mirror of
https://github.com/peterosterlund2/droidfish.git
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974 lines
18 KiB
C
974 lines
18 KiB
C
/* hzip.c */
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/*
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| Routines designed to be used as a pilot experiment for compression
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| of tablebases. Not really optimized, but they are supposed to work
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| --Miguel A. Ballicora
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*/
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/*
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This Software is distributed with the following X11 License,
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sometimes also known as MIT license.
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Copyright (c) 2010 Miguel A. Ballicora
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Permission is hereby granted, free of charge, to any person
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obtaining a copy of this software and associated documentation
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files (the "Software"), to deal in the Software without
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restriction, including without limitation the rights to use,
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copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following
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conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include "hzip.h"
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/*-------------------------------------------------------------------*\
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| Huffman coding compression
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\*-------------------------------------------------------------------*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <assert.h>
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#define MAXDIVERSITY (256)
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#define MAXHEAP (MAXDIVERSITY+1)
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#define MAXSTREAM (1<<18)
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#define MAXHUFF (2*MAXDIVERSITY)
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typedef int bool_t;
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#define TRUE 1
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#define FALSE 0;
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/* huffman tree */
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struct huff {
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int freq;
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int value;
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int pleft;
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int pright;
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bool_t isleaf;
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};
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static int huff_end;
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static struct huff hufftree[MAXHUFF];
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/* heap */
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struct element {
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int freq;
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int huffidx;
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};
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static int heap_end;
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static struct element heap[MAXHEAP];
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unsigned char streambuffer[MAXSTREAM];
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/* stream */
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struct STREAM {
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unsigned long pbit;
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unsigned char *x;
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};
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typedef struct STREAM stream_t;
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/* read only */
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struct RO_STREAM {
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unsigned long pbit;
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const unsigned char *x;
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};
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typedef struct RO_STREAM ro_stream_t;
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/*
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| VARIABLES
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\*---------------------------*/
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static int freq[MAXDIVERSITY];
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static unsigned code_table[MAXDIVERSITY];
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static unsigned size_table[MAXDIVERSITY];
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static stream_t Stream = {0, NULL};
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static ro_stream_t RO_Stream = {0, NULL};
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static const unsigned int VALUEBITS = 8u;
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/*==== PROTOTYPES======================================*/
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/* heap */
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static void freq_init (const unsigned char *in, size_t max);
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static void heap_init (void);
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static void heap_append (struct element e);
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static void heap_sift_up (int x);
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static void heap_adjust_down (int top, int last);
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/* hufftree */
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static int hufftree_from_freq (void);
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static int hufftree_from_heap (void);
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static void hufftree_to_codes (int start, int n, unsigned code);
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static void hufftree_reset (void);
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static int hufftree_frombits (ro_stream_t *stream, bool_t *pok);
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static void hufftree_tobits (int thisnode, stream_t *stream);
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static unsigned int hufftree_readstream (int root, ro_stream_t *s);
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/* stream */
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/* read only */
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static void ro_stream_rewind (ro_stream_t *s);
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static void ro_stream_init (ro_stream_t *s, const unsigned char *buffer);
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static void ro_stream_done (ro_stream_t *s);
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/* read and write */
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static void stream_clear (stream_t *s);
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static void stream_init (stream_t *s, unsigned char *buffer);
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static void stream_done (stream_t *s);
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static size_t stream_len (stream_t *s);
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static void stream_rewind (stream_t *s);
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static unsigned int stream_nextbit (ro_stream_t *s);
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static unsigned int stream_nextbit_n (ro_stream_t *s, unsigned int width);
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static void stream_writebit (stream_t *s, unsigned z);
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static void stream_write_n (unsigned code, unsigned width, stream_t *s);
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static bool_t decode_from_stream (ro_stream_t *stream, size_t n, unsigned char *out);
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static void encode_to_stream (const unsigned char *in, size_t inlen, stream_t *stream);
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/*static unsigned int stream_next8 (stream_t *s);*/
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/*static void stream_write8 (stream_t *s, unsigned z);*/
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/* supporting functions */
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/*
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static void heap_plot (void);
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static int fill_block(unsigned char *out);
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static char *binstream(unsigned int x, int n);
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static void stream_print(stream_t *s, int n);
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static void stream_printnext (stream_t *s, int n);
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static void stream_dump (stream_t *s, int ori, int n);
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static void freq_report (void);
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*/
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/*=== ENCODE/DECODE=================================================*/
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size_t TB_hzip_unused;
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static int
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huffman_decode (size_t z, const unsigned char *bz, size_t n, unsigned char *bp)
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/* bz:buffer huffman zipped to bp:buffer decoded */
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{
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bool_t ok;
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TB_hzip_unused = z; /* to silence compiler */
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ro_stream_init (&RO_Stream, bz);
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ok = decode_from_stream (&RO_Stream, n, bp);
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ro_stream_done (&RO_Stream);
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return ok;
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}
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static int
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huffman_encode (size_t n, const unsigned char *bp, size_t *z, unsigned char *bz)
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/* bz:buffer huffman zipped to bp:buffer decoded */
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{
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size_t i, zz;
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stream_init (&Stream, streambuffer);
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encode_to_stream (bp, n, &Stream);
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zz = stream_len (&Stream);
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for (i = 0; i < zz; i++) {
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bz[i] = Stream.x[i];
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}
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*z = zz;
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stream_done (&Stream);
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return TRUE;
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}
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extern int
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huff_decode
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(const unsigned char *in_start, size_t in_len, unsigned char *out_start, size_t *pout_len, size_t out_max)
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{
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size_t n = (size_t)in_start[0]
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| ((size_t)in_start[1] << 8)
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| ((size_t)in_start[2] << 16)
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| ((size_t)in_start[3] << 24);
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TB_hzip_unused = out_max;
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*pout_len = n;
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return huffman_decode (in_len-4, in_start+4, n, out_start);
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}
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extern int
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huff_encode
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(const unsigned char *in_start, size_t in_len, unsigned char *out_start, size_t *pout_len, size_t out_max)
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{
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bool_t ok;
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size_t hlen = 0;
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TB_hzip_unused = out_max;
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out_start[0] = (unsigned char) ((in_len ) & 0xffu);
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out_start[1] = (unsigned char) ((in_len >> 8) & 0xffu);
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out_start[2] = (unsigned char) ((in_len >> 16) & 0xffu);
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out_start[3] = (unsigned char) ((in_len >> 24) & 0xffu);
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ok = huffman_encode (in_len, in_start, &hlen, out_start+4);
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*pout_len = hlen + 4;
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return ok;
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}
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static bool_t
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decode_from_stream (ro_stream_t *s, size_t n, unsigned char *out)
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{
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int root;
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bool_t ok = TRUE; /* default */
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hufftree_reset ();
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ro_stream_rewind (s);
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root = hufftree_frombits (s, &ok);
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if (ok) {
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while (n-->0) {
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*out++ = (unsigned char) hufftree_readstream (root, s); /* cast to silence compiler */
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}
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}
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return ok;
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}
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static void
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encode_to_stream (const unsigned char *in, size_t inlen, stream_t *stream)
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{
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size_t i;
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unsigned x, c, s;
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int root;
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stream_clear (&Stream);
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stream_rewind(&Stream);
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/* pass to collect frequencies */
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freq_init (in, inlen);
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/* frequency --> heap --> hufftrees */
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root = hufftree_from_freq();
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/* hufftree --> codes */
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hufftree_to_codes (root, 0, 0);
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/* hufftrees --> stored in bits (stream) */
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hufftree_tobits (root, stream) ;
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/* input + codes --> stored in bits (stream) */
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for (i = 0; i < inlen; i++) {
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x = in[i];
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c = code_table[x];
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s = size_table[x];
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stream_write_n (c, s, stream);
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}
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return;
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}
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/*=== STREAM =================================================*/
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/*
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static char buffer[256];
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*/
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/*
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static char *
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binstream(unsigned int x, int n)
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{
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char *s = buffer;
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int i;
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for (i = 0; i < n; i++) {
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if (0!=(x&(1<<i))) {
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s[i] = '1';
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} else {
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s[i] = '0';
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}
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}
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s[i] = '\0';
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return buffer;
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}
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*/
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/* READ ONLY */
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static void ro_stream_rewind (ro_stream_t *s) {s->pbit = 0; return;}
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static void
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ro_stream_init (ro_stream_t *s, const unsigned char *buffer)
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{
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s->x = buffer;
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s->pbit = 0;
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return;
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}
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static void
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ro_stream_done (ro_stream_t *s)
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{
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s->x = NULL;
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s->pbit = 0;
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return;
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}
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/* READ AND WRITE */
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static void stream_rewind (stream_t *s) {s->pbit = 0; return;}
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static void
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stream_init (stream_t *s, unsigned char *buffer)
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{
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s->x = buffer;
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s->pbit = 0;
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return;
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}
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static void
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stream_done (stream_t *s)
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{
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s->x = NULL;
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s->pbit = 0;
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return;
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}
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static void
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stream_clear (stream_t *s)
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{ int i;
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for (i = 0; i < MAXSTREAM; i++) {
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s->x[i] = 0;
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}
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s->pbit = 0;
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return;
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}
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static size_t
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stream_len (stream_t *s)
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{
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return 1 + s->pbit/8;
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}
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static unsigned int
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stream_nextbit (ro_stream_t *s)
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{
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unsigned long y, byte, bit;
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y = s->pbit++;
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byte = y / 8;
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bit = y & 7;
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return 1u & (((unsigned)s->x[byte]) >> bit);
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}
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static unsigned int
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stream_nextbit_n (ro_stream_t *s, unsigned int width)
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{
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unsigned i;
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unsigned x;
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unsigned r = 0;
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for (i = 0; i < width; i++) {
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x = stream_nextbit (s);
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r |= (x << i);
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}
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return r;
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}
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/*
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static unsigned int
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stream_next8 (stream_t *s)
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{
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unsigned a,b,y,byte,bit;
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y = s->pbit;
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s->pbit += 8;
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byte = y / 8;
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bit = y & 7;
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a = 0xff & s->x[byte];
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b = 0xff & s->x[byte+1];
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return 0xff & ((a >> bit) | (b << (8-bit)));
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}
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*/
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#if 1
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static void
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stream_writebit (stream_t *s, unsigned z)
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{
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unsigned long y,byte,bit;
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y = s->pbit++;
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byte = y / 8;
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bit = y & 7;
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/* s->x[byte] &= ~(1u << bit);*/
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s->x[byte] = (unsigned char) (s->x[byte] | ((z&1u) << bit)); /* cast to silence compiler */
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return;
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}
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#else
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static void
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stream_writebit (stream_t *s, unsigned z)
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{
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/* This function will write the next bit, 0 or 1 depending on z, and will clear
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| the following bits (when bit == 0) or some future bytes
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| Do not use for writing after random access
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| It is only useful when this function is use for sequential writing on a
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| empty buffer.
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*/
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unsigned long y, byte, bit;
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unsigned char *p;
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y = s->pbit++;
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byte = y / 8;
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bit = y & 7;
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p = &(s->x[byte]);
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/* hack to clear the byte only when bit == 0, otherwise, it clears future bytes
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| This will avoid clearing the whole buffer beforehand or doing
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| *p &= (unsigned char)(~(1u << bit));
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*/
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p[bit] = 0;
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*p |= (unsigned char)(z&1u) << bit);
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return;
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}
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#endif
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/*
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static void
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stream_write8 (stream_t *s, unsigned z)
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{
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unsigned a,b,c,y,byte,bit;
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y = s->pbit;
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s->pbit += 8;
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byte = y / 8;
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bit = y & 7;
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a = 0xff & s->x[byte];
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b = 0xff & s->x[byte+1];
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c = a | (b << 8);
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c &= ~(0xff << bit);
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c |= z << bit;
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s->x[byte] = c & 0xff;
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s->x[byte+1] = 0xff & (c >> 8);
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return;
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}
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*/
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static void
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stream_write_n (unsigned code, unsigned width, stream_t *s)
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{
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unsigned i;
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for (i = 0; i < width; i++) {
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stream_writebit (s, 1u & (code >> i));
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}
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return;
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}
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/*
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static void
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stream_printnext (stream_t *s, int n)
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{
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int i; unsigned int x;
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unsigned long int oldpos = s->pbit;
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printf("\n");
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for (i = 0; i < n; i++) {
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if ((i & 7) == 0)
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printf ("\n");
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x = stream_next8 (s);
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printf ("%s ", binstream(x,8) );
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}
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printf("\n");
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s->pbit = oldpos;
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return;
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}
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*/
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/*
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static void
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stream_dump (stream_t *s, int ori, int n)
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{
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int i; unsigned int x;
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unsigned long int oldpos = s->pbit;
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s->pbit = ori;
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printf("\n");
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for (i = 0; i < n; i++) {
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if ((i & 7) == 0)
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printf ("\n");
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x = stream_next8 (s);
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printf ("%s ", binstream(x,8) );
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}
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printf("\n");
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s->pbit = oldpos;
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return;
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}
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*/
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/*=== HUFFTREE=================================================*/
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#define LEFTCODE 0u
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#define RIGHTCODE 1u
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#define BITLEAF 1
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#define BITNODE 0
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static void
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hufftree_reset (void)
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{
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struct huff h;
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int i;
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for (i = 0; i < 2*MAXDIVERSITY; i++) {
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h.isleaf = FALSE;
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h.value = 0;
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h.freq = 0;
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h.pleft = 0;
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h.pright = 0;
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hufftree[i] = h;
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}
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huff_end = 0;
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}
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static int
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hufftree_from_heap (void)
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{
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int top, newidx /*, left, right, lesser */ ;
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struct huff h;
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for (;;)
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{
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if (heap_end == 2) { /* at least top element */
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/* done */
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break;
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}
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/* work at the top */
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top = 1;
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/*
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left = 2*top;
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right = left + 1;
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lesser = left;
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if (right < heap_end && (heap[right].freq < heap[left].freq))
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lesser = right;
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*/
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/* new huff node */
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newidx = huff_end++;
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h.isleaf = FALSE;
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h.value = -1;
|
|
h.freq = heap[top].freq; /* will be incremented later when in 'combine' */
|
|
h.pleft = heap[top].huffidx;
|
|
h.pright = -1; /* will be attached the next element */
|
|
|
|
|
|
#ifdef TRACE
|
|
printf ("\n\nBefore Eliminate Top\n");
|
|
heap_plot();
|
|
#endif
|
|
|
|
/* eliminate top */
|
|
heap[top] = heap[--heap_end];
|
|
|
|
/* next 'lesser' element at 'top' */
|
|
heap_adjust_down (1, heap_end-1);
|
|
|
|
#ifdef TRACE
|
|
printf ("\n\nEliminate Top\n");
|
|
heap_plot ();
|
|
#endif
|
|
|
|
/* combine */
|
|
h.pright = heap[1].huffidx;
|
|
h.freq += heap[1].freq; /* combine frequencies */
|
|
hufftree[newidx] = h;
|
|
|
|
heap[1].freq = h.freq;
|
|
heap[1].huffidx = newidx;
|
|
|
|
/* adjust the combined elements */
|
|
heap_adjust_down (1, heap_end-1);
|
|
|
|
#ifdef TRACE
|
|
printf ("\n\nAfter Combine\n");
|
|
heap_plot ();
|
|
#endif
|
|
|
|
}
|
|
|
|
return heap[1].huffidx;
|
|
}
|
|
|
|
|
|
static void
|
|
hufftree_to_codes (int start, int n, unsigned code)
|
|
{
|
|
int x, m;
|
|
unsigned c;
|
|
int value;
|
|
|
|
#ifdef TRACK
|
|
if (n == 0)
|
|
printf ("\nHufftree to codes\n");
|
|
#endif
|
|
|
|
assert (n >= 0);
|
|
|
|
x = hufftree[start].pleft;
|
|
c = code | (LEFTCODE << n);
|
|
m = n + 1;
|
|
|
|
/* LEFT */
|
|
if (hufftree[x].isleaf) {
|
|
value = hufftree[x].value;
|
|
code_table[value] = c;
|
|
size_table[value] = (unsigned)m;
|
|
|
|
#ifdef TRACK
|
|
printf ("value=%c:%d, code=%d \"%s\", size=%d\n", value,value, c, binstream(c,m), m);
|
|
#endif
|
|
|
|
} else {
|
|
hufftree_to_codes(x, m, c);
|
|
}
|
|
|
|
|
|
/* RIGHT */
|
|
x = hufftree[start].pright;
|
|
c = code | (RIGHTCODE << n);
|
|
m = n + 1;
|
|
|
|
if (hufftree[x].isleaf) {
|
|
value = hufftree[x].value;
|
|
code_table[value] = c;
|
|
size_table[value] = (unsigned)m;
|
|
|
|
#ifdef TRACK
|
|
printf ("value=%c:%d, code=%d \"%s\", size=%d\n", value,value, c, binstream(c,m), m);
|
|
#endif
|
|
|
|
} else {
|
|
hufftree_to_codes(x, m, c);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
|
|
static int
|
|
hufftree_frombits (ro_stream_t *stream, bool_t *pok)
|
|
{
|
|
unsigned bit;
|
|
unsigned value;
|
|
int thisnode;
|
|
struct huff h;
|
|
|
|
if (!*pok)
|
|
return 0;
|
|
|
|
bit = stream_nextbit(stream);
|
|
if (bit == BITLEAF) {
|
|
/* leaf */
|
|
value = stream_nextbit_n (stream, VALUEBITS);
|
|
thisnode = huff_end++;
|
|
h.isleaf = TRUE;
|
|
h.value = (int)value;
|
|
h.freq = 0;
|
|
h.pleft = 0;
|
|
h.pright = 0;
|
|
|
|
if (thisnode >= MAXHUFF) {
|
|
*pok = FALSE;
|
|
return 0;
|
|
}
|
|
|
|
hufftree[thisnode] = h;
|
|
|
|
#ifdef TRACK
|
|
printf ("Huff leaf, %d=%c\n", value, value);
|
|
#endif
|
|
|
|
return thisnode;
|
|
|
|
} else {
|
|
/* node */
|
|
thisnode = huff_end++;
|
|
|
|
if (thisnode >= MAXHUFF) {
|
|
*pok = FALSE;
|
|
return 0;
|
|
}
|
|
|
|
h.isleaf = FALSE;
|
|
h.value = -1;
|
|
h.freq = 0;
|
|
h.pleft = hufftree_frombits (stream, pok);
|
|
h.pright = hufftree_frombits (stream, pok);
|
|
hufftree[thisnode] = h;
|
|
return thisnode;
|
|
}
|
|
}
|
|
|
|
|
|
static void
|
|
hufftree_tobits (int thisnode, stream_t *stream)
|
|
{
|
|
|
|
if (hufftree[thisnode].isleaf) {
|
|
|
|
#ifdef TRACK
|
|
{int c = hufftree[thisnode].value; printf ("[leaf=1][%c:%d=%s]", c, c, binstream(c,8));}
|
|
#endif
|
|
|
|
assert (0 <= hufftree[thisnode].value);
|
|
|
|
stream_writebit (stream, BITLEAF);
|
|
stream_write_n ((unsigned)hufftree[thisnode].value, VALUEBITS, stream);
|
|
|
|
} else {
|
|
stream_writebit (stream, BITNODE);
|
|
|
|
#ifdef TRACK
|
|
printf ("[node=0]");
|
|
#endif
|
|
|
|
hufftree_tobits (hufftree[thisnode].pleft, stream);
|
|
hufftree_tobits (hufftree[thisnode].pright, stream);
|
|
|
|
}
|
|
return;
|
|
}
|
|
|
|
|
|
static unsigned int
|
|
hufftree_readstream (int root, ro_stream_t *s)
|
|
{
|
|
unsigned bit;
|
|
int next;
|
|
|
|
bit = stream_nextbit(s);
|
|
if (bit == RIGHTCODE) {
|
|
/* right */
|
|
next = hufftree[root].pright;
|
|
} else {
|
|
/*ASSERT (bit == LEFTCODE */
|
|
/* left */
|
|
next = hufftree[root].pleft;
|
|
}
|
|
|
|
if (hufftree[next].isleaf) {
|
|
assert (0 <= hufftree[next].value);
|
|
return (unsigned)hufftree[next].value;
|
|
} else {
|
|
return hufftree_readstream (next, s);
|
|
}
|
|
}
|
|
|
|
/*==== HEAP ==========================================*/
|
|
|
|
static void
|
|
heap_init (void)
|
|
{
|
|
heap_end = 1;
|
|
return;
|
|
}
|
|
|
|
static void
|
|
heap_append (struct element e)
|
|
{
|
|
/*ASSERT (heap_end < MAXHEAP);*/
|
|
heap[heap_end++] = e;
|
|
return;
|
|
}
|
|
|
|
static void
|
|
heap_sift_up (int x)
|
|
{
|
|
struct element t;
|
|
int p;
|
|
int c = x;
|
|
while (c > 1) {
|
|
p = c / 2;
|
|
if (heap[c].freq < heap[p].freq) {
|
|
t = heap[c]; heap[c] = heap[p]; heap[p] = t;
|
|
} else {
|
|
break;
|
|
}
|
|
c = p;
|
|
}
|
|
return;
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
heap_adjust_down (int top, int last)
|
|
{
|
|
struct element t;
|
|
int p;
|
|
int c;
|
|
int left, right;
|
|
|
|
if (last == top) { /* at least top element */
|
|
/* done */
|
|
return;
|
|
}
|
|
|
|
/* starts at the top */
|
|
p = top;
|
|
|
|
while (p <= last)
|
|
{
|
|
left = 2*p;
|
|
right = left + 1;
|
|
|
|
if (left > last)
|
|
break;
|
|
|
|
if (right <= last && (heap[right].freq < heap[left].freq))
|
|
c = right;
|
|
else
|
|
c = left;
|
|
|
|
if (c > last)
|
|
break;
|
|
|
|
if (heap[c].freq < heap[p].freq) {
|
|
t = heap[c]; heap[c] = heap[p]; heap[p] = t;
|
|
} else {
|
|
break;
|
|
}
|
|
p = c;
|
|
}
|
|
return;
|
|
}
|
|
|
|
|
|
/*
|
|
static void
|
|
heap_plot (void)
|
|
{
|
|
unsigned int line, limit, j;
|
|
int n = heap_end;
|
|
printf("===========================\n");
|
|
line = 1;
|
|
j = 1;
|
|
while (j < n) {
|
|
limit = 1 << line;
|
|
while (j < limit && j < n) {
|
|
printf("%3d:%c ",heap[j].freq, hufftree[heap[j].huffidx].value);
|
|
j++;
|
|
}
|
|
while (j < limit) {
|
|
printf("%3s ","--");
|
|
j++;
|
|
}
|
|
line++; printf("\n");
|
|
}
|
|
printf("===========================\n");
|
|
return;
|
|
}
|
|
*/
|
|
|
|
/*
|
|
static void
|
|
freq_report (void)
|
|
{
|
|
int i;
|
|
printf ("\nFREQUENCIES\n");
|
|
for (i = 0; i < MAXDIVERSITY; i++) {
|
|
if (freq[i] > 0) {
|
|
printf ("%c: %2d: %d: %d\n", i, i, freq[i], code_table[i]);
|
|
}
|
|
}
|
|
printf ("\n");
|
|
return;
|
|
}
|
|
*/
|
|
|
|
static void
|
|
freq_init (const unsigned char *in, size_t max)
|
|
{
|
|
size_t i;
|
|
|
|
/* clean up frequencies */
|
|
for (i = 0; i < MAXDIVERSITY; i++) {
|
|
freq [i] = 0;
|
|
code_table[i] = 0;
|
|
size_table[i] = 0;
|
|
}
|
|
|
|
/* build frequencies */
|
|
for (i = 0; i < max; i++) {
|
|
freq [in[i]]++;
|
|
}
|
|
|
|
#ifdef TRACK
|
|
freq_report();
|
|
#endif
|
|
|
|
return;
|
|
}
|
|
|
|
static int
|
|
hufftree_from_freq (void)
|
|
{
|
|
int i;
|
|
struct huff h;
|
|
struct element e;
|
|
int root;
|
|
|
|
hufftree_reset ();
|
|
|
|
/* build huff tree elements */
|
|
huff_end = 0;
|
|
for (i = 0; i < MAXDIVERSITY; i++) {
|
|
if (freq[i] > 0) {
|
|
h.isleaf = TRUE;
|
|
h.value = i;
|
|
h.freq = freq[i];
|
|
h.pleft = 0;
|
|
h.pright = 0;
|
|
hufftree[huff_end++] = h;
|
|
}
|
|
}
|
|
|
|
/* build heap */
|
|
heap_init();
|
|
for (i = 0; i < huff_end; i++) {
|
|
e.freq = hufftree[i].freq;
|
|
e.huffidx = i;
|
|
heap_append(e);
|
|
heap_sift_up(heap_end-1);
|
|
}
|
|
|
|
#ifdef TRACE
|
|
heap_plot ();
|
|
#endif
|
|
|
|
root = hufftree_from_heap();
|
|
|
|
/*hufftree_to_codes (root, 0, 0);*/
|
|
|
|
return root;
|
|
}
|
|
|
|
|
|
|