Genesis-Plus-GX/source/ngc/unzip.c

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2008-08-07 14:26:07 +02:00
/******************************************************************************
*
* Nintendo Gamecube Zip Support
*
* Only partial support is included, in that only the first file within the archive
* is considered to be a ROM image.
***************************************************************************/
#include "shared.h"
#include "dvd.h"
#include "font.h"
#include <zlib.h>
/* SDCARD File access */
extern FILE *sdfile;
/*
* PKWare Zip Header - adopted into zip standard
*/
#define PKZIPID 0x504b0304
#define MAXROM 0x500000
#define ZIPCHUNK 2048
/*
* Zip file header definition
*/
typedef struct
{
unsigned int zipid __attribute__ ((__packed__)); // 0x04034b50
unsigned short zipversion __attribute__ ((__packed__));
unsigned short zipflags __attribute__ ((__packed__));
unsigned short compressionMethod __attribute__ ((__packed__));
unsigned short lastmodtime __attribute__ ((__packed__));
unsigned short lastmoddate __attribute__ ((__packed__));
unsigned int crc32 __attribute__ ((__packed__));
unsigned int compressedSize __attribute__ ((__packed__));
unsigned int uncompressedSize __attribute__ ((__packed__));
unsigned short filenameLength __attribute__ ((__packed__));
unsigned short extraDataLength __attribute__ ((__packed__));
} PKZIPHEADER;
/*
* Zip files are stored little endian
* Support functions for short and int types
*/
static inline u32 FLIP32 (u32 b)
{
unsigned int c;
c = (b & 0xff000000) >> 24;
c |= (b & 0xff0000) >> 8;
c |= (b & 0xff00) << 8;
c |= (b & 0xff) << 24;
return c;
}
static inline u16 FLIP16 (u16 b)
{
u16 c;
c = (b & 0xff00) >> 8;
c |= (b & 0xff) << 8;
return c;
}
/****************************************************************************
* IsZipFile
*
* Returns TRUE when PKZIPID is first four characters of buffer
****************************************************************************/
int IsZipFile (char *buffer)
{
unsigned int *check;
check = (unsigned int *) buffer;
if (check[0] == PKZIPID) return 1;
return 0;
}
/*****************************************************************************
* UnZipBuffer
*
* It should be noted that there is a limit of 5MB total size for any ROM
******************************************************************************/
int UnZipBuffer (unsigned char *outbuffer, u64 discoffset, int length, u8 UseSDCARD)
{
PKZIPHEADER pkzip;
int zipoffset = 0;
int zipchunk = 0;
char out[ZIPCHUNK];
z_stream zs;
int res;
int bufferoffset = 0;
int have = 0;
char readbuffer[2048];
char msg[128];
/*** Read Zip Header ***/
if ( UseSDCARD )
{
fseek(sdfile, 0, SEEK_SET);
fread(readbuffer, 1, 2048, sdfile);
}
else
{
dvd_read (&readbuffer, 2048, discoffset);
}
/*** Copy PKZip header to local, used as info ***/
memcpy (&pkzip, &readbuffer, sizeof (PKZIPHEADER));
sprintf (msg, "Unzipping %d bytes ... Wait", FLIP32 (pkzip.uncompressedSize));
ShowAction (msg);
/*** Prepare the zip stream ***/
memset (&zs, 0, sizeof (z_stream));
zs.zalloc = Z_NULL;
zs.zfree = Z_NULL;
zs.opaque = Z_NULL;
zs.avail_in = 0;
zs.next_in = Z_NULL;
res = inflateInit2 (&zs, -MAX_WBITS);
if (res != Z_OK) return 0;
/*** Set ZipChunk for first pass ***/
zipoffset = (sizeof (PKZIPHEADER) + FLIP16 (pkzip.filenameLength) + FLIP16 (pkzip.extraDataLength));
zipchunk = ZIPCHUNK - zipoffset;
/*** Now do it! ***/
do
{
zs.avail_in = zipchunk;
zs.next_in = (Bytef *) & readbuffer[zipoffset];
/*** Now inflate until input buffer is exhausted ***/
do
{
zs.avail_out = ZIPCHUNK;
zs.next_out = (Bytef *) & out;
res = inflate (&zs, Z_NO_FLUSH);
if (res == Z_MEM_ERROR)
{
inflateEnd (&zs);
return 0;
}
have = ZIPCHUNK - zs.avail_out;
if (have)
{
/*** Copy to normal block buffer ***/
memcpy (&outbuffer[bufferoffset], &out, have);
bufferoffset += have;
}
}
while (zs.avail_out == 0);
/*** Readup the next 2k block ***/
zipoffset = 0;
zipchunk = ZIPCHUNK;
if (UseSDCARD)
{
fread(readbuffer, 1, 2048, sdfile);
}
else
{
discoffset += 2048;
dvd_read (&readbuffer, 2048, discoffset);
}
}
while (res != Z_STREAM_END);
inflateEnd (&zs);
if (res == Z_STREAM_END)
{
if (FLIP32 (pkzip.uncompressedSize) == (u32) bufferoffset) return bufferoffset;
else return FLIP32 (pkzip.uncompressedSize);
}
return 0;
}