File indexing completed on 2024-04-21 03:56:54

 /*
     This file is part of the KDE libraries
     SPDX-FileCopyrightText: 1999 Waldo Bastian <bastian@kde.org>
 
     SPDX-License-Identifier: LGPL-2.0-only
 */
 
 #ifndef KSYCOCADICT_H
 #define KSYCOCADICT_H
 
 #include "ksycocaentry.h"
 #include <kservice_export.h>
 
 #include <QList>
 
 #include <memory>
 
 class KSycocaDictPrivate;
 
 class QString;
 class QDataStream;
 
 /**
  * @internal
  * Hash table implementation for the sycoca database file
  *
  * Only exported for the unit test
  */
 class KSERVICE_EXPORT KSycocaDict // krazy:exclude=dpointer (not const because it gets deleted by clear())
 {
 public:
     /**
      * Create an empty dict, for building the database
      */
     KSycocaDict();
     /**
      * Create a dict from an existing database
      */
     KSycocaDict(QDataStream *str, int offset);
 
     ~KSycocaDict();
 
     /**
      * Adds a 'payload' to the dictionary with key 'key'.
      *
      * 'payload' should have a valid offset by the time
      * the dictionary gets saved.
      **/
     void add(const QString &key, const KSycocaEntry::Ptr &payload);
 
     /**
      * Removes the 'payload' from the dictionary with key 'key'.
      *
      * Not very fast, use with care O(N)
      **/
     void remove(const QString &key);
 
     /**
      * Looks up an entry identified by 'key'.
      *
      * If 0 is returned, no matching entry exists.
      * Otherwise, the offset of the entry is returned.
      *
      * NOTE: It is not guaranteed that this entry is
      * indeed the one you were looking for.
      * After loading the entry you should check that it
      * indeed matches the search key. If it doesn't
      * then no matching entry exists.
      */
     int find_string(const QString &key) const;
 
     /**
      * Looks up all entries identified by 'key'.
      * This is useful when the dict is used as a multi-hash.
      *
      * If an empty list is returned, no matching entry exists.
      * Otherwise, the offset of the matching entries are returned.
      *
      * NOTE: It is not guaranteed that each entry is
      * indeed among the ones you were looking for.
      * After loading each entry you should check that it
      * indeed matches the search key.
      */
     QList<int> findMultiString(const QString &key) const;
 
     /**
      * The number of entries in the dictionary.
      *
      * Only valid when building the database.
      */
     uint count() const;
 
     /**
      * Reset the dictionary.
      *
      * Only valid when building the database.
      */
     void clear();
 
     /**
      * Save the dictionary to the stream
      * A reasonable fast hash algorithm will be created.
      *
      * Typically this will find 90% of the entries directly.
      * Average hash table size: nrOfItems * 20 bytes.
      * Average duplicate list size: nrOfItms * avgKeyLength / 5.
      *
      * Unknown keys have an average 20% chance to give a false hit.
      * (That's why your program should check the result)
      *
      * Example:
      *   Assume 1000 items with an average key length of 60 bytes.
      *
      *   Approx. 900 items will hash directly to the right entry.
      *   Approx. 100 items require a lookup in the duplicate list.
      *
      *   The hash table size will be approx. 20Kb.
      *   The duplicate list size will be approx. 12Kb.
      **/
     void save(QDataStream &str);
 
 private:
     Q_DISABLE_COPY(KSycocaDict)
     std::unique_ptr<KSycocaDictPrivate> d;
 };
 
 #endif