| Index: third_party/bzip2/huffman.c
|
| ===================================================================
|
| --- third_party/bzip2/huffman.c (revision 199288)
|
| +++ third_party/bzip2/huffman.c (working copy)
|
| @@ -1,205 +0,0 @@
|
| -
|
| -/*-------------------------------------------------------------*/
|
| -/*--- Huffman coding low-level stuff ---*/
|
| -/*--- huffman.c ---*/
|
| -/*-------------------------------------------------------------*/
|
| -
|
| -/* ------------------------------------------------------------------
|
| - This file is part of bzip2/libbzip2, a program and library for
|
| - lossless, block-sorting data compression.
|
| -
|
| - bzip2/libbzip2 version 1.0.6 of 6 September 2010
|
| - Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org>
|
| -
|
| - Please read the WARNING, DISCLAIMER and PATENTS sections in the
|
| - README file.
|
| -
|
| - This program is released under the terms of the license contained
|
| - in the file LICENSE.
|
| - ------------------------------------------------------------------ */
|
| -
|
| -
|
| -#include "bzlib_private.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 BZ2_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;
|
| -
|
| - /* 17 Oct 04: keep-going condition for the following loop used
|
| - to be 'i < alphaSize', which missed the last element,
|
| - theoretically leading to the possibility of the compressor
|
| - looping. However, this count-scaling step is only needed if
|
| - one of the generated Huffman code words is longer than
|
| - maxLen, which up to and including version 1.0.2 was 20 bits,
|
| - which is extremely unlikely. In version 1.0.3 maxLen was
|
| - changed to 17 bits, which has minimal effect on compression
|
| - ratio, but does mean this scaling step is used from time to
|
| - time, enough to verify that it works.
|
| -
|
| - This means that bzip2-1.0.3 and later will only produce
|
| - Huffman codes with a maximum length of 17 bits. However, in
|
| - order to preserve backwards compatibility with bitstreams
|
| - produced by versions pre-1.0.3, the decompressor must still
|
| - handle lengths of up to 20. */
|
| -
|
| - for (i = 1; i <= alphaSize; i++) {
|
| - j = weight[i] >> 8;
|
| - j = 1 + (j / 2);
|
| - weight[i] = j << 8;
|
| - }
|
| - }
|
| -}
|
| -
|
| -
|
| -/*---------------------------------------------------*/
|
| -void BZ2_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 BZ2_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 ---*/
|
| -/*-------------------------------------------------------------*/
|
|
|