/*********************************************************************** * * * This software is part of the bzip package * * Copyright (c) 1996-2007 * * * * This software is provided 'as-is', without any express 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. * * * * This program, "bzip2" and associated library "libbzip2", are * * copyright (C) 1996-1998 Julian R Seward. All rights reserved. * * * * Redistribution and use in source and binary forms, with or without * * modification, are permitted provided that the following conditions * * are met: * * * * 1. Redistributions of source code must retain the above copyright * * notice, this list of conditions and the following disclaimer. * * * * 2. 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. * * * * 3. Altered source versions must be plainly marked as such, and must * * not be misrepresented as being the original software. * * * * 4. The name of the author may not be used to endorse or promote * * products derived from this software without specific prior written* * permission. * * * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS * * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * * * Julian Seward, Guildford, Surrey, UK. * * jseward@acm.org * * bzip2/libbzip2 version 0.9.0 of 28 June 1998 * * * * Julian R Seward * * * ***********************************************************************/ #pragma prototyped /*-------------------------------------------------------------*/ /*--- Huffman coding low-level stuff ---*/ /*--- huffman.c ---*/ /*-------------------------------------------------------------*/ /*-- This file is a part of bzip2 and/or libbzip2, a program and library for lossless, block-sorting data compression. Copyright (C) 1996-1998 Julian R Seward. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. 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. 3. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 4. The name of the author may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. Julian Seward, Guildford, Surrey, UK. jseward@acm.org bzip2/libbzip2 version 0.9.0c of 18 October 1998 This program is based on (at least) the work of: Mike Burrows David Wheeler Peter Fenwick Alistair Moffat Radford Neal Ian H. Witten Robert Sedgewick Jon L. Bentley For more information on these sources, see the manual. --*/ #include "bzhdr.h" /*---------------------------------------------------*/ #define WEIGHTOF(zz0) ((zz0) & 0xffffff00) #define DEPTHOF(zz1) ((zz1) & 0x000000ff) #define MYMAX(zz2,zz3) ((zz2) > (zz3) ? (zz2) : (zz3)) #define ADDWEIGHTS(zw1,zw2) \ (WEIGHTOF(zw1)+WEIGHTOF(zw2)) | \ (1 + MYMAX(DEPTHOF(zw1),DEPTHOF(zw2))) #define UPHEAP(z) \ { \ Int32 zz, tmp; \ zz = z; tmp = heap[zz]; \ while (weight[tmp] < weight[heap[zz >> 1]]) { \ heap[zz] = heap[zz >> 1]; \ zz >>= 1; \ } \ heap[zz] = tmp; \ } #define DOWNHEAP(z) \ { \ Int32 zz, yy, tmp; \ zz = z; tmp = heap[zz]; \ while (True) { \ yy = zz << 1; \ if (yy > nHeap) break; \ if (yy < nHeap && \ weight[heap[yy+1]] < weight[heap[yy]]) \ yy++; \ if (weight[tmp] < weight[heap[yy]]) break; \ heap[zz] = heap[yy]; \ zz = yy; \ } \ heap[zz] = tmp; \ } /*---------------------------------------------------*/ void hbMakeCodeLengths ( UChar *len, Int32 *freq, Int32 alphaSize, Int32 maxLen ) { /*-- Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. --*/ Int32 nNodes, nHeap, n1, n2, i, j, k; Bool tooLong; Int32 heap [ BZ_MAX_ALPHA_SIZE + 2 ]; Int32 weight [ BZ_MAX_ALPHA_SIZE * 2 ]; Int32 parent [ BZ_MAX_ALPHA_SIZE * 2 ]; for (i = 0; i < alphaSize; i++) weight[i+1] = (freq[i] == 0 ? 1 : freq[i]) << 8; while (True) { nNodes = alphaSize; nHeap = 0; heap[0] = 0; weight[0] = 0; parent[0] = -2; for (i = 1; i <= alphaSize; i++) { parent[i] = -1; nHeap++; heap[nHeap] = i; UPHEAP(nHeap); } AssertH( nHeap < (BZ_MAX_ALPHA_SIZE+2), 2001 ); while (nHeap > 1) { n1 = heap[1]; heap[1] = heap[nHeap]; nHeap--; DOWNHEAP(1); n2 = heap[1]; heap[1] = heap[nHeap]; nHeap--; DOWNHEAP(1); nNodes++; parent[n1] = parent[n2] = nNodes; weight[nNodes] = ADDWEIGHTS(weight[n1], weight[n2]); parent[nNodes] = -1; nHeap++; heap[nHeap] = nNodes; UPHEAP(nHeap); } AssertH( nNodes < (BZ_MAX_ALPHA_SIZE * 2), 2002 ); tooLong = False; for (i = 1; i <= alphaSize; i++) { j = 0; k = i; while (parent[k] >= 0) { k = parent[k]; j++; } len[i-1] = j; if (j > maxLen) tooLong = True; } if (! tooLong) break; for (i = 1; i < alphaSize; i++) { j = weight[i] >> 8; j = 1 + (j / 2); weight[i] = j << 8; } } } /*---------------------------------------------------*/ void hbAssignCodes ( Int32 *code, UChar *length, Int32 minLen, Int32 maxLen, Int32 alphaSize ) { Int32 n, vec, i; vec = 0; for (n = minLen; n <= maxLen; n++) { for (i = 0; i < alphaSize; i++) if (length[i] == n) { code[i] = vec; vec++; }; vec <<= 1; } } /*---------------------------------------------------*/ void hbCreateDecodeTables ( Int32 *limit, Int32 *base, Int32 *perm, UChar *length, Int32 minLen, Int32 maxLen, Int32 alphaSize ) { Int32 pp, i, j, vec; pp = 0; for (i = minLen; i <= maxLen; i++) for (j = 0; j < alphaSize; j++) if (length[j] == i) { perm[pp] = j; pp++; }; for (i = 0; i < BZ_MAX_CODE_LEN; i++) base[i] = 0; for (i = 0; i < alphaSize; i++) base[length[i]+1]++; for (i = 1; i < BZ_MAX_CODE_LEN; i++) base[i] += base[i-1]; for (i = 0; i < BZ_MAX_CODE_LEN; i++) limit[i] = 0; vec = 0; for (i = minLen; i <= maxLen; i++) { vec += (base[i+1] - base[i]); limit[i] = vec-1; vec <<= 1; } for (i = minLen + 1; i <= maxLen; i++) base[i] = ((limit[i-1] + 1) << 1) - base[i]; } /*-------------------------------------------------------------*/ /*--- end huffman.c ---*/ /*-------------------------------------------------------------*/

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