/****************************************************************************** * * bz2comprs.cpp - Bzip2Compress, a driver class that provides bzip2 * compression (Burrows–Wheeler with Huffman coding) * * $Id: bz2comprs.cpp 3156 2014-04-17 03:50:37Z greg.hellings $ * * Copyright 2000-2014 CrossWire Bible Society (http://www.crosswire.org) * CrossWire Bible Society * P. O. Box 2528 * Tempe, AZ 85280-2528 * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation version 2. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * */ #include #include #include #include #include SWORD_NAMESPACE_START /****************************************************************************** * Bzip2Compress Constructor - Initializes data for instance of Bzip2Compress * */ Bzip2Compress::Bzip2Compress() : SWCompress() { } /****************************************************************************** * Bzip2Compress Destructor - Cleans up instance of Bzip2Compress */ Bzip2Compress::~Bzip2Compress() { } /****************************************************************************** * Bzip2Compress::Encode - This function "encodes" the input stream into the * output stream. * The GetChars() and SendChars() functions are * used to separate this method from the actual * i/o. * NOTE: must set zlen for parent class to know length of * compressed buffer. */ void Bzip2Compress::Encode(void) { /* ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)); Compresses 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 at least 0.1% larger than sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. This function can be used to compress a whole file at once if the input file is mmap'ed. compress 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. */ direct = 0; // set direction needed by parent [Get|Send]Chars() // get buffer char chunk[1024]; char *buf = (char *)calloc(1, 1024); char *chunkbuf = buf; unsigned long chunklen; unsigned long len = 0; while((chunklen = GetChars(chunk, 1023))) { memcpy(chunkbuf, chunk, chunklen); len += chunklen; if (chunklen < 1023) break; else buf = (char *)realloc(buf, len + 1024); chunkbuf = buf+len; } zlen = (long) (len*1.001)+15; char *zbuf = new char[zlen+1]; if (len) { //printf("Doing compress\n"); if (compress((Bytef*)zbuf, &zlen, (const Bytef*)buf, len) != Z_OK) { printf("ERROR in compression\n"); } else { SendChars(zbuf, zlen); } } else { fprintf(stderr, "ERROR: no buffer to compress\n"); } delete [] zbuf; free (buf); } /****************************************************************************** * Bzip2Compress::Decode - This function "decodes" the input stream into the * output stream. * The GetChars() and SendChars() functions are * used to separate this method from the actual * i/o. */ void Bzip2Compress::Decode(void) { /* ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)); 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. */ // get buffer char chunk[1024]; char *zbuf = (char *)calloc(1, 1024); char *chunkbuf = zbuf; int chunklen; unsigned long zlen = 0; while((chunklen = GetChars(chunk, 1023))) { memcpy(chunkbuf, chunk, chunklen); zlen += chunklen; if (chunklen < 1023) break; else zbuf = (char *)realloc(zbuf, zlen + 1024); chunkbuf = zbuf + zlen; } //printf("Decoding complength{%ld} uncomp{%ld}\n", zlen, blen); if (zlen) { unsigned long blen = zlen*20; // trust compression is less than 1000% char *buf = new char[blen]; //printf("Doing decompress {%s}\n", zbuf); slen = 0; switch (uncompress((Bytef*)buf, &blen, (Bytef*)zbuf, zlen)){ case Z_OK: SendChars(buf, blen); slen = blen; break; case Z_MEM_ERROR: fprintf(stderr, "ERROR: not enough memory during decompression.\n"); break; case Z_BUF_ERROR: fprintf(stderr, "ERROR: not enough room in the out buffer during decompression.\n"); break; case Z_DATA_ERROR: fprintf(stderr, "ERROR: corrupt data during decompression.\n"); break; default: fprintf(stderr, "ERROR: an unknown error occured during decompression.\n"); break; } delete [] buf; } else { fprintf(stderr, "ERROR: no buffer to decompress!\n"); } //printf("Finished decoding\n"); free (zbuf); } SWORD_NAMESPACE_END