lzexpand.c

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/*
 * LZ Decompression functions
 *
 * Copyright 1996 Marcus Meissner
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * NOTES
 *
 * The LZ (Lempel Ziv) decompression was used in win16 installation programs.
 * It is a simple tabledriven decompression engine, the algorithm is not
 * documented as far as I know. WINE does not contain a compressor for
 * this format.
 *
 * The implementation is complete and there have been no reports of failures
 * for some time.
 *
 * TODO:
 *
 *   o Check whether the return values are correct
 *
 */

#ifdef __REACTOS__

#include <k32.h>

#define NDEBUG
#include <debug.h>
DEBUG_CHANNEL(kernel32file);

#define HFILE_ERROR ((HFILE)-1)

#include "lzexpand.h"

#define _lwrite(a, b, c) (long)(_hwrite(a, b, (long)c))

#else /* __REACTOS__ */

#include "config.h"

#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <stdarg.h>
#include <stdio.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#include "windef.h"
#include "winbase.h"
#include "lzexpand.h"

#include "wine/unicode.h"
#include "wine/debug.h"

WINE_DEFAULT_DEBUG_CHANNEL(file);

#endif /* __REACTOS__ */

/* The readahead length of the decompressor. Reading single bytes
 * using _lread() would be SLOW.
 */
#define GETLEN  2048

#define LZ_MAGIC_LEN    8
#define LZ_HEADER_LEN   14

/* Format of first 14 byte of LZ compressed file */
struct lzfileheader {
    BYTE    magic[LZ_MAGIC_LEN];
    BYTE    compressiontype;
    CHAR    lastchar;
    DWORD   reallength;
};
static const BYTE LZMagic[LZ_MAGIC_LEN]={'S','Z','D','D',0x88,0xf0,0x27,0x33};

#define LZ_TABLE_SIZE    0x1000

struct lzstate {
    HFILE   realfd;     /* the real filedescriptor */
    CHAR    lastchar;   /* the last char of the filename */

    DWORD   reallength; /* the decompressed length of the file */
    DWORD   realcurrent;    /* the position the decompressor currently is */
    DWORD   realwanted; /* the position the user wants to read from */

    BYTE    table[LZ_TABLE_SIZE];   /* the rotating LZ table */
    UINT    curtabent;  /* CURrent TABle ENTry */

    BYTE    stringlen;  /* length and position of current string */
    DWORD   stringpos;  /* from stringtable */


    WORD    bytetype;   /* bitmask within blocks */

    BYTE    *get;       /* GETLEN bytes */
    DWORD   getcur;     /* current read */
    DWORD   getlen;     /* length last got */
};

#define MAX_LZSTATES 16
static struct lzstate *lzstates[MAX_LZSTATES];

#define LZ_MIN_HANDLE  0x400
#define IS_LZ_HANDLE(h) (((h) >= LZ_MIN_HANDLE) && ((h) < LZ_MIN_HANDLE+MAX_LZSTATES))
#define GET_LZ_STATE(h) (IS_LZ_HANDLE(h) ? lzstates[(h)-LZ_MIN_HANDLE] : NULL)

/* reads one compressed byte, including buffering */
#define GET(lzs,b)  _lzget(lzs,&b)
#define GET_FLUSH(lzs)  lzs->getcur=lzs->getlen;

static int
_lzget(struct lzstate *lzs,BYTE *b) {
    if (lzs->getcur<lzs->getlen) {
        *b      = lzs->get[lzs->getcur++];
        return      1;
    } else {
        int ret = _lread(lzs->realfd,lzs->get,GETLEN);
        if (ret==HFILE_ERROR)
            return HFILE_ERROR;
        if (ret==0)
            return 0;
        lzs->getlen = ret;
        lzs->getcur = 1;
        *b      = *(lzs->get);
        return 1;
    }
}
/* internal function, reads lzheader
 * returns BADINHANDLE for non filedescriptors
 * return 0 for file not compressed using LZ
 * return UNKNOWNALG for unknown algorithm
 * returns lzfileheader in *head
 */
static INT read_header(HFILE fd,struct lzfileheader *head)
{
    BYTE    buf[LZ_HEADER_LEN];

    if (_llseek(fd,0,SEEK_SET)==-1)
        return LZERROR_BADINHANDLE;

    /* We can't directly read the lzfileheader struct due to
     * structure element alignment
     */
    if (_lread(fd,buf,LZ_HEADER_LEN)<LZ_HEADER_LEN)
        return 0;
    memcpy(head->magic,buf,LZ_MAGIC_LEN);
    memcpy(&(head->compressiontype),buf+LZ_MAGIC_LEN,1);
    memcpy(&(head->lastchar),buf+LZ_MAGIC_LEN+1,1);

    /* FIXME: consider endianness on non-intel architectures */
    memcpy(&(head->reallength),buf+LZ_MAGIC_LEN+2,4);

    if (memcmp(head->magic,LZMagic,LZ_MAGIC_LEN))
        return 0;
    if (head->compressiontype!='A')
        return LZERROR_UNKNOWNALG;
    return 1;
}


/***********************************************************************
 *           LZStart   (KERNEL32.@)
 */
INT WINAPI LZStart(void)
{
    TRACE("(void)\n");
    return 1;
}


/***********************************************************************
 *           LZInit   (KERNEL32.@)
 *
 * initializes internal decompression buffers, returns lzfiledescriptor.
 * (return value the same as hfSrc, if hfSrc is not compressed)
 * on failure, returns error code <0
 * lzfiledescriptors range from 0x400 to 0x410 (only 16 open files per process)
 *
 * since _llseek uses the same types as libc.lseek, we just use the macros of
 *  libc
 */
HFILE WINAPI LZInit( HFILE hfSrc )
{

    struct  lzfileheader    head;
    struct  lzstate     *lzs;
    int i, ret;

    TRACE("(%d)\n",hfSrc);
    ret=read_header(hfSrc,&head);
    if (ret<=0) {
        _llseek(hfSrc,0,SEEK_SET);
        return ret?ret:hfSrc;
    }
        for (i = 0; i < MAX_LZSTATES; i++) if (!lzstates[i]) break;
        if (i == MAX_LZSTATES) return LZERROR_GLOBALLOC;
    lzstates[i] = lzs = HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(*lzs) );
    if(lzs == NULL) return LZERROR_GLOBALLOC;

    lzs->realfd = hfSrc;
    lzs->lastchar   = head.lastchar;
    lzs->reallength = head.reallength;

    lzs->get    = HeapAlloc( GetProcessHeap(), 0, GETLEN );
    lzs->getlen = 0;
    lzs->getcur = 0;

    if(lzs->get == NULL) {
        HeapFree(GetProcessHeap(), 0, lzs);
        lzstates[i] = NULL;
        return LZERROR_GLOBALLOC;
    }

    /* Yes, preinitialize with spaces */
    memset(lzs->table,' ',LZ_TABLE_SIZE);
    /* Yes, start 16 byte from the END of the table */
    lzs->curtabent  = 0xff0;
    return LZ_MIN_HANDLE + i;
}


/***********************************************************************
 *           LZDone   (KERNEL32.@)
 */
void WINAPI LZDone(void)
{
    TRACE("(void)\n");
}


/***********************************************************************
 *           GetExpandedNameA   (KERNEL32.@)
 *
 * gets the full filename of the compressed file 'in' by opening it
 * and reading the header
 *
 * "file." is being translated to "file"
 * "file.bl_" (with lastchar 'a') is being translated to "file.bla"
 * "FILE.BL_" (with lastchar 'a') is being translated to "FILE.BLA"
 */

INT WINAPI GetExpandedNameA( LPSTR in, LPSTR out )
{
    struct lzfileheader head;
    HFILE       fd;
    OFSTRUCT    ofs;
    INT     fnislowercased,ret,len;
    LPSTR       s,t;

    TRACE("(%s)\n",in);
    fd=OpenFile(in,&ofs,OF_READ);
    if (fd==HFILE_ERROR)
        return (INT)(INT16)LZERROR_BADINHANDLE;
    strcpy(out,in);
    ret=read_header(fd,&head);
    if (ret<=0) {
        /* not a LZ compressed file, so the expanded name is the same
         * as the input name */
        _lclose(fd);
        return 1;
    }


    /* look for directory prefix and skip it. */
    s=out;
    while (NULL!=(t=strpbrk(s,"/\\:")))
        s=t+1;

    /* now mangle the basename */
    if (!*s) {
        /* FIXME: hmm. shouldn't happen? */
        WARN("Specified a directory or what? (%s)\n",in);
        _lclose(fd);
        return 1;
    }
    /* see if we should use lowercase or uppercase on the last char */
    fnislowercased=1;
    t=s+strlen(s)-1;
    while (t>=out) {
        if (!isalpha(*t)) {
            t--;
            continue;
        }
        fnislowercased=islower(*t);
        break;
    }
    if (isalpha(head.lastchar)) {
        if (fnislowercased)
            head.lastchar=tolower(head.lastchar);
        else
            head.lastchar=toupper(head.lastchar);
    }

    /* now look where to replace the last character */
    if (NULL!=(t=strchr(s,'.'))) {
        if (t[1]=='\0') {
            t[0]='\0';
        } else {
            len=strlen(t)-1;
            if (t[len]=='_')
                t[len]=head.lastchar;
        }
    } /* else no modification necessary */
    _lclose(fd);
    return 1;
}


/***********************************************************************
 *           GetExpandedNameW   (KERNEL32.@)
 */
INT WINAPI GetExpandedNameW( LPWSTR in, LPWSTR out )
{
    INT ret;
    DWORD len = WideCharToMultiByte( CP_ACP, 0, in, -1, NULL, 0, NULL, NULL );
    char *xin = HeapAlloc( GetProcessHeap(), 0, len );
    char *xout = HeapAlloc( GetProcessHeap(), 0, len+3 );
    WideCharToMultiByte( CP_ACP, 0, in, -1, xin, len, NULL, NULL );
    if ((ret = GetExpandedNameA( xin, xout )) > 0)
        MultiByteToWideChar( CP_ACP, 0, xout, -1, out, strlenW(in)+4 );
    HeapFree( GetProcessHeap(), 0, xin );
    HeapFree( GetProcessHeap(), 0, xout );
    return ret;
}


/***********************************************************************
 *           LZRead   (KERNEL32.@)
 */
INT WINAPI LZRead( HFILE fd, LPSTR vbuf, INT toread )
{
    int howmuch;
    BYTE    b,*buf;
    struct  lzstate *lzs;

    buf=(LPBYTE)vbuf;
    TRACE("(%d,%p,%d)\n",fd,buf,toread);
    howmuch=toread;
    if (!(lzs = GET_LZ_STATE(fd))) return _lread(fd,buf,toread);

/* The decompressor itself is in a define, cause we need it twice
 * in this function. (the decompressed byte will be in b)
 */
#define DECOMPRESS_ONE_BYTE                         \
        if (lzs->stringlen) {                   \
            b       = lzs->table[lzs->stringpos];   \
            lzs->stringpos  = (lzs->stringpos+1)&0xFFF; \
            lzs->stringlen--;               \
        } else {                        \
            if (!(lzs->bytetype&0x100)) {           \
                if (1!=GET(lzs,b))          \
                    return toread-howmuch;      \
                lzs->bytetype = b|0xFF00;       \
            }                       \
            if (lzs->bytetype & 1) {            \
                if (1!=GET(lzs,b))          \
                    return toread-howmuch;      \
            } else {                    \
                BYTE    b1,b2;              \
                                    \
                if (1!=GET(lzs,b1))         \
                    return toread-howmuch;      \
                if (1!=GET(lzs,b2))         \
                    return toread-howmuch;      \
                /* Format:              \
                 * b1 b2                \
                 * AB CD                \
                 * where CAB is the stringoffset in the table\
                 * and D+3 is the len of the string \
                 */                 \
                lzs->stringpos  = b1|((b2&0xf0)<<4);    \
                lzs->stringlen  = (b2&0xf)+2;       \
                /* 3, but we use a  byte already below ... */\
                b       = lzs->table[lzs->stringpos];\
                lzs->stringpos  = (lzs->stringpos+1)&0xFFF;\
            }                       \
            lzs->bytetype>>=1;              \
        }                           \
        /* store b in table */                  \
        lzs->table[lzs->curtabent++]= b;            \
        lzs->curtabent  &= 0xFFF;               \
        lzs->realcurrent++;

    /* if someone has seeked, we have to bring the decompressor
     * to that position
     */
    if (lzs->realcurrent!=lzs->realwanted) {
        /* if the wanted position is before the current position
         * I see no easy way to unroll ... We have to restart at
         * the beginning. *sigh*
         */
        if (lzs->realcurrent>lzs->realwanted) {
            /* flush decompressor state */
            _llseek(lzs->realfd,LZ_HEADER_LEN,SEEK_SET);
            GET_FLUSH(lzs);
            lzs->realcurrent= 0;
            lzs->bytetype   = 0;
            lzs->stringlen  = 0;
            memset(lzs->table,' ',LZ_TABLE_SIZE);
            lzs->curtabent  = 0xFF0;
        }
        while (lzs->realcurrent<lzs->realwanted) {
            DECOMPRESS_ONE_BYTE;
        }
    }

    while (howmuch) {
        DECOMPRESS_ONE_BYTE;
        lzs->realwanted++;
        *buf++      = b;
        howmuch--;
    }
    return  toread;
#undef DECOMPRESS_ONE_BYTE
}


/***********************************************************************
 *           LZSeek   (KERNEL32.@)
 */
LONG WINAPI LZSeek( HFILE fd, LONG off, INT type )
{
    struct  lzstate *lzs;
    LONG    newwanted;

    TRACE("(%d,%d,%d)\n",fd,off,type);
    /* not compressed? just use normal _llseek() */
        if (!(lzs = GET_LZ_STATE(fd))) return _llseek(fd,off,type);
    newwanted = lzs->realwanted;
    switch (type) {
    case 1: /* SEEK_CUR */
        newwanted      += off;
        break;
    case 2: /* SEEK_END */
        newwanted   = lzs->reallength-off;
        break;
    default:/* SEEK_SET */
        newwanted   = off;
        break;
    }
    if (newwanted>lzs->reallength)
        return LZERROR_BADVALUE;
    if (newwanted<0)
        return LZERROR_BADVALUE;
    lzs->realwanted = newwanted;
    return newwanted;
}


/***********************************************************************
 *           LZCopy   (KERNEL32.@)
 *
 * Copies everything from src to dest
 * if src is a LZ compressed file, it will be uncompressed.
 * will return the number of bytes written to dest or errors.
 */
LONG WINAPI LZCopy( HFILE src, HFILE dest )
{
    int usedlzinit = 0, ret, wret;
    LONG    len;
    HFILE   oldsrc = src, srcfd;
    FILETIME filetime;
    struct  lzstate *lzs;
#define BUFLEN  1000
    CHAR    buf[BUFLEN];
    /* we need that weird typedef, for i can't seem to get function pointer
     * casts right. (Or they probably just do not like WINAPI in general)
     */
    typedef UINT    (WINAPI *_readfun)(HFILE,LPVOID,UINT);

    _readfun    xread;

    TRACE("(%d,%d)\n",src,dest);
    if (!IS_LZ_HANDLE(src)) {
        src = LZInit(src);
                if ((INT)src <= 0) return 0;
        if (src != oldsrc) usedlzinit=1;
    }

    /* not compressed? just copy */
        if (!IS_LZ_HANDLE(src))
#ifdef __REACTOS__
        xread=(_readfun)_hread; // ROSHACK
#else
        xread=_lread;
#endif
    else
        xread=(_readfun)LZRead;
    len=0;
    while (1) {
        ret=xread(src,buf,BUFLEN);
        if (ret<=0) {
            if (ret==0)
                break;
            if (ret==-1)
                return LZERROR_READ;
            return ret;
        }
        len    += ret;
        wret    = _lwrite(dest,buf,ret);
        if (wret!=ret)
            return LZERROR_WRITE;
    }

    /* Maintain the timestamp of source file to destination file */
    srcfd = (!(lzs = GET_LZ_STATE(src))) ? src : lzs->realfd;
    GetFileTime( LongToHandle(srcfd), NULL, NULL, &filetime );
    SetFileTime( LongToHandle(dest), NULL, NULL, &filetime );

    /* close handle */
    if (usedlzinit)
        LZClose(src);
    return len;
#undef BUFLEN
}

/* reverses GetExpandedPathname */
static LPSTR LZEXPAND_MangleName( LPCSTR fn )
{
    char *p;
    char *mfn = HeapAlloc( GetProcessHeap(), 0, strlen(fn) + 3 ); /* "._" and \0 */
    if(mfn == NULL) return NULL;
    strcpy( mfn, fn );
    if (!(p = strrchr( mfn, '\\' ))) p = mfn;
    if ((p = strchr( p, '.' )))
    {
        p++;
        if (strlen(p) < 3) strcat( p, "_" );  /* append '_' */
        else p[strlen(p)-1] = '_';  /* replace last character */
    }
    else strcat( mfn, "._" );   /* append "._" */
    return mfn;
}


/***********************************************************************
 *           LZOpenFileA   (KERNEL32.@)
 *
 * Opens a file. If not compressed, open it as a normal file.
 */
HFILE WINAPI LZOpenFileA( LPSTR fn, LPOFSTRUCT ofs, WORD mode )
{
    HFILE   fd,cfd;
    BYTE    ofs_cBytes = ofs->cBytes;

    TRACE("(%s,%p,%d)\n",fn,ofs,mode);
    /* 0x70 represents all OF_SHARE_* flags, ignore them for the check */
    fd=OpenFile(fn,ofs,mode);
    if (fd==HFILE_ERROR)
        {
            LPSTR mfn = LZEXPAND_MangleName(fn);
            fd = OpenFile(mfn,ofs,mode);
            HeapFree( GetProcessHeap(), 0, mfn );
    }
    if (fd==HFILE_ERROR)
        ofs->cBytes = ofs_cBytes;
    if ((mode&~0x70)!=OF_READ)
        return fd;
    if (fd==HFILE_ERROR)
        return HFILE_ERROR;
    cfd=LZInit(fd);
    if ((INT)cfd <= 0) return fd;
    return cfd;
}


/***********************************************************************
 *           LZOpenFileW   (KERNEL32.@)
 */
HFILE WINAPI LZOpenFileW( LPWSTR fn, LPOFSTRUCT ofs, WORD mode )
{
    HFILE ret;
    DWORD len = WideCharToMultiByte( CP_ACP, 0, fn, -1, NULL, 0, NULL, NULL );
    LPSTR xfn = HeapAlloc( GetProcessHeap(), 0, len );
    WideCharToMultiByte( CP_ACP, 0, fn, -1, xfn, len, NULL, NULL );
    ret = LZOpenFileA(xfn,ofs,mode);
    HeapFree( GetProcessHeap(), 0, xfn );
    return ret;
}


/***********************************************************************
 *           LZClose   (KERNEL32.@)
 */
void WINAPI LZClose( HFILE fd )
{
    struct lzstate *lzs;

    TRACE("(%d)\n",fd);
        if (!(lzs = GET_LZ_STATE(fd))) _lclose(fd);
        else
        {
            HeapFree( GetProcessHeap(), 0, lzs->get );
            CloseHandle( LongToHandle(lzs->realfd) );
            lzstates[fd - LZ_MIN_HANDLE] = NULL;
            HeapFree( GetProcessHeap(), 0, lzs );
        }
}

#ifdef __REACTOS__

/*
 * @implemented
 */
VOID
WINAPI
LZCloseFile(IN HFILE FileHandle)
{
    /* One function uses _lclose, the other CloseHandle -- same thing */
    LZClose(FileHandle);
}

/*
 * @unimplemented
 */
ULONG
WINAPI
LZCreateFileW(IN LPCWSTR FileName,
              IN DWORD dwDesiredAccess,
              IN DWORD dwShareMode,
              IN DWORD dwCreationDisposition,
              IN LPWSTR lpString1)
{
    WARN(" LZCreateFileW Not implemented!\n");
    SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
    return ERROR_CALL_NOT_IMPLEMENTED;
}

#endif /* __REACTOS__ */