/* | |
* Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved. | |
* | |
* This library is free software; you can redistribute it and/or | |
* modify it under the terms of the GNU Library General Public | |
* License as published by the Free Software Foundation; either | |
* version 2 of the License, or (at your option) any later version. | |
* | |
* 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 PropertyMapHashTable_h | |
#define PropertyMapHashTable_h | |
#include "UString.h" | |
#include <wtf/Vector.h> | |
namespace JSC { | |
struct PropertyMapEntry { | |
UString::Rep* key; | |
unsigned offset; | |
unsigned attributes; | |
JSCell* specificValue; | |
unsigned index; | |
PropertyMapEntry(UString::Rep* key, unsigned attributes, JSCell* specificValue) | |
: key(key) | |
, offset(0) | |
, attributes(attributes) | |
, specificValue(specificValue) | |
, index(0) | |
{ | |
} | |
PropertyMapEntry(UString::Rep* key, unsigned offset, unsigned attributes, JSCell* specificValue, unsigned index) | |
: key(key) | |
, offset(offset) | |
, attributes(attributes) | |
, specificValue(specificValue) | |
, index(index) | |
{ | |
} | |
}; | |
// lastIndexUsed is an ever-increasing index used to identify the order items | |
// were inserted into the property map. It's required that getEnumerablePropertyNames | |
// return the properties in the order they were added for compatibility with other | |
// browsers' JavaScript implementations. | |
struct PropertyMapHashTable { | |
unsigned sizeMask; | |
unsigned size; | |
unsigned keyCount; | |
unsigned deletedSentinelCount; | |
unsigned anonymousSlotCount; | |
unsigned lastIndexUsed; | |
Vector<unsigned>* deletedOffsets; | |
unsigned entryIndices[1]; | |
PropertyMapEntry* entries() | |
{ | |
// The entries vector comes after the indices vector. | |
// The 0th item in the entries vector is not really used; it has to | |
// have a 0 in its key to allow the hash table lookup to handle deleted | |
// sentinels without any special-case code, but the other fields are unused. | |
return reinterpret_cast<PropertyMapEntry*>(&entryIndices[size]); | |
} | |
static size_t allocationSize(unsigned size) | |
{ | |
// We never let a hash table get more than half full, | |
// So the number of indices we need is the size of the hash table. | |
// But the number of entries is half that (plus one for the deleted sentinel). | |
return sizeof(PropertyMapHashTable) | |
+ (size - 1) * sizeof(unsigned) | |
+ (1 + size / 2) * sizeof(PropertyMapEntry); | |
} | |
}; | |
} // namespace JSC | |
#endif // PropertyMapHashTable_h |