os2zip.c

压缩算法的源代码

  ULONG cbList;               /* length of value + 22 */
#ifdef __32BIT__
  ULONG oNext;
#endif
  BYTE fEA;                   /* 0 */
  BYTE cbName;                /* length of ".LONGNAME" = 9 */
  USHORT cbValue;             /* length of value + 4 */
  BYTE szName[10];            /* ".LONGNAME" */
  USHORT eaType;              /* 0xFFFD for length-preceded ASCII */
  USHORT eaSize;              /* length of value */
  BYTE szValue[CCHMAXPATH];
}
FEALST;

typedef struct
{
  ULONG cbList;
#ifdef __32BIT__
  ULONG oNext;
#endif
  BYTE cbName;
  BYTE szName[10];            /* ".LONGNAME" */
}
GEALST;


char *GetLongNameEA(char *name)
{
  EAOP eaop;
  GEALST gealst;
  static FEALST fealst;

  if ( _osmode == DOS_MODE )
    return NULL;

  eaop.fpGEAList = (PGEALIST) &gealst;
  eaop.fpFEAList = (PFEALIST) &fealst;
  eaop.oError = 0;

  strcpy(gealst.szName, ".LONGNAME");
  gealst.cbName  = (BYTE) strlen(gealst.szName);
#ifdef __32BIT__
  gealst.oNext   = 0;
#endif

  gealst.cbList  = sizeof(gealst);
  fealst.cbList  = sizeof(fealst);

  if ( DosQueryPathInfo(name, FIL_QUERYEASFROMLIST,
                        (PBYTE) &eaop, sizeof(eaop)) )
    return NULL;

  if ( fealst.cbValue > 4 && fealst.eaType == 0xFFFD )
  {
    fealst.szValue[fealst.eaSize] = 0;
    return fealst.szValue;
  }

  return NULL;
}


char *GetLongPathEA(char *name)
{
  static char nbuf[CCHMAXPATH + 1];
  char *comp, *next, *ea, sep;
  BOOL bFound = FALSE;

  nbuf[0] = 0;
  next = name;

  while ( *next )
  {
    comp = next;

    while ( *next != '\\' && *next != '/' && *next != 0 )
      next++;

    sep = *next;
    *next = 0;

    ea = GetLongNameEA(name);
    strcat(nbuf, ea ? ea : comp);
    bFound = bFound || (ea != NULL);

    *next = sep;

    if ( *next )
    {
      strcat(nbuf, "\\");
      next++;
    }
  }

  return nbuf[0] && bFound ? nbuf : NULL;
}


/* general EA code */

typedef struct
{
  USHORT nID;
  USHORT nSize;
  ULONG lSize;
}
EAHEADER, *PEAHEADER;


#ifdef __32BIT__

/* Perhaps due to bugs in the current OS/2 2.0 kernel, the success or
   failure of the DosEnumAttribute() and DosQueryPathInfo() system calls
   depends on the area where the return buffers are allocated. This
   differs for the various compilers, for some alloca() works, for some
   malloc() works, for some, both work. We'll have to live with that. */

/* The use of malloc() is not very convenient, because it requires
   backtracking (i.e. free()) at error returns. We do that for system
   calls that may fail, but not for malloc() calls, because they are VERY
   unlikely to fail. If ever, we just leave some memory allocated ... */

#if defined(__GNUC__)
#define alloc alloca
#endif

#if defined(__WATCOMC__) || defined(__IBMC__)
#define alloc malloc
#define __FREE__
#endif

#ifndef alloc
#error memory allocation type (alloca or malloc) not specified
#endif

void GetEAs(char *path, char **bufptr, unsigned *size,
                        char **cbufptr, unsigned *csize)
{
  FILESTATUS4 fs;
  PDENA2 pDENA, pFound;
  EAOP2 eaop;
  PGEA2 pGEA;
  PGEA2LIST pGEAlist;
  PFEA2LIST pFEAlist;
  PEAHEADER pEAblock;
  ULONG ulAttributes, ulMemoryBlock;
  ULONG nLength;
  char szName[CCHMAXPATH];

  *size = *csize = 0;

  if ( _osmode == DOS_MODE )
    return;

  strcpy(szName, path);
  nLength = strlen(szName);
  if ( szName[nLength - 1] == '/' )
    szName[nLength - 1] = 0;

  if ( DosQueryPathInfo(szName, FIL_QUERYEASIZE, (PBYTE) &fs, sizeof(fs))
    || fs.cbList <= 2 * sizeof(ULONG)
    || (pDENA = alloc((size_t) fs.cbList)) == NULL )
    return;

  ulAttributes = -1;

  if ( DosEnumAttribute(ENUMEA_REFTYPE_PATH, szName, 1, pDENA, fs.cbList,
                        &ulAttributes, ENUMEA_LEVEL_NO_VALUE)
    || ulAttributes == 0
    || (pGEAlist = alloc((size_t) fs.cbList)) == NULL )
  {
#ifdef __FREE__
    free(pDENA);
#endif
    return;
  }

  pGEA = pGEAlist -> list;
  pFound = pDENA;

  while ( ulAttributes-- )
  {
    if ( !(strcmp(pFound -> szName, ".LONGNAME") == 0 && use_longname_ea) )
    {
      pGEA -> cbName = pFound -> cbName;
      strcpy(pGEA -> szName, pFound -> szName);

      nLength = sizeof(GEA2) + strlen(pGEA -> szName);
      nLength = ((nLength - 1) / sizeof(ULONG) + 1) * sizeof(ULONG);

      pGEA -> oNextEntryOffset = ulAttributes ? nLength : 0;
      pGEA   = (PGEA2)  ((PCH) pGEA + nLength);
    }

    pFound = (PDENA2) ((PCH) pFound + pFound -> oNextEntryOffset);
  }

  if ( pGEA == pGEAlist -> list ) /* no attributes to save */
  {
#ifdef __FREE__
    free(pDENA);
    free(pGEAlist);
#endif
    return;
  }

  pGEAlist -> cbList = (PCH) pGEA - (PCH) pGEAlist;

  pFEAlist = (PVOID) pDENA;  /* reuse buffer */
  pFEAlist -> cbList = fs.cbList;

  eaop.fpGEA2List = pGEAlist;
  eaop.fpFEA2List = pFEAlist;
  eaop.oError = 0;

  if ( DosQueryPathInfo(szName, FIL_QUERYEASFROMLIST,
                        (PBYTE) &eaop, sizeof(eaop)) )
  {
#ifdef __FREE__
    free(pDENA);
    free(pGEAlist);
#endif
    return;
  }

  /* The maximum compressed size is (in case of STORE type) the
     uncompressed size plus the size of the compression type field
     plus the size of the CRC field. */

  ulAttributes = pFEAlist -> cbList;
  ulMemoryBlock = ulAttributes + sizeof(USHORT) + sizeof(ULONG);
  pEAblock = (PEAHEADER) malloc(sizeof(EAHEADER) + ulMemoryBlock);

  if ( pEAblock == NULL )
    return;

  *bufptr = (char *) pEAblock;
  *size = sizeof(EAHEADER);

  pEAblock -> nID = EAID;
  pEAblock -> nSize = sizeof(pEAblock -> lSize);
  pEAblock -> lSize = ulAttributes; /* uncompressed size */

  nLength = memcompress((char *) (pEAblock + 1), ulMemoryBlock,
                        (char *) pFEAlist, ulAttributes);
  *size += nLength;
  pEAblock -> nSize += nLength;

  if ( (pEAblock = (PEAHEADER) malloc(sizeof(EAHEADER))) == NULL )
    return;

  *cbufptr = (char *) pEAblock;
  *csize = sizeof(EAHEADER);

  pEAblock -> nID = EAID;
  pEAblock -> nSize = sizeof(pEAblock -> lSize);
  pEAblock -> lSize = ulAttributes;

  if ( noisy )
    printf(" (%ld bytes EA's)", ulAttributes);
}

#else /* !__32BIT__ */

typedef struct
{
  ULONG oNextEntryOffset;
  BYTE fEA;
  BYTE cbName;
  USHORT cbValue;
  CHAR szName[1];
}
FEA2, *PFEA2;

typedef struct
{
  ULONG cbList;
  FEA2 list[1];
}
FEA2LIST, *PFEA2LIST;

void GetEAs(char *path, char **bufptr, unsigned *size,
                        char **cbufptr, unsigned *csize)
{
  FILESTATUS2 fs;
  PDENA1 pDENA, pFound;
  EAOP eaop;
  PGEALIST pGEAlist;
  PGEA pGEA;
  PFEALIST pFEAlist;
  PFEA pFEA;
  PFEA2LIST pFEA2list;
  PFEA2 pFEA2;
  EAHEADER *pEAblock;
  ULONG ulAttributes;
  USHORT nLength, nMaxSize;
  char szName[CCHMAXPATH];

  *size = *csize = 0;

  if ( _osmode == DOS_MODE )
    return;

  strcpy(szName, path);
  nLength = strlen(szName);
  if ( szName[nLength - 1] == '/' )
    szName[nLength - 1] = 0;

  if ( DosQueryPathInfo(szName, FIL_QUERYEASIZE, (PBYTE) &fs, sizeof(fs))
    || fs.cbList <= 2 * sizeof(ULONG) )
    return;

  ulAttributes = -1;
  nMaxSize = (USHORT) min(fs.cbList * 2, 65520L);

  if ( (pDENA = malloc((size_t) nMaxSize)) == NULL )
    return;

  if ( DosEnumAttribute(ENUMEA_REFTYPE_PATH, szName, 1, pDENA, fs.cbList,
                        &ulAttributes, ENUMEA_LEVEL_NO_VALUE)
    || ulAttributes == 0
    || (pGEAlist = malloc(nMaxSize)) == NULL )
  {
    free(pDENA);
    return;
  }

  pGEA = pGEAlist -> list;
  pFound = pDENA;

  while ( ulAttributes-- )
  {
    nLength = strlen(pFound -> szName);

    if ( !(strcmp(pFound -> szName, ".LONGNAME") == 0 && use_longname_ea) )
    {
      pGEA -> cbName = pFound -> cbName;
      strcpy(pGEA -> szName, pFound -> szName);

      pGEA = (PGEA) ((PCH) (pGEA++) + nLength);
    }

    pFound = (PDENA1) ((PCH) (pFound++) + nLength);
  }

  if ( pGEA == pGEAlist -> list )
  {
    free(pDENA);
    free(pGEAlist);
    return;
  }

  pGEAlist -> cbList = (PCH) pGEA - (PCH) pGEAlist;

  pFEAlist = (PFEALIST) pDENA; /* reuse buffer */
  pFEAlist -> cbList = fs.cbList;
  pFEA = pFEAlist -> list;

  eaop.fpGEAList = pGEAlist;
  eaop.fpFEAList = pFEAlist;
  eaop.oError = 0;

  if ( DosQueryPathInfo(szName, FIL_QUERYEASFROMLIST,
                    (PBYTE) &eaop, sizeof(eaop)) )
  {
    free(pDENA);
    free(pGEAlist);
    return;
  }

  /* now convert into new OS/2 2.0 32-bit format */

  pFEA2list = (PFEA2LIST) pGEAlist;  /* reuse buffer */
  pFEA2 = pFEA2list -> list;

  while ( (PCH) pFEA - (PCH) pFEAlist < pFEAlist -> cbList )
  {
    nLength = sizeof(FEA) + pFEA -> cbName + 1 + pFEA -> cbValue;
    memcpy((PCH) pFEA2 + sizeof(pFEA2 -> oNextEntryOffset), pFEA, nLength);
    memset((PCH) pFEA2 + sizeof(pFEA2 -> oNextEntryOffset) + nLength, 0, 3);
    pFEA = (PFEA) ((PCH) pFEA + nLength);

    nLength = sizeof(FEA2) + pFEA2 -> cbName + 1 + pFEA2 -> cbValue;
    nLength = ((nLength - 1) / sizeof(ULONG) + 1) * sizeof(ULONG);
    /* rounded up to 4-byte boundary */
    pFEA2 -> oNextEntryOffset =
      ((PCH) pFEA - (PCH) pFEAlist < pFEAlist -> cbList) ? nLength : 0;
    pFEA2 = (PFEA2) ((PCH) pFEA2 + nLength);
  }

  pFEA2list -> cbList = (PCH) pFEA2 - (PCH) pFEA2list;
  ulAttributes = pFEA2list -> cbList;

  pEAblock = (PEAHEADER) pDENA; /* reuse buffer */

  *bufptr = (char *) pEAblock;
  *size = sizeof(EAHEADER);

  pEAblock -> nID = EAID;
  pEAblock -> nSize = sizeof(pEAblock -> lSize);
  pEAblock -> lSize = ulAttributes; /* uncompressed size */

  nLength = (USHORT) memcompress((char *) (pEAblock + 1),
    nMaxSize - sizeof(EAHEADER), (char *) pFEA2list, ulAttributes);

  *size += nLength;
  pEAblock -> nSize += nLength;

  pEAblock = (PEAHEADER) pGEAlist;

  *cbufptr = (char *) pEAblock;
  *csize = sizeof(EAHEADER);

  pEAblock -> nID = EAID;
  pEAblock -> nSize = sizeof(pEAblock -> lSize);
  pEAblock -> lSize = ulAttributes;

  if ( noisy )
    printf(" (%ld bytes EA's)", ulAttributes);
}

#endif /* __32BIT__ */


#endif /* UTIL */


/* Initialize the table of uppercase characters including handling of
   country dependent characters. */

void init_upper()
{
  COUNTRYCODE cc;
  unsigned nCnt, nU;

  for ( nCnt = 0; nCnt < sizeof(upper); nCnt++ )
    upper[nCnt] = lower[nCnt] = (unsigned char) nCnt;

  cc.country = cc.codepage = 0;
  DosMapCase(sizeof(upper), &cc, (PCHAR) upper);

  for ( nCnt = 0; nCnt < 256; nCnt++ )
  {
    nU = upper[nCnt];
    if (nU != nCnt && lower[nU] == (unsigned char) nU)
      lower[nU] = (unsigned char) nCnt;
  }

  for ( nCnt = 'A'; nCnt <= 'Z'; nCnt++ )
    lower[nCnt] = (unsigned char) (nCnt - 'A' + 'a');
}


char *StringLower(char *szArg)
{
  unsigned char *szPtr;
  for ( szPtr = szArg; *szPtr; szPtr++ )
    *szPtr = lower[*szPtr];
  return szArg;
}