1 /* 2 * Copyright (C) 2001, 2002, and 2003 Roy Keene 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 * 18 * email: dact@rkeene.org 19 */ 20 21 22 /* 23 Example block compression routine for interfacing with DACT. 24 25 This does no compression. 26 27 (This is used as the minimum case, so block can be atmost blk_size 28 +3 bytes in size) 29 */ 30 31 32 #include "dact.h" 33 #include "comp_plain.h" 34 #include <stdio.h> 35 #ifdef HAVE_UNISTD_H 36 #include <unistd.h> 37 #endif 38 #ifdef HAVE_STDLIB_H 39 #include <stdlib.h> 40 #endif 41 #ifdef HAVE_STRING_H 42 #include <string.h> 43 #endif 44 45 46 /* 47 mode - DACT_MODE_COMPR or DACT_MODE_DECMP 48 Determine whether to compress or decompress. 49 prev_block - Previous (uncompressed) block. 50 curr_block - The data to be compressed. 51 out_block - Where to put data after compression. 52 blk_size - Size of prev_block and curr_block. 53 */ 54 int comp_plain_algo(int mode, unsigned char *prev_block, unsigned char *curr_block, char *out_block, int blk_size, int bufsize) { 55 switch(mode) { 56 case DACT_MODE_COMPR: 57 return(comp_plain_compress(prev_block, curr_block, out_block, blk_size, bufsize)); 58 break; /* Heh */ 59 case DACT_MODE_DECMP: 60 return(comp_plain_decompress(prev_block, curr_block, out_block, blk_size, bufsize)); 61 break; 62 default: 63 printf("Unsupported mode: %i\n", mode); 64 return(-1); 65 } 66 } 67 68 int comp_plain_compress(unsigned char *prev_block, unsigned char *curr_block, char *out_block, int blk_size, int bufsize) { 69 memcpy(out_block,curr_block,blk_size); 70 return(blk_size); 71 } 72 73 int comp_plain_decompress(unsigned char *prev_block, unsigned char *curr_block, char *out_block, int blk_size, int bufsize) { 74 memcpy(out_block,curr_block,blk_size); 75 return(blk_size); 76 } |