Symbian
Symbian OS Library

SYMBIAN OS V9.3

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Location: S32BTREE.H
Link against: estor.lib

Class MBtreeKey

class MBtreeKey;

Description

Interface for ordering and creating keys for entries in a B-tree.

Derived classes implement this interface for particular types of key.

Members

Defined in MBtreeKey:
Between(), Compare(), Key()


Member functions


Key()

virtual IMPORT_C const TAny *Key(const TAny *anEntry) const;

Description

Gets the key value for an entry.

Parameters

const TAny *anEntry

Object for which to get the key value

Return value

const TAny *

Pointer to the key value


Compare()

virtual TInt Compare(const TAny *aLeft, const TAny *aRight) const=0;

Description

Orders two keys.

Parameters

const TAny *aLeft

Pointer to first key

const TAny *aRight

Pointer to second key

Return value

TInt

Positive, if the first key is after the second key; negative, if the first key is before the second key; zero, if the keys are equal


Between()

virtual void Between(const TAny *aLeft, const TAny *aRight, TBtreePivot &aPivot) const=0;

Description

Gets the midpoint between two keys.

The generated midpoint will be greater or equal to aLeft (by a comparison performed by the Compare() function), and less than aRight.

Parameters

const TAny *aLeft

First key

const TAny *aRight

Second key

TBtreePivot &aPivot

On return, the midpoint between the two keys