unzip.c

NES game Emulator in Linux.c and asm codes.

/* unzip.c -- IO on .zip files using zlib
   Version 0.15 beta, Mar 19th, 1998,

   Read unzip.h for more info
*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "zlib.h"
#include "unzip.h"

#ifdef STDC
#  include <stddef.h>
#  include <string.h>
#  include <stdlib.h>
#endif
#ifdef NO_ERRNO_H
    extern int errno;
#else
#   include <errno.h>
#endif


#ifndef local
#  define local static
#endif
/* compile with -Dlocal if your debugger can't find static symbols */



#if !defined(unix) && !defined(CASESENSITIVITYDEFAULT_YES) && \
                      !defined(CASESENSITIVITYDEFAULT_NO)
#define CASESENSITIVITYDEFAULT_NO
#endif


#ifndef UNZ_BUFSIZE
#define UNZ_BUFSIZE (16384)
#endif

#ifndef UNZ_MAXFILENAMEINZIP
#define UNZ_MAXFILENAMEINZIP (256)
#endif

#ifndef ALLOC
# define ALLOC(size) (malloc(size))
#endif
#ifndef TRYFREE
# define TRYFREE(p) {if (p) free(p);}
#endif

#define SIZECENTRALDIRITEM (0x2e)
#define SIZEZIPLOCALHEADER (0x1e)


/* I've found an old Unix (a SunOS 4.1.3_U1) without all SEEK_* defined.... */

#ifndef SEEK_CUR
#define SEEK_CUR    1
#endif

#ifndef SEEK_END
#define SEEK_END    2
#endif

#ifndef SEEK_SET
#define SEEK_SET    0
#endif

const char unz_copyright[] =
   " unzip 0.15 Copyright 1998 Gilles Vollant ";

/* unz_file_info_interntal contain internal info about a file in zipfile*/
typedef struct unz_file_info_internal_s
{
    uLong offset_curfile;/* relative offset of local header 4 bytes */
} unz_file_info_internal;


/* file_in_zip_read_info_s contain internal information about a file in zipfile,
    when reading and decompress it */
typedef struct
{
    char  *read_buffer;         /* internal buffer for compressed data */
    z_stream stream;            /* zLib stream structure for inflate */

    uLong pos_in_zipfile;       /* position in byte on the zipfile, for fseek*/
    uLong stream_initialised;   /* flag set if stream structure is initialised*/

    uLong offset_local_extrafield;/* offset of the local extra field */
    uInt  size_local_extrafield;/* size of the local extra field */
    uLong pos_local_extrafield;   /* position in the local extra field in read*/

    uLong crc32;                /* crc32 of all data uncompressed */
    uLong crc32_wait;           /* crc32 we must obtain after decompress all */
    uLong rest_read_compressed; /* number of byte to be decompressed */
    uLong rest_read_uncompressed;/*number of byte to be obtained after decomp*/
    FILE* file;                 /* io structore of the zipfile */
    uLong compression_method;   /* compression method (0==store) */
    uLong byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
} file_in_zip_read_info_s;


/* unz_s contain internal information about the zipfile
*/
typedef struct
{
    FILE* file;                 /* io structore of the zipfile */
    unz_global_info gi;       /* public global information */
    uLong byte_before_the_zipfile;/* byte before the zipfile, (>0 for sfx)*/
    uLong num_file;             /* number of the current file in the zipfile*/
    uLong pos_in_central_dir;   /* pos of the current file in the central dir*/
    uLong current_file_ok;      /* flag about the usability of the current file*/
    uLong central_pos;          /* position of the beginning of the central dir*/

    uLong size_central_dir;     /* size of the central directory  */
    uLong offset_central_dir;   /* offset of start of central directory with
                                   respect to the starting disk number */

    unz_file_info cur_file_info; /* public info about the current file in zip*/
    unz_file_info_internal cur_file_info_internal; /* private info about it*/
    file_in_zip_read_info_s* pfile_in_zip_read; /* structure about the current
                                        file if we are decompressing it */
} unz_s;


/* ===========================================================================
     Read a byte from a gz_stream; update next_in and avail_in. Return EOF
   for end of file.
   IN assertion: the stream s has been sucessfully opened for reading.
*/


local int unzlocal_getByte(fin,pi)
    FILE *fin;
    int *pi;
{
    unsigned char c;
    int err = fread(&c, 1, 1, fin);
    if (err==1)
    {
        *pi = (int)c;
        return UNZ_OK;
    }
    else
    {
        if (ferror(fin)) 
            return UNZ_ERRNO;
        else
            return UNZ_EOF;
    }
}


/* ===========================================================================
   Reads a long in LSB order from the given gz_stream. Sets 
*/
local int unzlocal_getShort (fin,pX)
    FILE* fin;
    uLong *pX;
{
    uLong x ;
    int i;
    int err;

    err = unzlocal_getByte(fin,&i);
    x = (uLong)i;
    
    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<8;
   
    if (err==UNZ_OK)
        *pX = x;
    else
        *pX = 0;
    return err;
}

local int unzlocal_getLong (fin,pX)
    FILE* fin;
    uLong *pX;
{
    uLong x ;
    int i;
    int err;

    err = unzlocal_getByte(fin,&i);
    x = (uLong)i;
    
    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<8;

    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<16;

    if (err==UNZ_OK)
        err = unzlocal_getByte(fin,&i);
    x += ((uLong)i)<<24;
   
    if (err==UNZ_OK)
        *pX = x;
    else
        *pX = 0;
    return err;
}


/* My own strcmpi / strcasecmp */
local int strcmpcasenosensitive_internal (fileName1,fileName2)
    const char* fileName1;
    const char* fileName2;
{
    for (;;)
    {
        char c1=*(fileName1++);
        char c2=*(fileName2++);
        if ((c1>='a') && (c1<='z'))
            c1 -= 0x20;
        if ((c2>='a') && (c2<='z'))
            c2 -= 0x20;
        if (c1=='\0')
            return ((c2=='\0') ? 0 : -1);
        if (c2=='\0')
            return 1;
        if (c1<c2)
            return -1;
        if (c1>c2)
            return 1;
    }
}


#ifdef  CASESENSITIVITYDEFAULT_NO
#define CASESENSITIVITYDEFAULTVALUE 2
#else
#define CASESENSITIVITYDEFAULTVALUE 1
#endif

#ifndef STRCMPCASENOSENTIVEFUNCTION
#define STRCMPCASENOSENTIVEFUNCTION strcmpcasenosensitive_internal
#endif

/* 
   Compare two filename (fileName1,fileName2).
   If iCaseSenisivity = 1, comparision is case sensitivity (like strcmp)
   If iCaseSenisivity = 2, comparision is not case sensitivity (like strcmpi
                                                                or strcasecmp)
   If iCaseSenisivity = 0, case sensitivity is defaut of your operating system
        (like 1 on Unix, 2 on Windows)

*/
extern int ZEXPORT unzStringFileNameCompare (fileName1,fileName2,iCaseSensitivity)
    const char* fileName1;
    const char* fileName2;
    int iCaseSensitivity;
{
    if (iCaseSensitivity==0)
        iCaseSensitivity=CASESENSITIVITYDEFAULTVALUE;

    if (iCaseSensitivity==1)
        return strcmp(fileName1,fileName2);

    return STRCMPCASENOSENTIVEFUNCTION(fileName1,fileName2);
} 

#define BUFREADCOMMENT (0x400)

/*
  Locate the Central directory of a zipfile (at the end, just before
    the global comment)
*/
local uLong unzlocal_SearchCentralDir(fin)
    FILE *fin;
{
    unsigned char* buf;
    uLong uSizeFile;
    uLong uBackRead;
    uLong uMaxBack=0xffff; /* maximum size of global comment */
    uLong uPosFound=0;
    
    if (fseek(fin,0,SEEK_END) != 0)
        return 0;


    uSizeFile = ftell( fin );
    
    if (uMaxBack>uSizeFile)
        uMaxBack = uSizeFile;

    buf = (unsigned char*)ALLOC(BUFREADCOMMENT+4);
    if (buf==NULL)
        return 0;

    uBackRead = 4;
    while (uBackRead<uMaxBack)
    {
        uLong uReadSize,uReadPos ;
        int i;
        if (uBackRead+BUFREADCOMMENT>uMaxBack) 
            uBackRead = uMaxBack;
        else
            uBackRead+=BUFREADCOMMENT;
        uReadPos = uSizeFile-uBackRead ;
        
        uReadSize = ((BUFREADCOMMENT+4) < (uSizeFile-uReadPos)) ? 
                     (BUFREADCOMMENT+4) : (uSizeFile-uReadPos);
        if (fseek(fin,uReadPos,SEEK_SET)!=0)
            break;

        if (fread(buf,(uInt)uReadSize,1,fin)!=1)
            break;

                for (i=(int)uReadSize-3; (i--)>0;)
            if (((*(buf+i))==0x50) && ((*(buf+i+1))==0x4b) && 
                ((*(buf+i+2))==0x05) && ((*(buf+i+3))==0x06))
            {
                uPosFound = uReadPos+i;
                break;
            }

        if (uPosFound!=0)
            break;
    }
    TRYFREE(buf);
    return uPosFound;
}

/*
  Open a Zip file. path contain the full pathname (by example,
     on a Windows NT computer "c:\\test\\zlib109.zip" or on an Unix computer
     "zlib/zlib109.zip".
     If the zipfile cannot be opened (file don't exist or in not valid), the
       return value is NULL.
     Else, the return value is a unzFile Handle, usable with other function
       of this unzip package.
*/
extern unzFile ZEXPORT unzOpen (path)
    const char *path;
{
    unz_s us;
    unz_s *s;
    uLong central_pos,uL;
    FILE * fin ;

    uLong number_disk;          /* number of the current dist, used for 
                                   spaning ZIP, unsupported, always 0*/
    uLong number_disk_with_CD;  /* number the the disk with central dir, used
                                   for spaning ZIP, unsupported, always 0*/
    uLong number_entry_CD;      /* total number of entries in
                                   the central dir 
                                   (same than number_entry on nospan) */

    int err=UNZ_OK;

    if (unz_copyright[0]!=' ')
        return NULL;

    fin=fopen(path,"rb");
    if (fin==NULL)
        return NULL;

    central_pos = unzlocal_SearchCentralDir(fin);
    if (central_pos==0)
        err=UNZ_ERRNO;

    if (fseek(fin,central_pos,SEEK_SET)!=0)
        err=UNZ_ERRNO;

    /* the signature, already checked */
    if (unzlocal_getLong(fin,&uL)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* number of this disk */
    if (unzlocal_getShort(fin,&number_disk)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* number of the disk with the start of the central directory */
    if (unzlocal_getShort(fin,&number_disk_with_CD)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* total number of entries in the central dir on this disk */
    if (unzlocal_getShort(fin,&us.gi.number_entry)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* total number of entries in the central dir */
    if (unzlocal_getShort(fin,&number_entry_CD)!=UNZ_OK)
        err=UNZ_ERRNO;

    if ((number_entry_CD!=us.gi.number_entry) ||
        (number_disk_with_CD!=0) ||
        (number_disk!=0))
        err=UNZ_BADZIPFILE;

    /* size of the central directory */
    if (unzlocal_getLong(fin,&us.size_central_dir)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* offset of start of central directory with respect to the 
          starting disk number */
    if (unzlocal_getLong(fin,&us.offset_central_dir)!=UNZ_OK)
        err=UNZ_ERRNO;

    /* zipfile comment length */
    if (unzlocal_getShort(fin,&us.gi.size_comment)!=UNZ_OK)
        err=UNZ_ERRNO;

    if ((central_pos<us.offset_central_dir+us.size_central_dir) && 
        (err==UNZ_OK))
        err=UNZ_BADZIPFILE;

    if (err!=UNZ_OK)
    {
        fclose(fin);
        return NULL;
    }

    us.file=fin;
    us.byte_before_the_zipfile = central_pos -
                            (us.offset_central_dir+us.size_central_dir);
    us.central_pos = central_pos;
    us.pfile_in_zip_read = NULL;
    

    s=(unz_s*)ALLOC(sizeof(unz_s));
    *s=us;
    unzGoToFirstFile((unzFile)s);   
    return (unzFile)s;  
}