RPtrHashMap Class Reference

#include <e32hashtab.h>

class RPtrHashMap : public RHashTableBase

Inherits from

Detailed Description

A templated class which implements an associative array with key type K and value type V, using a probe-sequence hash table. Neither the key nor value objects are copied into the table when they are added - only pointers are stored.

Member Type Definition Documentation

Typedef TIter

typedef TPtrHashMapIter< K, V >TIter

A class which allows iteration over the elements of a RPtrHashMap<K,V> class.

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

See also: TPtrHashMapIter<K,V>

Constructor & Destructor Documentation

RPtrHashMap ( const THashFunction32< K > &, const TIdentityRelation< K > & )

RPtrHashMap(const THashFunction32< K > &aHash,
const TIdentityRelation< K > &aIdentity
)[inline]

Construct an associative array of key-value pairs of type (K,V) using a specified hash function and identity relation. The array initially contains no key-value pairs.

Parameters
aHashThe hash function used to hash the key objects of type K.
aIdentityThe identity relation used to determine if two key objects of type K should be considered identical.

RPtrHashMap ( )

RPtrHashMap()[inline]

Construct an associative array of key-value pairs of type (K,V) using a default hash function and identity relation. The array initially contains no key-value pairs.

Member Function Documentation

Close ( )

voidClose()[inline]

Reimplemented from RHashTableBase::Close()

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

Count ( )

TInt Count()const [inline]

Reimplemented from RHashTableBase::Count()const

Query the number of key-value pairs in the array.

Return Value
The number of key-value pairs currently in the array.

Find ( const K & )

const V *Find(const K &aKey)const [inline]

Look up a specified key in the associative array and return a pointer to the corresponding value.

Parameters
aKeyThe key object of type K to look up.
Return Value
A pointer to corresponding value object if the specified key object was found. The value object may not be modified via this pointer. NULL if the specified key object was not found.

Find ( const K & )

V *Find(const K &aKey)[inline]

Look up a specified key in the associative array and return a pointer to the corresponding value.

Parameters
aKeyThe key object of type K to look up.
Return Value
A pointer to corresponding value object if the specified key object was found. The value object may be modified via this pointer. NULL if the specified key object was not found.

FindL ( const K & )

const V &FindL(const K &aKey)const [inline]

Look up a specified key in the associative array and return a pointer to the corresponding value.

Parameters
aKeyThe key object of type K to look up.
Return Value
A reference to corresponding value object if the specified key object was found. The value object may not be modified via this reference.
Leave Codes
KErrNotFoundif the specified key object was not found.

FindL ( const K & )

V &FindL(const K &aKey)[inline]

Look up a specified key in the associative array and return a pointer to the corresponding value.

Parameters
aKeyThe key object of type K to look up.
Return Value
A reference to corresponding value object if the specified key object was found. The value object may be modified via this reference.
Leave Codes
KErrNotFoundif the specified key object was not found.

Insert ( const K *, const V * )

TInt Insert(const K *aKey,
const V *aValue
)[inline]

Insert a key-value pair into the array.

If the specified key object is not found in the array, a pointer to the key object along with a pointer to the value object are added to the array and KErrNone is returned. If the specified key object is found in the array, the existing pointers to both the key and value objects are replaced by the provided pointers and KErrNone is returned. In both cases only pointers are stored in the array - the objects themselves are not copied.

Parameters
aKeyA pointer to the key object of type K to add to the array.
aValueA pointer to the value object of type V to associate with aKey.
Return Value
KErrNone if the key-value pair was added successfully. KErrNoMemory if memory could not be allocated to store the pointers aKey and aValue.

InsertL ( const K *, const V * )

voidInsertL(const K *aKey,
const V *aValue
)[inline]

Insert a key-value pair into the array.

If the specified key object is not found in the array, a pointer to the key object along with a pointer to the value object are added to the array and KErrNone is returned. If the specified key object is found in the array, the existing pointers to both the key and value objects are replaced by the provided pointers and KErrNone is returned. In both cases only pointers are stored in the array - the objects themselves are not copied.

Parameters
aKeyA pointer to the key object of type K to add to the array.
aValueA pointer to the value object of type V to associate with aKey.
Leave Codes
KErrNoMemoryif memory could not be allocated to store the pointers aKey and aValue.

Remove ( const K * )

TInt Remove(const K *aKey)[inline]

Remove a key-value pair from the array.

Parameters
aKeyA pointer to the key to be removed.
Return Value
KErrNone if the pointers to the key object and corresponding value object were removed successfully. KErrNotFound if the key object was not present in the array.

Reserve ( TInt )

TInt Reserve(TIntaCount)[inline]

Reimplemented from RHashTableBase::Reserve(TInt)

Expand the array to accommodate a specified number of key-value pairs. 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
aCountThe number of key-value pairs for which space should be allocated.
Return Value
KErrNone if the operation completed successfully. KErrNoMemory if sufficient memory could not be allocated.

ReserveL ( TInt )

voidReserveL(TIntaCount)[inline]

Reimplemented from RHashTableBase::ReserveL(TInt)

Expand the array to accommodate a specified number of key-value pairs. 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
aCountThe number of key-value pairs for which space should be allocated.
Leave Codes
KErrNoMemoryif sufficient memory could not be allocated.

ResetAndDestroy ( )

voidResetAndDestroy()

Deletes all the key objects of type K and corresponding value objects of type V to which pointers are stored in this array. Then frees all the memory used by the array and returns the array to the same state as immediately following construction.