Class RPtrHashSet

class RPtrHashSet : public RHashTableBase;

Description

A templated class which implements an unordered extensional set of objects of type T using a probe-sequence hash table. The objects are not copied into the set when they are added; rather the set stores pointers to the contained objects.

Derivation

• RHashTableBase - No description.

• RPtrHashSet - A templated class which implements an unordered extensional set of objects of type T using a probe-sequence hash table

Members

Defined in RPtrHashSet:
Close(), Count(), Find(), Find(), FindL(), FindL(), Insert(), InsertL(), RPtrHashSet(), RPtrHashSet(), Remove(), Reserve(), ReserveL(), ResetAndDestroy(), TIter

inline RPtrHashSet(const THashFunction32< T > &aHash, const TIdentityRelation< T > &aIdentity);

Description

Construct a set of objects of type T using a specified hash function and identity relation. The set is initially empty.

Parameters

const THashFunction32< T > &aHash The hash function used to hash the objects of type T. const TIdentityRelation< T > &aIdentity The identity relation used to determine if two objects of type T should be considered identical.

inline RPtrHashSet();

Description

Construct a set of objects of type T using a default hash function and identity relation. The set is initially empty.

inline void Close();

Description

Free all memory used by this set. Returns the set to the same state it had following construction.

inline const T *Find(const T &aKey) const;

Description

Locate a specified element in the set.

Parameters

const T &aKey The object of type T to search for.

Return value

const T * A pointer to the specified object, if it is in the set. The object may not be modified via this pointer. NULL if the specified object is not a member of this set.

inline const T &FindL(const T &aKey) const;

Description

Locate a specified element in the set.

Parameters

const T &aKey The object of type T to search for.

Return value

const T & A reference to the specified object, if it is in the set. The object may not be modified via this reference.

Leave codes

KErrNotFound if the specified object is not a member of this set.

inline T *Find(const T &aKey);

Description

Locate a specified element in the set.

Parameters

const T &aKey The object of type T to search for.

Return value

T * A pointer to the specified object, if it is in the set. The object may be modified via this pointer. Care should be taken not to modify any parts of the object which are used by either the hash function or the identity relation for this set. If this is done the set may become inconsistent, resulting in malfunctions and/or panics at a later time. NULL if the specified object is not a member of this set.

inline T &FindL(const T &aKey);

Description

Locate a specified element in the set.

Parameters

const T &aKey The object of type T to search for.

Return value

T & A reference to the specified object, if it is in the set. The object may be modified via this reference. Care should be taken not to modify any parts of the object which are used by either the hash function or the identity relation for this set. If this is done the set may become inconsistent, resulting in malfunctions and/or panics at a later time.

Leave codes

KErrNotFound if the specified object is not a member of this set.

inline TInt Insert(const T *aKey);

Description

Insert an element into the set.

If the specified object is not currently a member of the set, a pointer to the object is added to the set and KErrNone is returned. If the specified object is currently a member of the set, the existing pointer to the object is replaced by the provided pointer and KErrNone is returned. In both cases only a pointer to the object is stored - the object is never copied.

Parameters

const T *aKey A pointer to the object of type T to add to the set.

Return value

TInt KErrNone if the object was added successfully. KErrNoMemory if memory could not be allocated to store the pointer to the new object.

inline void InsertL(const T *aKey);

Description

Insert an element into the set.

If the specified object is not currently a member of the set, a pointer to the object is added to the set and KErrNone is returned. If the specified object is currently a member of the set, the existing pointer to the object is replaced by the provided pointer and KErrNone is returned. In both cases only a pointer to the object is stored - the object is never copied.

Parameters

const T *aKey A pointer to the object of type T to add to the set.

Leave codes

KErrNoMemory if memory could not be allocated to store the pointer to the new object.

inline TInt Remove(const T *aKey);

Description

Remove an element from the set.

Parameters

const T *aKey A pointer to the object to be removed.

Return value

TInt KErrNone if the object was removed successfully. KErrNotFound if the object was not present in the set.

inline TInt Count() const;

Description

Query the number of elements in the set.

Return value

TInt The number of elements currently in the set.

inline TInt Reserve(TInt aCount);

Description

Expand the set to accommodate a specified number of elements. If the set already has enough space for the specified number of elements, no action is taken. Any elements already in the set are retained.

Parameters

TInt aCount The number of elements for which space should be allocated.

Return value

TInt KErrNone if the operation completed successfully. KErrNoMemory if sufficient memory could not be allocated.

inline void ReserveL(TInt aCount);

Description

Expand the set to accommodate a specified number of elements. If the set already has enough space for the specified number of elements, no action is taken. Any elements already in the set are retained.

Parameters

TInt aCount The number of elements for which space should be allocated.

Leave codes

KErrNoMemory if sufficient memory could not be allocated.

void ResetAndDestroy();

Description

Deletes all the objects of type T to which pointers are stored in this set. Then frees all the memory used by the set and returns the set to the same state as immediately following construction.

typedef TPtrHashSetIter<T> RPtrHashSet< T >::TIter;

Description

A class which allows iteration over the elements of a RPtrHashSet<T> class.

The set being iterated over may not be modified while an iteration is in progress or the iteration operations may malfunction or panic.