◆ _gpak_decompressor_zstd()

GPAK_API uint32_t _gpak_decompressor_zstd	(	gpak_t *	_pak,
		FILE *	_infile,
		FILE *	_outfile,
		size_t	_read_size
	)

Brief Description:\n Decompresses the input file using the Zstandard (zstd) algorithm.: This function decompresses the input file using the Zstandard (zstd) algorithm and writes the decompressed data to the output file.

Parameters

_pak	A pointer to the gpak_t.
_infile	A pointer to the input FILE.
_outfile	A pointer to the output FILE.
_read_size	The number of bytes to read from the input file.

Returns: The number of bytes written to the output file.

Definition at line 291 of file gpak_compressors.c.

 {
     size_t const buffInSize = ZSTD_DStreamInSize();
     void* const buffIn = malloc(buffInSize);
     size_t const buffOutSize = ZSTD_DStreamOutSize();
     void* const buffOut = malloc(buffOutSize);
  
     uint32_t _crc32 = crc32(0L, Z_NULL, 0);
  
     ZSTD_DCtx* const dctx = ZSTD_createDCtx();
     assert(dctx != NULL && "ZSTD_createDCtx() failed!");
  
     if (_pak->dictionary_ && _pak->header_.dictionary_size_ > 0)
         ZSTD_DCtx_loadDictionary(dctx, _pak->dictionary_, _pak->header_.dictionary_size_);
  
     size_t bytesRead = 0;
     size_t lastRet = 0;
     int isEmpty = 1;
  
     while (bytesRead < _read_size)
     {
         size_t const toRead = (bytesRead + buffInSize <= _read_size) ? buffInSize : (_read_size - bytesRead);
         size_t read = _freadb(buffIn, 1, toRead, _infile);
  
         if (!read)
         {
             break;
         }
  
         bytesRead += read;
  
         _gpak_pass_progress(_pak, bytesRead, _read_size, GPAK_STAGE_DECOMPRESSION);
  
         isEmpty = 0;
         ZSTD_inBuffer input = { buffIn, read, 0 };
         while (input.pos < input.size)
         {
             ZSTD_outBuffer output = { buffOut, buffOutSize, 0 };
             size_t const ret = ZSTD_decompressStream(dctx, &output, &input);
  
             _crc32 = crc32(_crc32, buffOut, output.pos);
  
             _fwriteb(buffOut, 1, output.pos, _outfile);
             lastRet = ret;
         }
     }
  
     if (isEmpty)
     {
         _gpak_make_error(_pak, GPAK_ERROR_EMPTY_INPUT);
         goto clear;
     }
  
     if (lastRet != 0)
     {
         _gpak_make_error(_pak, GPAK_ERROR_EOF_BEFORE_EOS);
         goto clear;
     }
  
 clear:
     ZSTD_freeDCtx(dctx);
     free(buffIn);
     free(buffOut);
  
     return _crc32;
 }

References gpak::dictionary_, gpak_header::dictionary_size_, GPAK_ERROR_EMPTY_INPUT, GPAK_ERROR_EOF_BEFORE_EOS, GPAK_STAGE_DECOMPRESSION, and gpak::header_.

Referenced by gpak_fopen().