the input and output buffers for -deflate(). -

-    int ret, flush;
-    unsigned have;
-    z_stream strm;
-    char in[CHUNK];
-    char out[CHUNK];
-
-The first thing we do is to initialize the zlib state for compression using -deflateInit(). This must be done before the first use of deflate(). -The zalloc, zfree, and opaque fields in the strm -structure must be initialized before calling deflateInit(). Here they are -set to the zlib constant Z_NULL to request that zlib use -the default memory allocation routines. An application may also choose to provide -custom memory allocation routines here. deflateInit() will allocate on the -order of 256K bytes for the internal state. -(See zlib Technical Details.) -

-deflateInit() is called with a pointer to the structure to be initialized and -the compression level, which is an integer in the range of -1 to 9. Lower compression -levels result in faster execution, but less compression. Higher levels result in -greater compression, but slower execution. The zlib constant Z_DEFAULT_COMPRESSION, -equal to -1, -provides a good compromise between compression and speed and is equivalent to level 6. -Level 0 actually does no compression at all, and in fact expands the data slightly to produce -the zlib format (it is not a byte-for-byte copy of the input). -More advanced applications of zlib -may use deflateInit2() here instead. Such an application may want to reduce how -much memory will be used, at some price in compression. Or it may need to request a -gzip header and trailer instead of a zlib header and trailer, or raw -encoding with no header or trailer at all. -

-We must check the return value of deflateInit() against the zlib constant -Z_OK to make sure that it was able to -allocate memory for the internal state, and that the provided arguments were valid. -deflateInit() will also check that the version of zlib that the zlib.h -file came from matches the version of zlib actually linked with the program. This -is especially important for environments in which zlib is a shared library. -

-Note that an application can initialize multiple, independent zlib streams, which can -operate in parallel. The state information maintained in the structure allows the zlib -routines to be reentrant. -


-    /* allocate deflate state */
-    strm.zalloc = Z_NULL;
-    strm.zfree = Z_NULL;
-    strm.opaque = Z_NULL;
-    ret = deflateInit(&strm, level);
-    if (ret != Z_OK)
-        return ret;
-
-With the pleasantries out of the way, now we can get down to business. The outer do-loop -reads all of the input file and exits at the bottom of the loop once end-of-file is reached. -This loop contains the only call of deflate(). So we must make sure that all of the -input data has been processed and that all of the output data has been generated and consumed -before we fall out of the loop at the bottom. -

-    /* compress until end of file */
-    do {
-
-We start off by reading data from the input file. The number of bytes read is put directly -into avail_in, and a pointer to those bytes is put into next_in. We also -check to see if end-of-file on the input has been reached. If we are at the end of file, then flush is set to the -zlib constant Z_FINISH, which is later passed to deflate() to -indicate that this is the last chunk of input data to compress. We need to use feof() -to check for end-of-file as opposed to seeing if fewer than CHUNK bytes have been read. The -reason is that if the input file length is an exact multiple of CHUNK, we will miss -the fact that we got to the end-of-file, and not know to tell deflate() to finish -up the compressed stream. If we are not yet at the end of the input, then the zlib -constant Z_NO_FLUSH will be passed to deflate to indicate that we are still -in the middle of the uncompressed data. -

-If there is an error in reading from the input file, the process is aborted with -deflateEnd() being called to free the allocated zlib state before returning -the error. We wouldn't want a memory leak, now would we? deflateEnd() can be called -at any time after the state has been initialized. Once that's done, deflateInit() (or -deflateInit2()) would have to be called to start a new compression process. There is -no point here in checking the deflateEnd() return code. The deallocation can't fail. -


-        strm.avail_in = fread(in, 1, CHUNK, source);
-        if (ferror(source)) {
-            (void)deflateEnd(&strm);
-            return Z_ERRNO;
-        }
-        flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
-        strm.next_in = in;
-
-The inner do-loop passes our chunk of input data to deflate(), and then -keeps calling deflate() until it is done producing output. Once there is no more -new output, deflate() is guaranteed to have consumed all of the input, i.e., -avail_in will be zero. -

-        /* run deflate() on input until output buffer not full, finish
-           compression if all of source has been read in */
-        do {
-
-Output space is provided to deflate() by setting avail_out to the number -of available output bytes and next_out to a pointer to that space. -

-            strm.avail_out = CHUNK;
-            strm.next_out = out;
-
-Now we call the compression engine itself, deflate(). It takes as many of the -avail_in bytes at next_in as it can process, and writes as many as -avail_out bytes to next_out. Those counters and pointers are then -updated past the input data consumed and the output data written. It is the amount of -output space available that may limit how much input is consumed. -Hence the inner loop to make sure that -all of the input is consumed by providing more output space each time. Since avail_in -and next_in are updated by deflate(), we don't have to mess with those -between deflate() calls until it's all used up. -

-The parameters to deflate() are a pointer to the strm structure containing -the input and output information and the internal compression engine state, and a parameter -indicating whether and how to flush data to the output. Normally deflate will consume -several K bytes of input data before producing any output (except for the header), in order -to accumulate statistics on the data for optimum compression. It will then put out a burst of -compressed data, and proceed to consume more input before the next burst. Eventually, -deflate() -must be told to terminate the stream, complete the compression with provided input data, and -write out the trailer check value. deflate() will continue to compress normally as long -as the flush parameter is Z_NO_FLUSH. Once the Z_FINISH parameter is provided, -deflate() will begin to complete the compressed output stream. However depending on how -much output space is provided, deflate() may have to be called several times until it -has provided the complete compressed stream, even after it has consumed all of the input. The flush -parameter must continue to be Z_FINISH for those subsequent calls. -

-There are other values of the flush parameter that are used in more advanced applications. You can -force deflate() to produce a burst of output that encodes all of the input data provided -so far, even if it wouldn't have otherwise, for example to control data latency on a link with -compressed data. You can also ask that deflate() do that as well as erase any history up to -that point so that what follows can be decompressed independently, for example for random access -applications. Both requests will degrade compression by an amount depending on how often such -requests are made. -

-deflate() has a return value that can indicate errors, yet we do not check it here. Why -not? Well, it turns out that deflate() can do no wrong here. Let's go through -deflate()'s return values and dispense with them one by one. The possible values are -Z_OK, Z_STREAM_END, Z_STREAM_ERROR, or Z_BUF_ERROR. Z_OK -is, well, ok. Z_STREAM_END is also ok and will be returned for the last call of -deflate(). This is already guaranteed by calling deflate() with Z_FINISH -until it has no more output. Z_STREAM_ERROR is only possible if the stream is not -initialized properly, but we did initialize it properly. There is no harm in checking for -Z_STREAM_ERROR here, for example to check for the possibility that some -other part of the application inadvertently clobbered the memory containing the zlib state. -Z_BUF_ERROR will be explained further below, but -suffice it to say that this is simply an indication that deflate() could not consume -more input or produce more output. deflate() can be called again with more output space -or more available input, which it will be in this code. -


-            ret = deflate(&strm, flush);    /* no bad return value */
-            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
-
-Now we compute how much output deflate() provided on the last call, which is the -difference between how much space was provided before the call, and how much output space -is still available after the call. Then that data, if any, is written to the output file. -We can then reuse the output buffer for the next call of deflate(). Again if there -is a file i/o error, we call deflateEnd() before returning to avoid a memory leak. -

-            have = CHUNK - strm.avail_out;
-            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
-                (void)deflateEnd(&strm);
-                return Z_ERRNO;
-            }
-
-The inner do-loop is repeated until the last deflate() call fails to fill the -provided output buffer. Then we know that deflate() has done as much as it can with -the provided input, and that all of that input has been consumed. We can then fall out of this -loop and reuse the input buffer. -

-The way we tell that deflate() has no more output is by seeing that it did not fill -the output buffer, leaving avail_out greater than zero. However suppose that -deflate() has no more output, but just so happened to exactly fill the output buffer! -avail_out is zero, and we can't tell that deflate() has done all it can. -As far as we know, deflate() -has more output for us. So we call it again. But now deflate() produces no output -at all, and avail_out remains unchanged as CHUNK. That deflate() call -wasn't able to do anything, either consume input or produce output, and so it returns -Z_BUF_ERROR. (See, I told you I'd cover this later.) However this is not a problem at -all. Now we finally have the desired indication that deflate() is really done, -and so we drop out of the inner loop to provide more input to deflate(). -

-With flush set to Z_FINISH, this final set of deflate() calls will -complete the output stream. Once that is done, subsequent calls of deflate() would return -Z_STREAM_ERROR if the flush parameter is not Z_FINISH, and do no more processing -until the state is reinitialized. -

-Some applications of zlib have two loops that call deflate() -instead of the single inner loop we have here. The first loop would call -without flushing and feed all of the data to deflate(). The second loop would call -deflate() with no more -data and the Z_FINISH parameter to complete the process. As you can see from this -example, that can be avoided by simply keeping track of the current flush state. -


-        } while (strm.avail_out == 0);
-        assert(strm.avail_in == 0);     /* all input will be used */
-
-Now we check to see if we have already processed all of the input file. That information was -saved in the flush variable, so we see if that was set to Z_FINISH. If so, -then we're done and we fall out of the outer loop. We're guaranteed to get Z_STREAM_END -from the last deflate() call, since we ran it until the last chunk of input was -consumed and all of the output was generated. -

-        /* done when last data in file processed */
-    } while (flush != Z_FINISH);
-    assert(ret == Z_STREAM_END);        /* stream will be complete */
-
-The process is complete, but we still need to deallocate the state to avoid a memory leak -(or rather more like a memory hemorrhage if you didn't do this). Then -finally we can return with a happy return value. -

-    /* clean up and return */
-    (void)deflateEnd(&strm);
-    return Z_OK;
-}
-
-Now we do the same thing for decompression in the inf() routine. inf() -decompresses what is hopefully a valid zlib stream from the input file and writes the -uncompressed data to the output file. Much of the discussion above for def() -applies to inf() as well, so the discussion here will focus on the differences between -the two. -

-/* Decompress from file source to file dest until stream ends or EOF.
-   inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be
-   allocated for processing, Z_DATA_ERROR if the deflate data is
-   invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and
-   the version of the library linked do not match, or Z_ERRNO if there
-   is an error reading or writing the files. */
-int inf(FILE *source, FILE *dest)
-{
-
-The local variables have the same functionality as they do for def(). The -only difference is that there is no flush variable, since inflate() -can tell from the zlib stream itself when the stream is complete. -

-    int ret;
-    unsigned have;
-    z_stream strm;
-    char in[CHUNK];
-    char out[CHUNK];
-
-The initialization of the state is the same, except that there is no compression level, -of course, and two more elements of the structure are initialized. avail_in -and next_in must be initialized before calling inflateInit(). This -is because the application has the option to provide the start of the zlib stream in -order for inflateInit() to have access to information about the compression -method to aid in memory allocation. In the current implementation of zlib -(up through versions 1.2.x), the method-dependent memory allocations are deferred to the first call of -inflate() anyway. However those fields must be initialized since later versions -of zlib that provide more compression methods may take advantage of this interface. -In any case, no decompression is performed by inflateInit(), so the -avail_out and next_out fields do not need to be initialized before calling. -

-Here avail_in is set to zero and next_in is set to Z_NULL to -indicate that no input data is being provided. -


-    /* allocate inflate state */
-    strm.zalloc = Z_NULL;
-    strm.zfree = Z_NULL;
-    strm.opaque = Z_NULL;
-    strm.avail_in = 0;
-    strm.next_in = Z_NULL;
-    ret = inflateInit(&strm);
-    if (ret != Z_OK)
-        return ret;
-
-The outer do-loop decompresses input until inflate() indicates -that it has reached the end of the compressed data and has produced all of the uncompressed -output. This is in contrast to def() which processes all of the input file. -If end-of-file is reached before the compressed data self-terminates, then the compressed -data is incomplete and an error is returned. -

-    /* decompress until deflate stream ends or end of file */
-    do {
-
-We read input data and set the strm structure accordingly. If we've reached the -end of the input file, then we leave the outer loop and report an error, since the -compressed data is incomplete. Note that we may read more data than is eventually consumed -by inflate(), if the input file continues past the zlib stream. -For applications where zlib streams are embedded in other data, this routine would -need to be modified to return the unused data, or at least indicate how much of the input -data was not used, so the application would know where to pick up after the zlib stream. -

-        strm.avail_in = fread(in, 1, CHUNK, source);
-        if (ferror(source)) {
-            (void)inflateEnd(&strm);
-            return Z_ERRNO;
-        }
-        if (strm.avail_in == 0)
-            break;
-        strm.next_in = in;
-
-The inner do-loop has the same function it did in def(), which is to -keep calling inflate() until has generated all of the output it can with the -provided input. -

-        /* run inflate() on input until output buffer not full */
-        do {
-
-Just like in def(), the same output space is provided for each call of inflate(). -

-            strm.avail_out = CHUNK;
-            strm.next_out = out;
-
-Now we run the decompression engine itself. There is no need to adjust the flush parameter, since -the zlib format is self-terminating. The main difference here is that there are -return values that we need to pay attention to. Z_DATA_ERROR -indicates that inflate() detected an error in the zlib compressed data format, -which means that either the data is not a zlib stream to begin with, or that the data was -corrupted somewhere along the way since it was compressed. The other error to be processed is -Z_MEM_ERROR, which can occur since memory allocation is deferred until inflate() -needs it, unlike deflate(), whose memory is allocated at the start by deflateInit(). -

-Advanced applications may use -deflateSetDictionary() to prime deflate() with a set of likely data to improve the -first 32K or so of compression. This is noted in the zlib header, so inflate() -requests that that dictionary be provided before it can start to decompress. Without the dictionary, -correct decompression is not possible. For this routine, we have no idea what the dictionary is, -so the Z_NEED_DICT indication is converted to a Z_DATA_ERROR. -

-inflate() can also return Z_STREAM_ERROR, which should not be possible here, -but could be checked for as noted above for def(). Z_BUF_ERROR does not need to be -checked for here, for the same reasons noted for def(). Z_STREAM_END will be -checked for later. -


-            ret = inflate(&strm, Z_NO_FLUSH);
-            assert(ret != Z_STREAM_ERROR);  /* state not clobbered */
-            switch (ret) {
-            case Z_NEED_DICT:
-                ret = Z_DATA_ERROR;     /* and fall through */
-            case Z_DATA_ERROR:
-            case Z_MEM_ERROR:
-                (void)inflateEnd(&strm);
-                return ret;
-            }
-
-The output of inflate() is handled identically to that of deflate(). -

-            have = CHUNK - strm.avail_out;
-            if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
-                (void)inflateEnd(&strm);
-                return Z_ERRNO;
-            }
-
-The inner do-loop ends when inflate() has no more output as indicated -by not filling the output buffer, just as for deflate(). In this case, we cannot -assert that strm.avail_in will be zero, since the deflate stream may end before the file -does. -

-        } while (strm.avail_out == 0);
-
-The outer do-loop ends when inflate() reports that it has reached the -end of the input zlib stream, has completed the decompression and integrity -check, and has provided all of the output. This is indicated by the inflate() -return value Z_STREAM_END. The inner loop is guaranteed to leave ret -equal to Z_STREAM_END if the last chunk of the input file read contained the end -of the zlib stream. So if the return value is not Z_STREAM_END, the -loop continues to read more input. -

-        /* done when inflate() says it's done */
-    } while (ret != Z_STREAM_END);
-
-At this point, decompression successfully completed, or we broke out of the loop due to no -more data being available from the input file. If the last inflate() return value -is not Z_STREAM_END, then the zlib stream was incomplete and a data error -is returned. Otherwise, we return with a happy return value. Of course, inflateEnd() -is called first to avoid a memory leak. -

-    /* clean up and return */
-    (void)inflateEnd(&strm);
-    return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR;
-}
-
-That ends the routines that directly use zlib. The following routines make this -a command-line program by running data through the above routines from stdin to -stdout, and handling any errors reported by def() or inf(). -

-zerr() is used to interpret the possible error codes from def() -and inf(), as detailed in their comments above, and print out an error message. -Note that these are only a subset of the possible return values from deflate() -and inflate(). -


-/* report a zlib or i/o error */
-void zerr(int ret)
-{
-    fputs("zpipe: ", stderr);
-    switch (ret) {
-    case Z_ERRNO:
-        if (ferror(stdin))
-            fputs("error reading stdin\n", stderr);
-        if (ferror(stdout))
-            fputs("error writing stdout\n", stderr);
-        break;
-    case Z_STREAM_ERROR:
-        fputs("invalid compression level\n", stderr);
-        break;
-    case Z_DATA_ERROR:
-        fputs("invalid or incomplete deflate data\n", stderr);
-        break;
-    case Z_MEM_ERROR:
-        fputs("out of memory\n", stderr);
-        break;
-    case Z_VERSION_ERROR:
-        fputs("zlib version mismatch!\n", stderr);
-    }
-}
-
-Here is the main() routine used to test def() and inf(). The -zpipe command is simply a compression pipe from stdin to stdout, if -no arguments are given, or it is a decompression pipe if zpipe -d is used. If any other -arguments are provided, no compression or decompression is performed. Instead a usage -message is displayed. Examples are zpipe < foo.txt > foo.txt.z to compress, and -zpipe -d < foo.txt.z > foo.txt to decompress. -

-/* compress or decompress from stdin to stdout */
-int main(int argc, char **argv)
-{
-    int ret;
-
-    /* do compression if no arguments */
-    if (argc == 1) {
-        ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION);
-        if (ret != Z_OK)
-            zerr(ret);
-        return ret;
-    }
-
-    /* do decompression if -d specified */
-    else if (argc == 2 && strcmp(argv[1], "-d") == 0) {
-        ret = inf(stdin, stdout);
-        if (ret != Z_OK)
-            zerr(ret);
-        return ret;
-    }
-
-    /* otherwise, report usage */
-    else {
-        fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr);
-        return 1;
-    }
-}
-
-
-Copyright (c) 2004 by Mark Adler
Last modified 13 November 2004 - - Index: trunk/minix/lib/zlib-1.2.3/examples/zpipe.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/zpipe.c (revision 9) +++ (revision ) @@ -1,191 +1,0 @@ -/* zpipe.c: example of proper use of zlib's inflate() and deflate() - Not copyrighted -- provided to the public domain - Version 1.2 9 November 2004 Mark Adler */ - -/* Version history: - 1.0 30 Oct 2004 First version - 1.1 8 Nov 2004 Add void casting for unused return values - Use switch statement for inflate() return values - 1.2 9 Nov 2004 Add assertions to document zlib guarantees - 1.3 6 Apr 2005 Remove incorrect assertion in inf() - */ - -#include -#include -#include -#include "zlib.h" - -#define CHUNK 16384 - -/* Compress from file source to file dest until EOF on source. - def() returns Z_OK on success, Z_MEM_ERROR if memory could not be - allocated for processing, Z_STREAM_ERROR if an invalid compression - level is supplied, Z_VERSION_ERROR if the version of zlib.h and the - version of the library linked do not match, or Z_ERRNO if there is - an error reading or writing the files. */ -int def(FILE *source, FILE *dest, int level) -{ - int ret, flush; - unsigned have; - z_stream strm; - char in[CHUNK]; - char out[CHUNK]; - - /* allocate deflate state */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - ret = deflateInit(&strm, level); - if (ret != Z_OK) - return ret; - - /* compress until end of file */ - do { - strm.avail_in = fread(in, 1, CHUNK, source); - if (ferror(source)) { - (void)deflateEnd(&strm); - return Z_ERRNO; - } - flush = feof(source) ? Z_FINISH : Z_NO_FLUSH; - strm.next_in = in; - - /* run deflate() on input until output buffer not full, finish - compression if all of source has been read in */ - do { - strm.avail_out = CHUNK; - strm.next_out = out; - ret = deflate(&strm, flush); /* no bad return value */ - assert(ret != Z_STREAM_ERROR); /* state not clobbered */ - have = CHUNK - strm.avail_out; - if (fwrite(out, 1, have, dest) != have || ferror(dest)) { - (void)deflateEnd(&strm); - return Z_ERRNO; - } - } while (strm.avail_out == 0); - assert(strm.avail_in == 0); /* all input will be used */ - - /* done when last data in file processed */ - } while (flush != Z_FINISH); - assert(ret == Z_STREAM_END); /* stream will be complete */ - - /* clean up and return */ - (void)deflateEnd(&strm); - return Z_OK; -} - -/* Decompress from file source to file dest until stream ends or EOF. - inf() returns Z_OK on success, Z_MEM_ERROR if memory could not be - allocated for processing, Z_DATA_ERROR if the deflate data is - invalid or incomplete, Z_VERSION_ERROR if the version of zlib.h and - the version of the library linked do not match, or Z_ERRNO if there - is an error reading or writing the files. */ -int inf(FILE *source, FILE *dest) -{ - int ret; - unsigned have; - z_stream strm; - char in[CHUNK]; - char out[CHUNK]; - - /* allocate inflate state */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - strm.avail_in = 0; - strm.next_in = Z_NULL; - ret = inflateInit(&strm); - if (ret != Z_OK) - return ret; - - /* decompress until deflate stream ends or end of file */ - do { - strm.avail_in = fread(in, 1, CHUNK, source); - if (ferror(source)) { - (void)inflateEnd(&strm); - return Z_ERRNO; - } - if (strm.avail_in == 0) - break; - strm.next_in = in; - - /* run inflate() on input until output buffer not full */ - do { - strm.avail_out = CHUNK; - strm.next_out = out; - ret = inflate(&strm, Z_NO_FLUSH); - assert(ret != Z_STREAM_ERROR); /* state not clobbered */ - switch (ret) { - case Z_NEED_DICT: - ret = Z_DATA_ERROR; /* and fall through */ - case Z_DATA_ERROR: - case Z_MEM_ERROR: - (void)inflateEnd(&strm); - return ret; - } - have = CHUNK - strm.avail_out; - if (fwrite(out, 1, have, dest) != have || ferror(dest)) { - (void)inflateEnd(&strm); - return Z_ERRNO; - } - } while (strm.avail_out == 0); - - /* done when inflate() says it's done */ - } while (ret != Z_STREAM_END); - - /* clean up and return */ - (void)inflateEnd(&strm); - return ret == Z_STREAM_END ? Z_OK : Z_DATA_ERROR; -} - -/* report a zlib or i/o error */ -void zerr(int ret) -{ - fputs("zpipe: ", stderr); - switch (ret) { - case Z_ERRNO: - if (ferror(stdin)) - fputs("error reading stdin\n", stderr); - if (ferror(stdout)) - fputs("error writing stdout\n", stderr); - break; - case Z_STREAM_ERROR: - fputs("invalid compression level\n", stderr); - break; - case Z_DATA_ERROR: - fputs("invalid or incomplete deflate data\n", stderr); - break; - case Z_MEM_ERROR: - fputs("out of memory\n", stderr); - break; - case Z_VERSION_ERROR: - fputs("zlib version mismatch!\n", stderr); - } -} - -/* compress or decompress from stdin to stdout */ -int main(int argc, char **argv) -{ - int ret; - - /* do compression if no arguments */ - if (argc == 1) { - ret = def(stdin, stdout, Z_DEFAULT_COMPRESSION); - if (ret != Z_OK) - zerr(ret); - return ret; - } - - /* do decompression if -d specified */ - else if (argc == 2 && strcmp(argv[1], "-d") == 0) { - ret = inf(stdin, stdout); - if (ret != Z_OK) - zerr(ret); - return ret; - } - - /* otherwise, report usage */ - else { - fputs("zpipe usage: zpipe [-d] < source > dest\n", stderr); - return 1; - } -} Index: trunk/minix/lib/zlib-1.2.3/examples/zran.c =================================================================== --- trunk/minix/lib/zlib-1.2.3/examples/zran.c (revision 9) +++ (revision ) @@ -1,404 +1,0 @@ -/* zran.c -- example of zlib/gzip stream indexing and random access - * Copyright (C) 2005 Mark Adler - * For conditions of distribution and use, see copyright notice in zlib.h - Version 1.0 29 May 2005 Mark Adler */ - -/* Illustrate the use of Z_BLOCK, inflatePrime(), and inflateSetDictionary() - for random access of a compressed file. A file containing a zlib or gzip - stream is provided on the command line. The compressed stream is decoded in - its entirety, and an index built with access points about every SPAN bytes - in the uncompressed output. The compressed file is left open, and can then - be read randomly, having to decompress on the average SPAN/2 uncompressed - bytes before getting to the desired block of data. - - An access point can be created at the start of any deflate block, by saving - the starting file offset and bit of that block, and the 32K bytes of - uncompressed data that precede that block. Also the uncompressed offset of - that block is saved to provide a referece for locating a desired starting - point in the uncompressed stream. build_index() works by decompressing the - input zlib or gzip stream a block at a time, and at the end of each block - deciding if enough uncompressed data has gone by to justify the creation of - a new access point. If so, that point is saved in a data structure that - grows as needed to accommodate the points. - - To use the index, an offset in the uncompressed data is provided, for which - the latest accees point at or preceding that offset is located in the index. - The input file is positioned to the specified location in the index, and if - necessary the first few bits of the compressed data is read from the file. - inflate is initialized with those bits and the 32K of uncompressed data, and - the decompression then proceeds until the desired offset in the file is - reached. Then the decompression continues to read the desired uncompressed - data from the file. - - Another approach would be to generate the index on demand. In that case, - requests for random access reads from the compressed data would try to use - the index, but if a read far enough past the end of the index is required, - then further index entries would be generated and added. - - There is some fair bit of overhead to starting inflation for the random - access, mainly copying the 32K byte dictionary. So if small pieces of the - file are being accessed, it would make sense to implement a cache to hold - some lookahead and avoid many calls to extract() for small lengths. - - Another way to build an index would be to use inflateCopy(). That would - not be constrained to have access points at block boundaries, but requires - more memory per access point, and also cannot be saved to file due to the - use of pointers in the state. The approach here allows for storage of the - index in a file. - */ - -#include -#include -#include -#include "zlib.h" - -#define local static - -#define SPAN 1048576L /* desired distance between access points */ -#define WINSIZE 32768U /* sliding window size */ -#define CHUNK 16384 /* file input buffer size */ - -/* access point entry */ -struct point { - off_t out; /* corresponding offset in uncompressed data */ - off_t in; /* offset in input file of first full byte */ - int bits; /* number of bits (1-7) from byte at in - 1, or 0 */ - unsigned char window[WINSIZE]; /* preceding 32K of uncompressed data */ -}; - -/* access point list */ -struct access { - int have; /* number of list entries filled in */ - int size; /* number of list entries allocated */ - struct point *list; /* allocated list */ -}; - -/* Deallocate an index built by build_index() */ -local void free_index(struct access *index) -{ - if (index != NULL) { - free(index->list); - free(index); - } -} - -/* Add an entry to the access point list. If out of memory, deallocate the - existing list and return NULL. */ -local struct access *addpoint(struct access *index, int bits, - off_t in, off_t out, unsigned left, unsigned char *window) -{ - struct point *next; - - /* if list is empty, create it (start with eight points) */ - if (index == NULL) { - index = malloc(sizeof(struct access)); - if (index == NULL) return NULL; - index->list = malloc(sizeof(struct point) << 3); - if (index->list == NULL) { - free(index); - return NULL; - } - index->size = 8; - index->have = 0; - } - - /* if list is full, make it bigger */ - else if (index->have == index->size) { - index->size <<= 1; - next = realloc(index->list, sizeof(struct point) * index->size); - if (next == NULL) { - free_index(index); - return NULL; - } - index->list = next; - } - - /* fill in entry and increment how many we have */ - next = index->list + index->have; - next->bits = bits; - next->in = in; - next->out = out; - if (left) - memcpy(next->window, window + WINSIZE - left, left); - if (left < WINSIZE) - memcpy(next->window + left, window, WINSIZE - left); - index->have++; - - /* return list, possibly reallocated */ - return index; -} - -/* Make one entire pass through the compressed stream and build an index, with - access points about every span bytes of uncompressed output -- span is - chosen to balance the speed of random access against the memory requirements - of the list, about 32K bytes per access point. Note that data after the end - of the first zlib or gzip stream in the file is ignored. build_index() - returns the number of access points on success (>= 1), Z_MEM_ERROR for out - of memory, Z_DATA_ERROR for an error in the input file, or Z_ERRNO for a - file read error. On success, *built points to the resulting index. */ -local int build_index(FILE *in, off_t span, struct access **built) -{ - int ret; - off_t totin, totout; /* our own total counters to avoid 4GB limit */ - off_t last; /* totout value of last access point */ - struct access *index; /* access points being generated */ - z_stream strm; - unsigned char input[CHUNK]; - unsigned char window[WINSIZE]; - - /* initialize inflate */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - strm.avail_in = 0; - strm.next_in = Z_NULL; - ret = inflateInit2(&strm, 47); /* automatic zlib or gzip decoding */ - if (ret != Z_OK) - return ret; - - /* inflate the input, maintain a sliding window, and build an index -- this - also validates the integrity of the compressed data using the check - information at the end of the gzip or zlib stream */ - totin = totout = last = 0; - index = NULL; /* will be allocated by first addpoint() */ - strm.avail_out = 0; - do { - /* get some compressed data from input file */ - strm.avail_in = fread(input, 1, CHUNK, in); - if (ferror(in)) { - ret = Z_ERRNO; - goto build_index_error; - } - if (strm.avail_in == 0) { - ret = Z_DATA_ERROR; - goto build_index_error; - } - strm.next_in = input; - - /* process all of that, or until end of stream */ - do { - /* reset sliding window if necessary */ - if (strm.avail_out == 0) { - strm.avail_out = WINSIZE; - strm.next_out = window; - } - - /* inflate until out of input, output, or at end of block -- - update the total input and output counters */ - totin += strm.avail_in; - totout += strm.avail_out; - ret = inflate(&strm, Z_BLOCK); /* return at end of block */ - totin -= strm.avail_in; - totout -= strm.avail_out; - if (ret == Z_NEED_DICT) - ret = Z_DATA_ERROR; - if (ret == Z_MEM_ERROR || ret == Z_DATA_ERROR) - goto build_index_error; - if (ret == Z_STREAM_END) - break; - - /* if at end of block, consider adding an index entry (note that if - data_type indicates an end-of-block, then all of the - uncompressed data from that block has been delivered, and none - of the compressed data after that block has been consumed, - except for up to seven bits) -- the totout == 0 provides an - entry point after the zlib or gzip header, and assures that the - index always has at least one access point; we avoid creating an - access point after the last block by checking bit 6 of data_type - */ - if ((strm.data_type & 128) && !(strm.data_type & 64) && - (totout == 0 || totout - last > span)) { - index = addpoint(index, strm.data_type & 7, totin, - totout, strm.avail_out, window); - if (index == NULL) { - ret = Z_MEM_ERROR; - goto build_index_error; - } - last = totout; - } - } while (strm.avail_in != 0); - } while (ret != Z_STREAM_END); - - /* clean up and return index (release unused entries in list) */ - (void)inflateEnd(&strm); - index = realloc(index, sizeof(struct point) * index->have); - index->size = index->have; - *built = index; - return index->size; - - /* return error */ - build_index_error: - (void)inflateEnd(&strm); - if (index != NULL) - free_index(index); - return ret; -} - -/* Use the index to read len bytes from offset into buf, return bytes read or - negative for error (Z_DATA_ERROR or Z_MEM_ERROR). If data is requested past - the end of the uncompressed data, then extract() will return a value less - than len, indicating how much as actually read into buf. This function - should not return a data error unless the file was modified since the index - was generated. extract() may also return Z_ERRNO if there is an error on - reading or seeking the input file. */ -local int extract(FILE *in, struct access *index, off_t offset, - unsigned char *buf, int len) -{ - int ret, skip; - z_stream strm; - struct point *here; - unsigned char input[CHUNK]; - unsigned char discard[WINSIZE]; - - /* proceed only if something reasonable to do */ - if (len < 0) - return 0; - - /* find where in stream to start */ - here = index->list; - ret = index->have; - while (--ret && here[1].out <= offset) - here++; - - /* initialize file and inflate state to start there */ - strm.zalloc = Z_NULL; - strm.zfree = Z_NULL; - strm.opaque = Z_NULL; - strm.avail_in = 0; - strm.next_in = Z_NULL; - ret = inflateInit2(&strm, -15); /* raw inflate */ - if (ret != Z_OK) - return ret; - ret = fseeko(in, here->in - (here->bits ? 1 : 0), SEEK_SET); - if (ret == -1) - goto extract_ret; - if (here->bits) { - ret = getc(in); - if (ret == -1) { - ret = ferror(in) ? Z_ERRNO : Z_DATA_ERROR; - goto extract_ret; - } - (void)inflatePrime(&strm, here->bits, ret >> (8 - here->bits)); - } - (void)inflateSetDictionary(&strm, here->window, WINSIZE); - - /* skip uncompressed bytes until offset reached, then satisfy request */ - offset -= here->out; - strm.avail_in = 0; - skip = 1; /* while skipping to offset */ - do { - /* define where to put uncompressed data, and how much */ - if (offset == 0 && skip) { /* at offset now */ - strm.avail_out = len; - strm.next_out = buf; - skip = 0; /* only do this once */ - } - if (offset > WINSIZE) { /* skip WINSIZE bytes */ - strm.avail_out = WINSIZE; - strm.next_out = discard; - offset -= WINSIZE; - } - else if (offset != 0) { /* last skip */ - strm.avail_out = (unsigned)offset; - strm.next_out = discard; - offset = 0; - } - - /* uncompress until avail_out filled, or end of stream */ - do { - if (strm.avail_in == 0) { - strm.avail_in = fread(input, 1, CHUNK, in); - if (ferror(in)) { - ret = Z_ERRNO; - goto extract_ret; - } - if (strm.avail_in == 0) { - ret = Z_DATA_ERROR; - goto extract_ret; - } - strm.next_in = input; - } - ret = inflate(&strm, Z_NO_FLUSH); /* normal inflate */ - if (ret == Z_NEED_DICT) - ret = Z_DATA_ERROR; - if (ret == Z_MEM_ERROR || ret == Z_DATA_ERROR) - goto extract_ret; - if (ret == Z_STREAM_END) - break; - } while (strm.avail_out != 0); - - /* if reach end of stream, then don't keep trying to get more */ - if (ret == Z_STREAM_END) - break; - - /* do until offset reached and requested data read, or stream ends */ - } while (skip); - - /* compute number of uncompressed bytes read after offset */ - ret = skip ? 0 : len - strm.avail_out; - - /* clean up and return bytes read or error */ - extract_ret: - (void)inflateEnd(&strm); - return ret; -} - -/* Demonstrate the use of build_index() and extract() by processing the file - provided on the command line, and the extracting 16K from about 2/3rds of - the way through the uncompressed output, and writing that to stdout. */ -int main(int argc, char **argv) -{ - int len; - off_t offset; - FILE *in; - struct access *index; - unsigned char buf[CHUNK]; - - /* open input file */ - if (argc != 2) { - fprintf(stderr, "usage: zran file.gz\n"); - return 1; - } - in = fopen(argv[1], "rb"); - if (in == NULL) { - fprintf(stderr, "zran: could not open %s for reading\n", argv[1]); - return 1; - } - - /* build index */ - len = build_index(in, SPAN, &index); - if (len < 0) { - fclose(in); - switch (len) { - case Z_MEM_ERROR: - fprintf(stderr, "zran: out of memory\n"); - break; - case Z_DATA_ERROR: - fprintf(stderr, "zran: compressed data error in %s\n", argv[1]); - break; - case Z_ERRNO: - fprintf(stderr, "zran: read error on %s\n", argv[1]); - break; - default: - fprintf(stderr, "zran: error %d while building index\n", len); - } - return 1; - } - fprintf(stderr, "zran: built index with %d access points\n", len); - - /* use index by reading some bytes from an arbitrary offset */ - offset = (index->list[index->have - 1].out << 1) / 3; - len = extract(in, index, offset, buf, CHUNK); - if (len < 0) - fprintf(stderr, "zran: extraction failed: %s error\n", - len == Z_MEM_ERROR ? "out of memory" : "input corrupted"); - else { - fwrite(buf, 1, len, stdout); - fprintf(stderr, "zran: extracted %d bytes at %llu\n", len, offset); - } - - /* clean up and exit */ - free_index(index); - fclose(in); - return 0; -}