DBArray< T > Class Template Reference

Class for accessing arrays of objects in the database. More...

#include <DBArray.h>

Inheritance diagram for DBArray< T >:

Public Types
typedef ObjArrayIterator< const TClonesArray, const T >	const_iterator
	STL-like const_iterator over the T objects (not T* ).

Public Member Functions
	DBArray (const std::string &name="", bool required=true)
	Constructor to access an array of objects in the DBStore.
int	getEntries () const
	Get the number of objects in the array.
const T *	operator[] (int i) const
	Access to the stored objects.
template<class KEY >
const T *	getByKey (KEY(T::*method)(void) const, KEY key) const
	Access object by key instead of by index.
const_iterator	begin () const
	Return const_iterator to first entry.
const_iterator	end () const
	Return const_iterator to last entry +1.
const std::string &	getName () const
	Return name under which the object is saved in the DBStore.
bool	isValid () const
	Check whether a valid object was obtained from the database.
	operator bool () const
	Imitate pointer functionality.
virtual bool	operator== (const DBAccessorBase &other) const
	Check if two store accessors point to the same object/array.
virtual bool	operator!= (const DBAccessorBase &other) const
	Check if two store accessors point to a different object/array.
bool	hasChanged ()
	Check whether the object has changed since the last call to hasChanged of the accessor).
void	addCallback (std::function< void(const std::string &)> callback, bool onDestruction=false)
	Add a callback method.
void	addCallback (std::function< void()> callback, bool onDestruction=false)
	Add a callback method.
template<class T >
void	addCallback (T *object, void(T::*callback)())
	Add a callback method of an object.
const std::string &	getGlobaltag () const
	Return the globaltag name (or testing payloads path) this object is loaded from.
unsigned int	getRevision () const
	Return current revision of the object.
IntervalOfValidity	getIoV () const
	Return current IoV of the object.
const std::string &	getChecksum () const
	Get current checksum.
const std::string &	getFilename () const
	Get the filename this object is loaded from.
bool	isIntraRunDependent () const
	Check wether this conditions object has some intra-run dependencies.
const std::vector< unsigned int >	getIntraRunBoundaries () const
	Get the intra-run boundaries, if any.
bool	isRequired () const
	Check whether this conditions object is required (at least one user declared it as required)

Protected Member Functions
template<class T = TObject>
const T *	getObject () const
	Return a pointer to the Object already cast to the correct type.
bool	ensureAttached () const
	Make sure we are attached to the the DBStore.
void	storeEntryChanged (bool destructed)
	Callback function which gets called by the DBStoreEntry object if it changes.

Protected Attributes
const DBStoreEntry::EPayloadType	m_type
	Type of the payload.
const std::string	m_name
	Name of the payload in the database.
const TClass *	m_objClass
	Class of the payload if type is c_Object.
const bool	m_isArray
	True if the payload is an array of objects.
const bool	m_isRequired
	True if the payload is required, otherwise no errors will be raised if it cannot be found.
DBStoreEntry *	m_entry
	Pointer to the entry in the DBStore.
bool	m_changed {false}
	Internal flag whether the object has changed since we last checked.
std::vector< std::pair< std::function< void(const std::string &)>, bool > >	m_callbacks
	List of all registered callback functions.

Detailed Description

template<class T>
class Belle2::DBArray< T >

Class for accessing arrays of objects in the database.

Definition at line 26 of file DBArray.h.

Member Typedef Documentation

const_iterator

typedef ObjArrayIterator<const TClonesArray, const T> const_iterator

STL-like const_iterator over the T objects (not T* ).

Definition at line 29 of file DBArray.h.

Constructor & Destructor Documentation

DBArray()

DBArray ( const std::string &  name = "", bool  required = true  )

inlineexplicit

Constructor to access an array of objects in the DBStore.

Parameters

name	Name under which the array is stored in the database (and DBStore).
required	if false there will be no errors if the object cannot be found in the database. However this will require the user to check if the object is valid before each use.

Definition at line 38 of file DBArray.h.

                                                                      :
      DBAccessorBase(DBStore::arrayName<T>(name), T::Class(), true, required) {}

Member Function Documentation

addCallback() [1/3]

void addCallback ( std::function< void()>  callback, bool  onDestruction = false  )

inlineinherited

Add a callback method.

The given method will be called whenever there is a new database entry for this DBAccessor.

Parameters

callback	function pointer to a callback function
onDestruction	if true the callback will not be called for each change but only when the Database entry is deleted and can be used to remove dangling pointers to the entry.

Definition at line 118 of file DBAccessorBase.h.

    {
      addCallback([callback](const std::string&) -> void { callback(); }, onDestruction);
    }

addCallback() [2/3]

void addCallback ( std::function< void(const std::string &)>  callback, bool  onDestruction = false  )

inlineinherited

Add a callback method.

The given method will be called whenever there is a new database entry for this DBAccessor. The one parameter is the name of the DB entry which changed (in case the same callback method is to be used for multiple payloads.

Parameters

callback	function pointer to a callback function
onDestruction	if true the callback will not be called for each change but only when the Database entry is deleted and can be used to remove dangling pointers to the entry.

Definition at line 105 of file DBAccessorBase.h.

    {
      m_callbacks.emplace_back(callback, onDestruction);
    }

addCallback() [3/3]

void addCallback ( T *  object, void(T::*)()  callback  )

inlineinherited

Add a callback method of an object.

The given method will be called whenever there is a new database entry for this DBAccessor.

Parameters

object	The object with the callback method.
callback	The callback method.

Definition at line 130 of file DBAccessorBase.h.

    {
      addCallback([ = ](const std::string&) {(*object.*callback)();});
    }

begin()

const_iterator begin ( ) const

inline

Return const_iterator to first entry.

Definition at line 82 of file DBArray.h.

{ return const_iterator(getObject<TClonesArray>(), false); }

end()

const_iterator end ( ) const

inline

Return const_iterator to last entry +1.

Definition at line 84 of file DBArray.h.

{ return const_iterator(getObject<TClonesArray>(), true); }

ensureAttached()

bool ensureAttached ( ) const

inlineprotectedinherited

Make sure we are attached to the the DBStore.

If not try to reconnect

Definition at line 171 of file DBAccessorBase.h.

    {
      if (!m_entry) {
        B2DEBUG(32, "DBAccessor " << m_name << " lost connection, reattaching");
        m_entry = DBStore::Instance().getEntry(m_type, m_name, m_objClass, m_isArray, m_isRequired);
        m_changed = true;
        if (!m_entry) return false;
        m_entry->registerAccessor(const_cast<DBAccessorBase*>(this));
      }
      return true;
    }

getByKey()

const T * getByKey ( KEY(T::*)(void) const  method, KEY  key  ) const

inline

Access object by key instead of by index.

Parameters

method	pointer to a member function of the objects in the array which will return the key for a given element
key	key to look for. If none of the elements return this key then NULL is returned

Definition at line 69 of file DBArray.h.

    {
      const TClonesArray& array = *getObject<TClonesArray>();
      for (int i = 0; i < getEntries(); i++) {
        T* obj = static_cast<T*>(array.At(i));
        if ((*obj.*method)() == key) {
          return obj;
        }
      }
      return nullptr;
    }

getChecksum()

const std::string & getChecksum ( ) const

inlineinherited

Get current checksum.

Definition at line 145 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getChecksum(); }

getEntries()

int getEntries ( ) const

inline

Get the number of objects in the array.

Definition at line 42 of file DBArray.h.

{ return isValid() ? getObject<TClonesArray>()->GetEntriesFast() : 0;}

getFilename()

const std::string & getFilename ( ) const

inlineinherited

Get the filename this object is loaded from.

Definition at line 148 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getFilename(); }

getGlobaltag()

const std::string & getGlobaltag ( ) const

inlineinherited

Return the globaltag name (or testing payloads path) this object is loaded from.

Definition at line 136 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getGlobaltag(); }

getIntraRunBoundaries()

const std::vector< unsigned int > getIntraRunBoundaries ( ) const

inlineinherited

Get the intra-run boundaries, if any.

If the intra-run dependency is by event number, the event numbers used as boundaries are returned.

Definition at line 157 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getIntraRunBoundaries(); }

getIoV()

IntervalOfValidity getIoV ( ) const

inlineinherited

Return current IoV of the object.

Definition at line 142 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getIoV(); }

getName()

const std::string & getName ( ) const

inlineinherited

Return name under which the object is saved in the DBStore.

Definition at line 66 of file DBAccessorBase.h.

{ return m_name; }

getObject()

const T * getObject ( ) const

inlineprotectedinherited

Return a pointer to the Object already cast to the correct type.

Definition at line 164 of file DBAccessorBase.h.

    {
      if (!ensureAttached()) return nullptr;
      return reinterpret_cast<const T*>(m_entry->getObject());
    }

getRevision()

unsigned int getRevision ( ) const

inlineinherited

Return current revision of the object.

Definition at line 139 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->getRevision(); }

hasChanged()

bool hasChanged ( )

inlineinherited

Check whether the object has changed since the last call to hasChanged of the accessor).

Definition at line 89 of file DBAccessorBase.h.

    {
      const bool ret = m_changed;
      m_changed = false;
      return ret;
    }

isIntraRunDependent()

bool isIntraRunDependent ( ) const

inlineinherited

Check wether this conditions object has some intra-run dependencies.

Definition at line 151 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->isIntraRunDependent(); }

isRequired()

bool isRequired ( ) const

inlineinherited

Check whether this conditions object is required (at least one user declared it as required)

Definition at line 160 of file DBAccessorBase.h.

{ ensureAttached(); return m_entry->isRequired(); }

isValid()

bool isValid ( ) const

inlineinherited

Check whether a valid object was obtained from the database.

Returns

True if the object exists.

Definition at line 72 of file DBAccessorBase.h.

{if (!ensureAttached()) return false; return (m_entry->getObject() != nullptr);}

operator bool()

operator bool ( ) const

inlineinherited

Imitate pointer functionality.

Definition at line 74 of file DBAccessorBase.h.

operator!=()

virtual bool operator!= ( const DBAccessorBase &  other ) const

inlinevirtualinherited

Check if two store accessors point to a different object/array.

Definition at line 83 of file DBAccessorBase.h.

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

operator==()

virtual bool operator== ( const DBAccessorBase &  other ) const

inlinevirtualinherited

Check if two store accessors point to the same object/array.

Definition at line 77 of file DBAccessorBase.h.

    {
      return getName() == other.getName();
    }

operator[]()

const T * operator[] ( int  i ) const

inline

Access to the stored objects.

Out-of-bounds accesses throw an std::out_of_range exception

Parameters

i	Array index, should be in 0..getEntries()-1

Returns

pointer to the object

Definition at line 51 of file DBArray.h.

    {
      if (!isValid()) {
        throw std::out_of_range("Out-of-range access in DBArray::operator[], for " + getName() + ": Object not valid");
      }
      //At() checks for out-of-range and returns NULL in that case
      TObject* obj = getObject<TClonesArray>()->At(i);
      if (obj == nullptr)
        throw std::out_of_range("Out-of-range access in DBArray::operator[], for " + getName() + ", index " + std::to_string(i));
      return static_cast<T*>(obj); //type was checked by DataStore, so the cast is safe.
    }

storeEntryChanged()

void storeEntryChanged ( bool  destructed )

inlineprotectedinherited

Callback function which gets called by the DBStoreEntry object if it changes.

Definition at line 184 of file DBAccessorBase.h.

    {
      // we obviously changed
      m_changed = true;
      // StoreEntry is destructed, remove reference
      if (destructed) m_entry = nullptr;
      // Now run all registered callbacks
      // TODO: We could guard m_callbacks against insertions during callback
      // execution to prevent exponential growth of callbacks
      for (const auto& cb : m_callbacks) {
        if (destructed == cb.second) cb.first(m_name);
      }
    }

Member Data Documentation

m_callbacks

std::vector<std::pair<std::function<void(const std::string&)>, bool> > m_callbacks

protectedinherited

List of all registered callback functions.

Definition at line 213 of file DBAccessorBase.h.

m_changed

bool m_changed {false}

mutableprotectedinherited

Internal flag whether the object has changed since we last checked.

Definition at line 211 of file DBAccessorBase.h.

m_entry

DBStoreEntry* m_entry

mutableprotectedinherited

Pointer to the entry in the DBStore.

Definition at line 209 of file DBAccessorBase.h.

m_isArray

const bool m_isArray

protectedinherited

True if the payload is an array of objects.

Definition at line 205 of file DBAccessorBase.h.

m_isRequired

const bool m_isRequired

protectedinherited

True if the payload is required, otherwise no errors will be raised if it cannot be found.

Definition at line 207 of file DBAccessorBase.h.

m_name

const std::string m_name

protectedinherited

Name of the payload in the database.

Definition at line 201 of file DBAccessorBase.h.

m_objClass

const TClass* m_objClass

protectedinherited

Class of the payload if type is c_Object.

Definition at line 203 of file DBAccessorBase.h.

m_type

const DBStoreEntry::EPayloadType m_type

protectedinherited

Type of the payload.

Definition at line 199 of file DBAccessorBase.h.

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

• framework/database/include/DBArray.h