RageFileBasic *RageFileDriverZip::Open( const CString &sPath, int iMode, int &iErr )
{
if( iMode & RageFile::WRITE )
{
iErr = ERROR_WRITING_NOT_SUPPORTED;
return NULL;
}
FileInfo *info = (FileInfo *) FDB->GetFilePriv( sPath );
if( info == NULL )
{
iErr = ENOENT;
return NULL;
}
m_Mutex.Lock();
/* If we havn't figured out the offset to the real data yet, do so now. */
if( info->m_iDataOffset == -1 )
{
if( !ReadLocalFileHeader(*info) )
{
m_Mutex.Unlock();
return NULL;
}
}
/* We won't do any further access to zip, except to copy it (which is
* threadsafe), so we can unlock now. */
m_Mutex.Unlock();
RageFileDriverSlice *pSlice = new RageFileDriverSlice( m_pZip->Copy(), info->m_iDataOffset, info->m_iCompressedSize );
pSlice->DeleteFileWhenFinished();
switch( info->m_iCompressionMethod )
{
case STORED:
return pSlice;
case DEFLATED:
{
RageFileObjInflate *pInflate = new RageFileObjInflate( pSlice, info->m_iUncompressedSize );
pInflate->DeleteFileWhenFinished();
return pInflate;
}
default:
/* unknown compression method */
iErr = ENOSYS;
return NULL;
}
}
/*
* Parse a .gz file, check the header CRC16 if present, and return the data
* CRC32 and a decompressor. pFile will be deleted.
*/
RageFileObjInflate *GunzipFile( RageFileBasic *pFile_, RString &sError, uint32_t *iCRC32 )
{
auto_ptr<RageFileBasic> pFile(pFile_);
sError = "";
pFile->Seek(0);
pFile->EnableCRC32( true );
{
char magic[2];
FileReading::ReadBytes( *pFile, magic, 2, sError );
if( sError != "" )
return NULL;
if( magic[0] != '\x1f' || magic[1] != '\x8b' )
{
sError = "Not a gzipped file";
return NULL;
}
}
uint8_t iCompressionMethod = FileReading::read_8( *pFile, sError );
uint8_t iFlags = FileReading::read_8( *pFile, sError );
FileReading::read_32_le( *pFile, sError ); /* time */
FileReading::read_8( *pFile, sError ); /* xfl */
FileReading::read_8( *pFile, sError ); /* os */
if( sError != "" )
return NULL;
#define FTEXT 1<<0
#define FHCRC 1<<1
#define FEXTRA 1<<2
#define FNAME 1<<3
#define FCOMMENT 1<<4
#define UNSUPPORTED_MASK ~((1<<5)-1)
if( iCompressionMethod != 8 )
{
sError = ssprintf( "Unsupported compression: %i", iCompressionMethod );
return NULL;
}
/* Warning: flags other than FNAME are untested, since gzip doesn't
* actually output them. */
if( iFlags & UNSUPPORTED_MASK )
{
sError = ssprintf( "Unsupported flags: %x", iFlags );
return NULL;
}
if( iFlags & FEXTRA )
{
int16_t iSize = FileReading::read_16_le( *pFile, sError );
FileReading::SkipBytes( *pFile, iSize, sError );
}
if( iFlags & FNAME )
while( sError == "" && FileReading::read_8( *pFile, sError ) != 0 )
;
if( iFlags & FCOMMENT )
while( sError == "" && FileReading::read_8( *pFile, sError ) != 0 )
;
if( iFlags & FHCRC )
{
/* Get the CRC of the data read so far. Be sure to do this before
* reading iExpectedCRC16. */
uint32_t iActualCRC32;
bool bOK = pFile->GetCRC32( &iActualCRC32 );
ASSERT( bOK );
uint16_t iExpectedCRC16 = FileReading::read_u16_le( *pFile, sError );
uint16_t iActualCRC16 = int16_t( iActualCRC32 & 0xFFFF );
if( sError != "" )
return NULL;
if( iActualCRC16 != iExpectedCRC16 )
{
sError = "Header CRC error";
return NULL;
}
}
/* We only need CRC checking on the raw data for the header, so disable
* it. */
pFile->EnableCRC32( false );
if( sError != "" )
return NULL;
int iDataPos = pFile->Tell();
/* Seek to the end, and grab the uncompressed flie size and CRC. */
int iFooterPos = pFile->GetFileSize() - 8;
FileReading::Seek( *pFile, iFooterPos, sError );
uint32_t iExpectedCRC32 = FileReading::read_u32_le( *pFile, sError );
uint32_t iUncompressedSize = FileReading::read_u32_le( *pFile, sError );
if( iCRC32 != NULL )
*iCRC32 = iExpectedCRC32;
FileReading::Seek( *pFile, iDataPos, sError );
if( sError != "" )
return NULL;
RageFileDriverSlice *pSliceFile = new RageFileDriverSlice( pFile.release(), iDataPos, iFooterPos-iDataPos );
pSliceFile->DeleteFileWhenFinished();
RageFileObjInflate *pInflateFile = new RageFileObjInflate( pSliceFile, iUncompressedSize );
pInflateFile->DeleteFileWhenFinished();
/* Enable CRC calculation only if the caller is interested. */
if( iCRC32 != NULL )
pInflateFile->EnableCRC32();
return pInflateFile;
}
