| # Gaudi Framework, version v25r0 |

Home |  | Generated: Mon Feb 17 2014

- Main Page
- Related Pages
- Modules
- Namespaces
- Classes
- Files

- Class List
- Class Index
- Class Hierarchy
- Class Members

All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Properties Friends Macros Groups Pages
Public Member Functions | Private Attributes | List of all members
Gaudi::StringKey Class Reference

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

`#include <StringKey.h>`

Collaboration diagram for Gaudi::StringKey:
[legend]

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

## Private Attributes
std::string | m_str
| the actual string:
std::size_t | m_hash
| the hash:

## 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 std::string & | key = `""` | ) |

constructor from the string, perform hashing

Definition at line 25 of file StringKey.cpp.

: m_str ( key )
, m_hash ( boost::hash_value( key ) ) // 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 49 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 114 of file StringKey.h.

{ return m_hash ; }

bool Gaudi::StringKey::__neq__ | ( | const StringKey & | right | ) | const

non-equality operator for python

Definition at line 54 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 59 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 49 of file StringKey.h.

{ return m_str.empty() ; }

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

implicit cast to std::string

Definition at line 47 of file StringKey.h.

{ return str() ; }

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

empty key?

Definition at line 51 of file StringKey.h.

{ return empty() ; }

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

non equality Key

Definition at line 68 of file StringKey.h.

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

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

non-equality string

Definition at line 70 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 94 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 99 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 58 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 63 of file StringKey.h.

{ return m_str == o ; }

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

greater key

Definition at line 97 of file StringKey.h.

{ return o < *this ; }

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

greater or equal key

Definition at line 101 of file StringKey.h.

{ return !(*this < o ) ; }

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

the actual string

Definition at line 45 of file StringKey.h.

{ return m_str ; }

std::string Gaudi::StringKey::toString | ( |  | ) | const

string representation (for properties)

Definition at line 32 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 139 of file StringKey.h.

std::string Gaudi::StringKey::m_str
| private

the actual string:

Definition at line 137 of file StringKey.h.

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

- /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v25r0/GaudiKernel/GaudiKernel/StringKey.h
- /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v25r0/GaudiKernel/src/Lib/StringKey.cpp