Defines a wrapper around a file whose internal structure can be accessed using the NeXus API. More...

#include <NexusDescriptor.h>

Public Types
enum	Version { Version4 , Version5 , AnyVersion }
	Enumerate HDF possible versions. More...

Public Member Functions
bool	classTypeExists (const std::string &classType) const
	Query if a given type exists somewhere in the file. More...

inline ::NeXus::File &	data ()
	Access the open NeXus File object. More...

const std::string &	extension () const
	Access the file extension. More...

const std::string &	filename () const
	Access the filename. More...

const std::pair< std::string, std::string > &	firstEntryNameType () const
	Returns the name & type of the first entry in the file. More...

bool	hasRootAttr (const std::string &name) const
	Query if the given attribute exists on the root node. More...

	NexusDescriptor ()=delete
	Disable default constructor. More...

	NexusDescriptor (const NexusDescriptor &)=delete
	Disable copy operator. More...

	NexusDescriptor (const std::string &filename, const bool init=true)
	Constructor accepting a filename. More...

NexusDescriptor &	operator= (const NexusDescriptor &)=delete
	Disable assignment operator. More...

bool	pathExists (const std::string &path) const
	Query if a path exists. More...

std::string	pathOfType (const std::string &type) const
	return the path of a given type More...

bool	pathOfTypeExists (const std::string &path, const std::string &type) const
	Query if a path exists of a given type. More...

	~NexusDescriptor ()
	Destructor. More...

Static Public Member Functions
static bool	isReadable (const std::string &filename, const Version version=AnyVersion)
	Returns true if the file is considered to store data in a hierarchy. More...

Static Public Attributes
static const unsigned char	HDF5Signature [8] = {137, 'H', 'D', 'F', '\r', '\n', '\032', '\n'}
	signature identifying a HDF5 file. More...

static size_t	HDF5SignatureSize = 8
	Size of HDF5 signature. More...

static const unsigned char	HDFMagic [4] = {'\016', '\003', '\023', '\001'}
	HDF cookie that is stored in the first 4 bytes of the file. More...

static const size_t	HDFMagicSize = 4
	Size of HDF magic number. More...

Private Member Functions
void	initialize (const std::string &filename)
	Initialize object with filename. More...

void	walkFile (::NeXus::File &file, const std::string &rootPath, const std::string &className, std::map< std::string, std::string > &pmap, int level)
	Walk the tree and cache the structure. More...

Private Attributes
std::string	m_extension
	Extension. More...

std::unique_ptr<::NeXus::File >	m_file
	Open NeXus handle. More...

std::string	m_filename
	Full filename. More...

std::pair< std::string, std::string >	m_firstEntryNameType
	First entry name/type. More...

std::map< std::string, std::string >	m_pathsToTypes
	Map of full path strings to types. Can check if path exists quickly. More...

std::unordered_set< std::string >	m_rootAttrs
	Root attributes. More...

Detailed Description

Defines a wrapper around a file whose internal structure can be accessed using the NeXus API.

On construction the simple details about the layout of the file are cached for faster querying later.

Definition at line 31 of file NexusDescriptor.h.

Member Enumeration Documentation

◆ Version

enum Mantid::Kernel::NexusDescriptor::Version

Enumerate HDF possible versions.

Enumerator
Version4
Version5
AnyVersion

Definition at line 34 of file NexusDescriptor.h.

Constructor & Destructor Documentation

◆ NexusDescriptor() [1/3]

Mantid::Kernel::NexusDescriptor::NexusDescriptor	(	const std::string &	filename,
		const bool	init = `true`
	)

Constructor accepting a filename.

Constructs the wrapper.

Parameters

filename	input filename
init	true: expensive init including walking through the file, false: don't init
filename	A string pointing to an existing file

Exceptions

std::invalid_argument if the file is not identified to be hierarchical. This currently involves simply checking for the signature if a HDF file at the start of the file

Definition at line 111 of file NexusDescriptor.cpp.

References Mantid::DataHandling::exists(), filename(), and initialize().

◆ ~NexusDescriptor()

Mantid::Kernel::NexusDescriptor::~NexusDescriptor ( )

default

Destructor.

◆ NexusDescriptor() [2/3]

Mantid::Kernel::NexusDescriptor::NexusDescriptor ( )

delete

Disable default constructor.

◆ NexusDescriptor() [3/3]

Mantid::Kernel::NexusDescriptor::NexusDescriptor ( const NexusDescriptor & )

delete

Disable copy operator.

Member Function Documentation

◆ classTypeExists()

bool Mantid::Kernel::NexusDescriptor::classTypeExists ( const std::string & classType ) const

Query if a given type exists somewhere in the file.

Parameters

classType A string name giving a class type

Returns: True if the type exists in the file, false otherwise

Definition at line 183 of file NexusDescriptor.cpp.

References m_pathsToTypes.

Referenced by Mantid::DataHandling::LoadTOFRawNexus::confidence(), and Mantid::DataHandling::LoadGeometry::isNexus().

◆ data()

inline ::NeXus::File & Mantid::Kernel::NexusDescriptor::data ( )

inline

Access the open NeXus File object.

Returns: A reference to the open NeXus file object

Definition at line 82 of file NexusDescriptor.h.

Referenced by Mantid::DataHandling::LoadMuonNexus1::confidence(), Mantid::DataHandling::LoadMuonNexus2::confidence(), and Mantid::DataHandling::LoadNXcanSAS::confidence().

◆ extension()

const std::string & Mantid::Kernel::NexusDescriptor::extension ( ) const

inline

Access the file extension.

Defined as the string after and including the last period character

Returns: A reference to a const string containing the file extension

Definition at line 77 of file NexusDescriptor.h.

Referenced by Mantid::DataHandling::LoadEMUHdf::confidence(), Mantid::DataHandling::LoadNXcanSAS::confidence(), and Mantid::DataHandling::LoadPLN::confidence().

◆ filename()

const std::string & Mantid::Kernel::NexusDescriptor::filename ( ) const

inline

Access the filename.

Returns: A reference to a const string containing the filename

Definition at line 71 of file NexusDescriptor.h.

Referenced by Mantid::DataHandling::LoadMcStas::confidence(), Mantid::DataHandling::LoadNXSPE::confidence(), initialize(), isReadable(), and NexusDescriptor().

◆ firstEntryNameType()

const std::pair< std::string, std::string > & Mantid::Kernel::NexusDescriptor::firstEntryNameType ( ) const

Returns the name & type of the first entry in the file.

Definition at line 134 of file NexusDescriptor.cpp.

References m_firstEntryNameType.

Referenced by Mantid::DataHandling::LoadMcStas::confidence(), Mantid::DataHandling::LoadMuonNexus1::confidence(), and Mantid::DataHandling::LoadMuonNexus2::confidence().

◆ hasRootAttr()

bool Mantid::Kernel::NexusDescriptor::hasRootAttr ( const std::string & name ) const

Query if the given attribute exists on the root node.

Parameters

name	The name of an attribute

Returns: True if the attribute exists, false otherwise

Definition at line 140 of file NexusDescriptor.cpp.

References m_rootAttrs.

◆ initialize()

void Mantid::Kernel::NexusDescriptor::initialize ( const std::string & filename )

private

Initialize object with filename.

Creates the internal cached structure of the file as a tree of nodes.

Definition at line 199 of file NexusDescriptor.cpp.

References filename(), m_extension, m_file, m_filename, m_pathsToTypes, m_rootAttrs, and walkFile().

Referenced by NexusDescriptor().

◆ isReadable()

bool Mantid::Kernel::NexusDescriptor::isReadable	(	const std::string &	filename,
		const Version	version = `AnyVersion`
	)

static

Returns true if the file is considered to store data in a hierarchy.

Checks for the HDF signatures and returns true if one of them is found.

Parameters

filename	A string filename to check
version	One of the NexusDescriptor::Version enumerations specifying the required version

Returns: True if the file is considered hierarchical, false otherwise

Definition at line 90 of file NexusDescriptor.cpp.

References filename().

Referenced by Mantid::API::FileLoaderRegistryImpl::canLoad(), Mantid::API::FileLoaderRegistryImpl::chooseLoader(), Mantid::DataHandling::LoadMuonNexus2::exec(), Mantid::DataHandling::UpdateInstrumentFromFile::exec(), Mantid::DataHandling::LoadGeometry::isNexus(), and Mantid::Kernel::NexusHDF5Descriptor::isReadable().

◆ operator=()

NexusDescriptor & Mantid::Kernel::NexusDescriptor::operator= ( const NexusDescriptor & )

delete

Disable assignment operator.

◆ pathExists()

bool Mantid::Kernel::NexusDescriptor::pathExists ( const std::string & path ) const

Query if a path exists.

Parameters

path	A string giving a path using UNIX-style path separators (/), e.g. /raw_data_1, /entry/bank1

Returns: True if the path exists in the file, false otherwise

Definition at line 147 of file NexusDescriptor.cpp.

References m_pathsToTypes.

◆ pathOfType()

std::string Mantid::Kernel::NexusDescriptor::pathOfType ( const std::string & type ) const

return the path of a given type

Parameters

type	A string specifying the required type

Returns: path A string giving a path using UNIX-style path separators (/), e.g. /raw_data_1, /entry/bank1

Definition at line 170 of file NexusDescriptor.cpp.

References m_pathsToTypes.

◆ pathOfTypeExists()

bool Mantid::Kernel::NexusDescriptor::pathOfTypeExists	(	const std::string &	path,
		const std::string &	type
	)		const

Query if a path exists of a given type.

Parameters

path	A string giving a path using UNIX-style path separators (/), e.g. /raw_data_1, /entry/bank1
type	A string specifying the required type

Returns: True if the path exists in the file, false otherwise

Definition at line 157 of file NexusDescriptor.cpp.

References m_pathsToTypes.

Referenced by Mantid::DataHandling::LoadISISNexus2::confidence(), and Mantid::DataHandling::LoadTOFRawNexus::confidence().

◆ walkFile()

void Mantid::Kernel::NexusDescriptor::walkFile	(	::NeXus::File &	file,
		const std::string &	rootPath,
		const std::string &	className,
		std::map< std::string, std::string > &	pmap,
		int	level
	)

private

Walk the tree and cache the structure.

Cache the structure in the given maps.

Parameters

file	An open NeXus File object
rootPath	The current path that is open in the file
className	The class of the current open path
pmap	[Out] An output map filled with mappings of path->type
level	An integer defining the current level in the file

Definition at line 219 of file NexusDescriptor.cpp.

References m_firstEntryNameType, m_rootAttrs, and walkFile().

Referenced by initialize(), and walkFile().

Member Data Documentation

◆ HDF5Signature

const unsigned char Mantid::Kernel::NexusDescriptor::HDF5Signature = {137, 'H', 'D', 'F', '\r', '\n', '\032', '\n'}

static

signature identifying a HDF5 file.

Definition at line 42 of file NexusDescriptor.h.

◆ HDF5SignatureSize

size_t Mantid::Kernel::NexusDescriptor::HDF5SignatureSize = 8

static

Size of HDF5 signature.

Definition at line 40 of file NexusDescriptor.h.

◆ HDFMagic

const unsigned char Mantid::Kernel::NexusDescriptor::HDFMagic = {'\016', '\003', '\023', '\001'}

static

HDF cookie that is stored in the first 4 bytes of the file.

Definition at line 38 of file NexusDescriptor.h.

◆ HDFMagicSize

const size_t Mantid::Kernel::NexusDescriptor::HDFMagicSize = 4

static

Size of HDF magic number.

Definition at line 36 of file NexusDescriptor.h.

◆ m_extension

std::string Mantid::Kernel::NexusDescriptor::m_extension

private

Extension.

Definition at line 107 of file NexusDescriptor.h.

Referenced by initialize().

◆ m_file

std::unique_ptr<::NeXus::File> Mantid::Kernel::NexusDescriptor::m_file

private

Open NeXus handle.

Definition at line 116 of file NexusDescriptor.h.

Referenced by initialize().

◆ m_filename

std::string Mantid::Kernel::NexusDescriptor::m_filename

private

Full filename.

Definition at line 105 of file NexusDescriptor.h.

Referenced by initialize().

◆ m_firstEntryNameType

std::pair<std::string, std::string> Mantid::Kernel::NexusDescriptor::m_firstEntryNameType

private

First entry name/type.

Definition at line 109 of file NexusDescriptor.h.

Referenced by firstEntryNameType(), and walkFile().

◆ m_pathsToTypes

std::map<std::string, std::string> Mantid::Kernel::NexusDescriptor::m_pathsToTypes

private

Map of full path strings to types. Can check if path exists quickly.

Definition at line 113 of file NexusDescriptor.h.

Referenced by classTypeExists(), initialize(), pathExists(), pathOfType(), and pathOfTypeExists().

◆ m_rootAttrs

std::unordered_set<std::string> Mantid::Kernel::NexusDescriptor::m_rootAttrs

private

Root attributes.

Definition at line 111 of file NexusDescriptor.h.

Referenced by hasRootAttr(), initialize(), and walkFile().

The documentation for this class was generated from the following files:

Framework/Kernel/inc/MantidKernel/NexusDescriptor.h
Framework/Kernel/src/NexusDescriptor.cpp

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Member Functions

Private Attributes

Detailed Description

Member Enumeration Documentation

◆ Version

Constructor & Destructor Documentation

◆ NexusDescriptor() [1/3]

◆ ~NexusDescriptor()

◆ NexusDescriptor() [2/3]

◆ NexusDescriptor() [3/3]

Member Function Documentation

◆ classTypeExists()

◆ data()

◆ extension()

◆ filename()

◆ firstEntryNameType()

◆ hasRootAttr()

◆ initialize()

◆ isReadable()

◆ operator=()

◆ pathExists()

◆ pathOfType()

◆ pathOfTypeExists()

◆ walkFile()

Member Data Documentation

◆ HDF5Signature

◆ HDF5SignatureSize

◆ HDFMagic

◆ HDFMagicSize

◆ m_extension

◆ m_file

◆ m_filename

◆ m_firstEntryNameType

◆ m_pathsToTypes

◆ m_rootAttrs