mirror of
https://github.com/cc65/cc65.git
synced 2024-11-15 11:05:56 +00:00
176 lines
6.9 KiB
C
176 lines
6.9 KiB
C
/*****************************************************************************/
|
|
/* */
|
|
/* zlib.h */
|
|
/* */
|
|
/* Decompression routines for the 'deflate' format */
|
|
/* */
|
|
/* */
|
|
/* */
|
|
/* (C) 2000-2015 Piotr Fusik <fox@scene.pl> */
|
|
/* */
|
|
/* This file is based on the zlib.h from 'zlib' general purpose compression */
|
|
/* library, version 1.1.3, (C) 1995-1998 Jean-loup Gailly and Mark Adler. */
|
|
/* */
|
|
/* Jean-loup Gailly Mark Adler */
|
|
/* jloup@gzip.org madler@alumni.caltech.edu */
|
|
/* */
|
|
/* This software is provided 'as-is', without any expressed or implied */
|
|
/* warranty. In no event will the authors be held liable for any damages */
|
|
/* arising from the use of this software. */
|
|
/* */
|
|
/* Permission is granted to anyone to use this software for any purpose, */
|
|
/* including commercial applications, and to alter it and redistribute it */
|
|
/* freely, subject to the following restrictions: */
|
|
/* */
|
|
/* 1. The origin of this software must not be misrepresented; you must not */
|
|
/* claim that you wrote the original software. If you use this software */
|
|
/* in a product, an acknowledgment in the product documentation would be */
|
|
/* appreciated but is not required. */
|
|
/* 2. Altered source versions must be plainly marked as such, and must not */
|
|
/* be misrepresented as being the original software. */
|
|
/* 3. This notice may not be removed or altered from any source */
|
|
/* distribution. */
|
|
/* */
|
|
/*****************************************************************************/
|
|
|
|
|
|
|
|
#ifndef _ZLIB_H
|
|
#define _ZLIB_H
|
|
|
|
#define Z_OK 0
|
|
#define Z_DATA_ERROR (-3)
|
|
/* Return codes for uncompress() */
|
|
|
|
#define Z_DEFLATED 8
|
|
/* The deflate compression method (the only one supported) */
|
|
|
|
#define Z_NULL 0
|
|
|
|
|
|
unsigned __fastcall__ inflatemem (unsigned char* dest,
|
|
const unsigned char* source);
|
|
/*
|
|
Decompresses the source buffer into the destination buffer.
|
|
Returns the size of the uncompressed data (number of bytes written starting
|
|
from dest).
|
|
|
|
This function expects data in the DEFLATE format, described in RFC
|
|
(Request for Comments) 1951 in the file
|
|
ftp://ds.internic.net/rfc/rfc1951.txt.
|
|
|
|
This function does not exist in the original zlib. Its implementation
|
|
using original zlib might be following:
|
|
|
|
unsigned inflatemem (char* dest, const char* source)
|
|
{
|
|
z_stream stream;
|
|
|
|
stream.next_in = (Bytef*) source;
|
|
stream.avail_in = 65535;
|
|
|
|
stream.next_out = dest;
|
|
stream.avail_out = 65535;
|
|
|
|
stream.zalloc = (alloc_func) 0;
|
|
stream.zfree = (free_func) 0;
|
|
|
|
inflateInit2(&stream, -MAX_WBITS);
|
|
inflate(&stream, Z_FINISH);
|
|
inflateEnd(&stream);
|
|
|
|
return stream.total_out;
|
|
}
|
|
*/
|
|
|
|
|
|
int __fastcall__ uncompress (unsigned char* dest, unsigned* destLen,
|
|
const unsigned char* source, unsigned sourceLen);
|
|
/*
|
|
Original zlib description:
|
|
|
|
Decompresses the source buffer into the destination buffer. sourceLen is
|
|
the byte length of the source buffer. Upon entry, destLen is the total
|
|
size of the destination buffer, which must be large enough to hold the
|
|
entire uncompressed data. (The size of the uncompressed data must have
|
|
been saved previously by the compressor and transmitted to the decompressor
|
|
by some mechanism outside the scope of this compression library.)
|
|
Upon exit, destLen is the actual size of the compressed buffer.
|
|
This function can be used to decompress a whole file at once if the
|
|
input file is mmap'ed.
|
|
|
|
uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
|
|
enough memory, Z_BUF_ERROR if there was not enough room in the output
|
|
buffer, or Z_DATA_ERROR if the input data was corrupted.
|
|
|
|
Implementation notes:
|
|
|
|
This function expects data in the ZLIB format, described in RFC 1950
|
|
in the file ftp://ds.internic.net/rfc/rfc1950.txt. The ZLIB format is
|
|
essentially the DEFLATE format plus a very small header and Adler-32
|
|
checksum.
|
|
|
|
Z_MEM_ERROR and Z_BUF_ERROR are never returned in this implementation.
|
|
*/
|
|
|
|
|
|
unsigned long __fastcall__ adler32 (unsigned long adler,
|
|
const unsigned char* buf,
|
|
unsigned len);
|
|
|
|
/*
|
|
Original zlib description:
|
|
|
|
Update a running Adler-32 checksum with the bytes buf[0..len-1] and
|
|
return the updated checksum. If buf is NULL, this function returns
|
|
the required initial value for the checksum.
|
|
An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
|
|
much faster. Usage example:
|
|
|
|
unsigned long adler = adler32(0L, Z_NULL, 0);
|
|
|
|
while (read_buffer(buffer, length) != EOF) {
|
|
adler = adler32(adler, buffer, length);
|
|
}
|
|
if (adler != original_adler) error();
|
|
|
|
Implementation notes:
|
|
|
|
This function isn't actually much faster than crc32(), but it is smaller
|
|
and does not use any lookup tables.
|
|
*/
|
|
|
|
|
|
unsigned long __fastcall__ crc32 (unsigned long crc,
|
|
const unsigned char* buf,
|
|
unsigned len);
|
|
/*
|
|
Original zlib description:
|
|
|
|
Update a running crc with the bytes buf[0..len-1] and return the updated
|
|
crc. If buf is NULL, this function returns the required initial value
|
|
for the crc. Pre- and post-conditioning (one's complement) is performed
|
|
within this function so it shouldn't be done by the application.
|
|
Usage example:
|
|
|
|
unsigned long crc = crc32(0L, Z_NULL, 0);
|
|
|
|
while (read_buffer(buffer, length) != EOF) {
|
|
crc = crc32(crc, buffer, length);
|
|
}
|
|
if (crc != original_crc) error();
|
|
|
|
Implementation notes:
|
|
|
|
This function uses statically allocated 1 KB lookup table. The table is
|
|
initialised before it is used for the first time (that is, if buffer is
|
|
NULL or length is zero, then the lookup table isn't initialised).
|
|
*/
|
|
|
|
|
|
/* end of zlib.h */
|
|
#endif
|
|
|
|
|
|
|