Gaudi::StringKey Class Reference

The helper class to represent the efficient "key" for access. More...

#include <GaudiKernel/StringKey.h>

Collaboration diagram for Gaudi::StringKey:

Public Member Functions
	StringKey (const char *key="")
	constructor from plain C-string, perform hashing More...
	StringKey (std::string key)
	constructor from std::string, perform hashing More...
const std::string &	str () const
	the actual string More...
	operator const std::string & () const
	implicit cast to std::string More...
bool	empty () const
	empty key? More...
bool	operator! () const
	empty key? More...
bool	operator== (const StringKey &o) const
	equality Key for efficiency reason compare the hash-values first More...
bool	operator== (const std::string &o) const
	equality, without hashing string rely on the native string equality More...
bool	operator!= (const StringKey &o) const
	non equality Key More...
bool	operator!= (const std::string &o) const
	non-equality string More...
bool	operator< (const StringKey &o) const
	less key It can be used as a key for std::map, e.g. More...
bool	operator> (const StringKey &o) const
	greater key More...
bool	operator<= (const StringKey &o) const
	less or equal key More...
bool	operator>= (const StringKey &o) const
	greater or equal key More...
std::size_t	__hash__ () const
	the actual access to the hash More...
std::string	__str__ () const
	the representation of the object More...
std::string	__repr__ () const
	the representation of the object More...
bool	__eq__ (const StringKey &right) const
	equality operator for python More...
bool	__eq__ (const std::string &right) const
	equality operators for python More...
bool	__neq__ (const StringKey &right) const
	non-equality operator for python More...
bool	__neq__ (const std::string &right) const
	non-equality operator for python More...
std::string	toString () const
	string representation (for properties) More...

Private Attributes
std::string	m_str
	the actual string: More...
std::size_t	m_hash
	the hash: More...

Detailed Description

The helper class to represent the efficient "key" for access.

Essentially it is a bit modified version ("boost-free") of the original class stringKey by Gerhard Raven, which is heavily used now in HLT

Attention

NEVER use the actual hash value for anything stored in files, as it is not guaranteed that the hashing scheme will remain the same.

Author

Vanya BELYAEV Ivan..nosp@m.Bely.nosp@m.aev@n.nosp@m.ikhe.nosp@m.f.nl

Date

2009-04-08

Definition at line 35 of file StringKey.h.

Constructor & Destructor Documentation

Gaudi::StringKey::StringKey

(

const char *

key = ""

)

constructor from plain C-string, perform hashing

Definition at line 26 of file StringKey.cpp.

    : m_str( key ), m_hash( std::hash<std::string>()( m_str ) ) // NB! hashing here!!!
{
}

Gaudi::StringKey::StringKey

(

std::string

key

)

constructor from std::string, perform hashing

Definition at line 19 of file StringKey.cpp.

    : m_str( std::move( key ) ), m_hash( std::hash<std::string>()( m_str ) ) // NB! hashing here!!!
{
}

Member Function Documentation

bool Gaudi::StringKey::__eq__

(

const StringKey &

right

)

const

equality operator for python

Definition at line 44 of file StringKey.cpp.

{ return this == &right || *this == right; }

bool Gaudi::StringKey::__eq__

(

const std::string &

right

)

const

equality operators for python

Definition at line 48 of file StringKey.cpp.

{ return *this == right; }

std::size_t Gaudi::StringKey::__hash__ ( ) const

inline

the actual access to the hash

Attention

NEVER use the actual hash value for anything stored in files, as it is not guaranteed that the hashing scheme will remain the same. The two reason for this function are:

• transparent usage of this object for hashmap-like containers
• Python the actual hash value

Definition at line 116 of file StringKey.h.

{ return m_hash; }

bool Gaudi::StringKey::__neq__

(

const StringKey &

right

)

const

non-equality operator for python

Definition at line 52 of file StringKey.cpp.

{ return this != &right && *this != right; }

bool Gaudi::StringKey::__neq__

(

const std::string &

right

)

const

non-equality operator for python

Definition at line 56 of file StringKey.cpp.

{ return *this != right; }

std::string Gaudi::StringKey::__repr__

(

)

const

the representation of the object

Definition at line 41 of file StringKey.cpp.

{ return toString(); }

std::string Gaudi::StringKey::__str__

(

)

const

the representation of the object

Definition at line 37 of file StringKey.cpp.

{ return toString(); }

bool Gaudi::StringKey::empty ( ) const

inline

empty key?

Definition at line 51 of file StringKey.h.

{ return m_str.empty(); }

Gaudi::StringKey::operator const std::string & ( ) const

inline

implicit cast to std::string

Definition at line 49 of file StringKey.h.

{ return str(); }

bool Gaudi::StringKey::operator! ( ) const

inline

empty key?

Definition at line 53 of file StringKey.h.

{ return empty(); }

bool Gaudi::StringKey::operator!= ( const StringKey &  o ) const

inline

non equality Key

Definition at line 69 of file StringKey.h.

{ return !( *this == o ); }

bool Gaudi::StringKey::operator!= ( const std::string &  o ) const

inline

non-equality string

Definition at line 71 of file StringKey.h.

{ return !( *this == o ); }

bool Gaudi::StringKey::operator< ( const StringKey &  o ) const

inline

less key It can be used as a key for std::map, e.g.

std::map<StringKey,double> Note that with such maps one can gain if using prehashed key:

 typedef std::map<StringKey,double> MAP ;

 const StringKey& key = ...  ;

 const MAP& m = ... ;

 // EFFICIENT:
MAP::const_iterator i1 = m.find ( key ) ;

// CAN BE VERY INEFICIENT:
MAP::const_iterator i2 = m_find( "SomeLongKey,_e.g._TES_Locaiton" );

Definition at line 96 of file StringKey.h.

{ return m_hash == o.m_hash ? m_str < o.m_str : m_hash < o.m_hash; }

bool Gaudi::StringKey::operator<= ( const StringKey &  o ) const

inline

less or equal key

Definition at line 100 of file StringKey.h.

{ return !( *this > o ); }

bool Gaudi::StringKey::operator== ( const StringKey &  o ) const

inline

equality Key for efficiency reason compare the hash-values first

Definition at line 60 of file StringKey.h.

{ return m_hash == o.m_hash && m_str == o.m_str; }

bool Gaudi::StringKey::operator== ( const std::string &  o ) const

inline

equality, without hashing string rely on the native string equality

Definition at line 64 of file StringKey.h.

{ return m_str == o; }

bool Gaudi::StringKey::operator> ( const StringKey &  o ) const

inline

greater key

Definition at line 98 of file StringKey.h.

{ return o < *this; }

bool Gaudi::StringKey::operator>= ( const StringKey &  o ) const

inline

greater or equal key

Definition at line 102 of file StringKey.h.

{ return !( *this < o ); }

const std::string& Gaudi::StringKey::str ( ) const

inline

the actual string

Definition at line 47 of file StringKey.h.

{ return m_str; }

std::string Gaudi::StringKey::toString

(

)

const

string representation (for properties)

Definition at line 33 of file StringKey.cpp.

{ return Gaudi::Utils::toString( m_str ); }

Member Data Documentation

std::size_t Gaudi::StringKey::m_hash

private

the hash:

Definition at line 141 of file StringKey.h.

std::string Gaudi::StringKey::m_str

private

the actual string:

Definition at line 139 of file StringKey.h.

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

• GaudiKernel/GaudiKernel/StringKey.h
• GaudiKernel/src/Lib/StringKey.cpp