| # kdecore Library API Documentation
Overview | Class Hierarchy | Classes | Classes (annotated) | Members | Source Files

# ksycocadict.cpp

    00001 /*  This file is part of the KDE libraries
    00002  *  Copyright (C) 1999 Waldo Bastian <bastian@kde.org>
    00003  *
    00004  *  This library is free software; you can redistribute it and/or
    00005  *  modify it under the terms of the GNU Library General Public
    00006  *  License version 2 as published by the Free Software Foundation;
    00007  *
    00008  *  This library is distributed in the hope that it will be useful,
    00009  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
    00010  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00011  *  Library General Public License for more details.
    00012  *
    00013  *  You should have received a copy of the GNU Library General Public License
    00014  *  along with this library; see the file COPYING.LIB.  If not, write to
    00015  *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00016  *  Boston, MA 02111-1307, USA.
    00017  **/
    00018
    00019 #include "ksycocadict.h"
    00020 #include "ksycocaentry.h"
    00021 #include "ksycoca.h"
    00022
    00023 #include <qptrlist.h>
    00024 #include <qvaluelist.h>
    00025 #include <kdebug.h>
    00026 #include <stdlib.h>
    00027
    00028 struct string_entry {
    00029   string_entry(QString _key, KSycocaEntry *_payload)
    00030   { keyStr = _key; key = keyStr.unicode(); length = keyStr.length(); payload = _payload; hash = 0; }
    00031   uint hash;
    00032   int length;
    00033   const QChar *key;
    00034   QString keyStr;
    00035   KSycocaEntry *payload;
    00036 };
    00037
    00038 template class QPtrList<string_entry>;
    00039
    00040 class KSycocaDictStringList : public QPtrList<string_entry>
    00041 {
    00042 public:
    00043    KSycocaDictStringList();
    00044 };
    00045
    00046 KSycocaDictStringList::KSycocaDictStringList()
    00047 {
    00048    setAutoDelete(true);
    00049 }
    00050
    00051 KSycocaDict::KSycocaDict()
    00052   : d(0), mStr(0), mOffset(0)
    00053 {
    00054 }
    00055
    00056 KSycocaDict::KSycocaDict(QDataStream *str, int offset)
    00057   : d(0), mStr(str), mOffset(offset)
    00058 {
    00059    Q_UINT32 test1, test2;
    00060    str->device()->at(offset);
    00061    (*str) >> test1 >> test2;
    00062    if ((test1 > 0x000fffff) || (test2 > 1024))
    00063    {
    00064        KSycoca::flagError();
    00065        mHashTableSize = 0;
    00066        mOffset = 0;
    00067        return;
    00068    }
    00069
    00070    str->device()->at(offset);
    00071    (*str) >> mHashTableSize;
    00072    (*str) >> mHashList;
    00073    mOffset = str->device()->at(); // Start of hashtable
    00074 }
    00075
    00076 KSycocaDict::~KSycocaDict()
    00077 {
    00078    delete d;
    00079 }
    00080
    00081 void
    00082 KSycocaDict::add(const QString &key, KSycocaEntry *payload)
    00083 {
    00084    if (key.isEmpty()) return; // Not allowed (should never happen)
    00085    if (!payload) return; // Not allowed!
    00086    if (!d)
    00087    {
    00088        d = new KSycocaDictStringList();
    00089    }
    00090
    00091    string_entry *entry= new string_entry(key, payload);
    00092    d->append(entry);
    00093 }
    00094
    00095 int
    00096 KSycocaDict::find_string(const QString &key )
    00097 {
    00098    //kdDebug(7011) << QString("KSycocaDict::find_string(%1)").arg(key) << endl;
    00099
    00100    if (!mStr || !mOffset)
    00101    {
    00102       kdError(7011) << "No database available!" << endl;
    00103       return 0;
    00104    }
    00105
    00106    if (mHashTableSize == 0)
    00107       return 0; // Unlikely to find anything :-]
    00108
    00109    // Read hash-table data
    00110    uint hash = hashKey(key) % mHashTableSize;
    00111    //kdDebug(7011) << QString("hash is %1").arg(hash) << endl;
    00112
    00113    uint off = mOffset+sizeof(Q_INT32)*hash;
    00114    //kdDebug(7011) << QString("off is %1").arg(off,8,16) << endl;
    00115    mStr->device()->at( off );
    00116
    00117    Q_INT32 offset;
    00118    (*mStr) >> offset;
    00119
    00120    //kdDebug(7011) << QString("offset is %1").arg(offset,8,16) << endl;
    00121    if (offset == 0)
    00122       return 0;
    00123
    00124    if (offset > 0)
    00125       return offset; // Positive ID
    00126
    00127    // Lookup duplicate list.
    00128    offset = -offset;
    00129
    00130    mStr->device()->at(offset);
    00131    //kdDebug(7011) << QString("Looking up duplicate list at %1").arg(offset,8,16) << endl;
    00132
    00133    while(true)
    00134    {
    00135        (*mStr) >> offset;
    00136        if (offset == 0) break;
    00137        QString dupkey;
    00138        (*mStr) >> dupkey;
    00139        //kdDebug(7011) << QString(">> %1 %2").arg(offset,8,16).arg(dupkey) << endl;
    00140        if (dupkey == key) return offset;
    00141    }
    00142    //kdWarning(7011) << "Not found!" << endl;
    00143
    00144    return 0;
    00145 }
    00146
    00147 uint
    00148 KSycocaDict::count()
    00149 {
    00150    if (!d) return 0;
    00151
    00152    return d->count();
    00153 }
    00154
    00155 void
    00156 KSycocaDict::clear()
    00157 {
    00158    delete d;
    00159    d = 0;
    00160 }
    00161
    00162 uint
    00163 KSycocaDict::hashKey( const QString &key)
    00164 {
    00165    int l = key.length();
    00166    register uint h = 0;
    00167
    00168    for(uint i = 0; i < mHashList.count(); i++)
    00169    {
    00170       int pos = mHashList[i];
    00171       if (pos < 0)
    00172       {
    00173          pos = -pos-1;
    00174          if (pos < l)
    00175             h = ((h * 13) + (key[l-pos].cell() % 29)) & 0x3ffffff;
    00176       }
    00177       else
    00178       {
    00179          pos = pos-1;
    00180          if (pos < l)
    00181             h = ((h * 13) + (key[pos].cell() % 29)) & 0x3ffffff;
    00182       }
    00183    }
    00184    return h;
    00185 }
    00186
    00187 //
    00188 // Calculate the diversity of the strings at position 'pos'
    00189 int
    00190 calcDiversity(KSycocaDictStringList *d, int pos, int sz)
    00191 {
    00192    if (pos == 0) return 0;
    00193    bool *matrix = (bool *) calloc(sz, sizeof(bool));
    00194    uint usz = sz;
    00195
    00196    if (pos < 0)
    00197    {
    00198       pos = -pos-1;
    00199       for(string_entry *entry=d->first(); entry; entry = d->next())
    00200       {
    00201         register int l = entry->length;
    00202          if (pos < l && pos != 0)
    00203          {
    00204            register uint hash = ((entry->hash * 13) + (entry->key[l-pos].cell() % 29)) & 0x3ffffff;
    00205            matrix[ hash % usz ] = true;
    00206          }
    00207       }
    00208    }
    00209    else
    00210    {
    00211       pos = pos-1;
    00212       for(string_entry *entry=d->first(); entry; entry = d->next())
    00213       {
    00214          if (pos < entry->length)
    00215          {
    00216             register uint hash = ((entry->hash * 13) + (entry->key[pos].cell() % 29)) & 0x3ffffff;
    00217             matrix[ hash % usz ] = true;
    00218          }
    00219       }
    00220    }
    00221    int diversity = 0;
    00222    for(int i=0;i< sz;i++)
    00223       if (matrix[i]) diversity++;
    00224
    00225    free((void *) matrix);
    00226
    00227    return diversity;
    00228 }
    00229
    00230 //
    00231 // Add the diversity of the strings at position 'pos'
    00232 void
    00233 addDiversity(KSycocaDictStringList *d, int pos)
    00234 {
    00235    if (pos == 0) return;
    00236    if (pos < 0)
    00237    {
    00238       pos = -pos-1;
    00239       for(string_entry *entry=d->first(); entry; entry = d->next())
    00240       {
    00241          register int l = entry->length;
    00242          if (pos < l)
    00243             entry->hash = ((entry->hash * 13) + (entry->key[l-pos].cell() % 29)) & 0x3fffffff;
    00244       }
    00245    }
    00246    else
    00247    {
    00248       pos = pos - 1;
    00249       for(string_entry *entry=d->first(); entry; entry = d->next())
    00250       {
    00251          if (pos < entry->length)
    00252             entry->hash = ((entry->hash * 13) + (entry->key[pos].cell() % 29)) & 0x3fffffff;
    00253       }
    00254    }
    00255 }
    00256
    00257
    00258 void
    00259 KSycocaDict::save(QDataStream &str)
    00260 {
    00261    if (count() == 0)
    00262    {
    00263       mHashTableSize = 0;
    00264       mHashList.clear();
    00265       str << mHashTableSize;
    00266       str << mHashList;
    00267       return;
    00268    }
    00269
    00270    mOffset = str.device()->at();
    00271
    00272    //kdDebug(7011) << QString("KSycocaDict: %1 entries.").arg(count()) << endl;
    00273
    00274    //kdDebug(7011) << "Calculating hash keys.." << endl;
    00275
    00276    int maxLength = 0;
    00277    //kdDebug(7011) << "Finding maximum string length" << endl;
    00278    for(string_entry *entry=d->first(); entry; entry = d->next())
    00279    {
    00280       entry->hash = 0;
    00281       if (entry->length > maxLength)
    00282          maxLength = entry->length;
    00283    }
    00284
    00285    //kdDebug(7011) << QString("Max string length = %1").arg(maxLength) << endl;
    00286
    00287    // use "almost prime" number for sz (to calculate diversity) and later
    00288    // for the table size of big tables
    00289    // int sz = d->count()*5-1;
    00290    register unsigned int sz = count()*4 + 1;
    00291    while(!(((sz % 3) && (sz % 5) && (sz % 7) && (sz % 11) && (sz % 13)))) sz+=2;
    00292
    00293    int maxDiv = 0;
    00294    int maxPos = 0;
    00295    int lastDiv = 0;
    00296
    00297    mHashList.clear();
    00298
    00299    // try to limit diversity scan by "predicting" positions
    00300    // with high diversity
    00301    int *oldvec=new int[maxLength*2+1];
    00302    for (int i=0; i<(maxLength*2+1); i++) oldvec[i]=0;
    00303    int mindiv=0;
    00304
    00305    while(true)
    00306    {
    00307       int divsum=0,divnum=0;
    00308
    00309       maxDiv = 0;
    00310       maxPos = 0;
    00311       for(int pos=-maxLength; pos <= maxLength; pos++)
    00312       {
    00313          // cut off
    00314          if (oldvec[pos+maxLength]<mindiv)
    00315          { oldvec[pos+maxLength]=0; continue; }
    00316
    00317          int diversity = calcDiversity(d, pos, sz);
    00318          if (diversity > maxDiv)
    00319          {
    00320             maxDiv = diversity;
    00321             maxPos = pos;
    00322          }
    00323          oldvec[pos+maxLength]=diversity;
    00324          divsum+=diversity; divnum++;
    00325       }
    00326       // arbitrary cut-off value 3/4 of average seems to work
    00327       if (divnum)
    00328          mindiv=(3*divsum)/(4*divnum);
    00329
    00330       if (maxDiv <= lastDiv)
    00331          break;
    00332       // qWarning("Max Div = %d at pos %d", maxDiv, maxPos);
    00333       lastDiv = maxDiv;
    00334       addDiversity(d, maxPos);
    00335       mHashList.append(maxPos);
    00336    }
    00337
    00338    delete [] oldvec;
    00339
    00340    for(string_entry *entry=d->first(); entry; entry = d->next())
    00341    {
    00342       entry->hash = hashKey(entry->keyStr);
    00343    }
    00344 // fprintf(stderr, "Calculating minimum table size..\n");
    00345
    00346    mHashTableSize = sz;
    00347
    00348    struct hashtable_entry {
    00349       string_entry *entry;
    00350       QPtrList<string_entry> *duplicates;
    00351       int duplicate_offset;
    00352    };
    00353
    00354    hashtable_entry *hashTable = new hashtable_entry[ sz ];
    00355
    00356    //kdDebug(7011) << "Clearing hashtable..." << endl;
    00357    for (unsigned int i=0; i < sz; i++)
    00358    {
    00359       hashTable[i].entry = 0;
    00360       hashTable[i].duplicates = 0;
    00361    }
    00362
    00363    //kdDebug(7011) << "Filling hashtable..." << endl;
    00364    for(string_entry *entry=d->first(); entry; entry = d->next())
    00365    {
    00366       int hash = entry->hash % sz;
    00367       if (!hashTable[hash].entry)
    00368       { // First entry
    00369          hashTable[hash].entry = entry;
    00370       }
    00371       else
    00372       {
    00373          if (!hashTable[hash].duplicates)
    00374          { // Second entry, build duplicate list.
    00375             hashTable[hash].duplicates = new QPtrList<string_entry>();
    00376             hashTable[hash].duplicates->append(hashTable[hash].entry);
    00377             hashTable[hash].duplicate_offset = 0;
    00378          }
    00379          hashTable[hash].duplicates->append(entry);
    00380       }
    00381    }
    00382
    00383    str << mHashTableSize;
    00384    str << mHashList;
    00385
    00386    mOffset = str.device()->at(); // mOffset points to start of hashTable
    00387    //kdDebug(7011) << QString("Start of Hash Table, offset = %1").arg(mOffset,8,16) << endl;
    00388
    00389    for(int pass = 1; pass <= 2; pass++)
    00390    {
    00391       str.device()->at(mOffset);
    00392       //kdDebug(7011) << QString("Writing hash table (pass #%1)").arg(pass) << endl;
    00393       for(uint i=0; i < mHashTableSize; i++)
    00394       {
    00395          Q_INT32 tmpid;
    00396          if (!hashTable[i].entry)
    00397             tmpid = (Q_INT32) 0;
    00398          else if (!hashTable[i].duplicates)
    00399             tmpid = (Q_INT32) hashTable[i].entry->payload->offset(); // Positive ID
    00400          else
    00401             tmpid = (Q_INT32) -hashTable[i].duplicate_offset; // Negative ID
    00402          str << tmpid;
    00403          //kdDebug(7011) << QString("Hash table : %1").arg(tmpid,8,16) << endl;
    00404       }
    00405       //kdDebug(7011) << QString("End of Hash Table, offset = %1").arg(str.device()->at(),8,16) << endl;
    00406
    00407       //kdDebug(7011) << QString("Writing duplicate lists (pass #%1)").arg(pass) << endl;
    00408       for(uint i=0; i < mHashTableSize; i++)
    00409       {
    00410          if (hashTable[i].duplicates)
    00411          {
    00412             QPtrList<string_entry> *dups = hashTable[i].duplicates;
    00413             hashTable[i].duplicate_offset = str.device()->at();
    00414
    00415             /*kdDebug(7011) << QString("Duplicate lists: Offset = %1 list_size = %2")                           .arg(hashTable[i].duplicate_offset,8,16).arg(dups->count()) << endl;
    00416 */
    00417             for(string_entry *dup = dups->first(); dup; dup=dups->next())
    00418             {
    00419                str << (Q_INT32) dup->payload->offset(); // Positive ID
    00420                str << dup->keyStr;                      // Key (QString)
    00421             }
    00422             str << (Q_INT32) 0;               // End of list marker (0)
    00423          }
    00424       }
    00425       //kdDebug(7011) << QString("End of Dict, offset = %1").arg(str.device()->at(),8,16) << endl;
    00426    }
    00427
    00428    //kdDebug(7011) << "Cleaning up hash table." << endl;
    00429    for(uint i=0; i < mHashTableSize; i++)
    00430    {
    00431       delete hashTable[i].duplicates;
    00432    }
    00433    delete [] hashTable;
    00434 }
    00435

This file is part of the documentation for kdelibs Version 3.1.5.
Documentation copyright © 1996-2002 the KDE developers.
Generated on Wed Jan 28 12:46:58 2004 by doxygen 1.3.4 written by Dimitri van Heesch, © 1997-2001