urarlib.c

一个解RAR文件的开发库源码

  tseek(ArcPtr,NewMhd.HeadSize-MainHeadSize,SEEK_CUR);
#endif

  /* do while file is not extracted and there's no error                    */
  do
  {

    if (ReadBlock(FILE_HEAD | READSUBBLOCK) <= 0) /* read name of the next  */
    {                                       /* file within the RAR archive  */
/*
 * 
 * 21.11.2000  UnQ  There's a problem with some linux distros when a file
 *                  can not be found in an archive.
 *
 *    debug_log("Couldn't read next filename from archive (I/O error).");
 *
*/
      ReturnCode=FALSE;
      break;                                /* error, file not found in     */
    }                                       /* archive or I/O error         */
    if (BlockHead.HeadType==SUB_HEAD)
    {
      debug_log("Sorry, sub-headers not supported.");
      ReturnCode=FALSE;
      break;                                /* error => exit                */
    }


    if(TRUE == (FileFound=(stricomp(ArgName, ArcFileName) == 0)))
    /* *** file found! ***                                                  */
    {
      {
        temp_output_buffer=malloc(NewLhd.UnpSize);/* allocate memory for the*/
      }
      *temp_output_buffer_offset=0;         /* file. The default offset     */
                                            /* within the buffer is 0       */

      if(temp_output_buffer == NULL)
      {
        debug_log("can't allocate memory for the file decompression");
        ReturnCode=FALSE;
        break;                              /* error, can't extract file!   */
      }


    }

    /* in case of a solid archive, we need to decompress any single file till
     * we have found the one we are looking for. In case of normal archives 
     * (recommended!!), we skip the files until we are sure that it is the 
     * one we want.
     */
    if((NewMhd.Flags & 0x08) || FileFound)
    {
      if (NewLhd.UnpVer<13 || NewLhd.UnpVer>UNP_VER)
      {
        debug_log("unknown compression method");
        ReturnCode=FALSE;
        break;                              /* error, can't extract file!   */
      }

      CurUnpRead=CurUnpWrite=0;
      if ((*Password!=0) && (NewLhd.Flags & LHD_PASSWORD))
        Encryption=NewLhd.UnpVer;
      else
        Encryption=0;
      if (Encryption) SetCryptKeys(Password);

      UnpPackedSize=NewLhd.PackSize;
      DestUnpSize=NewLhd.UnpSize;

      if (NewLhd.Method==0x30)
      {
        UnstoreFile();
      } else
      {
        Unpack(UnpMemory);
      }


      
#ifdef _DO_CRC32_CHECK                      /* calculate CRC32              */
      if((UBYTE*)temp_output_buffer != NULL)
      {
        if(NewLhd.FileCRC!=~CalcCRC32(0xFFFFFFFFL,
                                      (UBYTE*)temp_output_buffer,
                                      NewLhd.UnpSize))
        {
          debug_log("CRC32 error - file couldn't be decompressed correctly!");
          ReturnCode=FALSE;
          break;                              /* error, can't extract file! */
        }
      }
#endif

    }

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
    MemRARFile->offset = NextBlockPos;
#else
    if (ArcPtr!=NULL) tseek(ArcPtr,NextBlockPos,SEEK_SET);
#endif
  } while(stricomp(ArgName, ArcFileName) != 0);/* exit if file is extracted */

  /* free memory, clear password and close archive                          */
  free(UnpMemory);
  UnpMemory=NULL;
#ifndef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  if (ArcPtr!=NULL){
      fclose(ArcPtr);
      ArcPtr = NULL;
  }
#endif

  return ReturnCode;                        /* file extracted successful!   */
}

/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */


















/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 *******             G L O B A L   F U N C T I O N S                  *******
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */


int tread(void *stream,void *buf,unsigned len)
{
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION

  if(((MemRARFile->offset + len) > MemRARFile->size) || (len == 0)) 
     return 0;

  memcpy(buf, 
         (BYTE*)(((MemoryFile*)stream)->data)+((MemoryFile*)stream)->offset,
         len % ((((MemoryFile*)stream)->size) - 1));

  MemRARFile->offset+=len;                  /* update read pointer          */
  return len % ((((MemoryFile*)stream)->size) - 1);
#else
  return(fread(buf,1,len,(FILE*)stream));
#endif
}


#ifndef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
int tseek(void *stream,long offset,int fromwhere)
{
  return(fseek((FILE*)stream,offset,fromwhere));
}
#endif


char* strupper(char *Str)
{
  char *ChPtr;
  for (ChPtr=Str;*ChPtr;ChPtr++)
    *ChPtr=(char)toupper(*ChPtr);
  return(Str);
}


int stricomp(char *Str1,char *Str2)
/* compare strings without regard of '\' and '/'                            */
{
  char S1[512],S2[512];
  char *chptr;

  strncpy(S1,Str1,sizeof(S1));
  strncpy(S2,Str2,sizeof(S2));

  while((chptr = strchr(S1, '\\')) != NULL) /* ignore backslash             */
  {
    *chptr = '_';
  }

  while((chptr = strchr(S2, '\\')) != NULL) /* ignore backslash             */
  {
    *chptr = '_';
  }
  
  while((chptr = strchr(S1, '/')) != NULL)  /* ignore slash                 */
  {
    *chptr = '_';
  }
   
  while((chptr = strchr(S2, '/')) != NULL)  /* ignore slash                 */
  {
    *chptr = '_';
  }

  return(strcmp(strupper(S1),strupper(S2)));
}


/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */


















/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 *******                   U N P A C K   C O D E                      *******
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */


/* *****************************
 * ** unpack stored RAR files **
 * *****************************/

BOOL UnstoreFile(void)
{
  if ((long)(*temp_output_buffer_offset=UnpRead(temp_output_buffer,
                                                NewLhd.UnpSize))==-1)
  {
    debug_log("Read error of stored file!");
    return FALSE;
  }
  return TRUE;
}




/* ****************************************
 * ** RAR decompression code starts here **
 * ****************************************/

#define NC 298                              /* alphabet = {0,1,2, .,NC - 1} */
#define DC 48
#define RC 28
#define BC 19
#define MC 257

enum {CODE_HUFFMAN=0,CODE_LZ=1,CODE_LZ2=2,CODE_REPEATLZ=3,CODE_CACHELZ=4,
      CODE_STARTFILE=5,CODE_ENDFILE=6,CODE_STARTMM=8,CODE_ENDMM=7,
      CODE_MMDELTA=9};

struct AudioVariables
{
  int K1,K2,K3,K4,K5;
  int D1,D2,D3,D4;
  int LastDelta;
  unsigned int Dif[11];
  unsigned int ByteCount;
  int LastChar;
};


#define NC 298  /* alphabet = {0, 1, 2, ..., NC - 1} */
#define DC 48
#define RC 28
#define BC 19
#define MC 257


struct AudioVariables AudV[4];

#define GetBits()                                                 \
        BitField = ( ( ( (UDWORD)InBuf[InAddr]   << 16 ) |        \
                       ( (UWORD) InBuf[InAddr+1] <<  8 ) |        \
                       (         InBuf[InAddr+2]       ) )        \
                       >> (8-InBit) ) & 0xffff;


#define AddBits(Bits)                          \
        InAddr += ( InBit + (Bits) ) >> 3;     \
        InBit  =  ( InBit + (Bits) ) &  7;

static unsigned char *UnpBuf;
static unsigned int BitField;
static unsigned int Number;

unsigned char InBuf[8192];                  /* input read buffer            */

unsigned char UnpOldTable[MC*4];

unsigned int InAddr,InBit,ReadTop;

unsigned int LastDist,LastLength;
static unsigned int Length,Distance;

unsigned int OldDist[4],OldDistPtr;


struct LitDecode
{
  unsigned int MaxNum;
  unsigned int DecodeLen[16];
  unsigned int DecodePos[16];
  unsigned int DecodeNum[NC];
} LD;

struct DistDecode
{
  unsigned int MaxNum;
  unsigned int DecodeLen[16];
  unsigned int DecodePos[16];
  unsigned int DecodeNum[DC];
} DD;

struct RepDecode
{
  unsigned int MaxNum;
  unsigned int DecodeLen[16];
  unsigned int DecodePos[16];
  unsigned int DecodeNum[RC];
} RD;

struct MultDecode
{
  unsigned int MaxNum;
  unsigned int DecodeLen[16];
  unsigned int DecodePos[16];
  unsigned int DecodeNum[MC];
} MD[4];

struct BitDecode
{
  unsigned int MaxNum;
  unsigned int DecodeLen[16];
  unsigned int DecodePos[16];
  unsigned int DecodeNum[BC];
} BD;

static struct MultDecode *MDPtr[4]={&MD[0],&MD[1],&MD[2],&MD[3]};

int UnpAudioBlock,UnpChannels,CurChannel,ChannelDelta;


void Unpack(unsigned char *UnpAddr)
/* *** 38.3% of all CPU time is spent within this function!!!               */
{
  static unsigned char LDecode[]={0,1,2,3,4,5,6,7,8,10,12,14,16,20,24,28,32,
                                  40,48,56,64,80,96,112,128,160,192,224};
  static unsigned char LBits[]=  {0,0,0,0,0,0,0,0,1,1,1,1,2,2,2,2,3,
                                  3,3,3,4,4,4,4,5,5,5,5};
  static int DDecode[]={0,1,2,3,4,6,8,12,16,24,32,48,64,96,128,192,256,384,
                        512,768,1024,1536,2048,3072,4096,6144,8192,12288,
                        16384,24576,32768U,49152U,65536,98304,131072,196608,
                        262144,327680,393216,458752,524288,589824,655360,
                        720896,786432,851968,917504,983040};
  static unsigned char DBits[]=  {0,0,0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,
                                  9,10,10,11,11,12,12,13,13,14,14,15,15,16,
                                  16,16,16,16,16,16,16,16,16,16,16,16,16};
  static unsigned char SDDecode[]={0,4,8,16,32,64,128,192};
  static unsigned char SDBits[]={2,2,3, 4, 5, 6,  6,  6};
  unsigned int Bits;


  UnpBuf=UnpAddr;                           /* UnpAddr is a pointer to the  */
  UnpInitData();                            /* unpack buffer                */
  UnpReadBuf(1);
  if (!(NewLhd.Flags & LHD_SOLID))
     ReadTables();
   DestUnpSize--;

  while (DestUnpSize>=0)
  {
    UnpPtr&=MAXWINMASK;

    if (InAddr>sizeof(InBuf)-30)
      UnpReadBuf(0);
    if (((WrPtr-UnpPtr) & MAXWINMASK)<270 && WrPtr!=UnpPtr)
    {

    
      if (FileFound)
      {

        if (UnpPtr<WrPtr)
        {
			if((*temp_output_buffer_offset + UnpPtr) > NewLhd.UnpSize)
			{
 			  debug_log("Fatal! Buffer overrun during decompression!");
			  DestUnpSize=-1;

		    } else
			{
              /* copy extracted data to output buffer                         */
              memcpy(temp_output_buffer + *temp_output_buffer_offset, 
                     &UnpBuf[WrPtr], (0-WrPtr) & MAXWINMASK);   
              /* update offset within buffer                                  */
              *temp_output_buffer_offset+= (0-WrPtr) & MAXWINMASK;
              /* copy extracted data to output buffer                         */
              memcpy(temp_output_buffer + *temp_output_buffer_offset, UnpBuf, 
                     UnpPtr);
              /* update offset within buffer                                  */
              *temp_output_buffer_offset+=UnpPtr;
			}
        } else
        {
			if((*temp_output_buffer_offset + (UnpPtr-WrPtr)) > NewLhd.UnpSize)
			{
	 		  debug_log("Fatal! Buffer overrun during decompression!");
			  DestUnpSize=-1;						
		    } else
			{
	          /* copy extracted data to output buffer                       */
              memcpy(temp_output_buffer + *temp_output_buffer_offset, 
                     &UnpBuf[WrPtr], UnpPtr-WrPtr);   
              *temp_output_buffer_offset+=UnpPtr-WrPtr;                                                /* update offset within buffer */
		    }