Functions
std::string	GetCompressString (void)

std::string	GetBitSizeStr (void)

void	BinaryStrToBase64Str (std::string &compressedDataString, std::string &base64string)

void	Base64StrToBinaryStr (std::string &base64string, std::string &compressedDataString)

template<class T >
int	ZlibEncode (std::vector< T > &in, std::string &out)

template<class T >
int	ZlibEncodeToBase64Str (std::vector< T > &in, std::string &out64)

template<class T >
int	ZlibDecode (std::string &in, std::vector< T > &out)

template<class T >
int	ZlibDecodeFromBase64Str (std::string &in64, std::vector< T > &out)

Function Documentation

◆ Base64StrToBinaryStr()

void Nektar::LibUtilities::CompressData::Base64StrToBinaryStr	(	std::string &	base64string,
		std::string &	compressedDataString
	)

Convert a Base 64 string into a binary string

Convert a string containing base 64 (i.e. from xml file) into a binary string

Definition at line 143 of file CompressData.cpp.

 {
     // Convert from base64 to binary.
     typedef boost::archive::iterators::transform_width<
         boost::archive::iterators::binary_from_base64<
             std::string::const_iterator>,
         8, 6>
         binary_t;
     compressedDataString = std::string(binary_t(base64string.begin()),
                                        binary_t(base64string.end()));
 }

Referenced by ZlibDecodeFromBase64Str().

◆ BinaryStrToBase64Str()

void Nektar::LibUtilities::CompressData::BinaryStrToBase64Str	(	std::string &	compressedDataString,
		std::string &	base64string
	)

Convert a binary string to Base 64 string

Convert a string containing compressed binary (i.e. from deflate) into a base 64 string

Definition at line 114 of file CompressData.cpp.

 {
     // If the string length is not divisible by 3,
     // pad it. There is a bug in transform_width
     // that will make it reference past the end
     // and crash.
     switch (compressedDataString.length() % 3)
     {
         case 1:
             compressedDataString += '\0';
             /* Falls through. */
         case 2:
             compressedDataString += '\0';
             break;
     }
  
     // Convert from binary to base64.
     typedef boost::archive::iterators::base64_from_binary<
         boost::archive::iterators::transform_width<std::string::const_iterator,
                                                    6, 8>>
         base64_t;
     base64string = std::string(base64_t(compressedDataString.begin()),
                                base64_t(compressedDataString.end()));
 }

Referenced by ZlibEncodeToBase64Str().

◆ GetBitSizeStr()

std::string Nektar::LibUtilities::CompressData::GetBitSizeStr ( void )

Definition at line 106 of file CompressData.cpp.

 {
     return boost::lexical_cast<std::string>(sizeof(void *) * 8);
 }

◆ GetCompressString()

std::string Nektar::LibUtilities::CompressData::GetCompressString ( void )

Return a string describing this compression and endianness

Definition at line 101 of file CompressData.cpp.

 {
     return "B64Z-" + EndianTypeMap[Endianness()];
 }

References Nektar::LibUtilities::Endianness(), and Nektar::LibUtilities::EndianTypeMap.

◆ ZlibDecode()

template<class T >

int Nektar::LibUtilities::CompressData::ZlibDecode	(	std::string &	in,
		std::vector< T > &	out
	)

Decompress a zlib-compressed string into a vector of NekDouble values.

Definition at line 147 of file CompressData.h.

 {
     int ret;
     unsigned have;
     z_stream strm;
     std::string buffer;
     buffer.resize(CHUNK);
     std::string output;
  
     strm.zalloc   = Z_NULL;
     strm.zfree    = Z_NULL;
     strm.opaque   = Z_NULL;
     strm.avail_in = 0;
     strm.next_in  = Z_NULL;
     ret           = inflateInit(&strm);
     ASSERTL0(ret == Z_OK, "Error initializing zlib decompression.");
  
     strm.avail_in = (unsigned int)in.size();
     strm.next_in  = (unsigned char *)(&in[0]);
  
     do
     {
         strm.avail_out = CHUNK;
         strm.next_out  = (unsigned char *)(&buffer[0]);
  
         ret = inflate(&strm, Z_NO_FLUSH);
  
         ASSERTL0(ret != Z_STREAM_ERROR, "Stream error occured.");
  
         switch (ret)
         {
             case Z_NEED_DICT:
                 ret = Z_DATA_ERROR;
                 /* Falls through. */
             case Z_DATA_ERROR:
             case Z_MEM_ERROR:
                 (void)inflateEnd(&strm);
                 return ret;
         }
  
         have = CHUNK - strm.avail_out;
         output += buffer.substr(0, have);
  
     } while (strm.avail_out == 0);
  
     (void)inflateEnd(&strm);
  
     if (ret == Z_STREAM_END)
     {
         T *readFieldData = (T *)output.c_str();
         unsigned int len =
             (unsigned int)output.size() * sizeof(*output.c_str()) / sizeof(T);
         out.assign(readFieldData, readFieldData + len);
         return Z_OK;
     }
     else
     {
         return Z_DATA_ERROR;
     }
 }

References ASSERTL0, CHUNK, and Nektar::void.

Referenced by ZlibDecodeFromBase64Str().

◆ ZlibDecodeFromBase64Str()

template<class T >

int Nektar::LibUtilities::CompressData::ZlibDecodeFromBase64Str	(	std::string &	in64,
		std::vector< T > &	out
	)

Decompress a base 64 compressed binary string into a vector of NekDouble values.

Definition at line 220 of file CompressData.h.

 {
     std::string in;
     Base64StrToBinaryStr(in64, in);
  
     return ZlibDecode(in, out);
 }

References Base64StrToBinaryStr(), and ZlibDecode().

Referenced by Nektar::LibUtilities::FieldIOXml::ImportFieldData(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadCurves(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadEdges(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadElements1D(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadElements2D(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadElements3D(), Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadFaces(), and Nektar::SpatialDomains::MeshGraphXmlCompressed::v_ReadVertices().

◆ ZlibEncode()

template<class T >

int Nektar::LibUtilities::CompressData::ZlibEncode	(	std::vector< T > &	in,
		std::string &	out
	)

Compress a vector of NekDouble values into a string using zlib.

Definition at line 73 of file CompressData.h.

 {
     int ret;
     unsigned have;
     std::string buffer;
     buffer.resize(CHUNK);
     z_stream strm;
     unsigned char *input = (unsigned char *)(&in[0]);
  
     /* allocate deflate state */
     strm.zalloc = Z_NULL;
     strm.zfree  = Z_NULL;
     strm.opaque = Z_NULL;
     ret         = deflateInit(&strm, Z_DEFAULT_COMPRESSION);
  
     ASSERTL0(ret == Z_OK, "Error initializing Zlib.");
  
     strm.avail_in = (unsigned int)in.size() * sizeof(T) / sizeof(char);
     strm.next_in  = input;
  
     // Deflate input until output buffer is no longer full.
     do
     {
         strm.avail_out = CHUNK;
         strm.next_out  = (unsigned char *)(&buffer[0]);
  
         ret = deflate(&strm, Z_FINISH);
  
         // Deflate can return Z_OK, Z_STREAM_ERROR, Z_BUF_ERROR or
         // Z_STREAM_END. All, except Z_STREAM_ERROR are ok.
         ASSERTL0(ret != Z_STREAM_ERROR, "Zlib stream error");
  
         have = CHUNK - strm.avail_out;
         out += buffer.substr(0, have);
  
     } while (strm.avail_out == 0);
  
     // Check all input was processed.
     ASSERTL0(strm.avail_in == 0, "Not all input was used.");
  
     // Check stream is complete.
     ASSERTL0(ret == Z_STREAM_END, "Stream not finished");
  
     // Clean-up and return
     (void)deflateEnd(&strm);
     return Z_OK;
 }

References ASSERTL0, CHUNK, and Nektar::void.

Referenced by ZlibEncodeToBase64Str().

◆ ZlibEncodeToBase64Str()

template<class T >

int Nektar::LibUtilities::CompressData::ZlibEncodeToBase64Str	(	std::vector< T > &	in,
		std::string &	out64
	)

Compress a vector of NekDouble values into a base64 string.

Definition at line 132 of file CompressData.h.

 {
     std::string out;
  
     int ok = ZlibEncode(in, out);
  
     BinaryStrToBase64Str(out, out64);
  
     return ok;
 }

References BinaryStrToBase64Str(), and ZlibEncode().

Functions

Function Documentation

◆ Base64StrToBinaryStr()

◆ BinaryStrToBase64Str()

◆ GetBitSizeStr()

◆ GetCompressString()

◆ ZlibDecode()

◆ ZlibDecodeFromBase64Str()

◆ ZlibEncode()

◆ ZlibEncodeToBase64Str()