1 /* blast.h -- interface for blast.c 2 Copyright (C) 2003 Mark Adler 3 version 1.1, 16 Feb 2003 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the author be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20 21 Mark Adler madler (at) alumni.caltech.edu 22 */ 23 24 25 /* 26 * blast() decompresses the PKWare Data Compression Library (DCL) compressed 27 * format. It provides the same functionality as the explode() function in 28 * that library. (Note: PKWare overused the "implode" verb, and the format 29 * used by their library implode() function is completely different and 30 * incompatible with the implode compression method supported by PKZIP.) 31 */ 32 33 34 typedef unsigned (*blast_in)(void *how, unsigned char **buf); 35 typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len); 36 /* Definitions for input/output functions passed to blast(). See below for 37 * what the provided functions need to do. 38 */ 39 40 41 int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow); 42 /* Decompress input to output using the provided infun() and outfun() calls. 43 * On success, the return value of blast() is zero. If there is an error in 44 * the source data, i.e. it is not in the proper format, then a negative value 45 * is returned. If there is not enough input available or there is not enough 46 * output space, then a positive error is returned. 47 * 48 * The input function is invoked: len = infun(how, &buf), where buf is set by 49 * infun() to point to the input buffer, and infun() returns the number of 50 * available bytes there. If infun() returns zero, then blast() returns with 51 * an input error. (blast() only asks for input if it needs it.) inhow is for 52 * use by the application to pass an input descriptor to infun(), if desired. 53 * 54 * The output function is invoked: err = outfun(how, buf, len), where the bytes 55 * to be written are buf[0..len-1]. If err is not zero, then blast() returns 56 * with an output error. outfun() is always called with len <= 4096. outhow 57 * is for use by the application to pass an output descriptor to outfun(), if 58 * desired. 59 * 60 * The return codes are: 61 * 62 * 2: ran out of input before completing decompression 63 * 1: output error before completing decompression 64 * 0: successful decompression 65 * -1: literal flag not zero or one 66 * -2: dictionary size not in 4..6 67 * -3: distance is too far back 68 * 69 * At the bottom of blast.c is an example program that uses blast() that can be 70 * compiled to produce a command-line decompression filter by defining TEST. 71 */ 72
