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denyhosts/clamav/libclamav/7z/Ppmd7.c

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/* Ppmd7.c -- PPMdH codec
2010-03-12 : Igor Pavlov : Public domain
This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
#include <memory.h>
#include "Ppmd7.h"
const Byte PPMD7_kExpEscape[16] = { 25, 14, 9, 7, 5, 5, 4, 4, 4, 3, 3, 3, 2, 2, 2, 2 };
static const UInt16 kInitBinEsc[] = { 0x3CDD, 0x1F3F, 0x59BF, 0x48F3, 0x64A1, 0x5ABC, 0x6632, 0x6051};
#define MAX_FREQ 124
#define UNIT_SIZE 12
#define U2B(nu) ((UInt32)(nu) * UNIT_SIZE)
#define U2I(nu) (p->Units2Indx[(nu) - 1])
#define I2U(indx) (p->Indx2Units[indx])
#ifdef PPMD_32BIT
#define REF(ptr) (ptr)
#else
#define REF(ptr) ((UInt32)((Byte *)(ptr) - (p)->Base))
#endif
#define STATS_REF(ptr) ((CPpmd_State_Ref)REF(ptr))
#define CTX(ref) ((CPpmd7_Context *)Ppmd7_GetContext(p, ref))
#define STATS(ctx) Ppmd7_GetStats(p, ctx)
#define ONE_STATE(ctx) Ppmd7Context_OneState(ctx)
#define SUFFIX(ctx) CTX((ctx)->Suffix)
typedef CPpmd7_Context * CTX_PTR;
struct CPpmd7_Node_;
typedef
#ifdef PPMD_32BIT
struct CPpmd7_Node_ *
#else
UInt32
#endif
CPpmd7_Node_Ref;
typedef struct CPpmd7_Node_
{
UInt16 Stamp; /* must be at offset 0 as CPpmd7_Context::NumStats. Stamp=0 means free */
UInt16 NU;
CPpmd7_Node_Ref Next; /* must be at offset >= 4 */
CPpmd7_Node_Ref Prev;
} CPpmd7_Node;
union NodeOrRef {
CPpmd7_Node node;
CPpmd7_Node_Ref ref;
};
#ifdef PPMD_32BIT
#define NODE(ptr) (ptr)
#else
#define NODE(offs) ((CPpmd7_Node *)(p->Base + (offs)))
#endif
void Ppmd7_Construct(CPpmd7 *p)
{
unsigned i, k, m;
p->Base = 0;
for (i = 0, k = 0; i < PPMD_NUM_INDEXES; i++)
{
unsigned step = (i >= 12 ? 4 : (i >> 2) + 1);
do { p->Units2Indx[k++] = (Byte)i; } while(--step);
p->Indx2Units[i] = (Byte)k;
}
p->NS2BSIndx[0] = (0 << 1);
p->NS2BSIndx[1] = (1 << 1);
memset(p->NS2BSIndx + 2, (2 << 1), 9);
memset(p->NS2BSIndx + 11, (3 << 1), 256 - 11);
for (i = 0; i < 3; i++)
p->NS2Indx[i] = (Byte)i;
for (m = i, k = 1; i < 256; i++)
{
p->NS2Indx[i] = (Byte)m;
if (--k == 0)
k = (++m) - 2;
}
memset(p->HB2Flag, 0, 0x40);
memset(p->HB2Flag + 0x40, 8, 0x100 - 0x40);
}
void Ppmd7_Free(CPpmd7 *p, ISzAlloc *alloc)
{
alloc->Free(alloc, p->Base);
p->Size = 0;
p->Base = 0;
}
Bool Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAlloc *alloc)
{
if (p->Base == 0 || p->Size != size)
{
Ppmd7_Free(p, alloc);
p->AlignOffset =
#ifdef PPMD_32BIT
(4 - size) & 3;
#else
4 - (size & 3);
#endif
if ((p->Base = (Byte *)alloc->Alloc(alloc, p->AlignOffset + size
#ifndef PPMD_32BIT
+ UNIT_SIZE
#endif
)) == 0)
return False;
p->Size = size;
}
return True;
}
static void InsertNode(CPpmd7 *p, void *node, unsigned indx)
{
*((CPpmd_Void_Ref *)node) = p->FreeList[indx];
p->FreeList[indx] = REF(node);
}
static void *RemoveNode(CPpmd7 *p, unsigned indx)
{
CPpmd_Void_Ref *node = (CPpmd_Void_Ref *)Ppmd7_GetPtr(p, p->FreeList[indx]);
p->FreeList[indx] = *node;
return node;
}
static void SplitBlock(CPpmd7 *p, void *ptr, unsigned oldIndx, unsigned newIndx)
{
unsigned i, nu = I2U(oldIndx) - I2U(newIndx);
ptr = (Byte *)ptr + U2B(I2U(newIndx));
if (I2U(i = U2I(nu)) != nu)
{
unsigned k = I2U(--i);
InsertNode(p, ((Byte *)ptr) + U2B(k), nu - k - 1);
}
InsertNode(p, ptr, i);
}
static void GlueFreeBlocks(CPpmd7 *p)
{
#ifdef PPMD_32BIT
CPpmd7_Node headItem;
CPpmd7_Node_Ref head = &headItem;
#else
CPpmd7_Node_Ref head = p->AlignOffset + p->Size;
#endif
CPpmd7_Node_Ref n = head;
unsigned i;
p->GlueCount = 255;
/* create doubly-linked list of free blocks */
for (i = 0; i < PPMD_NUM_INDEXES; i++)
{
UInt16 nu = I2U(i);
CPpmd7_Node_Ref next = (CPpmd7_Node_Ref)p->FreeList[i];
p->FreeList[i] = 0;
while (next != 0)
{
CPpmd7_Node *node = NODE(next);
node->Next = n;
n = NODE(n)->Prev = next;
next = ((const union NodeOrRef *)node)->ref;
node->Stamp = 0;
node->NU = (UInt16)nu;
}
}
NODE(head)->Stamp = 1;
NODE(head)->Next = n;
NODE(n)->Prev = head;
if (p->LoUnit != p->HiUnit)
((CPpmd7_Node *)p->LoUnit)->Stamp = 1;
/* Glue free blocks */
while (n != head)
{
CPpmd7_Node *node = NODE(n);
UInt32 nu = (UInt32)node->NU;
for (;;)
{
CPpmd7_Node *node2 = NODE(n) + nu;
nu += node2->NU;
if (node2->Stamp != 0 || nu >= 0x10000)
break;
NODE(node2->Prev)->Next = node2->Next;
NODE(node2->Next)->Prev = node2->Prev;
node->NU = (UInt16)nu;
}
n = node->Next;
}
/* Fill lists of free blocks */
for (n = NODE(head)->Next; n != head;)
{
CPpmd7_Node *node = NODE(n);
unsigned nu;
CPpmd7_Node_Ref next = node->Next;
for (nu = node->NU; nu > 128; nu -= 128, node += 128)
InsertNode(p, node, PPMD_NUM_INDEXES - 1);
if (I2U(i = U2I(nu)) != nu)
{
unsigned k = I2U(--i);
InsertNode(p, node + k, nu - k - 1);
}
InsertNode(p, node, i);
n = next;
}
}
static void *AllocUnitsRare(CPpmd7 *p, unsigned indx)
{
unsigned i;
void *retVal;
if (p->GlueCount == 0)
{
GlueFreeBlocks(p);
if (p->FreeList[indx] != 0)
return RemoveNode(p, indx);
}
i = indx;
do
{
if (++i == PPMD_NUM_INDEXES)
{
UInt32 numBytes = U2B(I2U(indx));
p->GlueCount--;
return ((UInt32)(p->UnitsStart - p->Text) > numBytes) ? (p->UnitsStart -= numBytes) : (NULL);
}
}
while (p->FreeList[i] == 0);
retVal = RemoveNode(p, i);
SplitBlock(p, retVal, i, indx);
return retVal;
}
static void *AllocUnits(CPpmd7 *p, unsigned indx)
{
UInt32 numBytes;
if (p->FreeList[indx] != 0)
return RemoveNode(p, indx);
numBytes = U2B(I2U(indx));
if (numBytes <= (UInt32)(p->HiUnit - p->LoUnit))
{
void *retVal = p->LoUnit;
p->LoUnit += numBytes;
return retVal;
}
return AllocUnitsRare(p, indx);
}
#define MyMem12Cpy(dest, src, num) \
{ UInt32 *d = (UInt32 *)dest; const UInt32 *s = (const UInt32 *)src; UInt32 n = num; \
do { d[0] = s[0]; d[1] = s[1]; d[2] = s[2]; s += 3; d += 3; } while(--n); }
static void *ShrinkUnits(CPpmd7 *p, void *oldPtr, unsigned oldNU, unsigned newNU)
{
unsigned i0 = U2I(oldNU);
unsigned i1 = U2I(newNU);
if (i0 == i1)
return oldPtr;
if (p->FreeList[i1] != 0)
{
void *ptr = RemoveNode(p, i1);
MyMem12Cpy(ptr, oldPtr, newNU);
InsertNode(p, oldPtr, i0);
return ptr;
}
SplitBlock(p, oldPtr, i0, i1);
return oldPtr;
}
#define SUCCESSOR(p) ((CPpmd_Void_Ref)((p)->SuccessorLow | ((UInt32)(p)->SuccessorHigh << 16)))
static void SetSuccessor(CPpmd_State *p, CPpmd_Void_Ref v)
{
(p)->SuccessorLow = (UInt16)((UInt32)(v) & 0xFFFF);
(p)->SuccessorHigh = (UInt16)(((UInt32)(v) >> 16) & 0xFFFF);
}
static void RestartModel(CPpmd7 *p)
{
unsigned i, k, m;
memset(p->FreeList, 0, sizeof(p->FreeList));
p->Text = p->Base + p->AlignOffset;
p->HiUnit = p->Text + p->Size;
p->LoUnit = p->UnitsStart = p->HiUnit - p->Size / 8 / UNIT_SIZE * 7 * UNIT_SIZE;
p->GlueCount = 0;
p->OrderFall = p->MaxOrder;
p->RunLength = p->InitRL = -(Int32)((p->MaxOrder < 12) ? p->MaxOrder : 12) - 1;
p->PrevSuccess = 0;
p->MinContext = p->MaxContext = (CTX_PTR)(p->HiUnit -= UNIT_SIZE); /* AllocContext(p); */
p->MinContext->Suffix = 0;
p->MinContext->NumStats = 256;
p->MinContext->SummFreq = 256 + 1;
p->FoundState = (CPpmd_State *)p->LoUnit; /* AllocUnits(p, PPMD_NUM_INDEXES - 1); */
p->LoUnit += U2B(256 / 2);
p->MinContext->Stats = REF(p->FoundState);
for (i = 0; i < 256; i++)
{
CPpmd_State *s = &p->FoundState[i];
s->Symbol = (Byte)i;
s->Freq = 1;
SetSuccessor(s, 0);
}
for (i = 0; i < 128; i++)
for (k = 0; k < 8; k++)
{
UInt16 *dest = p->BinSumm[i] + k;
UInt16 val = (UInt16)(PPMD_BIN_SCALE - kInitBinEsc[k] / (i + 2));
for (m = 0; m < 64; m += 8)
dest[m] = val;
}
for (i = 0; i < 25; i++)
for (k = 0; k < 16; k++)
{
CPpmd_See *s = &p->See[i][k];
s->Summ = (UInt16)((5 * i + 10) << (s->Shift = PPMD_PERIOD_BITS - 4));
s->Count = 4;
}
}
void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder)
{
p->MaxOrder = maxOrder;
RestartModel(p);
p->DummySee.Shift = PPMD_PERIOD_BITS;
p->DummySee.Summ = 0; /* unused */
p->DummySee.Count = 64; /* unused */
}
static CTX_PTR CreateSuccessors(CPpmd7 *p, Bool skip)
{
CPpmd_State upState;
CTX_PTR c = p->MinContext;
CPpmd_Byte_Ref upBranch = (CPpmd_Byte_Ref)SUCCESSOR(p->FoundState);
CPpmd_State *ps[PPMD7_MAX_ORDER];
unsigned numPs = 0;
if (!skip)
ps[numPs++] = p->FoundState;
while (c->Suffix)
{
CPpmd_Void_Ref successor;
CPpmd_State *s;
c = SUFFIX(c);
if (c->NumStats != 1)
{
for (s = STATS(c); s->Symbol != p->FoundState->Symbol; s++);
}
else
s = ONE_STATE(c);
successor = SUCCESSOR(s);
if (successor != upBranch)
{
c = CTX(successor);
if (numPs == 0)
return c;
break;
}
ps[numPs++] = s;
}
upState.Symbol = *(const Byte *)Ppmd7_GetPtr(p, upBranch);
SetSuccessor(&upState, upBranch + 1);
if (c->NumStats == 1)
upState.Freq = ONE_STATE(c)->Freq;
else
{
UInt32 cf, s0;
CPpmd_State *s;
for (s = STATS(c); s->Symbol != upState.Symbol; s++);
cf = s->Freq - 1;
s0 = c->SummFreq - c->NumStats - cf;
upState.Freq = (Byte)(1 + ((2 * cf <= s0) ? (5 * cf > s0) : ((2 * cf + 3 * s0 - 1) / (2 * s0))));
}
do
{
/* Create Child */
CTX_PTR c1; /* = AllocContext(p); */
if (p->HiUnit != p->LoUnit)
c1 = (CTX_PTR)(p->HiUnit -= UNIT_SIZE);
else if (p->FreeList[0] != 0)
c1 = (CTX_PTR)RemoveNode(p, 0);
else
{
c1 = (CTX_PTR)AllocUnitsRare(p, 0);
if (!c1)
return NULL;
}
c1->NumStats = 1;
*ONE_STATE(c1) = upState;
c1->Suffix = REF(c);
SetSuccessor(ps[--numPs], REF(c1));
c = c1;
}
while (numPs != 0);
return c;
}
static void SwapStates(CPpmd_State *t1, CPpmd_State *t2)
{
CPpmd_State tmp = *t1;
*t1 = *t2;
*t2 = tmp;
}
static void UpdateModel(CPpmd7 *p)
{
CPpmd_Void_Ref successor, fSuccessor = SUCCESSOR(p->FoundState);
CTX_PTR c;
unsigned s0, ns;
if (p->FoundState->Freq < MAX_FREQ / 4 && p->MinContext->Suffix != 0)
{
c = SUFFIX(p->MinContext);
if (c->NumStats == 1)
{
CPpmd_State *s = ONE_STATE(c);
if (s->Freq < 32)
s->Freq++;
}
else
{
CPpmd_State *s = STATS(c);
if (s->Symbol != p->FoundState->Symbol)
{
do { s++; } while (s->Symbol != p->FoundState->Symbol);
if (s[0].Freq >= s[-1].Freq)
{
SwapStates(&s[0], &s[-1]);
s--;
}
}
if (s->Freq < MAX_FREQ - 9)
{
s->Freq += 2;
c->SummFreq += 2;
}
}
}
if (p->OrderFall == 0)
{
p->MinContext = p->MaxContext = CreateSuccessors(p, True);
if (p->MinContext == 0)
{
RestartModel(p);
return;
}
SetSuccessor(p->FoundState, REF(p->MinContext));
return;
}
*p->Text++ = p->FoundState->Symbol;
successor = REF(p->Text);
if (p->Text >= p->UnitsStart)
{
RestartModel(p);
return;
}
if (fSuccessor)
{
if (fSuccessor <= successor)
{
CTX_PTR cs = CreateSuccessors(p, False);
if (cs == NULL)
{
RestartModel(p);
return;
}
fSuccessor = REF(cs);
}
if (--p->OrderFall == 0)
{
successor = fSuccessor;
p->Text -= (p->MaxContext != p->MinContext);
}
}
else
{
SetSuccessor(p->FoundState, successor);
fSuccessor = REF(p->MinContext);
}
s0 = p->MinContext->SummFreq - (ns = p->MinContext->NumStats) - (p->FoundState->Freq - 1);
for (c = p->MaxContext; c != p->MinContext; c = SUFFIX(c))
{
unsigned ns1;
UInt32 cf, sf;
if ((ns1 = c->NumStats) != 1)
{
if ((ns1 & 1) == 0)
{
/* Expand for one UNIT */
unsigned oldNU = ns1 >> 1;
unsigned i = U2I(oldNU);
if (i != U2I(oldNU + 1))
{
void *ptr = AllocUnits(p, i + 1);
void *oldPtr;
if (!ptr)
{
RestartModel(p);
return;
}
oldPtr = STATS(c);
MyMem12Cpy(ptr, oldPtr, oldNU);
InsertNode(p, oldPtr, i);
c->Stats = STATS_REF(ptr);
}
}
c->SummFreq = (UInt16)(c->SummFreq + (2 * ns1 < ns) + 2 * ((4 * ns1 <= ns) & (c->SummFreq <= 8 * ns1)));
}
else
{
CPpmd_State *s = (CPpmd_State*)AllocUnits(p, 0);
if (!s)
{
RestartModel(p);
return;
}
*s = *ONE_STATE(c);
c->Stats = REF(s);
if (s->Freq < MAX_FREQ / 4 - 1)
s->Freq <<= 1;
else
s->Freq = MAX_FREQ - 4;
c->SummFreq = (UInt16)(s->Freq + p->InitEsc + (ns > 3));
}
cf = 2 * (UInt32)p->FoundState->Freq * (c->SummFreq + 6);
sf = (UInt32)s0 + c->SummFreq;
if (cf < 6 * sf)
{
cf = 1 + (cf > sf) + (cf >= 4 * sf);
c->SummFreq += 3;
}
else
{
cf = 4 + (cf >= 9 * sf) + (cf >= 12 * sf) + (cf >= 15 * sf);
c->SummFreq = (UInt16)(c->SummFreq + cf);
}
{
CPpmd_State *s = STATS(c) + ns1;
SetSuccessor(s, successor);
s->Symbol = p->FoundState->Symbol;
s->Freq = (Byte)cf;
c->NumStats = (UInt16)(ns1 + 1);
}
}
p->MaxContext = p->MinContext = CTX(fSuccessor);
}
static void Rescale(CPpmd7 *p)
{
unsigned i, adder, sumFreq, escFreq;
CPpmd_State *stats = STATS(p->MinContext);
CPpmd_State *s = p->FoundState;
{
CPpmd_State tmp = *s;
for (; s != stats; s--)
s[0] = s[-1];
*s = tmp;
}
escFreq = p->MinContext->SummFreq - s->Freq;
s->Freq += 4;
adder = (p->OrderFall != 0);
s->Freq = (Byte)((s->Freq + adder) >> 1);
sumFreq = s->Freq;
i = p->MinContext->NumStats - 1;
do
{
escFreq -= (++s)->Freq;
s->Freq = (Byte)((s->Freq + adder) >> 1);
sumFreq += s->Freq;
if (s[0].Freq > s[-1].Freq)
{
CPpmd_State *s1 = s;
CPpmd_State tmp = *s1;
do
s1[0] = s1[-1];
while (--s1 != stats && tmp.Freq > s1[-1].Freq);
*s1 = tmp;
}
}
while (--i);
if (s->Freq == 0)
{
unsigned numStats = p->MinContext->NumStats;
unsigned n0, n1;
do { i++; } while ((--s)->Freq == 0);
escFreq += i;
p->MinContext->NumStats = (UInt16)(p->MinContext->NumStats - i);
if (p->MinContext->NumStats == 1)
{
CPpmd_State tmp = *stats;
do
{
tmp.Freq = (Byte)(tmp.Freq - (tmp.Freq >> 1));
escFreq >>= 1;
}
while (escFreq > 1);
InsertNode(p, stats, U2I(((numStats + 1) >> 1)));
*(p->FoundState = ONE_STATE(p->MinContext)) = tmp;
return;
}
n0 = (numStats + 1) >> 1;
n1 = (p->MinContext->NumStats + 1) >> 1;
if (n0 != n1)
p->MinContext->Stats = STATS_REF(ShrinkUnits(p, stats, n0, n1));
}
p->MinContext->SummFreq = (UInt16)(sumFreq + escFreq - (escFreq >> 1));
p->FoundState = STATS(p->MinContext);
}
CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *escFreq)
{
CPpmd_See *see;
unsigned nonMasked = p->MinContext->NumStats - numMasked;
if (p->MinContext->NumStats != 256)
{
see = p->See[p->NS2Indx[nonMasked - 1]] +
(nonMasked < (unsigned)SUFFIX(p->MinContext)->NumStats - p->MinContext->NumStats) +
2 * (p->MinContext->SummFreq < 11 * p->MinContext->NumStats) +
4 * (numMasked > nonMasked) +
p->HiBitsFlag;
{
unsigned r = (see->Summ >> see->Shift);
see->Summ = (UInt16)(see->Summ - r);
*escFreq = r + (r == 0);
}
}
else
{
see = &p->DummySee;
*escFreq = 1;
}
return see;
}
static void NextContext(CPpmd7 *p)
{
CTX_PTR c = CTX(SUCCESSOR(p->FoundState));
if (p->OrderFall == 0 && (Byte *)c > p->Text)
p->MinContext = p->MaxContext = c;
else
UpdateModel(p);
}
void Ppmd7_Update1(CPpmd7 *p)
{
CPpmd_State *s = p->FoundState;
s->Freq += 4;
p->MinContext->SummFreq += 4;
if (s[0].Freq > s[-1].Freq)
{
SwapStates(&s[0], &s[-1]);
p->FoundState = --s;
if (s->Freq > MAX_FREQ)
Rescale(p);
}
NextContext(p);
}
void Ppmd7_Update1_0(CPpmd7 *p)
{
p->PrevSuccess = (2 * p->FoundState->Freq > p->MinContext->SummFreq);
p->RunLength += p->PrevSuccess;
p->MinContext->SummFreq += 4;
if ((p->FoundState->Freq += 4) > MAX_FREQ)
Rescale(p);
NextContext(p);
}
void Ppmd7_UpdateBin(CPpmd7 *p)
{
p->FoundState->Freq = (Byte)(p->FoundState->Freq + (p->FoundState->Freq < 128 ? 1: 0));
p->PrevSuccess = 1;
p->RunLength++;
NextContext(p);
}
void Ppmd7_Update2(CPpmd7 *p)
{
p->MinContext->SummFreq += 4;
if ((p->FoundState->Freq += 4) > MAX_FREQ)
Rescale(p);
p->RunLength = p->InitRL;
UpdateModel(p);
}
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