IO.h File Reference

Implements I/O for NanoVDB grids. Features optional BLOSC and ZIP file compression, support for multiple grids per file as well as multiple grid types. More...

#include <nanovdb/NanoVDB.h>
#include "GridHandle.h"
#include "GridChecksum.h"
#include <fstream>
#include <iostream>
#include <string>
#include <sstream>
#include <cstring>
#include <memory>
#include <vector>

Go to the source code of this file.

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

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

Typedefs
using	fileSize_t = uint64_t

Functions
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...
template<typename BufferT >
static fileSize_t	write (std::ostream &os, const GridHandle< BufferT > &handle, Codec codec, uint32_t n)
template<typename BufferT >
static void	read (std::istream &is, BufferT &buffer, Codec codec)
static void	read (std::istream &is, char *data, fileSize_t size, Codec codec)
	read compressed grid from stream 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())
template<typename T >
std::ostream &	operator<< (std::ostream &os, const BBox< Vec3< T >> &b)
std::ostream &	operator<< (std::ostream &os, const CoordBBox &b)
std::ostream &	operator<< (std::ostream &os, const Coord &ijk)
template<typename T >
std::ostream &	operator<< (std::ostream &os, const Vec3< T > &v)
template<typename T >
std::ostream &	operator<< (std::ostream &os, const Vec4< T > &v)

Variables
static constexpr fileSize_t	MAX_SIZE = 1UL << 30

Detailed Description

Implements I/O for NanoVDB grids. Features optional BLOSC and ZIP file compression, support for multiple grids per file as well as multiple grid types.

Author

Ken Museth

Date

May 1, 2020

Note

This file does NOT depend on OpenVDB, but optionally on ZIP and BLOSC

NanoVDB files take on of two formats: 1) multiple segments each with multiple grids (segments have easy to access metadata about its grids) 2) starting with verion 32.6.0 nanovdb files also support a raw buffer with one or more grids (just a dump of a raw grid buffer, so no new metadata).

1: Segment: FileHeader, MetaData0, gridName0...MetaDataN, gridNameN, compress Grid0,...compressed GridN 2: Raw: Grid0,...GridN