File indexing completed on 2024-04-28 15:39:55

 /* SPDX-FileCopyrightText: 2003-2020 The KPhotoAlbum Development Team
 
    SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "GroupCounter.h"
 
 #include "ImageDB.h"
 #include "MemberMap.h"
 
 #include <kpabase/StringSet.h>
 using namespace DB;
 
 /**
  * \class DB::GroupCounter
  * \brief Utility class to help counting matches for member groups.
  *
  * This class is used to count the member group matches when
  * categorizing. The class is instantiating with the category we currently
  * are counting items for.
  *
  * The class builds the inverse member map, that is a map pointing from items
  * to parent.
  *
  * As an example, imagine we have the following member map (stored in the
  * variable groupToMemberMap in  the code):
  * \code
  *    { USA |-> [Chicago, Santa Clara],
  *      California |-> [Santa Clara, Los Angeles] }
  * \endcode
  *
  * The inverse map (stored in m_memberToGroup in the code ) will then look
  * like this:
  * \code
  *  { Chicago |-> [USA],
  *    Sanata Clara |-> [ USA, California ],
  *    Los Angeless |-> [ California ] }
  * \endcode
  */
 GroupCounter::GroupCounter(const QString &category)
 {
     const MemberMap map = DB::ImageDB::instance()->memberMap();
     QMap<QString, StringSet> groupToMemberMap = map.groupMap(category);
 
     m_memberToGroup.reserve(2729 /* A large prime */);
     m_groupCount.reserve(2729 /* A large prime */);
 
     // Populate the m_memberToGroup map
     for (QMap<QString, StringSet>::Iterator groupToMemberIt = groupToMemberMap.begin(); groupToMemberIt != groupToMemberMap.end(); ++groupToMemberIt) {
         const StringSet members = groupToMemberIt.value();
         const QString group = groupToMemberIt.key();
 
         for (const auto &member : members) {
             m_memberToGroup[member].append(group);
         }
         m_groupCount.insert(group, CountWithRange());
     }
 }
 
 /**
  * categories is the selected categories for one image, members may be Las Vegas, Chicago, and Los Angeles if the
  * category in question is Places.
  * This function then increases m_groupCount with 1 for each of the groups the relavant items belongs to
  * Las Vegas might increase the m_groupCount[Nevada] by one.
  * The tricky part is to avoid increasing it by more than 1 per image, that is what the countedGroupDict is
  * used for.
  */
 void GroupCounter::count(const StringSet &categories, const ImageDate &date)
 {
     static StringSet countedGroupDict;
 
     countedGroupDict.clear();
     for (StringSet::const_iterator categoryIt = categories.begin(); categoryIt != categories.end(); ++categoryIt) {
         if (m_memberToGroup.contains(*categoryIt)) {
             const QStringList groups = m_memberToGroup[*categoryIt];
             for (const QString &group : groups) {
                 if (!countedGroupDict.contains(group)) {
                     countedGroupDict.insert(group);
                     m_groupCount[group].add(date);
                 }
             }
         }
         // The item Nevada should itself go into the group Nevada.
         if (!countedGroupDict.contains(*categoryIt) && m_groupCount.contains(*categoryIt)) {
             countedGroupDict.insert(*categoryIt);
             m_groupCount[*categoryIt].add(date);
         }
     }
 }
 
 QMap<QString, CountWithRange> GroupCounter::result()
 {
     QMap<QString, CountWithRange> res;
 
     for (QHash<QString, CountWithRange>::const_iterator it = m_groupCount.constBegin(); it != m_groupCount.constEnd(); ++it) {
         if (it.value().count != 0)
             res.insert(it.key(), it.value());
     }
     return res;
 }
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