diff options
Diffstat (limited to 'kdecore/ksycocadict.h')
-rw-r--r-- | kdecore/ksycocadict.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/kdecore/ksycocadict.h b/kdecore/ksycocadict.h new file mode 100644 index 000000000..dec6a8cc8 --- /dev/null +++ b/kdecore/ksycocadict.h @@ -0,0 +1,123 @@ +/* This file is part of the KDE libraries + * Copyright (C) 1999 Waldo Bastian <bastian@kde.org> + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License version 2 as published by the Free Software Foundation; + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public License + * along with this library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + **/ + +#ifndef __ksycocadict_h__ +#define __ksycocadict_h__ + +#include <qstring.h> +#include <qvaluelist.h> +#include <qdatastream.h> +#include "kdelibs_export.h" + +class KSycocaEntry; +class KSycocaDictStringList; + +/** + * @internal + * Hash table implementation for the sycoca database file + */ +class KDECORE_EXPORT KSycocaDict +{ +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, KSycocaEntry *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 ); + + /** + * The number of entries in the dictionary. + * + * Only valid when building the database. + */ + uint count(); + + /** + * 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); + +protected: + Q_UINT32 hashKey( const QString &); +private: + KSycocaDictStringList *d; + QDataStream *mStr; + Q_INT32 mOffset; + Q_UINT32 mHashTableSize; + QValueList<Q_INT32> mHashList; +}; + +#endif |