21.02

C/Ppmd7.h

@@ -1,10 +1,8 @@
-/* Ppmd7.h -- PPMdH compression codec
-2018-07-04 : Igor Pavlov : Public domain
-This code is based on PPMd var.H (2001): Dmitry Shkarin : Public domain */
-
-/* This code supports virtual RangeDecoder and includes the implementation
-of RangeCoder from 7z, instead of RangeCoder from original PPMd var.H.
-If you need the compatibility with original PPMd var.H, you can use external RangeDecoder */
+/* Ppmd7.h -- Ppmd7 (PPMdH) compression codec
+2021-04-13 : Igor Pavlov : Public domain
+This code is based on:
+  PPMd var.H (2001): Dmitry Shkarin : Public domain */
+ 
 
 #ifndef __PPMD7_H
 #define __PPMD7_H
@@ -21,23 +19,56 @@ EXTERN_C_BEGIN
 
 struct CPpmd7_Context_;
 
-typedef
-  #ifdef PPMD_32BIT
-    struct CPpmd7_Context_ *
-  #else
-    UInt32
-  #endif
-  CPpmd7_Context_Ref;
+typedef Ppmd_Ref_Type(struct CPpmd7_Context_) CPpmd7_Context_Ref;
+
+// MY_CPU_pragma_pack_push_1
 
 typedef struct CPpmd7_Context_
 {
   UInt16 NumStats;
-  UInt16 SummFreq;
-  CPpmd_State_Ref Stats;
+
+
+  union
+  {
+    UInt16 SummFreq;
+    CPpmd_State2 State2;
+  } Union2;
+
+  union
+  {
+    CPpmd_State_Ref Stats;
+    CPpmd_State4 State4;
+  } Union4;
+
   CPpmd7_Context_Ref Suffix;
 } CPpmd7_Context;
 
-#define Ppmd7Context_OneState(p) ((CPpmd_State *)&(p)->SummFreq)
+// MY_CPU_pragma_pop
+
+#define Ppmd7Context_OneState(p) ((CPpmd_State *)&(p)->Union2)
+
+
+
+
+typedef struct
+{
+  UInt32 Range;
+  UInt32 Code;
+  UInt32 Low;
+  IByteIn *Stream;
+} CPpmd7_RangeDec;
+
+
+typedef struct
+{
+  UInt32 Range;
+  Byte Cache;
+  // Byte _dummy_[3];
+  UInt64 Low;
+  UInt64 CacheSize;
+  IByteOut *Stream;
+} CPpmd7z_RangeEnc;
+
 
 typedef struct
 {
@@ -48,17 +79,30 @@ typedef struct
 
   UInt32 Size;
   UInt32 GlueCount;
-  Byte *Base, *LoUnit, *HiUnit, *Text, *UnitsStart;
   UInt32 AlignOffset;
+  Byte *Base, *LoUnit, *HiUnit, *Text, *UnitsStart;
 
-  Byte Indx2Units[PPMD_NUM_INDEXES];
+
+  
+  
+  union
+  {
+    CPpmd7_RangeDec dec;
+    CPpmd7z_RangeEnc enc;
+  } rc;
+  
+  Byte Indx2Units[PPMD_NUM_INDEXES + 2]; // +2 for alignment
   Byte Units2Indx[128];
   CPpmd_Void_Ref FreeList[PPMD_NUM_INDEXES];
-  Byte NS2Indx[256], NS2BSIndx[256], HB2Flag[256];
+
+  Byte NS2BSIndx[256], NS2Indx[256];
+  Byte ExpEscape[16];
   CPpmd_See DummySee, See[25][16];
   UInt16 BinSumm[128][64];
+  // int LastSymbol;
 } CPpmd7;
 
+
 void Ppmd7_Construct(CPpmd7 *p);
 BoolInt Ppmd7_Alloc(CPpmd7 *p, UInt32 size, ISzAllocPtr alloc);
 void Ppmd7_Free(CPpmd7 *p, ISzAllocPtr alloc);
@@ -68,74 +112,69 @@ void Ppmd7_Init(CPpmd7 *p, unsigned maxOrder);
 
 /* ---------- Internal Functions ---------- */
 
-extern const Byte PPMD7_kExpEscape[16];
-
-#ifdef PPMD_32BIT
-  #define Ppmd7_GetPtr(p, ptr) (ptr)
-  #define Ppmd7_GetContext(p, ptr) (ptr)
-  #define Ppmd7_GetStats(p, ctx) ((ctx)->Stats)
-#else
-  #define Ppmd7_GetPtr(p, offs) ((void *)((p)->Base + (offs)))
-  #define Ppmd7_GetContext(p, offs) ((CPpmd7_Context *)Ppmd7_GetPtr((p), (offs)))
-  #define Ppmd7_GetStats(p, ctx) ((CPpmd_State *)Ppmd7_GetPtr((p), ((ctx)->Stats)))
-#endif
+#define Ppmd7_GetPtr(p, ptr)     Ppmd_GetPtr(p, ptr)
+#define Ppmd7_GetContext(p, ptr) Ppmd_GetPtr_Type(p, ptr, CPpmd7_Context)
+#define Ppmd7_GetStats(p, ctx)   Ppmd_GetPtr_Type(p, (ctx)->Union4.Stats, CPpmd_State)
 
 void Ppmd7_Update1(CPpmd7 *p);
 void Ppmd7_Update1_0(CPpmd7 *p);
 void Ppmd7_Update2(CPpmd7 *p);
-void Ppmd7_UpdateBin(CPpmd7 *p);
+
+#define PPMD7_HiBitsFlag_3(sym) ((((unsigned)sym + 0xC0) >> (8 - 3)) & (1 << 3))
+#define PPMD7_HiBitsFlag_4(sym) ((((unsigned)sym + 0xC0) >> (8 - 4)) & (1 << 4))
+// #define PPMD7_HiBitsFlag_3(sym) ((sym) < 0x40 ? 0 : (1 << 3))
+// #define PPMD7_HiBitsFlag_4(sym) ((sym) < 0x40 ? 0 : (1 << 4))
 
 #define Ppmd7_GetBinSumm(p) \
-    &p->BinSumm[(size_t)(unsigned)Ppmd7Context_OneState(p->MinContext)->Freq - 1][p->PrevSuccess + \
-    p->NS2BSIndx[(size_t)Ppmd7_GetContext(p, p->MinContext->Suffix)->NumStats - 1] + \
-    (p->HiBitsFlag = p->HB2Flag[p->FoundState->Symbol]) + \
-    2 * p->HB2Flag[(unsigned)Ppmd7Context_OneState(p->MinContext)->Symbol] + \
-    ((p->RunLength >> 26) & 0x20)]
+    &p->BinSumm[(size_t)(unsigned)Ppmd7Context_OneState(p->MinContext)->Freq - 1] \
+    [ p->PrevSuccess + ((p->RunLength >> 26) & 0x20) \
+    + p->NS2BSIndx[(size_t)Ppmd7_GetContext(p, p->MinContext->Suffix)->NumStats - 1] \
+    + PPMD7_HiBitsFlag_4(Ppmd7Context_OneState(p->MinContext)->Symbol) \
+    + (p->HiBitsFlag = PPMD7_HiBitsFlag_3(p->FoundState->Symbol)) ]
 
 CPpmd_See *Ppmd7_MakeEscFreq(CPpmd7 *p, unsigned numMasked, UInt32 *scale);
 
 
+/*
+We support two versions of Ppmd7 (PPMdH) methods that use same CPpmd7 structure:
+  1) Ppmd7a_*: original PPMdH
+  2) Ppmd7z_*: modified PPMdH with 7z Range Coder
+Ppmd7_*: the structures and functions that are common for both versions of PPMd7 (PPMdH)
+*/
+
 /* ---------- Decode ---------- */
 
-typedef struct IPpmd7_RangeDec IPpmd7_RangeDec;
+#define PPMD7_SYM_END    (-1)
+#define PPMD7_SYM_ERROR  (-2)
 
-struct IPpmd7_RangeDec
-{
-  UInt32 (*GetThreshold)(const IPpmd7_RangeDec *p, UInt32 total);
-  void (*Decode)(const IPpmd7_RangeDec *p, UInt32 start, UInt32 size);
-  UInt32 (*DecodeBit)(const IPpmd7_RangeDec *p, UInt32 size0);
-};
+/*
+You must set (CPpmd7::rc.dec.Stream) before Ppmd7*_RangeDec_Init()
 
-typedef struct
-{
-  IPpmd7_RangeDec vt;
-  UInt32 Range;
-  UInt32 Code;
-  IByteIn *Stream;
-} CPpmd7z_RangeDec;
+Ppmd7*_DecodeSymbol()
+out:
+  >= 0 : decoded byte
+    -1 : PPMD7_SYM_END   : End of payload marker
+    -2 : PPMD7_SYM_ERROR : Data error
+*/
 
-void Ppmd7z_RangeDec_CreateVTable(CPpmd7z_RangeDec *p);
-BoolInt Ppmd7z_RangeDec_Init(CPpmd7z_RangeDec *p);
+/* Ppmd7a_* : original PPMdH */
+BoolInt Ppmd7a_RangeDec_Init(CPpmd7_RangeDec *p);
+#define Ppmd7a_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
+int Ppmd7a_DecodeSymbol(CPpmd7 *p);
+
+/* Ppmd7z_* : modified PPMdH with 7z Range Coder */
+BoolInt Ppmd7z_RangeDec_Init(CPpmd7_RangeDec *p);
 #define Ppmd7z_RangeDec_IsFinishedOK(p) ((p)->Code == 0)
-
-int Ppmd7_DecodeSymbol(CPpmd7 *p, const IPpmd7_RangeDec *rc);
+int Ppmd7z_DecodeSymbol(CPpmd7 *p);
+// Byte *Ppmd7z_DecodeSymbols(CPpmd7 *p, Byte *buf, const Byte *lim);
 
 
 /* ---------- Encode ---------- */
 
-typedef struct
-{
-  UInt64 Low;
-  UInt32 Range;
-  Byte Cache;
-  UInt64 CacheSize;
-  IByteOut *Stream;
-} CPpmd7z_RangeEnc;
-
-void Ppmd7z_RangeEnc_Init(CPpmd7z_RangeEnc *p);
-void Ppmd7z_RangeEnc_FlushData(CPpmd7z_RangeEnc *p);
-
-void Ppmd7_EncodeSymbol(CPpmd7 *p, CPpmd7z_RangeEnc *rc, int symbol);
+void Ppmd7z_Init_RangeEnc(CPpmd7 *p);
+void Ppmd7z_Flush_RangeEnc(CPpmd7 *p);
+// void Ppmd7z_EncodeSymbol(CPpmd7 *p, int symbol);
+void Ppmd7z_EncodeSymbols(CPpmd7 *p, const Byte *buf, const Byte *lim);
 
 EXTERN_C_END