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# property_map.cpp

    00001 /*
    00002  *  This file is part of the KDE libraries
    00003  *  Copyright (C) 2003 Apple Computer, Inc.
    00004  *
    00005  *  This library is free software; you can redistribute it and/or
    00006  *  modify it under the terms of the GNU Library General Public
    00007  *  License as published by the Free Software Foundation; either
    00008  *  version 2 of the License, or (at your option) any later version.
    00009  *
    00010  *  This library is distributed in the hope that it will be useful,
    00011  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
    00012  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00013  *  Library General Public License for more details.
    00014  *
    00015  *  You should have received a copy of the GNU Library General Public License
    00016  *  along with this library; see the file COPYING.LIB.  If not, write to
    00017  *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    00018  *  Boston, MA 02111-1307, USA.
    00019  *
    00020  */
    00021
    00022 #include "property_map.h"
    00023
    00024 #include "object.h"
    00025 #include "reference_list.h"
    00026
    00027 #include <assert.h>
    00028
    00029 #define DEBUG_PROPERTIES 0
    00030 #define DO_CONSISTENCY_CHECK 0
    00031 #define DUMP_STATISTICS 0
    00032 #define USE_SINGLE_ENTRY 1
    00033
    00034 // At the time I added USE_SINGLE_ENTRY, the optimization still gave a 1.5%
    00035 // performance boost to the iBench JavaScript benchmark so I didn't remove it.
    00036
    00037 #if !DO_CONSISTENCY_CHECK
    00038 #define checkConsistency() ((void)0)
    00039 #endif
    00040
    00041 namespace KJS {
    00042
    00043 #if DUMP_STATISTICS
    00044
    00045 static int numProbes;
    00046 static int numCollisions;
    00047
    00048 struct PropertyMapStatisticsExitLogger { ~PropertyMapStatisticsExitLogger(); };
    00049
    00050 static PropertyMapStatisticsExitLogger logger;
    00051
    00052 PropertyMapStatisticsExitLogger::~PropertyMapStatisticsExitLogger()
    00053 {
    00054     printf("\nKJS::PropertyMap statistics\n\n");
    00055     printf("%d probes\n", numProbes);
    00056     printf("%d collisions (%.1f%%)\n", numCollisions, 100.0 * numCollisions / numProbes);
    00057 }
    00058
    00059 #endif
    00060
    00061 struct PropertyMapHashTable
    00062 {
    00063     int sizeMask;
    00064     int size;
    00065     int keyCount;
    00066     PropertyMapHashTableEntry entries[1];
    00067 };
    00068
    00069 class SavedProperty {
    00070 public:
    00071     Identifier key;
    00072     Value value;
    00073     int attributes;
    00074 };
    00075
    00076 SavedProperties::SavedProperties() : _count(0), _properties(0) { }
    00077
    00078 SavedProperties::~SavedProperties()
    00079 {
    00080     delete [] _properties;
    00081 }
    00082
    00083 // Algorithm concepts from Algorithms in C++, Sedgewick.
    00084
    00085 PropertyMap::PropertyMap() : _table(0)
    00086 {
    00087 }
    00088
    00089 PropertyMap::~PropertyMap()
    00090 {
    00091     if (!_table) {
    00092 #if USE_SINGLE_ENTRY
    00093         UString::Rep *key = _singleEntry.key;
    00094         if (key)
    00095             key->deref();
    00096 #endif
    00097         return;
    00098     }
    00099
    00100     for (int i = 0; i < _table->size; i++) {
    00101         UString::Rep *key = _table->entries[i].key;
    00102         if (key)
    00103       key->deref();
    00104     }
    00105     free(_table);
    00106 }
    00107
    00108 void PropertyMap::clear()
    00109 {
    00110     if (!_table) {
    00111 #if USE_SINGLE_ENTRY
    00112         UString::Rep *key = _singleEntry.key;
    00113         if (key) {
    00114             key->deref();
    00115             _singleEntry.key = 0;
    00116         }
    00117 #endif
    00118         return;
    00119     }
    00120
    00121     for (int i = 0; i < _table->size; i++) {
    00122         UString::Rep *key = _table->entries[i].key;
    00123         if (key) {
    00124             key->deref();
    00125             _table->entries[i].key = 0;
    00126         }
    00127     }
    00128     _table->keyCount = 0;
    00129 }
    00130
    00131 inline int PropertyMap::hash(const UString::Rep *s) const
    00132 {
    00133     return s->hash() & _table->sizeMask;
    00134 }
    00135
    00136 ValueImp *PropertyMap::get(const Identifier &name, int &attributes) const
    00137 {
    00138     assert(!name.isNull());
    00139
    00140     UString::Rep *rep = name._ustring.rep;
    00141
    00142     if (!_table) {
    00143 #if USE_SINGLE_ENTRY
    00144         UString::Rep *key = _singleEntry.key;
    00145         if (rep == key) {
    00146             attributes = _singleEntry.attributes;
    00147             return _singleEntry.value;
    00148         }
    00149 #endif
    00150         return 0;
    00151     }
    00152
    00153     int i = hash(rep);
    00154 #if DUMP_STATISTICS
    00155     ++numProbes;
    00156     numCollisions += _table->entries[i].key && _table->entries[i].key != rep;
    00157 #endif
    00158     while (UString::Rep *key = _table->entries[i].key) {
    00159         if (rep == key) {
    00160             attributes = _table->entries[i].attributes;
    00161             return _table->entries[i].value;
    00162         }
    00163         i = (i + 1) & _table->sizeMask;
    00164     }
    00165     return 0;
    00166 }
    00167
    00168 ValueImp *PropertyMap::get(const Identifier &name) const
    00169 {
    00170     assert(!name.isNull());
    00171
    00172     UString::Rep *rep = name._ustring.rep;
    00173
    00174     if (!_table) {
    00175 #if USE_SINGLE_ENTRY
    00176         UString::Rep *key = _singleEntry.key;
    00177         if (rep == key)
    00178             return _singleEntry.value;
    00179 #endif
    00180         return 0;
    00181     }
    00182
    00183     int i = hash(rep);
    00184 #if DUMP_STATISTICS
    00185     ++numProbes;
    00186     numCollisions += _table->entries[i].key && _table->entries[i].key != rep;
    00187 #endif
    00188     while (UString::Rep *key = _table->entries[i].key) {
    00189         if (rep == key)
    00190             return _table->entries[i].value;
    00191         i = (i + 1) & _table->sizeMask;
    00192     }
    00193     return 0;
    00194 }
    00195
    00196 #if DEBUG_PROPERTIES
    00197 static void printAttributes(int attributes)
    00198 {
    00199     if (attributes == 0)
    00200         printf ("None ");
    00201     if (attributes & ReadOnly)
    00202         printf ("ReadOnly ");
    00203     if (attributes & DontEnum)
    00204         printf ("DontEnum ");
    00205     if (attributes & DontDelete)
    00206         printf ("DontDelete ");
    00207     if (attributes & Internal)
    00208         printf ("Internal ");
    00209     if (attributes & Function)
    00210         printf ("Function ");
    00211 }
    00212 #endif
    00213
    00214 void PropertyMap::put(const Identifier &name, ValueImp *value, int attributes)
    00215 {
    00216     assert(!name.isNull());
    00217     assert(value != 0);
    00218
    00219     checkConsistency();
    00220
    00221     UString::Rep *rep = name._ustring.rep;
    00222
    00223 #if DEBUG_PROPERTIES
    00224     printf("adding property %s, attributes = 0x%08x (", name.ascii(), attributes);
    00225     printAttributes(attributes);
    00226     printf(")\n");
    00227 #endif
    00228
    00229 #if USE_SINGLE_ENTRY
    00230     if (!_table) {
    00231         UString::Rep *key = _singleEntry.key;
    00232         if (key) {
    00233             if (rep == key) {
    00234                 _singleEntry.value = value;
    00235                 return;
    00236             }
    00237         } else {
    00238             rep->ref();
    00239             _singleEntry.key = rep;
    00240             _singleEntry.value = value;
    00241             _singleEntry.attributes = attributes;
    00242             checkConsistency();
    00243             return;
    00244         }
    00245     }
    00246 #endif
    00247
    00248     if (!_table || _table->keyCount * 2 >= _table->size)
    00249         expand();
    00250
    00251     int i = hash(rep);
    00252 #if DUMP_STATISTICS
    00253     ++numProbes;
    00254     numCollisions += _table->entries[i].key && _table->entries[i].key != rep;
    00255 #endif
    00256     while (UString::Rep *key = _table->entries[i].key) {
    00257         if (rep == key) {
    00258             // Put a new value in an existing hash table entry.
    00259             _table->entries[i].value = value;
    00260             // Attributes are intentionally not updated.
    00261             return;
    00262         }
    00263         i = (i + 1) & _table->sizeMask;
    00264     }
    00265
    00266     // Create a new hash table entry.
    00267     rep->ref();
    00268     _table->entries[i].key = rep;
    00269     _table->entries[i].value = value;
    00270     _table->entries[i].attributes = attributes;
    00271     ++_table->keyCount;
    00272
    00273     checkConsistency();
    00274 }
    00275
    00276 inline void PropertyMap::insert(UString::Rep *key, ValueImp *value, int attributes)
    00277 {
    00278     assert(_table);
    00279
    00280     int i = hash(key);
    00281 #if DUMP_STATISTICS
    00282     ++numProbes;
    00283     numCollisions += _table->entries[i].key && _table->entries[i].key != key;
    00284 #endif
    00285     while (_table->entries[i].key)
    00286         i = (i + 1) & _table->sizeMask;
    00287
    00288     _table->entries[i].key = key;
    00289     _table->entries[i].value = value;
    00290     _table->entries[i].attributes = attributes;
    00291 }
    00292
    00293 void PropertyMap::expand()
    00294 {
    00295     checkConsistency();
    00296
    00297     Table *oldTable = _table;
    00298     int oldTableSize = oldTable ? oldTable->size : 0;
    00299
    00300     int newTableSize = oldTableSize ? oldTableSize * 2 : 16;
    00301     _table = (Table *)calloc(1, sizeof(Table) + (newTableSize - 1) * sizeof(Entry) );
    00302     _table->size = newTableSize;
    00303     _table->sizeMask = newTableSize - 1;
    00304     _table->keyCount = oldTable ? oldTable->keyCount : 0;
    00305
    00306 #if USE_SINGLE_ENTRY
    00307     UString::Rep *key = _singleEntry.key;
    00308     if (key) {
    00309         insert(key, _singleEntry.value, _singleEntry.attributes);
    00310     _table->keyCount++;
    00311         _singleEntry.key = 0;
    00312     }
    00313 #endif
    00314
    00315     for (int i = 0; i != oldTableSize; ++i) {
    00316         UString::Rep *key = oldTable->entries[i].key;
    00317         if (key)
    00318             insert(key, oldTable->entries[i].value, oldTable->entries[i].attributes);
    00319     }
    00320
    00321     free(oldTable);
    00322
    00323     checkConsistency();
    00324 }
    00325
    00326 void PropertyMap::remove(const Identifier &name)
    00327 {
    00328     assert(!name.isNull());
    00329
    00330     checkConsistency();
    00331
    00332     UString::Rep *rep = name._ustring.rep;
    00333
    00334     UString::Rep *key;
    00335
    00336     if (!_table) {
    00337 #if USE_SINGLE_ENTRY
    00338         key = _singleEntry.key;
    00339         if (rep == key) {
    00340             key->deref();
    00341             _singleEntry.key = 0;
    00342             checkConsistency();
    00343         }
    00344 #endif
    00345         return;
    00346     }
    00347
    00348     // Find the thing to remove.
    00349     int i = hash(rep);
    00350 #if DUMP_STATISTICS
    00351     ++numProbes;
    00352     numCollisions += _table->entries[i].key && _table->entries[i].key != rep;
    00353 #endif
    00354     while ((key = _table->entries[i].key)) {
    00355         if (rep == key)
    00356             break;
    00357         i = (i + 1) & _table->sizeMask;
    00358     }
    00359     if (!key)
    00360         return;
    00361
    00362     // Remove the one key.
    00363     key->deref();
    00364     _table->entries[i].key = 0;
    00365     assert(_table->keyCount >= 1);
    00366     --_table->keyCount;
    00367
    00368     // Reinsert all the items to the right in the same cluster.
    00369     while (1) {
    00370         i = (i + 1) & _table->sizeMask;
    00371         key = _table->entries[i].key;
    00372         if (!key)
    00373             break;
    00374         _table->entries[i].key = 0;
    00375         insert(key, _table->entries[i].value, _table->entries[i].attributes);
    00376     }
    00377
    00378     checkConsistency();
    00379 }
    00380
    00381 void PropertyMap::mark() const
    00382 {
    00383     if (!_table) {
    00384 #if USE_SINGLE_ENTRY
    00385         if (_singleEntry.key) {
    00386             ValueImp *v = _singleEntry.value;
    00387             if (!v->marked())
    00388                 v->mark();
    00389         }
    00390 #endif
    00391         return;
    00392     }
    00393
    00394     for (int i = 0; i != _table->size; ++i) {
    00395         if (_table->entries[i].key) {
    00396             ValueImp *v = _table->entries[i].value;
    00397             if (!v->marked())
    00398                 v->mark();
    00399         }
    00400     }
    00401 }
    00402
    00403 void PropertyMap::addEnumerablesToReferenceList(ReferenceList &list, const Object &base) const
    00404 {
    00405     if (!_table) {
    00406 #if USE_SINGLE_ENTRY
    00407         UString::Rep *key = _singleEntry.key;
    00408         if (key && !(_singleEntry.attributes & DontEnum))
    00409             list.append(Reference(base, Identifier(key)));
    00410 #endif
    00411         return;
    00412     }
    00413
    00414     for (int i = 0; i != _table->size; ++i) {
    00415         UString::Rep *key = _table->entries[i].key;
    00416         if (key && !(_table->entries[i].attributes & DontEnum))
    00417             list.append(Reference(base, Identifier(key)));
    00418     }
    00419 }
    00420
    00421 void PropertyMap::addSparseArrayPropertiesToReferenceList(ReferenceList &list, const Object &base) const
    00422 {
    00423     if (!_table) {
    00424 #if USE_SINGLE_ENTRY
    00425         UString::Rep *key = _singleEntry.key;
    00426         if (key) {
    00427             UString k(key);
    00428             bool fitsInULong;
    00429             unsigned long i = k.toULong(&fitsInULong);
    00430             if (fitsInULong && i <= 0xFFFFFFFFU)
    00431                 list.append(Reference(base, Identifier(key)));
    00432         }
    00433 #endif
    00434         return;
    00435     }
    00436
    00437     for (int i = 0; i != _table->size; ++i) {
    00438         UString::Rep *key = _table->entries[i].key;
    00439         if (key) {
    00440             UString k(key);
    00441             bool fitsInULong;
    00442             unsigned long i = k.toULong(&fitsInULong);
    00443             if (fitsInULong && i <= 0xFFFFFFFFU)
    00444                 list.append(Reference(base, Identifier(key)));
    00445         }
    00446     }
    00447 }
    00448
    00449 void PropertyMap::save(SavedProperties &p) const
    00450 {
    00451     int count = 0;
    00452
    00453     if (!_table) {
    00454 #if USE_SINGLE_ENTRY
    00455         if (_singleEntry.key && !(_singleEntry.attributes & (ReadOnly | DontEnum | Function)))
    00456             ++count;
    00457 #endif
    00458     } else {
    00459         for (int i = 0; i != _table->size; ++i)
    00460             if (_table->entries[i].key && !(_table->entries[i].attributes & (ReadOnly | DontEnum | Function)))
    00461                 ++count;
    00462     }
    00463
    00464     delete [] p._properties;
    00465
    00466     p._count = count;
    00467
    00468     if (count == 0) {
    00469         p._properties = 0;
    00470         return;
    00471     }
    00472
    00473     p._properties = new SavedProperty [count];
    00474
    00475     SavedProperty *prop = p._properties;
    00476
    00477     if (!_table) {
    00478 #if USE_SINGLE_ENTRY
    00479         if (_singleEntry.key && !(_singleEntry.attributes & (ReadOnly | DontEnum | Function))) {
    00480             prop->key = Identifier(_singleEntry.key);
    00481             prop->value = Value(_singleEntry.value);
    00482             prop->attributes = _singleEntry.attributes;
    00483             ++prop;
    00484         }
    00485 #endif
    00486     } else {
    00487         for (int i = 0; i != _table->size; ++i) {
    00488             if (_table->entries[i].key && !(_table->entries[i].attributes & (ReadOnly | DontEnum | Function))) {
    00489                 prop->key = Identifier(_table->entries[i].key);
    00490                 prop->value = Value(_table->entries[i].value);
    00491                 prop->attributes = _table->entries[i].attributes;
    00492                 ++prop;
    00493             }
    00494         }
    00495     }
    00496 }
    00497
    00498 void PropertyMap::restore(const SavedProperties &p)
    00499 {
    00500     for (int i = 0; i != p._count; ++i)
    00501         put(p._properties[i].key, p._properties[i].value.imp(), p._properties[i].attributes);
    00502 }
    00503
    00504 #if DO_CONSISTENCY_CHECK
    00505
    00506 void PropertyMap::checkConsistency()
    00507 {
    00508     if (!_table)
    00509         return;
    00510
    00511     int count = 0;
    00512     for (int j = 0; j != _table->size; ++j) {
    00513         UString::Rep *rep = _table->entries[j].key;
    00514         if (!rep)
    00515             continue;
    00516         int i = hash(rep);
    00517         while (UString::Rep *key = _table->entries[i].key) {
    00518             if (rep == key)
    00519                 break;
    00520             i = (i + 1) & _table->sizeMask;
    00521         }
    00522         assert(i == j);
    00523         count++;
    00524     }
    00525     assert(count == _table->keyCount);
    00526     assert(_table->size >= 16);
    00527     assert(_table->sizeMask);
    00528     assert(_table->size == _table->sizeMask + 1);
    00529 }
    00530
    00531 #endif // DO_CONSISTENCY_CHECK
    00532
    00533 } // namespace KJS

This file is part of the documentation for kjs Library Version 3.4.1.
Documentation copyright © 1996-2004 the KDE developers.
Generated on Sat Jun 11 20:23:07 2005 by doxygen 1.4.1 written by Dimitri van Heesch, © 1997-2003