//C- -*- C++ -*-
//C- -------------------------------------------------------------------
//C- DjVuLibre-3.5
//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun.
//C- Copyright (c) 2001 AT&T
//C-
//C- This software is subject to, and may be distributed under, the
//C- GNU General Public License, either Version 2 of the license,
//C- or (at your option) any later version. The license should have
//C- accompanied the software or you may obtain a copy of the license
//C- from the Free Software Foundation at http://www.fsf.org .
//C-
//C- This program is distributed in the hope that it will be useful,
//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
//C- GNU General Public License for more details.
//C-
//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library from
//C- Lizardtech Software. Lizardtech Software has authorized us to
//C- replace the original DjVu(r) Reference Library notice by the following
//C- text (see doc/lizard2002.djvu and doc/lizardtech2007.djvu):
//C-
//C- ------------------------------------------------------------------
//C- | DjVu (r) Reference Library (v. 3.5)
//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
//C- | The DjVu Reference Library is protected by U.S. Pat. No.
//C- | 6,058,214 and patents pending.
//C- |
//C- | This software is subject to, and may be distributed under, the
//C- | GNU General Public License, either Version 2 of the license,
//C- | or (at your option) any later version. The license should have
//C- | accompanied the software or you may obtain a copy of the license
//C- | from the Free Software Foundation at http://www.fsf.org .
//C- |
//C- | The computer code originally released by LizardTech under this
//C- | license and unmodified by other parties is deemed "the LIZARDTECH
//C- | ORIGINAL CODE." Subject to any third party intellectual property
//C- | claims, LizardTech grants recipient a worldwide, royalty-free,
//C- | non-exclusive license to make, use, sell, or otherwise dispose of
//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the
//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU
//C- | General Public License. This grant only confers the right to
//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to
//C- | the extent such infringement is reasonably necessary to enable
//C- | recipient to make, have made, practice, sell, or otherwise dispose
//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to
//C- | any greater extent that may be necessary to utilize further
//C- | modifications or combinations.
//C- |
//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
//C- +------------------------------------------------------------------
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if NEED_GNUG_PRAGMAS
# pragma implementation
#endif
// - Author: Leon Bottou, 07/1998
#include "BSByteStream.h"
#include "GString.h"
#undef BSORT_TIMER
#ifdef BSORT_TIMER
#include "GOS.h"
#endif
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef HAVE_NAMESPACES
namespace DJVU {
# ifdef NOT_DEFINED // Just to fool emacs c++ mode
}
#endif
#endif
// ========================================
// --- Assertion
#define ASSERT(expr) do{if(!(expr))G_THROW("assertion ("#expr") failed");}while(0)
// ========================================
// --- Global Definitions
#ifdef OVERFLOW
#undef OVERFLOW
#endif
// Overflow required when encoding
static const int OVERFLOW=32;
// Sorting tresholds
static const int RANKSORT_THRESH=10;
static const int QUICKSORT_STACK=512;
static const int PRESORT_THRESH=10;
static const int PRESORT_DEPTH=8;
static const int RADIX_THRESH=32768;
static const int FREQS0=100000;
static const int FREQS1=1000000;
// ========================================
// -- Sorting Routines
class _BSort // DJVU_CLASS
{
public:
~_BSort();
_BSort(unsigned char *data, int size);
void run(int &markerpos);
private:
// Members
int size;
unsigned char *data;
unsigned int *posn;
GPBuffer<unsigned int> gposn;
int *rank;
GPBuffer<int> grank;
// Helpers
inline int GT(int p1, int p2, int depth);
inline int GTD(int p1, int p2, int depth);
// -- final in-depth sort
void ranksort(int lo, int hi, int d);
// -- doubling sort
int pivot3r(int *rr, int lo, int hi);
void quicksort3r(int lo, int hi, int d);
// -- presort to depth PRESORT_DEPTH
unsigned char pivot3d(unsigned char *dd, int lo, int hi);
void quicksort3d(int lo, int hi, int d);
// -- radixsort
void radixsort16(void);
void radixsort8(void);
};
// blocksort -- the main entry point
static void
blocksort(unsigned char *data, int size, int &markerpos)
{
_BSort bsort(data, size);
bsort.run(markerpos);
}
// _BSort construction
_BSort::_BSort(unsigned char *xdata, int xsize)
: size(xsize), data(xdata), gposn(posn,xsize), grank(rank,xsize+1)
{
ASSERT(size>0 && size<0x1000000);
rank[size] = -1;
}
_BSort::~_BSort()
{
}
// GT -- compare suffixes using rank information
inline int
_BSort::GT(int p1, int p2, int depth)
{
int r1, r2;
int twod = depth + depth;
while (1)
{
r1=rank[p1+depth]; r2=rank[p2+depth];
p1+=twod; p2+=twod;
if (r1!=r2)
return (r1>r2);
r1=rank[p1]; r2=rank[p2];
if (r1!=r2)
return (r1>r2);
r1=rank[p1+depth]; r2=rank[p2+depth];
p1+=twod; p2+=twod;
if (r1!=r2)
return (r1>r2);
r1=rank[p1]; r2=rank[p2];
if (r1!=r2)
return (r1>r2);
r1=rank[p1+depth]; r2=rank[p2+depth];
p1+=twod; p2+=twod;
if (r1!=r2)
return (r1>r2);
r1=rank[p1]; r2=rank[p2];
if (r1!=r2)
return (r1>r2);
r1=rank[p1+depth]; r2=rank[p2+depth];
p1+=twod; p2+=twod;
if (r1!=r2)
return (r1>r2);
r1=rank[p1]; r2=rank[p2];
if (r1!=r2)
return (r1>r2);
};
}
// _BSort::ranksort --
// -- a simple insertion sort based on GT
void
_BSort::ranksort(int lo, int hi, int depth)
{
int i,j;
for (i=lo+1; i<=hi; i++)
{
int tmp = posn[i];
for(j=i-1; j>=lo && GT(posn[j], tmp, depth); j--)
posn[j+1] = posn[j];
posn[j+1] = tmp;
}
for(i=lo;i<=hi;i++)
rank[posn[i]]=i;
}
// pivot -- return suitable pivot
inline int
_BSort::pivot3r(int *rr, int lo, int hi)
{
int c1, c2, c3;
if (hi-lo > 256)
{
c1 = pivot3r(rr, lo, (6*lo+2*hi)/8);
c2 = pivot3r(rr, (5*lo+3*hi)/8, (3*lo+5*hi)/8);
c3 = pivot3r(rr, (2*lo+6*hi)/8, hi);
}
else
{
c1 = rr[posn[lo]];
c2 = rr[posn[(lo+hi)/2]];
c3 = rr[posn[hi]];
}
// Extract median
if (c1>c3)
{ int tmp=c1; c1=c3; c3=tmp; }
if (c2<=c1)
return c1;
else if (c2>=c3)
return c3;
else
return c2;
}
// _BSort::quicksort3r -- Three way quicksort algorithm
// Sort suffixes based on rank at pos+depth
// The algorithm breaks into ranksort when size is
// smaller than RANKSORT_THRESH
static inline int
mini(int a, int b)
{
return (a<=b) ? a : b;
}
static inline void
vswap(int i, int j, int n, unsigned int *x)
{
while (n-- > 0)
{ int tmp = x[i]; x[i++]=x[j]; x[j++]=tmp; }
}
void
_BSort::quicksort3r(int lo, int hi, int depth)
{
/* Initialize stack */
int slo[QUICKSORT_STACK];
int shi[QUICKSORT_STACK];
int sp = 1;
slo[0] = lo;
shi[0] = hi;
// Recursion elimination loop
while (--sp>=0)
{
lo = slo[sp];
hi = shi[sp];
// Test for insertion sort
if (hi-lo<RANKSORT_THRESH)
{
ranksort(lo, hi, depth);
}
else
{
int tmp;
int *rr=rank+depth;
int med = pivot3r(rr,lo,hi);
// -- positions are organized as follows:
// [lo..l1[ [l1..l[ ]h..h1] ]h1..hi]
// = < > =
int l1 = lo;
int h1 = hi;
while (rr[posn[l1]]==med && l1<h1) { l1++; }
while (rr[posn[h1]]==med && l1<h1) { h1--; }
int l = l1;
int h = h1;
// -- partition set
for (;;)
{
while (l<=h)
{
int c = rr[posn[l]] - med;
if (c > 0) break;
if (c == 0) { tmp=posn[l]; posn[l]=posn[l1]; posn[l1++]=tmp; }
l++;
}
while (l<=h)
{
int c = rr[posn[h]] - med;
if (c < 0) break;
if (c == 0) { tmp=posn[h]; posn[h]=posn[h1]; posn[h1--]=tmp; }
h--;
}
if (l>h) break;
tmp=posn[l]; posn[l]=posn[h]; posn[h]=tmp;
}
// -- reorganize as follows
// [lo..l1[ [l1..h1] ]h1..hi]
// < = >
tmp = mini(l1-lo, l-l1);
vswap(lo, l-tmp, tmp, posn);
l1 = lo + (l-l1);
tmp = mini(hi-h1, h1-h);
vswap(hi-tmp+1, h+1, tmp, posn);
h1 = hi - (h1-h);
// -- process segments
ASSERT(sp+2<QUICKSORT_STACK);
// ----- middle segment (=?) [l1, h1]
for(int i=l1;i<=h1;i++)
rank[posn[i]] = h1;
// ----- lower segment (<) [lo, l1[
if (l1 > lo)
{
for(int i=lo;i<l1;i++)
rank[posn[i]]=l1-1;
slo[sp]=lo;
shi[sp]=l1-1;
if (slo[sp] < shi[sp])
sp++;
}
// ----- upper segment (>) ]h1, hi]
if (h1 < hi)
{
slo[sp]=h1+1;
shi[sp]=hi;
if (slo[sp] < shi[sp])
sp++;
}
}
}
}
// GTD -- compare suffixes using data information
// (up to depth PRESORT_DEPTH)
inline int
_BSort::GTD(int p1, int p2, int depth)
{
unsigned char c1, c2;
p1+=depth; p2+=depth;
while (depth < PRESORT_DEPTH)
{
// Perform two
c1=data[p1]; c2=data[p2];
if (c1!=c2)
return (c1>c2);
c1=data[p1+1]; c2=data[p2+1];
p1+=2; p2+=2; depth+=2;
if (c1!=c2)
return (c1>c2);
}
if (p1<size && p2<size)
return 0;
return (p1<p2);
}
// pivot3d -- return suitable pivot
inline unsigned char
_BSort::pivot3d(unsigned char *rr, int lo, int hi)
{
unsigned char c1, c2, c3;
if (hi-lo > 256)
{
c1 = pivot3d(rr, lo, (6*lo+2*hi)/8);
c2 = pivot3d(rr, (5*lo+3*hi)/8, (3*lo+5*hi)/8);
c3 = pivot3d(rr, (2*lo+6*hi)/8, hi);
}
else
{
c1 = rr[posn[lo]];
c2 = rr[posn[(lo+hi)/2]];
c3 = rr[posn[hi]];
}
// Extract median
if (c1>c3)
{ int tmp=c1; c1=c3; c3=tmp; }
if (c2<=c1)
return c1;
else if (c2>=c3)
return c3;
else
return c2;
}
// _BSort::quicksort3d -- Three way quicksort algorithm
// Sort suffixes based on strings until reaching
// depth rank at pos+depth
// The algorithm breaks into ranksort when size is
// smaller than PRESORT_THRESH
void
_BSort::quicksort3d(int lo, int hi, int depth)
{
/* Initialize stack */
int slo[QUICKSORT_STACK];
int shi[QUICKSORT_STACK];
int sd[QUICKSORT_STACK];
int sp = 1;
slo[0] = lo;
shi[0] = hi;
sd[0] = depth;
// Recursion elimination loop
while (--sp>=0)
{
lo = slo[sp];
hi = shi[sp];
depth = sd[sp];
// Test for insertion sort
if (depth >= PRESORT_DEPTH)
{
for (int i=lo; i<=hi; i++)
rank[posn[i]] = hi;
}
else if (hi-lo<PRESORT_THRESH)
{
int i,j;
for (i=lo+1; i<=hi; i++)
{
int tmp = posn[i];
for(j=i-1; j>=lo && GTD(posn[j], tmp, depth); j--)
posn[j+1] = posn[j];
posn[j+1] = tmp;
}
for(i=hi;i>=lo;i=j)
{
int tmp = posn[i];
rank[tmp] = i;
for (j=i-1; j>=lo && !GTD(tmp,posn[j],depth); j--)
rank[posn[j]] = i;
}
}
else
{
int tmp;
unsigned char *dd=data+depth;
unsigned char med = pivot3d(dd,lo,hi);
// -- positions are organized as follows:
// [lo..l1[ [l1..l[ ]h..h1] ]h1..hi]
// = < > =
int l1 = lo;
int h1 = hi;
while (dd[posn[l1]]==med && l1<h1) { l1++; }
while (dd[posn[h1]]==med && l1<h1) { h1--; }
int l = l1;
int h = h1;
// -- partition set
for (;;)
{
while (l<=h)
{
int c = (int)dd[posn[l]] - (int)med;
if (c > 0) break;
if (c == 0) { tmp=posn[l]; posn[l]=posn[l1]; posn[l1++]=tmp; }
l++;
}
while (l<=h)
{
int c = (int)dd[posn[h]] - (int)med;
if (c < 0) break;
if (c == 0) { tmp=posn[h]; posn[h]=posn[h1]; posn[h1--]=tmp; }
h--;
}
if (l>h) break;
tmp=posn[l]; posn[l]=posn[h]; posn[h]=tmp;
}
// -- reorganize as follows
// [lo..l1[ [l1..h1] ]h1..hi]
// < = >
tmp = mini(l1-lo, l-l1);
vswap(lo, l-tmp, tmp, posn);
l1 = lo + (l-l1);
tmp = mini(hi-h1, h1-h);
vswap(hi-tmp+1, h+1, tmp, posn);
h1 = hi - (h1-h);
// -- process segments
ASSERT(sp+3<QUICKSORT_STACK);
// ----- middle segment (=?) [l1, h1]
l = l1; h = h1;
if (med==0) // special case for marker [slow]
for (int i=l; i<=h; i++)
if ((int)posn[i]+depth == size-1)
{
tmp=posn[i]; posn[i]=posn[l]; posn[l]=tmp;
rank[tmp]=l++; break;
}
if (l<h)
{ slo[sp] = l; shi[sp] = h; sd[sp++] = depth+1; }
else if (l==h)
{ rank[posn[h]] = h; }
// ----- lower segment (<) [lo, l1[
l = lo;
h = l1-1;
if (l<h)
{ slo[sp] = l; shi[sp] = h; sd[sp++] = depth; }
else if (l==h)
{ rank[posn[h]] = h; }
// ----- upper segment (>) ]h1, hi]
l = h1+1;
h = hi;
if (l<h)
{ slo[sp] = l; shi[sp] = h; sd[sp++] = depth; }
else if (l==h)
{ rank[posn[h]] = h; }
}
}
}
// _BSort::radixsort8 -- 8 bit radix sort
void
_BSort::radixsort8(void)
{
int i;
// Initialize frequency array
int lo[256], hi[256];
for (i=0; i<256; i++)
hi[i] = lo[i] = 0;
// Count occurences
for (i=0; i<size-1; i++)
hi[data[i]] ++;
// Compute positions (lo)
int last = 1;
for (i=0; i<256; i++)
{
lo[i] = last;
hi[i] = last + hi[i] - 1;
last = hi[i] + 1;
}
for (i=0; i<size-1; i++)
{
posn[ lo[data[i]]++ ] = i;
rank[ i ] = hi[data[i]];
}
// Process marker "$"
posn[0] = size-1;
rank[size-1] = 0;
// Extra element
rank[size] = -1;
}
// _BSort::radixsort16 -- 16 bit radix sort
void
_BSort::radixsort16(void)
{
int i;
// Initialize frequency array
int *ftab;
GPBuffer<int> gftab(ftab,65536);
for (i=0; i<65536; i++)
ftab[i] = 0;
// Count occurences
unsigned char c1 = data[0];
for (i=0; i<size-1; i++)
{
unsigned char c2 = data[i+1];
ftab[(c1<<8)|c2] ++;
c1 = c2;
}
// Generate upper position
for (i=1;i<65536;i++)
ftab[i] += ftab[i-1];
// Fill rank array with upper bound
c1 = data[0];
for (i=0; i<size-2; i++)
{
unsigned char c2 = data[i+1];
rank[i] = ftab[(c1<<8)|c2];
c1 = c2;
}
// Fill posn array (backwards)
c1 = data[size-2];
for (i=size-3; i>=0; i--)
{
unsigned char c2 = data[i];
posn[ ftab[(c2<<8)|c1]-- ] = i;
c1 = c2;
}
// Fixup marker stuff
ASSERT(data[size-1]==0);
c1 = data[size-2];
posn[0] = size-1;
posn[ ftab[(c1<<8)] ] = size-2;
rank[size-1] = 0;
rank[size-2] = ftab[(c1<<8)];
// Extra element
rank[size] = -1;
}
// _BSort::run -- main sort loop
void
_BSort::run(int &markerpos)
{
int lo, hi;
ASSERT(size>0);
ASSERT(data[size-1]==0);
#ifdef BSORT_TIMER
long start = GOS::ticks();
#endif
// Step 1: Radix sort
int depth = 0;
if (size > RADIX_THRESH)
{
radixsort16();
depth=2;
}
else
{
radixsort8();
depth=1;
}
// Step 2: Perform presort to depth PRESORT_DEPTH
for (lo=0; lo<size; lo++)
{
hi = rank[posn[lo]];
if (lo < hi)
quicksort3d(lo, hi, depth);
lo = hi;
}
depth = PRESORT_DEPTH;
#ifdef BSORT_TIMER
long middle = GOS::ticks();
#endif
// Step 3: Perform rank doubling
int again = 1;
while (again)
{
again = 0;
int sorted_lo = 0;
for (lo=0; lo<size; lo++)
{
hi = rank[posn[lo]&0xffffff];
if (lo == hi)
{
lo += (posn[lo]>>24) & 0xff;
}
else
{
if (hi-lo < RANKSORT_THRESH)
{
ranksort(lo, hi, depth);
}
else
{
again += 1;
while (sorted_lo < lo-1)
{
int step = mini(255, lo-1-sorted_lo);
posn[sorted_lo] = (posn[sorted_lo]&0xffffff) | (step<<24);
sorted_lo += step+1;
}
quicksort3r(lo, hi, depth);
sorted_lo = hi + 1;
}
lo = hi;
}
}
// Finish threading
while (sorted_lo < lo-1)
{
int step = mini(255, lo-1-sorted_lo);
posn[sorted_lo] = (posn[sorted_lo]&0xffffff) | (step<<24);
sorted_lo += step+1;
}
// Double depth
depth += depth;
}
// Step 4: Permute data
int i;
markerpos = -1;
for (i=0; i<size; i++)
rank[i] = data[i];
for (i=0; i<size; i++)
{
int j = posn[i] & 0xffffff;
if (j>0)
{
data[i] = rank[j-1];
}
else
{
data[i] = 0;
markerpos = i;
}
}
ASSERT(markerpos>=0 && markerpos<size);
#ifdef BSORT_TIMER
long end = GOS::ticks();
DjVuPrintErrorUTF8("Sorting time: %d bytes in %ld + %ld = %ld ms\n",
size-1, middle-start, end-middle, end-start);
#endif
}
// ========================================
// -- Encoding
static void
encode_raw(ZPCodec &zp, int bits, int x)
{
int n = 1;
int m = (1<<bits);
while (n < m)
{
x = (x & (m-1)) << 1;
int b = (x >> bits);
zp.encoder(b);
n = (n<<1) | b;
}
}
static inline void
encode_binary(ZPCodec &zp, BitContext *ctx, int bits, int x)
{
// Require 2^bits-1 contexts
int n = 1;
int m = (1<<bits);
ctx = ctx - 1;
while (n < m)
{
x = (x & (m-1)) << 1;
int b = (x >> bits);
zp.encoder(b, ctx[n]);
n = (n<<1) | b;
}
}
class BSByteStream::Encode : public BSByteStream
{
public:
/** Creates a Static object for allocating the memory area of
length #sz# starting at address #buffer#. */
Encode(GP<ByteStream> bs);
~Encode();
void init(const int encoding);
// Virtual functions
virtual size_t write(const void *buffer, size_t sz);
virtual void flush(void);
protected:
unsigned int encode(void);
};
unsigned int
BSByteStream::Encode::encode()
{
/////////////////////////////////
//////////// Block Sort Tranform
int markerpos = size-1;
blocksort(data,size,markerpos);
/////////////////////////////////
//////////// Encode Output Stream
// Header
ZPCodec &zp=*gzp;
encode_raw(zp, 24, size);
// Determine and Encode Estimation Speed
int fshift = 0;
if (size < FREQS0)
{ fshift=0; zp.encoder(0); }
else if (size < FREQS1)
{ fshift = 1; zp.encoder(1); zp.encoder(0); }
else
{ fshift = 2; zp.encoder(1); zp.encoder(1); }
// MTF
unsigned char mtf[256];
unsigned char rmtf[256];
unsigned int freq[FREQMAX];
int m = 0;
for (m=0; m<256; m++)
mtf[m] = m;
for (m=0; m<256; m++)
rmtf[mtf[m]] = m;
int fadd = 4;
for (m=0; m<FREQMAX; m++)
freq[m] = 0;
// Encode
int i;
int mtfno = 3;
for (i=0; i<size; i++)
{
// Get MTF data
int c = data[i];
int ctxid = CTXIDS-1;
if (ctxid>mtfno) ctxid=mtfno;
mtfno = rmtf[c];
if (i==markerpos)
mtfno = 256;
// Encode using ZPCoder
int b;
BitContext *cx = ctx;
b = (mtfno==0);
zp.encoder(b, cx[ctxid]);
if (b) goto rotate; cx+=CTXIDS;
b = (mtfno==1);
zp.encoder(b, cx[ctxid]);
if (b) goto rotate; cx+=CTXIDS;
b = (mtfno<4);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,1,mtfno-2); goto rotate; }
cx+=1+1;
b = (mtfno<8);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,2,mtfno-4); goto rotate; }
cx+=1+3;
b = (mtfno<16);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,3,mtfno-8); goto rotate; }
cx+=1+7;
b = (mtfno<32);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,4,mtfno-16); goto rotate; }
cx+=1+15;
b = (mtfno<64);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,5,mtfno-32); goto rotate; }
cx+=1+31;
b = (mtfno<128);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,6,mtfno-64); goto rotate; }
cx+=1+63;
b = (mtfno<256);
zp.encoder(b, cx[0]);
if (b) { encode_binary(zp,cx+1,7,mtfno-128); goto rotate; }
continue;
// Rotate MTF according to empirical frequencies (new!)
rotate:
// Adjust frequencies for overflow
fadd = fadd + (fadd>>fshift);
if (fadd > 0x10000000)
{
fadd = fadd>>24;
freq[0] >>= 24;
freq[1] >>= 24;
freq[2] >>= 24;
freq[3] >>= 24;
for (int k=4; k<FREQMAX; k++)
freq[k] = freq[k]>>24;
}
// Relocate new char according to new freq
unsigned int fc = fadd;
if (mtfno < FREQMAX)
fc += freq[mtfno];
int k;
for (k=mtfno; k>=FREQMAX; k--)
{
mtf[k] = mtf[k-1];
rmtf[mtf[k]] = k;
}
for (; k>0 && fc>=freq[k-1]; k--)
{
mtf[k] = mtf[k-1];
freq[k] = freq[k-1];
rmtf[mtf[k]] = k;
}
mtf[k] = c;
freq[k] = fc;
rmtf[mtf[k]] = k;
}
// Terminate
return 0;
}
// ========================================
// --- Construction
BSByteStream::Encode::Encode(GP<ByteStream> xbs)
: BSByteStream(xbs) {}
void
BSByteStream::Encode::init(const int xencoding)
{
gzp=ZPCodec::create(gbs,true,true);
const int encoding=(xencoding<MINBLOCK)?MINBLOCK:xencoding;
if (encoding > MAXBLOCK)
G_THROW( ERR_MSG("ByteStream.blocksize") "\t" + GUTF8String(MAXBLOCK) );
// Record block size
blocksize = encoding * 1024;
// Initialize context array
}
BSByteStream::Encode::~Encode()
{
// Flush
flush();
// Encode EOF marker
encode_raw(*gzp, 24, 0);
// Free allocated memory
}
GP<ByteStream>
BSByteStream::create(GP<ByteStream> xbs,const int blocksize)
{
BSByteStream::Encode *rbs=new BSByteStream::Encode(xbs);
GP<ByteStream> retval=rbs;
rbs->init(blocksize);
return retval;
}
// ========================================
// -- ByteStream interface
void
BSByteStream::Encode::flush()
{
if (bptr>0)
{
ASSERT(bptr<(int)blocksize);
memset(data+bptr, 0, OVERFLOW);
size = bptr+1;
encode();
}
size = bptr = 0;
}
size_t
BSByteStream::Encode::write(const void *buffer, size_t sz)
{
// Trivial checks
if (sz == 0)
return 0;
// Loop
int copied = 0;
while (sz > 0)
{
// Initialize
if (!data)
{
bptr = 0;
gdata.resize(blocksize+OVERFLOW);
}
// Compute remaining
int bytes = blocksize - 1 - bptr;
if (bytes > (int)sz)
bytes = sz;
// Store date (todo: rle)
memcpy(data+bptr, buffer, bytes);
buffer = (void*)((char*)buffer + bytes);
bptr += bytes;
sz -= bytes;
copied += bytes;
offset += bytes;
// Flush when needed
if (bptr + 1 >= (int)blocksize)
flush();
}
// return
return copied;
}
#ifdef HAVE_NAMESPACES
}
# ifndef NOT_USING_DJVU_NAMESPACE
using namespace DJVU;
# endif
#endif