1 /*

     2 * Copyright (c) 2005,2006 Nokia Corporation and/or its subsidiary(-ies).

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

     5 * under the terms of "Eclipse Public License v1.0"

     6 * which accompanies this distribution, and is available

     7 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description:  Optimizer module for ChspsDomStringPool.

    15 *

    16 */

    17 

    18 #ifndef HSPS_DOM_STRING_POOL_OPTIMIZER_H

    19 #define HSPS_DOM_STRING_POOL_OPTIMIZER_H

    20 

    21 //  INCLUDES

    22 #include <e32base.h>

    23 

    24 // CLASS DECLARATION

    25 

    26 /**

    27 *  @ingroup group_hspsdom

    28 *  Optimizer module entry for ChspsDomStringPool.

    29 *

    30 *  @lib hspsdomdocument.lib

    31 *  @since Series 60 5.2

    32 */

    33 class ThspsDomStringPoolOptimizerEntry

    34     {

    35     public: // Construction.

    36         /**

    37          * Constructor.

    38          * 

    39          * @param aIndex    Index.

    40          * @param aString   String.

    41          */

    42         ThspsDomStringPoolOptimizerEntry( TInt aIndex, const TDesC8& aString ); 

    43 

    44     public: // Data.

    45         /**

    46          * Index of string in actual string pool.

    47          */

    48         TInt iIndex;

    49         

    50         /**

    51          * Reference to string in string pool.

    52          */

    53         const TDesC8& iString;                    

    54     };        

    55 

    56 /**

    57 *  @ingroup group_hspsdom

    58 *  Optimizer module for ChspsDomStringPool.

    59 *

    60 *  @lib hspsdomdocument.lib

    61 *  @since Series 60 5.2

    62 */

    63 class ThspsDomStringPoolOptimizer

    64     {

    65     public:

    66         /**

    67          * Add entry to optimizer list.

    68          * 

    69          * @param aEntry    Entry to be added.

    70          */

    71         void AddEntryL( ThspsDomStringPoolOptimizerEntry& aEntry );

    72         

    73         /**

    74          * Get index for string.

    75          * 

    76          * @param   aString     Reference to given string.

    77          * @return  TInt        Index to actual string pool for string if found.

    78          *                      If string is not found will return KErrNotFound. 

    79          */

    80         TInt GetIndex( const TDesC8& aString );

    81 

    82         /**

    83          * Reset.

    84          */

    85         void Reset();        

    86         

    87         /**

    88          * Close allocated resources.

    89          */

    90         void Close();

    91 

    92         /**

    93          * Get item count.

    94          */

    95         TInt Count();        

    96 

    97         /**

    98          * Get entry.

    99          * 

   100          * @param aIndex    Index to Entry.

   101          */

   102         ThspsDomStringPoolOptimizerEntry& Entry( const TInt aIndex );        

   103         

   104     private:

   105         /**

   106          * Find entry from alphabetic list.

   107          * Uses binary search.

   108          * 

   109          * @param       aString Reference to string to be searched for.

   110          * @param       aLeft   Left limit for binary search

   111          * @param       aRight  Right limit for binary search.

   112          * 

   113          * @return      Index to OPTIMIZER ARRAY. KErrNotFound if

   114          *              given string is not found.

   115          */

   116         TInt FindEntry( const TDesC8& aString,

   117                         const TInt aLeft,

   118                         const TInt aRight );

   119 

   120         /**

   121          * Find a position clue for given string.

   122          * 

   123          * Will return index that can be used to initiate linear

   124          * search. Uses binary search to limit required comparisons

   125          * when string pools starts to fill.

   126          * 

   127          * Note: Returned index is not absolute! it must be

   128          * only used as a start index for linear searching.

   129          * 

   130          * Returned index will be quite close to actual insertion position.

   131          * it will be 0 - 2 steps backward from actual position.

   132          * 

   133          * @param       aString Reference to string.

   134          * @param       aLeft   Left limit for binary search

   135          * @param       aRight  Right limit for binary search.

   136          * 

   137          * @return      Index to start searching for position

   138          *              for given string.

   139          */

   140         TInt FindInsertionIndexEstimate( const TDesC8& aString,

   141                                          const TInt aLeft,

   142                                          const TInt aRight );

   143         

   144     private: // Data.

   145         /**

   146          * Array of optimizer entries.

   147          */

   148         RArray<ThspsDomStringPoolOptimizerEntry> iEntries;

   149     }; 

   150 

   151 #endif      // HSPS_DOM_STRING_POOL_OPTIMIZER_H  

   152             

   153 // End of File