lzma encoding support using LZMA SDK. Original lzma executable decompresses faster than this code. I have no idea why.

Makefile.config.in

@@ -127,6 +127,7 @@ CONFIG_INTERLINK = @CONFIG_INTERLINK@
 CONFIG_IPV6 = @CONFIG_IPV6@
 CONFIG_JW = @CONFIG_JW@
 CONFIG_LEDS = @CONFIG_LEDS@
+CONFIG_LZMA = @CONFIG_LZMA@
 CONFIG_MAILCAP = @CONFIG_MAILCAP@
 CONFIG_MANUAL = @CONFIG_MANUAL@
 CONFIG_MARKS = @CONFIG_MARKS@

configure.in

@@ -450,6 +450,8 @@ if test "x{with_gc}" != xno; then
 		[  --with-gc            enable Boehm's garbage collector])
 fi
 
+EL_ARG_ENABLE(CONFIG_LZMA, lzma, [lzma],
+	      [  --enable-lzma          enable lzma encoding support])
 dnl ===================================================================
 dnl Bookmark and XBEL support
 dnl ===================================================================

src/encoding/LzmaDecode.c

@@ -0,0 +1,588 @@
+/*
+  LzmaDecode.c
+  LZMA Decoder (optimized for Speed version)
+  
+  LZMA SDK 4.22 Copyright (c) 1999-2005 Igor Pavlov (2005-06-10)
+  http://www.7-zip.org/
+
+  LZMA SDK is licensed under two licenses:
+  1) GNU Lesser General Public License (GNU LGPL)
+  2) Common Public License (CPL)
+  It means that you can select one of these two licenses and 
+  follow rules of that license.
+
+  SPECIAL EXCEPTION:
+  Igor Pavlov, as the author of this Code, expressly permits you to 
+  statically or dynamically link your Code (or bind by name) to the 
+  interfaces of this file without subjecting your linked Code to the 
+  terms of the CPL or GNU LGPL. Any modifications or additions 
+  to this file, however, are subject to the LGPL or CPL terms.
+*/
+
+#include "encoding/LzmaDecode.h"
+
+#ifndef Byte
+#define Byte unsigned char
+#endif
+
+#define kNumTopBits 24
+#define kTopValue ((UInt32)1 << kNumTopBits)
+
+#define kNumBitModelTotalBits 11
+#define kBitModelTotal (1 << kNumBitModelTotalBits)
+#define kNumMoveBits 5
+
+#define RC_READ_BYTE (*Buffer++)
+
+#define RC_INIT2 Code = 0; Range = 0xFFFFFFFF; \
+  { int i; for(i = 0; i < 5; i++) { RC_TEST; Code = (Code << 8) | RC_READ_BYTE; }}
+
+#ifdef _LZMA_IN_CB
+
+#define RC_TEST { if (Buffer == BufferLim) \
+  { SizeT size; int result = InCallback->Read(InCallback, &Buffer, &size); if (result != LZMA_RESULT_OK) return result; \
+  BufferLim = Buffer + size; if (size == 0) return LZMA_RESULT_DATA_ERROR; }}
+
+#define RC_INIT Buffer = BufferLim = 0; RC_INIT2
+
+#else
+
+#define RC_TEST { if (Buffer == BufferLim) return LZMA_RESULT_DATA_ERROR; }
+
+#define RC_INIT(buffer, bufferSize) Buffer = buffer; BufferLim = buffer + bufferSize; RC_INIT2
+ 
+#endif
+
+#define RC_NORMALIZE if (Range < kTopValue) { RC_TEST; Range <<= 8; Code = (Code << 8) | RC_READ_BYTE; }
+
+#define IfBit0(p) RC_NORMALIZE; bound = (Range >> kNumBitModelTotalBits) * *(p); if (Code < bound)
+#define UpdateBit0(p) Range = bound; *(p) += (kBitModelTotal - *(p)) >> kNumMoveBits;
+#define UpdateBit1(p) Range -= bound; Code -= bound; *(p) -= (*(p)) >> kNumMoveBits;
+
+#define RC_GET_BIT2(p, mi, A0, A1) IfBit0(p) \
+  { UpdateBit0(p); mi <<= 1; A0; } else \
+  { UpdateBit1(p); mi = (mi + mi) + 1; A1; } 
+  
+#define RC_GET_BIT(p, mi) RC_GET_BIT2(p, mi, ; , ;)               
+
+#define RangeDecoderBitTreeDecode(probs, numLevels, res) \
+  { int i = numLevels; res = 1; \
+  do { CProb *p = probs + res; RC_GET_BIT(p, res) } while(--i != 0); \
+  res -= (1 << numLevels); }
+
+
+#define kNumPosBitsMax 4
+#define kNumPosStatesMax (1 << kNumPosBitsMax)
+
+#define kLenNumLowBits 3
+#define kLenNumLowSymbols (1 << kLenNumLowBits)
+#define kLenNumMidBits 3
+#define kLenNumMidSymbols (1 << kLenNumMidBits)
+#define kLenNumHighBits 8
+#define kLenNumHighSymbols (1 << kLenNumHighBits)
+
+#define LenChoice 0
+#define LenChoice2 (LenChoice + 1)
+#define LenLow (LenChoice2 + 1)
+#define LenMid (LenLow + (kNumPosStatesMax << kLenNumLowBits))
+#define LenHigh (LenMid + (kNumPosStatesMax << kLenNumMidBits))
+#define kNumLenProbs (LenHigh + kLenNumHighSymbols) 
+
+
+#define kNumStates 12
+#define kNumLitStates 7
+
+#define kStartPosModelIndex 4
+#define kEndPosModelIndex 14
+#define kNumFullDistances (1 << (kEndPosModelIndex >> 1))
+
+#define kNumPosSlotBits 6
+#define kNumLenToPosStates 4
+
+#define kNumAlignBits 4
+#define kAlignTableSize (1 << kNumAlignBits)
+
+#define kMatchMinLen 2
+
+#define IsMatch 0
+#define IsRep (IsMatch + (kNumStates << kNumPosBitsMax))
+#define IsRepG0 (IsRep + kNumStates)
+#define IsRepG1 (IsRepG0 + kNumStates)
+#define IsRepG2 (IsRepG1 + kNumStates)
+#define IsRep0Long (IsRepG2 + kNumStates)
+#define PosSlot (IsRep0Long + (kNumStates << kNumPosBitsMax))
+#define SpecPos (PosSlot + (kNumLenToPosStates << kNumPosSlotBits))
+#define Align (SpecPos + kNumFullDistances - kEndPosModelIndex)
+#define LenCoder (Align + kAlignTableSize)
+#define RepLenCoder (LenCoder + kNumLenProbs)
+#define Literal (RepLenCoder + kNumLenProbs)
+
+#if Literal != LZMA_BASE_SIZE
+StopCompilingDueBUG
+#endif
+
+int LzmaDecodeProperties(CLzmaProperties *propsRes, const unsigned char *propsData, int size)
+{
+  unsigned char prop0;
+  if (size < LZMA_PROPERTIES_SIZE)
+    return LZMA_RESULT_DATA_ERROR;
+  prop0 = propsData[0];
+  if (prop0 >= (9 * 5 * 5))
+    return LZMA_RESULT_DATA_ERROR;
+  {
+    for (propsRes->pb = 0; prop0 >= (9 * 5); propsRes->pb++, prop0 -= (9 * 5));
+    for (propsRes->lp = 0; prop0 >= 9; propsRes->lp++, prop0 -= 9);
+    propsRes->lc = prop0;
+    /*
+    unsigned char remainder = (unsigned char)(prop0 / 9);
+    propsRes->lc = prop0 % 9;
+    propsRes->pb = remainder / 5;
+    propsRes->lp = remainder % 5;
+    */
+  }
+
+  #ifdef _LZMA_OUT_READ
+  {
+    int i;
+    propsRes->DictionarySize = 0;
+    for (i = 0; i < 4; i++)
+      propsRes->DictionarySize += (UInt32)(propsData[1 + i]) << (i * 8);
+    if (propsRes->DictionarySize == 0)
+      propsRes->DictionarySize = 1;
+  }
+  #endif
+  return LZMA_RESULT_OK;
+}
+
+#define kLzmaStreamWasFinishedId (-1)
+
+int LzmaDecode(CLzmaDecoderState *vs,
+    #ifdef _LZMA_IN_CB
+    ILzmaInCallback *InCallback,
+    #else
+    const unsigned char *inStream, SizeT inSize, SizeT *inSizeProcessed,
+    #endif
+    unsigned char *outStream, SizeT outSize, SizeT *outSizeProcessed)
+{
+  CProb *p = vs->Probs;
+  SizeT nowPos = 0;
+  Byte previousByte = 0;
+  UInt32 posStateMask = (1 << (vs->Properties.pb)) - 1;
+  UInt32 literalPosMask = (1 << (vs->Properties.lp)) - 1;
+  int lc = vs->Properties.lc;
+
+  #ifdef _LZMA_OUT_READ
+  
+  UInt32 Range = vs->Range;
+  UInt32 Code = vs->Code;
+  #ifdef _LZMA_IN_CB
+  const Byte *Buffer = vs->Buffer;
+  const Byte *BufferLim = vs->BufferLim;
+  #else
+  const Byte *Buffer = inStream;
+  const Byte *BufferLim = inStream + inSize;
+  #endif
+  int state = vs->State;
+  UInt32 rep0 = vs->Reps[0], rep1 = vs->Reps[1], rep2 = vs->Reps[2], rep3 = vs->Reps[3];
+  int len = vs->RemainLen;
+  UInt32 globalPos = vs->GlobalPos;
+  UInt32 distanceLimit = vs->DistanceLimit;
+
+  Byte *dictionary = vs->Dictionary;
+  UInt32 dictionarySize = vs->Properties.DictionarySize;
+  UInt32 dictionaryPos = vs->DictionaryPos;
+
+  Byte tempDictionary[4];
+
+  #ifndef _LZMA_IN_CB
+  *inSizeProcessed = 0;
+  #endif
+  *outSizeProcessed = 0;
+  if (len == kLzmaStreamWasFinishedId)
+    return LZMA_RESULT_OK;
+
+  if (dictionarySize == 0)
+  {
+    dictionary = tempDictionary;
+    dictionarySize = 1;
+    tempDictionary[0] = vs->TempDictionary[0];
+  }
+
+  if (len == kLzmaNeedInitId)
+  {
+    {
+      UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (lc + vs->Properties.lp));
+      UInt32 i;
+      for (i = 0; i < numProbs; i++)
+        p[i] = kBitModelTotal >> 1; 
+      rep0 = rep1 = rep2 = rep3 = 1;
+      state = 0;
+      globalPos = 0;
+      distanceLimit = 0;
+      dictionaryPos = 0;
+      dictionary[dictionarySize - 1] = 0;
+      #ifdef _LZMA_IN_CB
+      RC_INIT;
+      #else
+      RC_INIT(inStream, inSize);
+      #endif
+    }
+    len = 0;
+  }
+  while(len != 0 && nowPos < outSize)
+  {
+    UInt32 pos = dictionaryPos - rep0;
+    if (pos >= dictionarySize)
+      pos += dictionarySize;
+    outStream[nowPos++] = dictionary[dictionaryPos] = dictionary[pos];
+    if (++dictionaryPos == dictionarySize)
+      dictionaryPos = 0;
+    len--;
+  }
+  if (dictionaryPos == 0)
+    previousByte = dictionary[dictionarySize - 1];
+  else
+    previousByte = dictionary[dictionaryPos - 1];
+
+  #else /* if !_LZMA_OUT_READ */
+
+  int state = 0;
+  UInt32 rep0 = 1, rep1 = 1, rep2 = 1, rep3 = 1;
+  int len = 0;
+  const Byte *Buffer;
+  const Byte *BufferLim;
+  UInt32 Range;
+  UInt32 Code;
+
+  #ifndef _LZMA_IN_CB
+  *inSizeProcessed = 0;
+  #endif
+  *outSizeProcessed = 0;
+
+  {
+    UInt32 i;
+    UInt32 numProbs = Literal + ((UInt32)LZMA_LIT_SIZE << (lc + vs->Properties.lp));
+    for (i = 0; i < numProbs; i++)
+      p[i] = kBitModelTotal >> 1;
+  }
+  
+  #ifdef _LZMA_IN_CB
+  RC_INIT;
+  #else
+  RC_INIT(inStream, inSize);
+  #endif
+
+  #endif /* _LZMA_OUT_READ */
+
+  while(nowPos < outSize)
+  {
+    CProb *prob;
+    UInt32 bound;
+    int posState = (int)(
+        (nowPos 
+        #ifdef _LZMA_OUT_READ
+        + globalPos
+        #endif
+        )
+        & posStateMask);
+
+    prob = p + IsMatch + (state << kNumPosBitsMax) + posState;
+    IfBit0(prob)
+    {
+      int symbol = 1;
+      UpdateBit0(prob)
+      prob = p + Literal + (LZMA_LIT_SIZE * 
+        (((
+        (nowPos 
+        #ifdef _LZMA_OUT_READ
+        + globalPos
+        #endif
+        )
+        & literalPosMask) << lc) + (previousByte >> (8 - lc))));
+
+      if (state >= kNumLitStates)
+      {
+        int matchByte;
+        #ifdef _LZMA_OUT_READ
+        UInt32 pos = dictionaryPos - rep0;
+        if (pos >= dictionarySize)
+          pos += dictionarySize;
+        matchByte = dictionary[pos];
+        #else
+        matchByte = outStream[nowPos - rep0];
+        #endif
+        do
+        {
+          int bit;
+          CProb *probLit;
+          matchByte <<= 1;
+          bit = (matchByte & 0x100);
+          probLit = prob + 0x100 + bit + symbol;
+          RC_GET_BIT2(probLit, symbol, if (bit != 0) break, if (bit == 0) break)
+        }
+        while (symbol < 0x100);
+      }
+      while (symbol < 0x100)
+      {
+        CProb *probLit = prob + symbol;
+        RC_GET_BIT(probLit, symbol)
+      }
+      previousByte = (Byte)symbol;
+
+      outStream[nowPos++] = previousByte;
+      #ifdef _LZMA_OUT_READ
+      if (distanceLimit < dictionarySize)
+        distanceLimit++;
+
+      dictionary[dictionaryPos] = previousByte;
+      if (++dictionaryPos == dictionarySize)
+        dictionaryPos = 0;
+      #endif
+      if (state < 4) state = 0;
+      else if (state < 10) state -= 3;
+      else state -= 6;
+    }
+    else             
+    {
+      UpdateBit1(prob);
+      prob = p + IsRep + state;
+      IfBit0(prob)
+      {
+        UpdateBit0(prob);
+        rep3 = rep2;
+        rep2 = rep1;
+        rep1 = rep0;
+        state = state < kNumLitStates ? 0 : 3;
+        prob = p + LenCoder;
+      }
+      else
+      {
+        UpdateBit1(prob);
+        prob = p + IsRepG0 + state;
+        IfBit0(prob)
+        {
+          UpdateBit0(prob);
+          prob = p + IsRep0Long + (state << kNumPosBitsMax) + posState;
+          IfBit0(prob)
+          {
+            #ifdef _LZMA_OUT_READ
+            UInt32 pos;
+            #endif
+            UpdateBit0(prob);
+            
+            #ifdef _LZMA_OUT_READ
+            if (distanceLimit == 0)
+            #else
+            if (nowPos == 0)
+            #endif
+              return LZMA_RESULT_DATA_ERROR;
+            
+            state = state < kNumLitStates ? 9 : 11;
+            #ifdef _LZMA_OUT_READ
+            pos = dictionaryPos - rep0;
+            if (pos >= dictionarySize)
+              pos += dictionarySize;
+            previousByte = dictionary[pos];
+            dictionary[dictionaryPos] = previousByte;
+            if (++dictionaryPos == dictionarySize)
+              dictionaryPos = 0;
+            #else
+            previousByte = outStream[nowPos - rep0];
+            #endif
+            outStream[nowPos++] = previousByte;
+            #ifdef _LZMA_OUT_READ
+            if (distanceLimit < dictionarySize)
+              distanceLimit++;
+            #endif
+
+            continue;
+          }
+          else
+          {
+            UpdateBit1(prob);
+          }
+        }
+        else
+        {
+          UInt32 distance;
+          UpdateBit1(prob);
+          prob = p + IsRepG1 + state;
+          IfBit0(prob)
+          {
+            UpdateBit0(prob);
+            distance = rep1;
+          }
+          else 
+          {
+            UpdateBit1(prob);
+            prob = p + IsRepG2 + state;
+            IfBit0(prob)
+            {
+              UpdateBit0(prob);
+              distance = rep2;
+            }
+            else
+            {
+              UpdateBit1(prob);
+              distance = rep3;
+              rep3 = rep2;
+            }
+            rep2 = rep1;
+          }
+          rep1 = rep0;
+          rep0 = distance;
+        }
+        state = state < kNumLitStates ? 8 : 11;
+        prob = p + RepLenCoder;
+      }
+      {
+        int numBits, offset;
+        CProb *probLen = prob + LenChoice;
+        IfBit0(probLen)
+        {
+          UpdateBit0(probLen);
+          probLen = prob + LenLow + (posState << kLenNumLowBits);
+          offset = 0;
+          numBits = kLenNumLowBits;
+        }
+        else
+        {
+          UpdateBit1(probLen);
+          probLen = prob + LenChoice2;
+          IfBit0(probLen)
+          {
+            UpdateBit0(probLen);
+            probLen = prob + LenMid + (posState << kLenNumMidBits);
+            offset = kLenNumLowSymbols;
+            numBits = kLenNumMidBits;
+          }
+          else
+          {
+            UpdateBit1(probLen);
+            probLen = prob + LenHigh;
+            offset = kLenNumLowSymbols + kLenNumMidSymbols;
+            numBits = kLenNumHighBits;
+          }
+        }
+        RangeDecoderBitTreeDecode(probLen, numBits, len);
+        len += offset;
+      }
+
+      if (state < 4)
+      {
+        int posSlot;
+        state += kNumLitStates;
+        prob = p + PosSlot +
+            ((len < kNumLenToPosStates ? len : kNumLenToPosStates - 1) << 
+            kNumPosSlotBits);
+        RangeDecoderBitTreeDecode(prob, kNumPosSlotBits, posSlot);
+        if (posSlot >= kStartPosModelIndex)
+        {
+          int numDirectBits = ((posSlot >> 1) - 1);
+          rep0 = (2 | ((UInt32)posSlot & 1));
+          if (posSlot < kEndPosModelIndex)
+          {
+            rep0 <<= numDirectBits;
+            prob = p + SpecPos + rep0 - posSlot - 1;
+          }
+          else
+          {
+            numDirectBits -= kNumAlignBits;
+            do
+            {
+              RC_NORMALIZE
+              Range >>= 1;
+              rep0 <<= 1;
+              if (Code >= Range)
+              {
+                Code -= Range;
+                rep0 |= 1;
+              }
+            }
+            while (--numDirectBits != 0);
+            prob = p + Align;
+            rep0 <<= kNumAlignBits;
+            numDirectBits = kNumAlignBits;
+          }
+          {
+            int i = 1;
+            int mi = 1;
+            do
+            {
+              CProb *prob3 = prob + mi;
+              RC_GET_BIT2(prob3, mi, ; , rep0 |= i);
+              i <<= 1;
+            }
+            while(--numDirectBits != 0);
+          }
+        }
+        else
+          rep0 = posSlot;
+        if (++rep0 == (UInt32)(0))
+        {
+          /* it's for stream version */
+          len = kLzmaStreamWasFinishedId;
+          break;
+        }
+      }
+
+      len += kMatchMinLen;
+      #ifdef _LZMA_OUT_READ
+      if (rep0 > distanceLimit) 
+      #else
+      if (rep0 > nowPos)
+      #endif
+        return LZMA_RESULT_DATA_ERROR;
+
+      #ifdef _LZMA_OUT_READ
+      if (dictionarySize - distanceLimit > (UInt32)len)
+        distanceLimit += len;
+      else
+        distanceLimit = dictionarySize;
+      #endif
+
+      do
+      {
+        #ifdef _LZMA_OUT_READ
+        UInt32 pos = dictionaryPos - rep0;
+        if (pos >= dictionarySize)
+          pos += dictionarySize;
+        previousByte = dictionary[pos];
+        dictionary[dictionaryPos] = previousByte;
+        if (++dictionaryPos == dictionarySize)
+          dictionaryPos = 0;
+        #else
+        previousByte = outStream[nowPos - rep0];
+        #endif
+        len--;
+        outStream[nowPos++] = previousByte;
+      }
+      while(len != 0 && nowPos < outSize);
+    }
+  }
+  RC_NORMALIZE;
+
+  #ifdef _LZMA_OUT_READ
+  vs->Range = Range;
+  vs->Code = Code;
+  vs->DictionaryPos = dictionaryPos;
+  vs->GlobalPos = globalPos + (UInt32)nowPos;
+  vs->DistanceLimit = distanceLimit;
+  vs->Reps[0] = rep0;
+  vs->Reps[1] = rep1;
+  vs->Reps[2] = rep2;
+  vs->Reps[3] = rep3;
+  vs->State = state;
+  vs->RemainLen = len;
+  vs->TempDictionary[0] = tempDictionary[0];
+  #endif
+
+  #ifdef _LZMA_IN_CB
+  vs->Buffer = Buffer;
+  vs->BufferLim = BufferLim;
+  #else
+  *inSizeProcessed = (SizeT)(Buffer - inStream);
+  #endif
+  *outSizeProcessed = nowPos;
+  return LZMA_RESULT_OK;
+}

src/encoding/LzmaDecode.h

@@ -0,0 +1,131 @@
+/* 
+  LzmaDecode.h
+  LZMA Decoder interface
+
+  LZMA SDK 4.21 Copyright (c) 1999-2005 Igor Pavlov (2005-06-08)
+  http://www.7-zip.org/
+
+  LZMA SDK is licensed under two licenses:
+  1) GNU Lesser General Public License (GNU LGPL)
+  2) Common Public License (CPL)
+  It means that you can select one of these two licenses and 
+  follow rules of that license.
+
+  SPECIAL EXCEPTION:
+  Igor Pavlov, as the author of this code, expressly permits you to 
+  statically or dynamically link your code (or bind by name) to the 
+  interfaces of this file without subjecting your linked code to the 
+  terms of the CPL or GNU LGPL. Any modifications or additions 
+  to this file, however, are subject to the LGPL or CPL terms.
+*/
+
+#ifndef __LZMADECODE_H
+#define __LZMADECODE_H
+
+/* #define _LZMA_IN_CB */
+/* Use callback for input data */
+
+/* #define _LZMA_OUT_READ */
+/* Use read function for output data */
+
+/* #define _LZMA_PROB32 */
+/* It can increase speed on some 32-bit CPUs, 
+   but memory usage will be doubled in that case */
+
+#define _LZMA_LOC_OPT 1
+/* Enable local speed optimizations inside code */
+
+/* #define _LZMA_SYSTEM_SIZE_T */
+/* Use system's size_t. You can use it to enable 64-bit sizes supporting*/
+
+#ifndef UInt32
+#ifdef _LZMA_UINT32_IS_ULONG
+#define UInt32 unsigned long
+#else
+#define UInt32 unsigned int
+#endif
+#endif
+
+#ifndef SizeT
+#ifdef _LZMA_SYSTEM_SIZE_T
+#include <stddef.h>
+#define SizeT size_t
+#else
+#define SizeT UInt32
+#endif
+#endif
+
+#ifdef _LZMA_PROB32
+#define CProb UInt32
+#else
+#define CProb unsigned short
+#endif
+
+#define LZMA_RESULT_OK 0
+#define LZMA_RESULT_DATA_ERROR 1
+
+#ifdef _LZMA_IN_CB
+typedef struct _ILzmaInCallback
+{
+  int (*Read)(void *object, const unsigned char **buffer, SizeT *bufferSize);
+} ILzmaInCallback;
+#endif
+
+#define LZMA_BASE_SIZE 1846
+#define LZMA_LIT_SIZE 768
+
+#define LZMA_PROPERTIES_SIZE 5
+
+typedef struct _CLzmaProperties
+{
+  int lc;
+  int lp;
+  int pb;
+  #ifdef _LZMA_OUT_READ
+  UInt32 DictionarySize;
+  #endif
+}CLzmaProperties;
+
+int LzmaDecodeProperties(CLzmaProperties *propsRes, const unsigned char *propsData, int size);
+
+#define LzmaGetNumProbs(Properties) (LZMA_BASE_SIZE + (LZMA_LIT_SIZE << ((Properties)->lc + (Properties)->lp)))
+
+#define kLzmaNeedInitId (-2)
+
+typedef struct _CLzmaDecoderState
+{
+  CLzmaProperties Properties;
+  CProb *Probs;
+
+  #ifdef _LZMA_IN_CB
+  const unsigned char *Buffer;
+  const unsigned char *BufferLim;
+  #endif
+
+  #ifdef _LZMA_OUT_READ
+  unsigned char *Dictionary;
+  UInt32 Range;
+  UInt32 Code;
+  UInt32 DictionaryPos;
+  UInt32 GlobalPos;
+  UInt32 DistanceLimit;
+  UInt32 Reps[4];
+  int State;
+  int RemainLen;
+  unsigned char TempDictionary[4];
+  #endif
+} CLzmaDecoderState;
+
+#ifdef _LZMA_OUT_READ
+#define LzmaDecoderInit(vs) { (vs)->RemainLen = kLzmaNeedInitId; }
+#endif
+
+int LzmaDecode(CLzmaDecoderState *vs,
+    #ifdef _LZMA_IN_CB
+    ILzmaInCallback *inCallback,
+    #else
+    const unsigned char *inStream, SizeT inSize, SizeT *inSizeProcessed,
+    #endif
+    unsigned char *outStream, SizeT outSize, SizeT *outSizeProcessed);
+
+#endif

src/encoding/Makefile

@@ -3,6 +3,7 @@ include $(top_builddir)/Makefile.config
 
 OBJS-$(CONFIG_BZIP2)	+= bzip2.o
 OBJS-$(CONFIG_GZIP)	+= gzip.o
+OBJS-$(CONFIG_LZMA)	+= lzma.o LzmaDecode.o
 
 OBJS = encoding.o
 

src/encoding/encoding.c

@@ -94,11 +94,13 @@ static struct decoding_backend dummy_decoding_backend = {
 
 #include "encoding/bzip2.h"
 #include "encoding/gzip.h"
+#include "encoding/lzma.h"
 
 static struct decoding_backend *decoding_backends[] = {
 	&dummy_decoding_backend,
 	&gzip_decoding_backend,
 	&bzip2_decoding_backend,
+	&lzma_decoding_backend,
 };
 
 

src/encoding/encoding.h

@@ -8,6 +8,7 @@ enum stream_encoding {
 	ENCODING_NONE = 0,
 	ENCODING_GZIP,
 	ENCODING_BZIP2,
+	ENCODING_LZMA,
 
 	/* Max. number of known encoding including ENCODING_NONE. */
 	ENCODINGS_KNOWN,

src/encoding/lzma.c

@@ -0,0 +1,208 @@
+/* lzma encoding (ENCODING_LZMA) backend */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include "elinks.h"
+
+#include "encoding/LzmaDecode.h"
+#include "encoding/encoding.h"
+#include "encoding/lzma.h"
+#include "util/memory.h"
+
+
+struct lzma_enc_data {
+	unsigned char *output;
+	off_t current;
+	off_t outSize;
+};
+
+static void
+lzma_cleanup(struct lzma_enc_data *data)
+{
+	mem_free_if(data->output);
+	mem_free(data);
+}
+
+static int
+lzma_open(struct stream_encoded *stream, int fd)
+{
+	CLzmaDecoderState state;
+	struct stat buf;
+	struct lzma_enc_data *data;
+	ssize_t nb;
+	size_t inSize, inProcessed, outProcessed;
+	int res;
+	unsigned char *input, *inData;
+	unsigned int i;
+
+	if (fstat(fd, &buf)) return -1;
+	if (!S_ISREG(buf.st_mode)) return -1;
+	if (buf.st_size < LZMA_PROPERTIES_SIZE + 8) return -1;
+	data = mem_calloc(1, sizeof(*data));
+	if (!data) return -1;
+	input = mem_alloc(buf.st_size);
+	if (!input) {
+		mem_free(data);
+		return -1;
+	}
+	nb = safe_read(fd, input, buf.st_size);
+	close(fd);
+	if (nb != buf.st_size) {
+		mem_free(input);
+		lzma_cleanup(data);
+		return -1;
+	}
+	if (LzmaDecodeProperties(&state.Properties, input,
+	    LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) {
+	    mem_free(input);
+	    lzma_cleanup(data);
+	    return -1;
+	}
+	state.Probs = (CProb *)mem_alloc(LzmaGetNumProbs(
+		             &state.Properties) * sizeof(CProb));
+	if (!state.Probs) {
+		mem_free(input);
+		lzma_cleanup(data);
+		return -1;
+	}
+	inSize = buf.st_size - LZMA_PROPERTIES_SIZE - 8;
+	inData = input + LZMA_PROPERTIES_SIZE;
+	data->outSize = 0;
+	if (inData[0] == 0xff) {
+		/* End of stream */
+		mem_free(state.Probs);
+		mem_free(input);
+		lzma_cleanup(data);
+		return -1;
+	}
+	/* The size is 8 bytes long, but who wants such big files */
+	for (i = 0; i < 4; i++) {
+		unsigned char b = inData[i];
+		data->outSize += (unsigned int)(b) << (i * 8);
+	}
+	data->output = mem_alloc(data->outSize);
+	if (!data->output) {
+		mem_free(state.Probs);
+		mem_free(input);
+		lzma_cleanup(data);
+		return -1;
+	}
+	inData += 8;
+	res = LzmaDecode(&state, inData, inSize, &inProcessed,
+		data->output, data->outSize, &outProcessed);
+	if (res) {
+		mem_free(state.Probs);
+		mem_free(input);
+		lzma_cleanup(data);
+		return -1;
+	}
+	data->outSize = outProcessed;
+	data->current = 0;
+	mem_free(input);
+	mem_free(state.Probs);
+	stream->data = data;
+
+	return 0;
+}
+
+static int
+lzma_read(struct stream_encoded *stream, unsigned char *buf, int len)
+{
+	struct lzma_enc_data *data = (struct lzma_enc_data *) stream->data;
+
+	if (data->current + len > data->outSize)
+		len = data->outSize - data->current;
+
+	if (len < 0) return -1;
+	memcpy(buf, data->output + data->current, len);
+	data->current += len;
+
+	return len;
+}
+
+static unsigned char *
+lzma_decode(struct stream_encoded *stream, unsigned char *data, int len,
+	     int *new_len)
+{
+	*new_len = len;
+	return data;
+}
+
+static unsigned char *
+lzma_decode_buffer(unsigned char *data, int len, int *new_len)
+{
+	CLzmaDecoderState state;
+	size_t inSize, inProcessed, outProcessed;
+	int res, outSize;
+	unsigned char *inData;
+	unsigned char *output;
+	unsigned int i;
+
+	if (len < LZMA_PROPERTIES_SIZE + 8) return NULL;
+	if (LzmaDecodeProperties(&state.Properties, data,
+	    LZMA_PROPERTIES_SIZE) != LZMA_RESULT_OK) {
+	    return NULL;
+	}
+	state.Probs = (CProb *)mem_alloc(LzmaGetNumProbs(
+		             &state.Properties) * sizeof(CProb));
+	if (!state.Probs) {
+		return NULL;
+	}
+	inSize = len - LZMA_PROPERTIES_SIZE - 8;
+	inData = data + LZMA_PROPERTIES_SIZE;
+	outSize = 0;
+	if (inData[0] == 0xff) {
+		/* End of stream */
+		mem_free(state.Probs);
+		return NULL;
+	}
+	for (i = 0; i < 4; i++) {
+		unsigned char b = inData[i];
+		outSize += (unsigned int)(b) << (i * 8);
+	}
+	output = mem_alloc(outSize);
+	if (!output) {
+		mem_free(state.Probs);
+		return NULL;
+	}
+	inData += 8;
+	res = LzmaDecode(&state, inData, inSize, &inProcessed, output,
+		outSize, &outProcessed);
+	if (res) {
+		mem_free(state.Probs);
+		mem_free(output);
+		return NULL;
+	}
+	*new_len = outProcessed;
+
+	return output;
+}
+
+static void
+lzma_close(struct stream_encoded *stream)
+{
+	struct lzma_enc_data *data = (struct lzma_enc_data *) stream->data;
+
+	lzma_cleanup(data);
+}
+
+static unsigned char *lzma_extensions[] = { ".lzma", NULL };
+
+struct decoding_backend lzma_decoding_backend = {
+	"lzma",
+	lzma_extensions,
+	lzma_open,
+	lzma_read,
+	lzma_decode,
+	lzma_decode_buffer,
+	lzma_close,
+};