Namespaces
	Internal
	Internal functions for compressed read/write of a NanoVDB GridHandle into a stream.

Classes
struct	FileGridMetaData
	This class defines the meta data stored for each grid in a segment. More...

struct	FileHeader
	Data encoded at the head of each segment of a file or stream. More...

struct	FileMetaData

struct	Segment
	This class defines all the data stored in segment of a file. More...

Typedefs
using	fileSize_t = uint64_t

Enumerations
enum	Codec : uint16_t { NONE = 0, ZIP = 1, BLOSC = 2, END = 3 }
	Define compression codecs. More...

Functions
const char *	toStr (Codec codec)

template<typename StreamT >
void	writeUncompressedGrid (StreamT &os, const GridData *gridData, bool raw=false)
	This is a standalone alternative to io::writeGrid(...,Codec::NONE) defined in util/IO.h Unlike the latter this function has no dependencies at all, not even NanoVDB.h, so it also works if client code only includes PNanoVDB.h! More...

template<typename GridHandleT , template< typename... > class VecT>
void	writeUncompressedGrids (const char *fileName, const VecT< GridHandleT > &handles, bool raw=false)
	write multiple NanoVDB grids to a single file, without compression. More...

template<typename GridHandleT , typename StreamT , template< typename... > class VecT>
VecT< GridHandleT >	readUncompressedGrids (StreamT &is, const typename GridHandleT::BufferType &pool=typename GridHandleT::BufferType())
	read all uncompressed grids from a stream and return their handles. More...

template<typename GridHandleT , template< typename... > class VecT>
VecT< GridHandleT >	readUncompressedGrids (const char *fileName, const typename GridHandleT::BufferType &buffer=typename GridHandleT::BufferType())
	Read a multiple un-compressed NanoVDB grids from a file and return them as a vector. More...

template<typename BufferT >
void	writeGrid (const std::string &fileName, const GridHandle< BufferT > &handle, io::Codec codec=io::Codec::NONE, int verbose=0)
	Write a single grid to file (over-writing existing content of the file) More...

template<typename BufferT = HostBuffer, template< typename... > class VecT = std::vector>
void	writeGrids (const std::string &fileName, const VecT< GridHandle< BufferT >> &handles, Codec codec=Codec::NONE, int verbose=0)
	Write multiple grids to file (over-writing existing content of the file) More...

template<typename BufferT = HostBuffer>
GridHandle< BufferT >	readGrid (const std::string &fileName, int n=0, int verbose=0, const BufferT &buffer=BufferT())
	Read and return one or all grids from a file into a single GridHandle. More...

template<typename BufferT = HostBuffer>
GridHandle< BufferT >	readGrid (const std::string &fileName, const std::string &gridName, int verbose=0, const BufferT &buffer=BufferT())
	Read and return the first grid with a specific name from a file. More...

template<typename BufferT = HostBuffer, template< typename... > class VecT = std::vector>
VecT< GridHandle< BufferT > >	readGrids (const std::string &fileName, int verbose=0, const BufferT &buffer=BufferT())
	Read all the grids in the file and return them as a vector of multiple GridHandles, each containing all grids encoded in the same segment of the file (i.e. they where written together) More...

uint64_t	stringHash (const char *cstr)
	Standard hash function to use on strings; std::hash may vary by platform/implementation and is know to produce frequent collisions. More...

uint64_t	stringHash (const std::string &str)
	Return a uint64_t hash key of a std::string. More...

uint64_t	reverseEndianness (uint64_t val)
	Return a uint64_t with its bytes reversed so we can check for endianness. More...

bool	hasGrid (const std::string &fileName, const std::string &gridName)
	Return true if the file contains a grid with the specified name. More...

bool	hasGrid (std::istream &is, const std::string &gridName)
	Return true if the stream contains a grid with the specified name. More...

std::vector< FileGridMetaData >	readGridMetaData (const std::string &fileName)
	Reads and returns a vector of meta data for all the grids found in the specified file. More...

std::vector< FileGridMetaData >	readGridMetaData (std::istream &is)
	Reads and returns a vector of meta data for all the grids found in the specified stream. More...

template<typename BufferT >
void	writeGrid (std::ostream &os, const GridHandle< BufferT > &handle, Codec codec)

template<typename BufferT = HostBuffer, template< typename... > class VecT = std::vector>
void	writeGrids (std::ostream &os, const VecT< GridHandle< BufferT >> &handles, Codec codec=Codec::NONE)

template<typename BufferT >
GridHandle< BufferT >	readGrid (std::istream &is, int n, const BufferT &pool)

template<typename BufferT >
GridHandle< BufferT >	readGrid (std::istream &is, const std::string &gridName, const BufferT &pool)
	Read a specific grid from an input stream given the name of the grid. More...

template<typename BufferT = HostBuffer, template< typename... > class VecT = std::vector>
VecT< GridHandle< BufferT > >	readGrids (std::istream &is, const BufferT &pool=BufferT())

Typedef Documentation

using fileSize_t = uint64_t

We fix a specific size for counting bytes in files so that they are saved the same regardless of machine precision. (Note there are still little/bigendian issues, however)

Enumeration Type Documentation

enum Codec : uint16_t

strong

Define compression codecs.

Note: NONE is the default, ZIP is slow but compact and BLOSC offers a great balance.

Exceptions

NanoVDB optionally supports ZIP and BLOSC compression and will throw an exception if its support is required but missing.

Enumerator
NONE
ZIP
BLOSC
END

Function Documentation

bool hasGrid	(	const std::string &	fileName,
		const std::string &	gridName
	)

inline

Return true if the file contains a grid with the specified name.

bool hasGrid	(	std::istream &	is,
		const std::string &	gridName
	)

inline

Return true if the stream contains a grid with the specified name.

GridHandle< BufferT > readGrid	(	const std::string &	fileName,
		int	n = `0`,
		int	verbose = `0`,
		const BufferT &	buffer = `BufferT()`
	)

Read and return one or all grids from a file into a single GridHandle.

Read the n'th grid.

Template Parameters

BufferT Type of buffer used memory allocation

Parameters

fileName	string name of file to be read from
n	zero-based signed index of the grid to be read. The default value of 0 means read only first grid. A negative value of n means read all grids in the file.
verbose	specify verbosity level. Default value of zero means quiet.
buffer	optional buffer used for memory allocation

Returns: return a single GridHandle with one or all grids found in the file

Exceptions

will	throw a std::runtime_error if the file does not contain a grid with index n

GridHandle< BufferT > readGrid	(	const std::string &	fileName,
		const std::string &	gridName,
		int	verbose = `0`,
		const BufferT &	buffer = `BufferT()`
	)

Read and return the first grid with a specific name from a file.

Read the first grid with a specific name.

Template Parameters

BufferT Type of buffer used memory allocation

Parameters

fileName	string name of file to be read from
gridName	string name of the grid to be read
verbose	specify verbosity level. Default value of zero means quiet.
buffer	optional buffer used for memory allocation

Returns: return a single GridHandle containing the grid with the specific name

Exceptions

will	throw a std::runtime_error if the file does not contain a grid with the specific name

GridHandle<BufferT> nanovdb::io::readGrid	(	std::istream &	is,
		int	n,
		const BufferT &	pool
	)

GridHandle<BufferT> nanovdb::io::readGrid	(	std::istream &	is,
		const std::string &	gridName,
		const BufferT &	pool
	)

Read a specific grid from an input stream given the name of the grid.

Template Parameters

BufferT Buffer type used for allocation

Parameters

is	input stream from which to read the grid
gridName	string name of the (first) grid to be returned
pool	optional memory pool from which to allocate the grid buffer

Returns: Return the first grid in the input stream with a specific name

Exceptions

std::runtime_error with no grid exists with the specified name

std::vector< FileGridMetaData > readGridMetaData ( const std::string & fileName )

inline

Reads and returns a vector of meta data for all the grids found in the specified file.

std::vector< FileGridMetaData > readGridMetaData ( std::istream & is )

inline

Reads and returns a vector of meta data for all the grids found in the specified stream.

VecT< GridHandle< BufferT > > readGrids	(	const std::string &	fileName,
		int	verbose = `0`,
		const BufferT &	buffer = `BufferT()`
	)

Read all the grids in the file and return them as a vector of multiple GridHandles, each containing all grids encoded in the same segment of the file (i.e. they where written together)

Read all the grids.

Template Parameters

BufferT Type of buffer used memory allocation

Parameters

fileName	string name of file to be read from
verbose	specify verbosity level. Default value of zero means quiet.
buffer	optional buffer used for memory allocation

Returns: Return a vector of GridHandles each containing all grids encoded in the same segment of the file (i.e. they where written together).

VecT<GridHandle<BufferT> > nanovdb::io::readGrids	(	std::istream &	is,
		const BufferT &	pool = `BufferT()`
	)

VecT<GridHandleT> nanovdb::io::readUncompressedGrids	(	StreamT &	is,
		const typename GridHandleT::BufferType &	pool = `typename GridHandleT::BufferType()`
	)

read all uncompressed grids from a stream and return their handles.

Exceptions

std::invalid_argument if stream does not contain a single uncompressed valid NanoVDB grid

StreamT class must support: "bool read(char*, size_t)" and "void skip(uint32_t)"

VecT<GridHandleT> nanovdb::io::readUncompressedGrids	(	const char *	fileName,
		const typename GridHandleT::BufferType &	buffer = `typename GridHandleT::BufferType()`
	)

Read a multiple un-compressed NanoVDB grids from a file and return them as a vector.

uint64_t nanovdb::io::reverseEndianness ( uint64_t val )

inline

Return a uint64_t with its bytes reversed so we can check for endianness.

uint64_t stringHash ( const char * cstr )

inline

Standard hash function to use on strings; std::hash may vary by platform/implementation and is know to produce frequent collisions.

uint64_t nanovdb::io::stringHash ( const std::string & str )

inline

Return a uint64_t hash key of a std::string.

const char* nanovdb::io::toStr ( Codec codec )

inline

void writeGrid	(	const std::string &	fileName,
		const GridHandle< BufferT > &	handle,
		io::Codec	codec = `io::Codec::NONE`,
		int	verbose = `0`
	)

Write a single grid to file (over-writing existing content of the file)

void nanovdb::io::writeGrid	(	std::ostream &	os,
		const GridHandle< BufferT > &	handle,
		Codec	codec
	)

void writeGrids	(	const std::string &	fileName,
		const VecT< GridHandle< BufferT >> &	handles,
		Codec	codec = `Codec::NONE`,
		int	verbose = `0`
	)

Write multiple grids to file (over-writing existing content of the file)

void nanovdb::io::writeGrids	(	std::ostream &	os,
		const VecT< GridHandle< BufferT >> &	handles,
		Codec	codec = `Codec::NONE`
	)

void nanovdb::io::writeUncompressedGrid	(	StreamT &	os,
		const GridData *	gridData,
		bool	raw = `false`
	)

This is a standalone alternative to io::writeGrid(...,Codec::NONE) defined in util/IO.h Unlike the latter this function has no dependencies at all, not even NanoVDB.h, so it also works if client code only includes PNanoVDB.h!

Writes a raw NanoVDB buffer, possibly with multiple grids, to a stream WITHOUT compression. It follows all the conventions in util/IO.h so the stream can be read by all existing client code of NanoVDB.

Note: This method will always write uncompressed grids to the stream, i.e. Blosc or ZIP compression is never applied! This is a fundamental limitation and feature of this standalone function.

Exceptions

std::invalid_argument if buffer does not point to a valid NanoVDB grid.

Warning: This is pretty ugly code that involves lots of pointer and bit manipulations - not for the faint of heart :)

void nanovdb::io::writeUncompressedGrids	(	const char *	fileName,
		const VecT< GridHandleT > &	handles,
		bool	raw = `false`
	)

write multiple NanoVDB grids to a single file, without compression.

Note: To write all grids in a single GridHandle simply use handle.write("fieNane")

Namespaces

Classes

Typedefs

Enumerations

Functions

Typedef Documentation

Enumeration Type Documentation

Function Documentation