identifier.cpp
/*
* This file is part of the KDE libraries
* Copyright (C) 2003 Apple Computer, Inc
*
* 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.
*
*/
#include "identifier.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define DUMP_STATISTICS 0
namespace KJS {
#if DUMP_STATISTICS
static int numProbes;
static int numCollisions;
struct IdentifierStatisticsExitLogger { ~IdentifierStatisticsExitLogger(); };
static IdentifierStatisticsExitLogger logger;
IdentifierStatisticsExitLogger::~IdentifierStatisticsExitLogger()
{
printf("\nKJS::Identifier statistics\n\n");
printf("%d probes\n", numProbes);
printf("%d collisions (%.1f%%)\n", numCollisions, 100.0 * numCollisions / numProbes);
}
#endif
extern const Identifier argumentsPropertyName("arguments");
extern const Identifier calleePropertyName("callee");
extern const Identifier callerPropertyName("caller");
extern const Identifier constructorPropertyName("constructor");
extern const Identifier lengthPropertyName("length");
extern const Identifier messagePropertyName("message");
extern const Identifier namePropertyName("name");
extern const Identifier prototypePropertyName("prototype");
extern const Identifier specialPrototypePropertyName("__proto__");
extern const Identifier toLocaleStringPropertyName("toLocaleString");
extern const Identifier toStringPropertyName("toString");
extern const Identifier valueOfPropertyName("valueOf");
static const int _minTableSize = 64;
UString::Rep **Identifier::_table;
int Identifier::_tableSize;
int Identifier::_tableSizeMask;
int Identifier::_keyCount;
bool Identifier::equal(UString::Rep *r, const char *s)
{
int length = r->len;
const UChar *d = r->data();
for (int i = 0; i != length; ++i)
if (d[i].uc != (unsigned char)s[i])
return false;
return s[length] == 0;
}
bool Identifier::equal(UString::Rep *r, const UChar *s, int length)
{
if (r->len != length)
return false;
const UChar *d = r->data();
for (int i = 0; i != length; ++i)
if (d[i].uc != s[i].uc)
return false;
return true;
}
bool Identifier::equal(UString::Rep *r, UString::Rep *b)
{
int length = r->len;
if (length != b->len)
return false;
const UChar *d = r->data();
const UChar *s = b->data();
for (int i = 0; i != length; ++i)
if (d[i].uc != s[i].uc)
return false;
return true;
}
UString::Rep *Identifier::add(const char *c)
{
if (!c)
return &UString::Rep::null;
int length = strlen(c);
if (length == 0)
return &UString::Rep::empty;
if (!_table)
expand();
unsigned hash = UString::Rep::computeHash(c);
int i = hash & _tableSizeMask;
#if DUMP_STATISTICS
++numProbes;
numCollisions += _table[i] && !equal(_table[i], c);
#endif
while (UString::Rep *key = _table[i]) {
if (equal(key, c))
return key;
i = (i + 1) & _tableSizeMask;
}
UChar *d = new UChar[length];
for (int j = 0; j != length; j++)
d[j] = c[j];
UString::Rep *r = new UString::Rep;
r->dat = d;
r->len = length;
r->capacity = UString::Rep::capacityForIdentifier;
r->rc = 0;
r->_hash = hash;
_table[i] = r;
++_keyCount;
if (_keyCount * 2 >= _tableSize)
expand();
return r;
}
UString::Rep *Identifier::add(const UChar *s, int length)
{
if (length == 0)
return &UString::Rep::empty;
if (!_table)
expand();
unsigned hash = UString::Rep::computeHash(s, length);
int i = hash & _tableSizeMask;
#if DUMP_STATISTICS
++numProbes;
numCollisions += _table[i] && !equal(_table[i], s, length);
#endif
while (UString::Rep *key = _table[i]) {
if (equal(key, s, length))
return key;
i = (i + 1) & _tableSizeMask;
}
UChar *d = new UChar[length];
for (int j = 0; j != length; j++)
d[j] = s[j];
UString::Rep *r = new UString::Rep;
r->dat = d;
r->len = length;
r->capacity = UString::Rep::capacityForIdentifier;
r->rc = 0;
r->_hash = hash;
_table[i] = r;
++_keyCount;
if (_keyCount * 2 >= _tableSize)
expand();
return r;
}
UString::Rep *Identifier::add(UString::Rep *r)
{
if (r->capacity == UString::Rep::capacityForIdentifier)
return r;
if (r->len == 0)
return &UString::Rep::empty;
if (!_table)
expand();
unsigned hash = r->hash();
int i = hash & _tableSizeMask;
#if DUMP_STATISTICS
++numProbes;
numCollisions += _table[i] && !equal(_table[i], r);
#endif
while (UString::Rep *key = _table[i]) {
if (equal(key, r))
return key;
i = (i + 1) & _tableSizeMask;
}
r->capacity = UString::Rep::capacityForIdentifier;
_table[i] = r;
++_keyCount;
if (_keyCount * 2 >= _tableSize)
expand();
return r;
}
inline void Identifier::insert(UString::Rep *key)
{
unsigned hash = key->hash();
int i = hash & _tableSizeMask;
#if DUMP_STATISTICS
++numProbes;
numCollisions += _table[i] != 0;
#endif
while (_table[i])
i = (i + 1) & _tableSizeMask;
_table[i] = key;
}
void Identifier::remove(UString::Rep *r)
{
unsigned hash = r->hash();
UString::Rep *key;
int i = hash & _tableSizeMask;
#if DUMP_STATISTICS
++numProbes;
numCollisions += _table[i] && equal(_table[i], r);
#endif
while ((key = _table[i])) {
if (equal(key, r))
break;
i = (i + 1) & _tableSizeMask;
}
if (!key)
return;
_table[i] = 0;
--_keyCount;
if (_keyCount * 6 < _tableSize && _tableSize > _minTableSize) {
shrink();
return;
}
// Reinsert all the items to the right in the same cluster.
while (1) {
i = (i + 1) & _tableSizeMask;
key = _table[i];
if (!key)
break;
_table[i] = 0;
insert(key);
}
}
void Identifier::expand()
{
rehash(_tableSize == 0 ? _minTableSize : _tableSize * 2);
}
void Identifier::shrink()
{
rehash(_tableSize / 2);
}
void Identifier::rehash(int newTableSize)
{
int oldTableSize = _tableSize;
UString::Rep **oldTable = _table;
_tableSize = newTableSize;
_tableSizeMask = newTableSize - 1;
_table = (UString::Rep **)calloc(newTableSize, sizeof(UString::Rep *));
for (int i = 0; i != oldTableSize; ++i)
if (UString::Rep *key = oldTable[i])
insert(key);
free(oldTable);
}
const Identifier &Identifier::null()
{
static Identifier null;
return null;
}
} // namespace KJS
KStdAccel::key
int key(StdAccel) KDE_DEPRECATED
KJS::Identifier::null
static const Identifier & null()
Creates an empty Identifier.
Definition: identifier.cpp:302
KJS::Identifier
Represents an Identifier for a Javascript object.
Definition: identifier.h:32

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