84 lines
3.8 KiB
C
84 lines
3.8 KiB
C
/* blast.h -- interface for blast.c
|
|
Copyright (C) 2003, 2012, 2013 Mark Adler
|
|
version 1.3, 24 Aug 2013
|
|
|
|
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
|
|
*/
|
|
|
|
|
|
/*
|
|
* blast() decompresses the PKWare Data Compression Library (DCL) compressed
|
|
* format. It provides the same functionality as the explode() function in
|
|
* that library. (Note: PKWare overused the "implode" verb, and the format
|
|
* used by their library implode() function is completely different and
|
|
* incompatible with the implode compression method supported by PKZIP.)
|
|
*
|
|
* The binary mode for stdio functions should be used to assure that the
|
|
* compressed data is not corrupted when read or written. For example:
|
|
* fopen(..., "rb") and fopen(..., "wb").
|
|
*/
|
|
|
|
|
|
typedef unsigned (*blast_in)(void *how, unsigned char **buf);
|
|
typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len);
|
|
/* Definitions for input/output functions passed to blast(). See below for
|
|
* what the provided functions need to do.
|
|
*/
|
|
|
|
|
|
int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
|
|
unsigned *left, unsigned char **in);
|
|
/* Decompress input to output using the provided infun() and outfun() calls.
|
|
* On success, the return value of blast() is zero. If there is an error in
|
|
* the source data, i.e. it is not in the proper format, then a negative value
|
|
* is returned. If there is not enough input available or there is not enough
|
|
* output space, then a positive error is returned.
|
|
*
|
|
* The input function is invoked: len = infun(how, &buf), where buf is set by
|
|
* infun() to point to the input buffer, and infun() returns the number of
|
|
* available bytes there. If infun() returns zero, then blast() returns with
|
|
* an input error. (blast() only asks for input if it needs it.) inhow is for
|
|
* use by the application to pass an input descriptor to infun(), if desired.
|
|
*
|
|
* If left and in are not NULL and *left is not zero when blast() is called,
|
|
* then the *left bytes are *in are consumed for input before infun() is used.
|
|
*
|
|
* The output function is invoked: err = outfun(how, buf, len), where the bytes
|
|
* to be written are buf[0..len-1]. If err is not zero, then blast() returns
|
|
* with an output error. outfun() is always called with len <= 4096. outhow
|
|
* is for use by the application to pass an output descriptor to outfun(), if
|
|
* desired.
|
|
*
|
|
* If there is any unused input, *left is set to the number of bytes that were
|
|
* read and *in points to them. Otherwise *left is set to zero and *in is set
|
|
* to NULL. If left or in are NULL, then they are not set.
|
|
*
|
|
* The return codes are:
|
|
*
|
|
* 2: ran out of input before completing decompression
|
|
* 1: output error before completing decompression
|
|
* 0: successful decompression
|
|
* -1: literal flag not zero or one
|
|
* -2: dictionary size not in 4..6
|
|
* -3: distance is too far back
|
|
*
|
|
* At the bottom of blast.c is an example program that uses blast() that can be
|
|
* compiled to produce a command-line decompression filter by defining TEST.
|
|
*/
|