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zlib 1.2.2.4

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This commit is contained in:
Mark Adler
2011-09-09 23:24:52 -07:00
parent 6b8233bfe0
commit 9c3a583021
29 changed files with 1035 additions and 137 deletions
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5
examples/README.examples
View File

@@ -35,3 +35,8 @@ 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

14
examples/fitblk.c
View File

@@ -73,7 +73,7 @@ local void quit(char *why)
local int partcompress(FILE *in, z_streamp def)
{
int ret, flush;
char raw[RAWLEN];
unsigned char raw[RAWLEN];
flush = Z_NO_FLUSH;
do {
@@ -96,7 +96,7 @@ local int partcompress(FILE *in, z_streamp def)
local int recompress(z_streamp inf, z_streamp def)
{
int ret, flush;
char raw[RAWLEN];
unsigned char raw[RAWLEN];
flush = Z_NO_FLUSH;
do {
@@ -129,8 +129,8 @@ int main(int argc, char **argv)
int ret; /* return code */
unsigned size; /* requested fixed output block size */
unsigned have; /* bytes written by deflate() call */
char *blk; /* intermediate and final stream */
char *tmp; /* close to desired size stream */
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 */
@@ -163,8 +163,7 @@ int main(int argc, char **argv)
if (ret == Z_STREAM_END && def.avail_out >= EXCESS) {
/* write block to stdout */
have = size + EXCESS - def.avail_out;
ret = fwrite(blk, 1, have, stdout);
if (ret != have || ferror(stdout))
if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
quit("error writing output");
/* clean up and print results to stderr */
@@ -217,8 +216,7 @@ int main(int argc, char **argv)
/* done -- write block to stdout */
have = size - def.avail_out;
ret = fwrite(blk, 1, have, stdout);
if (ret != have || ferror(stdout))
if (fwrite(blk, 1, have, stdout) != have || ferror(stdout))
quit("error writing output");
/* clean up and print results to stderr */

23
examples/gun.c
View File

@@ -1,7 +1,7 @@
/* 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 1.2 20 March 2005 Mark Adler */
Version 1.3 12 June 2005 Mark Adler */
/* Version history:
1.0 16 Feb 2003 First version for testing of inflateBack()
@@ -14,6 +14,7 @@
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]
*/
/*
@@ -221,12 +222,12 @@ local int lunpipe(unsigned have, unsigned char *next, struct ind *indp,
if (last == -1)
return Z_BUF_ERROR;
if (flags & 0x60) {
strm->msg = "unknown lzw flags set";
strm->msg = (char *)"unknown lzw flags set";
return Z_DATA_ERROR;
}
max = flags & 0x1f;
if (max < 9 || max > 16) {
strm->msg = "lzw bits out of range";
strm->msg = (char *)"lzw bits out of range";
return Z_DATA_ERROR;
}
if (max == 9) /* 9 doesn't really mean 9 */
@@ -246,7 +247,7 @@ local int lunpipe(unsigned have, 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 = "invalid lzw code";
strm->msg = (char *)"invalid lzw code";
return Z_DATA_ERROR;
}
rem = (unsigned)last >> 1; /* remaining 7 bits */
@@ -313,7 +314,7 @@ local int lunpipe(unsigned have, 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 = "invalid lzw code";
strm->msg = (char *)"invalid lzw code";
return Z_DATA_ERROR;
}
match[stack++] = (unsigned char)final;
@@ -394,7 +395,7 @@ 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 = "incorrect header check";
strm->msg = (char *)"incorrect header check";
ret = first ? Z_DATA_ERROR : Z_ERRNO;
break; /* not a gzip or compress header */
}
@@ -410,7 +411,7 @@ 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 = "unknown compression method";
strm->msg = (char *)"unknown compression method";
ret = Z_DATA_ERROR;
break;
}
@@ -423,7 +424,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile)
NEXT();
if (last == -1) break;
if (flags & 0xe0) {
strm->msg = "unknown header flags set";
strm->msg = (char *)"unknown header flags set";
ret = Z_DATA_ERROR;
break;
}
@@ -476,7 +477,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile)
NEXT() != ((outd.crc >> 24) & 0xff)) {
/* crc error */
if (last != -1) {
strm->msg = "incorrect data check";
strm->msg = (char *)"incorrect data check";
ret = Z_DATA_ERROR;
}
break;
@@ -487,7 +488,7 @@ local int gunpipe(z_stream *strm, int infile, int outfile)
NEXT() != ((outd.total >> 24) & 0xff)) {
/* length error */
if (last != -1) {
strm->msg = "incorrect length check";
strm->msg = (char *)"incorrect length check";
ret = Z_DATA_ERROR;
}
break;
@@ -641,7 +642,7 @@ int main(int argc, char **argv)
argv++;
test = 0;
if (argc && strcmp(*argv, "-h") == 0) {
fprintf(stderr, "gun 1.2 (20 Mar 2005)\n");
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;

5
examples/gzjoin.c
View File

@@ -26,6 +26,7 @@
* Change history:
*
* 1.0 11 Dec 2004 - First version
* 1.1 12 Jun 2005 - Changed ssize_t to long for portability
*/
/*
@@ -118,7 +119,7 @@ local bin *bopen(char *name)
1 indicating that end-of-file was reached */
local int bload(bin *in)
{
ssize_t len;
long len;
if (in == NULL)
return -1;
@@ -126,7 +127,7 @@ local int bload(bin *in)
return 0;
in->next = in->buf;
do {
len = read(in->fd, in->buf + in->left, CHUNK - in->left);
len = (long)read(in->fd, in->buf + in->left, CHUNK - in->left);
if (len < 0)
return -1;
in->left += (unsigned)len;

404
examples/zran.c Normal file
View File

@@ -0,0 +1,404 @@
/* 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#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;
}