mirror of
https://git.do.srb2.org/STJr/SRB2.git
synced 2024-11-25 13:51:43 +00:00
449 lines
14 KiB
C
449 lines
14 KiB
C
/* gzjoin -- command to join gzip files into one gzip file
|
|
|
|
Copyright (C) 2004, 2005, 2012 Mark Adler, all rights reserved
|
|
version 1.2, 14 Aug 2012
|
|
|
|
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
|
|
* 1.2 14 Aug 2012 - Clean up for z_const usage
|
|
*/
|
|
|
|
/*
|
|
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 <stdio.h> /* fputs(), fprintf(), fwrite(), putc() */
|
|
#include <stdlib.h> /* exit(), malloc(), free() */
|
|
#include <fcntl.h> /* open() */
|
|
#include <unistd.h> /* 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 = in->next;
|
|
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)
|
|
in->buf[strm.next_in - in->buf - 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)
|
|
in->buf[strm.next_in - in->buf] &= ~1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* update buffer with unused input */
|
|
in->left = strm.avail_in;
|
|
in->next = in->buf + (strm.next_in - in->buf);
|
|
|
|
/* 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;
|
|
}
|