/*
* Copyright (C) 1999-2002 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2004, 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.
*
*/
#include "config.h"
#include "JSString.h"
#include "JSGlobalObject.h"
#include "JSObject.h"
#include "Operations.h"
#include "StringObject.h"
#include "StringPrototype.h"
namespace JSC {
void JSString::Rope::destructNonRecursive()
{
Vector<Rope*, 32> workQueue;
Rope* rope = this;
while (true) {
unsigned length = rope->ropeLength();
for (unsigned i = 0; i < length; ++i) {
Fiber& fiber = rope->fibers(i);
if (fiber.isString())
fiber.string()->deref();
else {
Rope* nextRope = fiber.rope();
if (nextRope->hasOneRef())
workQueue.append(nextRope);
else
nextRope->deref();
}
}
if (rope != this)
fastFree(rope);
if (workQueue.isEmpty())
return;
rope = workQueue.last();
workQueue.removeLast();
}
}
JSString::Rope::~Rope()
{
destructNonRecursive();
}
// Overview: this methods converts a JSString from holding a string in rope form
// down to a simple UString representation. It does so by building up the string
// backwards, since we want to avoid recursion, we expect that the tree structure
// representing the rope is likely imbalanced with more nodes down the left side
// (since appending to the string is likely more common) - and as such resolving
// in this fashion should minimize work queue size. (If we built the queue forwards
// we would likely have to place all of the constituent UString::Reps into the
// Vector before performing any concatenation, but by working backwards we likely
// only fill the queue with the number of substrings at any given level in a
// rope-of-ropes.)
void JSString::resolveRope(ExecState* exec) const
{
ASSERT(isRope());
// Allocate the buffer to hold the final string, position initially points to the end.
UChar* buffer;
if (PassRefPtr<UStringImpl> newImpl = UStringImpl::tryCreateUninitialized(m_stringLength, buffer))
m_value = newImpl;
else {
for (unsigned i = 0; i < m_ropeLength; ++i) {
m_fibers[i].deref();
m_fibers[i] = static_cast<void*>(0);
}
m_ropeLength = 0;
ASSERT(!isRope());
ASSERT(m_value == UString());
throwOutOfMemoryError(exec);
return;
}
UChar* position = buffer + m_stringLength;
// Start with the current Rope.
Vector<Rope::Fiber, 32> workQueue;
Rope::Fiber currentFiber;
for (unsigned i = 0; i < (m_ropeLength - 1); ++i)
workQueue.append(m_fibers[i]);
currentFiber = m_fibers[m_ropeLength - 1];
while (true) {
if (currentFiber.isRope()) {
Rope* rope = currentFiber.rope();
// Copy the contents of the current rope into the workQueue, with the last item in 'currentFiber'
// (we will be working backwards over the rope).
unsigned ropeLengthMinusOne = rope->ropeLength() - 1;
for (unsigned i = 0; i < ropeLengthMinusOne; ++i)
workQueue.append(rope->fibers(i));
currentFiber = rope->fibers(ropeLengthMinusOne);
} else {
UString::Rep* string = currentFiber.string();
unsigned length = string->size();
position -= length;
UStringImpl::copyChars(position, string->data(), length);
// Was this the last item in the work queue?
if (workQueue.isEmpty()) {
// Create a string from the UChar buffer, clear the rope RefPtr.
ASSERT(buffer == position);
for (unsigned i = 0; i < m_ropeLength; ++i) {
m_fibers[i].deref();
m_fibers[i] = static_cast<void*>(0);
}
m_ropeLength = 0;
ASSERT(!isRope());
return;
}
// No! - set the next item up to process.
currentFiber = workQueue.last();
workQueue.removeLast();
}
}
}
JSValue JSString::toPrimitive(ExecState*, PreferredPrimitiveType) const
{
return const_cast<JSString*>(this);
}
bool JSString::getPrimitiveNumber(ExecState* exec, double& number, JSValue& result)
{
result = this;
number = value(exec).toDouble();
return false;
}
bool JSString::toBoolean(ExecState*) const
{
return m_stringLength;
}
double JSString::toNumber(ExecState* exec) const
{
return value(exec).toDouble();
}
UString JSString::toString(ExecState* exec) const
{
return value(exec);
}
UString JSString::toThisString(ExecState* exec) const
{
return value(exec);
}
JSString* JSString::toThisJSString(ExecState*)
{
return this;
}
inline StringObject* StringObject::create(ExecState* exec, JSString* string)
{
return new (exec) StringObject(exec->lexicalGlobalObject()->stringObjectStructure(), string);
}
JSObject* JSString::toObject(ExecState* exec) const
{
return StringObject::create(exec, const_cast<JSString*>(this));
}
JSObject* JSString::toThisObject(ExecState* exec) const
{
return StringObject::create(exec, const_cast<JSString*>(this));
}
bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
{
// The semantics here are really getPropertySlot, not getOwnPropertySlot.
// This function should only be called by JSValue::get.
if (getStringPropertySlot(exec, propertyName, slot))
return true;
if (propertyName == exec->propertyNames().underscoreProto) {
slot.setValue(exec->lexicalGlobalObject()->stringPrototype());
return true;
}
slot.setBase(this);
JSObject* object;
for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {
object = asObject(prototype);
if (object->getOwnPropertySlot(exec, propertyName, slot))
return true;
}
slot.setUndefined();
return true;
}
bool JSString::getStringPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
{
if (propertyName == exec->propertyNames().length) {
descriptor.setDescriptor(jsNumber(exec, m_stringLength), DontEnum | DontDelete | ReadOnly);
return true;
}
bool isStrictUInt32;
unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
if (isStrictUInt32 && i < m_stringLength) {
descriptor.setDescriptor(jsSingleCharacterSubstring(exec, value(exec), i), DontDelete | ReadOnly);
return true;
}
return false;
}
bool JSString::getOwnPropertyDescriptor(ExecState* exec, const Identifier& propertyName, PropertyDescriptor& descriptor)
{
if (getStringPropertyDescriptor(exec, propertyName, descriptor))
return true;
if (propertyName != exec->propertyNames().underscoreProto)
return false;
descriptor.setDescriptor(exec->lexicalGlobalObject()->stringPrototype(), DontEnum);
return true;
}
bool JSString::getOwnPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
// The semantics here are really getPropertySlot, not getOwnPropertySlot.
// This function should only be called by JSValue::get.
if (getStringPropertySlot(exec, propertyName, slot))
return true;
return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);
}
} // namespace JSC