diff options
Diffstat (limited to 'examples')
| -rw-r--r-- | examples/enough.c | 24 | ||||
| -rw-r--r-- | examples/gun.c | 18 | ||||
| -rw-r--r-- | examples/gznorm.c | 4 | ||||
| -rw-r--r-- | examples/zlib_how.html | 15 | ||||
| -rw-r--r-- | examples/zpipe.c | 5 | ||||
| -rw-r--r-- | examples/zran.c | 227 | ||||
| -rw-r--r-- | examples/zran.h | 12 |
7 files changed, 163 insertions, 142 deletions
diff --git a/examples/enough.c b/examples/enough.c index 8a3cade4923a..43112a438c4a 100644 --- a/examples/enough.c +++ b/examples/enough.c @@ -1,7 +1,7 @@ /* enough.c -- determine the maximum size of inflate's Huffman code tables over * all possible valid and complete prefix codes, subject to a length limit. - * Copyright (C) 2007, 2008, 2012, 2018 Mark Adler - * Version 1.5 5 August 2018 Mark Adler + * Copyright (C) 2007, 2008, 2012, 2018, 2024 Mark Adler + * Version 1.6 29 July 2024 Mark Adler */ /* Version history: @@ -19,6 +19,7 @@ Clean up code indentation 1.5 5 Aug 2018 Clean up code style, formatting, and comments Show all the codes for the maximum, and only the maximum + 1.6 29 Jul 2024 Avoid use of uintmax_t */ /* @@ -88,33 +89,32 @@ need to be examined to cover all of the possible table memory usage cases for the default arguments of 286 symbols limited to 15-bit codes. - Note that the uintmax_t type is used for counting. It is quite easy to + Note that unsigned long long is used for counting. It is quite easy to exceed the capacity of an eight-byte integer with a large number of symbols and a large maximum code length, so multiple-precision arithmetic would need to replace the integer arithmetic in that case. This program will abort if an overflow occurs. The big_t type identifies where the counting takes place. - The uintmax_t type is also used for calculating the number of possible codes - remaining at the maximum length. This limits the maximum code length to the - number of bits in a long long minus the number of bits needed to represent - the symbols in a flat code. The code_t type identifies where the bit-pattern - counting takes place. + The unsigned long long type is also used for calculating the number of + possible codes remaining at the maximum length. This limits the maximum code + length to the number of bits in a long long minus the number of bits needed + to represent the symbols in a flat code. The code_t type identifies where + the bit-pattern counting takes place. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <stdarg.h> -#include <stdint.h> #include <assert.h> #define local static // Special data types. -typedef uintmax_t big_t; // type for code counting -#define PRIbig "ju" // printf format for big_t -typedef uintmax_t code_t; // type for bit pattern counting +typedef unsigned long long big_t; // type for code counting +#define PRIbig "llu" // printf format for big_t +typedef big_t code_t; // type for bit pattern counting struct tab { // type for been-here check size_t len; // allocated length of bit vector in octets char *vec; // allocated bit vector diff --git a/examples/gun.c b/examples/gun.c index bea5497e5c2b..dbd181c07169 100644 --- a/examples/gun.c +++ b/examples/gun.c @@ -227,12 +227,12 @@ local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp, if (last == -1) return Z_BUF_ERROR; if (flags & 0x60) { - strm->msg = (char *)"unknown lzw flags set"; + strm->msg = (z_const 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"; + strm->msg = (z_const char *)"lzw bits out of range"; return Z_DATA_ERROR; } if (max == 9) /* 9 doesn't really mean 9 */ @@ -252,7 +252,7 @@ local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp, if (NEXT() == -1) /* missing a bit */ return Z_BUF_ERROR; if (last & 1) { /* code must be < 256 */ - strm->msg = (char *)"invalid lzw code"; + strm->msg = (z_const char *)"invalid lzw code"; return Z_DATA_ERROR; } rem = (unsigned)last >> 1; /* remaining 7 bits */ @@ -319,7 +319,7 @@ local int lunpipe(unsigned have, z_const unsigned char *next, struct ind *indp, 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"; + strm->msg = (z_const char *)"invalid lzw code"; return Z_DATA_ERROR; } match[stack++] = (unsigned char)final; @@ -404,7 +404,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile) break; /* empty gzip stream is ok */ } if (last != 31 || (NEXT() != 139 && last != 157)) { - strm->msg = (char *)"incorrect header check"; + strm->msg = (z_const char *)"incorrect header check"; ret = first ? Z_DATA_ERROR : Z_ERRNO; break; /* not a gzip or compress header */ } @@ -420,7 +420,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile) ret = Z_BUF_ERROR; if (NEXT() != 8) { /* only deflate method allowed */ if (last == -1) break; - strm->msg = (char *)"unknown compression method"; + strm->msg = (z_const char *)"unknown compression method"; ret = Z_DATA_ERROR; break; } @@ -433,7 +433,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile) NEXT(); if (last == -1) break; if (flags & 0xe0) { - strm->msg = (char *)"unknown header flags set"; + strm->msg = (z_const char *)"unknown header flags set"; ret = Z_DATA_ERROR; break; } @@ -486,7 +486,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile) NEXT() != (int)((outd.crc >> 24) & 0xff)) { /* crc error */ if (last != -1) { - strm->msg = (char *)"incorrect data check"; + strm->msg = (z_const char *)"incorrect data check"; ret = Z_DATA_ERROR; } break; @@ -497,7 +497,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile) NEXT() != (int)((outd.total >> 24) & 0xff)) { /* length error */ if (last != -1) { - strm->msg = (char *)"incorrect length check"; + strm->msg = (z_const char *)"incorrect length check"; ret = Z_DATA_ERROR; } break; diff --git a/examples/gznorm.c b/examples/gznorm.c index 68e0a0f29be4..e8d9b480d982 100644 --- a/examples/gznorm.c +++ b/examples/gznorm.c @@ -10,6 +10,10 @@ // the data, so it is fast, but no advantage is gained from the history that // could be available across member boundaries. +#if defined(_WIN32) && !defined(_CRT_NONSTDC_NO_DEPRECATE) +# define _CRT_NONSTDC_NO_DEPRECATE +#endif + #include <stdio.h> // fread, fwrite, putc, fflush, ferror, fprintf, // vsnprintf, stdout, stderr, NULL, FILE #include <stdlib.h> // malloc, free diff --git a/examples/zlib_how.html b/examples/zlib_how.html index 43271b988a72..59af43e25ae9 100644 --- a/examples/zlib_how.html +++ b/examples/zlib_how.html @@ -4,7 +4,7 @@ <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>zlib Usage Example</title> -<!-- Copyright (c) 2004-2023 Mark Adler. --> +<!-- Copyright (c) 2004-2026 Mark Adler. --> </head> <body bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#00A000"> <h2 align="center"> zlib Usage Example </h2> @@ -21,7 +21,7 @@ Without further ado, here is the program <a href="zpipe.c"><tt>zpipe.c</tt></a>: <pre><b> /* zpipe.c: example of proper use of zlib's inflate() and deflate() Not copyrighted -- provided to the public domain - Version 1.4 11 December 2005 Mark Adler */ + Version 1.5 11 February 2026 Mark Adler */ /* Version history: 1.0 30 Oct 2004 First version @@ -31,6 +31,7 @@ Without further ado, here is the program <a href="zpipe.c"><tt>zpipe.c</tt></a>: 1.3 6 Apr 2005 Remove incorrect assertion in inf() 1.4 11 Dec 2005 Add hack to avoid MSDOS end-of-line conversions Avoid some compiler warnings for input and output buffers + 1.5 11 Feb 2026 Use underscores for Windows POSIX names */ </b></pre><!-- --> We now include the header files for the required definitions. From @@ -60,7 +61,7 @@ This sets the input and output to binary which suppresses the end-of-line conver #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__) # include <fcntl.h> # include <io.h> -# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) +# define SET_BINARY_MODE(file) _setmode(_fileno(file), _O_BINARY) #else # define SET_BINARY_MODE(file) #endif @@ -538,12 +539,12 @@ int main(int argc, char **argv) } </b></pre> <hr> -<i>Last modified 24 January 2023<br> -Copyright © 2004-2023 Mark Adler</i><br> -<a rel="license" href="http://creativecommons.org/licenses/by-nd/4.0/"> +<i>Last modified 12 February 2026<br> +Copyright © 2004-2026 Mark Adler</i><br> +<a rel="license" href="https://creativecommons.org/licenses/by-nd/4.0/"> <img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nd/4.0/88x31.png"></a> -<a rel="license" href="http://creativecommons.org/licenses/by-nd/4.0/"> +<a rel="license" href="https://creativecommons.org/licenses/by-nd/4.0/"> Creative Commons Attribution-NoDerivatives 4.0 International License</a>. </body> </html> diff --git a/examples/zpipe.c b/examples/zpipe.c index 83535d169358..021c85089028 100644 --- a/examples/zpipe.c +++ b/examples/zpipe.c @@ -1,6 +1,6 @@ /* zpipe.c: example of proper use of zlib's inflate() and deflate() Not copyrighted -- provided to the public domain - Version 1.4 11 December 2005 Mark Adler */ + Version 1.5 11 February 2026 Mark Adler */ /* Version history: 1.0 30 Oct 2004 First version @@ -10,6 +10,7 @@ 1.3 6 Apr 2005 Remove incorrect assertion in inf() 1.4 11 Dec 2005 Add hack to avoid MSDOS end-of-line conversions Avoid some compiler warnings for input and output buffers + 1.5 11 Feb 2026 Use underscores for Windows POSIX names */ #include <stdio.h> @@ -20,7 +21,7 @@ #if defined(MSDOS) || defined(OS2) || defined(WIN32) || defined(__CYGWIN__) # include <fcntl.h> # include <io.h> -# define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) +# define SET_BINARY_MODE(file) _setmode(_fileno(file), _O_BINARY) #else # define SET_BINARY_MODE(file) #endif diff --git a/examples/zran.c b/examples/zran.c index d3135955b02b..731d34d67c39 100644 --- a/examples/zran.c +++ b/examples/zran.c @@ -1,7 +1,7 @@ /* zran.c -- example of deflate stream indexing and random access - * Copyright (C) 2005, 2012, 2018, 2023 Mark Adler + * Copyright (C) 2005, 2012, 2018, 2023, 2024, 2025 Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h - * Version 1.4 13 Apr 2023 Mark Adler */ + * Version 1.7 16 May 2025 Mark Adler */ /* Version History: 1.0 29 May 2005 First version @@ -14,6 +14,13 @@ Do a binary search over the index for an access point Expose the access point type to enable save and load 1.4 13 Apr 2023 Add a NOPRIME define to not use inflatePrime() + 1.5 4 Feb 2024 Set returned index to NULL on an index build error + Stop decoding once request is satisfied + Provide a reusable inflate engine in the index + Allocate the dictionaries to reduce memory usage + 1.6 2 Aug 2024 Remove unneeded dependency on limits.h + 1.7 16 May 2025 Remove redundant frees of point list on error + Clean out point list structure when freed */ // Illustrate the use of Z_BLOCK, inflatePrime(), and inflateSetDictionary() @@ -57,7 +64,6 @@ #include <stdio.h> #include <stdlib.h> #include <string.h> -#include <limits.h> #include "zlib.h" #include "zran.h" @@ -67,57 +73,48 @@ // See comments in zran.h. void deflate_index_free(struct deflate_index *index) { if (index != NULL) { + while (index->have) + free(index->list[--index->have].window); free(index->list); + index->list = NULL; + inflateEnd(&index->strm); free(index); } } -// Add an access point to the list. If out of memory, deallocate the existing -// list and return NULL. index->mode is temporarily the allocated number of -// access points, until it is time for deflate_index_build() to return. Then -// index->mode is set to the mode of inflation. -static struct deflate_index *add_point(struct deflate_index *index, int bits, - off_t in, off_t out, unsigned left, +// Add an access point to the list. If out of memory, return NULL. index->mode +// is temporarily the allocated number of access points, until it is time for +// deflate_index_build() to return. Then index->mode is set to the mode of +// inflation. +static struct deflate_index *add_point(struct deflate_index *index, off_t in, + off_t out, off_t beg, unsigned char *window) { - if (index == NULL) { - // The list is empty. Create it, starting with eight access points. - index = malloc(sizeof(struct deflate_index)); - if (index == NULL) - return NULL; - index->have = 0; - index->mode = 8; - index->list = malloc(sizeof(point_t) * index->mode); - if (index->list == NULL) { - free(index); - return NULL; - } - } - - else if (index->have == index->mode) { + if (index->have == index->mode) { // The list is full. Make it bigger. - index->mode <<= 1; + index->mode = index->mode ? index->mode << 1 : 8; point_t *next = realloc(index->list, sizeof(point_t) * index->mode); - if (next == NULL) { - deflate_index_free(index); + if (next == NULL) return NULL; - } index->list = next; } // Fill in the access point and increment how many we have. point_t *next = (point_t *)(index->list) + index->have++; - if (index->have < 0) { + if (index->have < 0) // Overflowed the int! - deflate_index_free(index); return NULL; - } next->out = out; next->in = in; - next->bits = bits; - if (left) - memcpy(next->window, window + WINSIZE - left, left); - if (left < WINSIZE) - memcpy(next->window + left, window, WINSIZE - left); + next->bits = index->strm.data_type & 7; + next->dict = out - beg > WINSIZE ? WINSIZE : (unsigned)(out - beg); + next->window = malloc(next->dict); + if (next->window == NULL) + return NULL; + unsigned recent = WINSIZE - index->strm.avail_out; + unsigned copy = recent > next->dict ? next->dict : recent; + memcpy(next->window + next->dict - copy, window + recent - copy, copy); + copy = next->dict - copy; + memcpy(next->window, window + WINSIZE - copy, copy); // Return the index, which may have been newly allocated or destroyed. return index; @@ -130,25 +127,39 @@ static struct deflate_index *add_point(struct deflate_index *index, int bits, // See comments in zran.h. int deflate_index_build(FILE *in, off_t span, struct deflate_index **built) { - // Set up inflation state. - z_stream strm = {0}; // inflate engine (gets fired up later) + // If this returns with an error, any attempt to use the index will cleanly + // return an error. + *built = NULL; + + // Create and initialize the index list. + struct deflate_index *index = malloc(sizeof(struct deflate_index)); + if (index == NULL) + return Z_MEM_ERROR; + index->have = 0; + index->mode = 0; // entries in index->list allocation + index->list = NULL; + index->strm.state = Z_NULL; // so inflateEnd() can work + + // Set up the inflation state. + index->strm.avail_in = 0; + index->strm.avail_out = 0; unsigned char buf[CHUNK]; // input buffer unsigned char win[WINSIZE] = {0}; // output sliding window off_t totin = 0; // total bytes read from input off_t totout = 0; // total bytes uncompressed + off_t beg = 0; // starting offset of last history reset int mode = 0; // mode: RAW, ZLIB, or GZIP (0 => not set yet) // Decompress from in, generating access points along the way. int ret; // the return value from zlib, or Z_ERRNO off_t last; // last access point uncompressed offset - struct deflate_index *index = NULL; // list of access points do { // Assure available input, at least until reaching EOF. - if (strm.avail_in == 0) { - strm.avail_in = fread(buf, 1, sizeof(buf), in); - totin += strm.avail_in; - strm.next_in = buf; - if (strm.avail_in < sizeof(buf) && ferror(in)) { + if (index->strm.avail_in == 0) { + index->strm.avail_in = fread(buf, 1, sizeof(buf), in); + totin += index->strm.avail_in; + index->strm.next_in = buf; + if (index->strm.avail_in < sizeof(buf) && ferror(in)) { ret = Z_ERRNO; break; } @@ -159,11 +170,14 @@ int deflate_index_build(FILE *in, off_t span, struct deflate_index **built) { // in a false positive for zlib, but in practice the fill bits // after a stored block are always zeros, so a raw stream won't // start with an 8 in the low nybble. - mode = strm.avail_in == 0 ? RAW : // empty -- will fail - (strm.next_in[0] & 0xf) == 8 ? ZLIB : - strm.next_in[0] == 0x1f ? GZIP : + mode = index->strm.avail_in == 0 ? RAW : // will fail + (index->strm.next_in[0] & 0xf) == 8 ? ZLIB : + index->strm.next_in[0] == 0x1f ? GZIP : /* else */ RAW; - ret = inflateInit2(&strm, mode); + index->strm.zalloc = Z_NULL; + index->strm.zfree = Z_NULL; + index->strm.opaque = Z_NULL; + ret = inflateInit2(&index->strm, mode); if (ret != Z_OK) break; } @@ -171,32 +185,32 @@ int deflate_index_build(FILE *in, off_t span, struct deflate_index **built) { // Assure available output. This rotates the output through, for use as // a sliding window on the uncompressed data. - if (strm.avail_out == 0) { - strm.avail_out = sizeof(win); - strm.next_out = win; + if (index->strm.avail_out == 0) { + index->strm.avail_out = sizeof(win); + index->strm.next_out = win; } - if (mode == RAW && index == NULL) + if (mode == RAW && index->have == 0) // We skip the inflate() call at the start of raw deflate data in // order generate an access point there. Set data_type to imitate // the end of a header. - strm.data_type = 0x80; + index->strm.data_type = 0x80; else { // Inflate and update the number of uncompressed bytes. - unsigned before = strm.avail_out; - ret = inflate(&strm, Z_BLOCK); - totout += before - strm.avail_out; + unsigned before = index->strm.avail_out; + ret = inflate(&index->strm, Z_BLOCK); + totout += before - index->strm.avail_out; } - if ((strm.data_type & 0xc0) == 0x80 && - (index == NULL || totout - last >= span)) { + if ((index->strm.data_type & 0xc0) == 0x80 && + (index->have == 0 || totout - last >= span)) { // We are at the end of a header or a non-last deflate block, so we // can add an access point here. Furthermore, we are either at the // very start for the first access point, or there has been span or // more uncompressed bytes since the last access point, so we want // to add an access point here. - index = add_point(index, strm.data_type & 7, totin - strm.avail_in, - totout, strm.avail_out, win); + index = add_point(index, totin - index->strm.avail_in, totout, beg, + win); if (index == NULL) { ret = Z_MEM_ERROR; break; @@ -205,16 +219,17 @@ int deflate_index_build(FILE *in, off_t span, struct deflate_index **built) { } if (ret == Z_STREAM_END && mode == GZIP && - (strm.avail_in || ungetc(getc(in), in) != EOF)) + (index->strm.avail_in || ungetc(getc(in), in) != EOF)) { // There is more input after the end of a gzip member. Reset the // inflate state to read another gzip member. On success, this will // set ret to Z_OK to continue decompressing. - ret = inflateReset2(&strm, GZIP); + ret = inflateReset2(&index->strm, GZIP); + beg = totout; // reset history + } // Keep going until Z_STREAM_END or error. If the compressed data ends // prematurely without a file read error, Z_BUF_ERROR is returned. } while (ret == Z_OK); - inflateEnd(&strm); if (ret != Z_STREAM_END) { // An error was encountered. Discard the index and return a negative @@ -223,17 +238,9 @@ int deflate_index_build(FILE *in, off_t span, struct deflate_index **built) { return ret == Z_NEED_DICT ? Z_DATA_ERROR : ret; } - // Shrink the index to only the occupied access points and return it. + // Return the index. index->mode = mode; index->length = totout; - point_t *list = realloc(index->list, sizeof(point_t) * index->have); - if (list == NULL) { - // Seems like a realloc() to make something smaller should always work, - // but just in case. - deflate_index_free(index); - return Z_MEM_ERROR; - } - index->list = list; *built = index; return index->have; } @@ -330,7 +337,8 @@ static int inflatePreface(z_stream *strm, int bits, int value) { ptrdiff_t deflate_index_extract(FILE *in, struct deflate_index *index, off_t offset, unsigned char *buf, size_t len) { // Do a quick sanity check on the index. - if (index == NULL || index->have < 1 || index->list[0].out != 0) + if (index == NULL || index->have < 1 || index->list[0].out != 0 || + index->strm.state == Z_NULL) return Z_STREAM_ERROR; // If nothing to extract, return zero bytes extracted. @@ -356,13 +364,13 @@ ptrdiff_t deflate_index_extract(FILE *in, struct deflate_index *index, int ch = 0; if (point->bits && (ch = getc(in)) == EOF) return ferror(in) ? Z_ERRNO : Z_BUF_ERROR; - z_stream strm = {0}; - ret = inflateInit2(&strm, RAW); + index->strm.avail_in = 0; + ret = inflateReset2(&index->strm, RAW); if (ret != Z_OK) return ret; if (point->bits) - INFLATEPRIME(&strm, point->bits, ch >> (8 - point->bits)); - inflateSetDictionary(&strm, point->window, WINSIZE); + INFLATEPRIME(&index->strm, point->bits, ch >> (8 - point->bits)); + inflateSetDictionary(&index->strm, point->window, point->dict); // Skip uncompressed bytes until offset reached, then satisfy request. unsigned char input[CHUNK]; @@ -372,48 +380,54 @@ ptrdiff_t deflate_index_extract(FILE *in, struct deflate_index *index, do { if (offset) { // Discard up to offset uncompressed bytes. - strm.avail_out = offset < WINSIZE ? (unsigned)offset : WINSIZE; - strm.next_out = discard; + index->strm.avail_out = offset < WINSIZE ? (unsigned)offset : + WINSIZE; + index->strm.next_out = discard; } else { // Uncompress up to left bytes into buf. - strm.avail_out = left < UINT_MAX ? (unsigned)left : UINT_MAX; - strm.next_out = buf + len - left; + index->strm.avail_out = left < (unsigned)-1 ? (unsigned)left : + (unsigned)-1; + index->strm.next_out = buf + len - left; } // Uncompress, setting got to the number of bytes uncompressed. - if (strm.avail_in == 0) { + if (index->strm.avail_in == 0) { // Assure available input. - strm.avail_in = fread(input, 1, CHUNK, in); - if (strm.avail_in < CHUNK && ferror(in)) { + index->strm.avail_in = fread(input, 1, CHUNK, in); + if (index->strm.avail_in < CHUNK && ferror(in)) { ret = Z_ERRNO; break; } - strm.next_in = input; + index->strm.next_in = input; } - unsigned got = strm.avail_out; - ret = inflate(&strm, Z_NO_FLUSH); - got -= strm.avail_out; + unsigned got = index->strm.avail_out; + ret = inflate(&index->strm, Z_NO_FLUSH); + got -= index->strm.avail_out; // Update the appropriate count. if (offset) offset -= got; - else + else { left -= got; + if (left == 0) + // Request satisfied. + break; + } // If we're at the end of a gzip member and there's more to read, // continue to the next gzip member. if (ret == Z_STREAM_END && index->mode == GZIP) { // Discard the gzip trailer. unsigned drop = 8; // length of gzip trailer - if (strm.avail_in >= drop) { - strm.avail_in -= drop; - strm.next_in += drop; + if (index->strm.avail_in >= drop) { + index->strm.avail_in -= drop; + index->strm.next_in += drop; } else { // Read and discard the remainder of the gzip trailer. - drop -= strm.avail_in; - strm.avail_in = 0; + drop -= index->strm.avail_in; + index->strm.avail_in = 0; do { if (getc(in) == EOF) // The input does not have a complete trailer. @@ -421,33 +435,32 @@ ptrdiff_t deflate_index_extract(FILE *in, struct deflate_index *index, } while (--drop); } - if (strm.avail_in || ungetc(getc(in), in) != EOF) { + if (index->strm.avail_in || ungetc(getc(in), in) != EOF) { // There's more after the gzip trailer. Use inflate to skip the // gzip header and resume the raw inflate there. - inflateReset2(&strm, GZIP); + inflateReset2(&index->strm, GZIP); do { - if (strm.avail_in == 0) { - strm.avail_in = fread(input, 1, CHUNK, in); - if (strm.avail_in < CHUNK && ferror(in)) { + if (index->strm.avail_in == 0) { + index->strm.avail_in = fread(input, 1, CHUNK, in); + if (index->strm.avail_in < CHUNK && ferror(in)) { ret = Z_ERRNO; break; } - strm.next_in = input; + index->strm.next_in = input; } - strm.avail_out = WINSIZE; - strm.next_out = discard; - ret = inflate(&strm, Z_BLOCK); // stop at end of header - } while (ret == Z_OK && (strm.data_type & 0x80) == 0); + index->strm.avail_out = WINSIZE; + index->strm.next_out = discard; + ret = inflate(&index->strm, Z_BLOCK); // stop after header + } while (ret == Z_OK && (index->strm.data_type & 0x80) == 0); if (ret != Z_OK) break; - inflateReset2(&strm, RAW); + inflateReset2(&index->strm, RAW); } } // Continue until we have the requested data, the deflate data has // ended, or an error is encountered. - } while (ret == Z_OK && left); - inflateEnd(&strm); + } while (ret == Z_OK); // Return the number of uncompressed bytes read into buf, or the error. return ret == Z_OK || ret == Z_STREAM_END ? len - left : ret; diff --git a/examples/zran.h b/examples/zran.h index ebf780d0c1f1..16a84feb9fc0 100644 --- a/examples/zran.h +++ b/examples/zran.h @@ -1,7 +1,7 @@ -/* zran.h -- example of deflated stream indexing and random access - * Copyright (C) 2005, 2012, 2018, 2023 Mark Adler +/* zran.h -- example of deflate stream indexing and random access + * Copyright (C) 2005, 2012, 2018, 2023, 2024, 2025 Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h - * Version 1.3 18 Feb 2023 Mark Adler */ + * Version 1.7 16 May 2025 Mark Adler */ #include <stdio.h> #include "zlib.h" @@ -11,7 +11,8 @@ typedef struct point { off_t out; // offset in uncompressed data off_t in; // offset in compressed file of first full byte int bits; // 0, or number of bits (1-7) from byte at in-1 - unsigned char window[32768]; // preceding 32K of uncompressed data + unsigned dict; // number of bytes in window to use as a dictionary + unsigned char *window; // preceding 32K (or less) of uncompressed data } point_t; // Access point list. @@ -20,6 +21,7 @@ struct deflate_index { int mode; // -15 for raw, 15 for zlib, or 31 for gzip off_t length; // total length of uncompressed data point_t *list; // allocated list of access points + z_stream strm; // re-usable inflate engine for extraction }; // Make one pass through a zlib, gzip, or raw deflate compressed stream and @@ -30,7 +32,7 @@ struct deflate_index { // the number of access points on success (>= 1), Z_MEM_ERROR for out of // memory, Z_BUF_ERROR for a premature end of input, Z_DATA_ERROR for a format // or verification error in the input file, or Z_ERRNO for a file read error. -// On success, *built points to the resulting index. +// On success, *built points to the resulting index, otherwise it's NULL. int deflate_index_build(FILE *in, off_t span, struct deflate_index **built); // Use the index to read len bytes from offset into buf. Return the number of |