/* | |
* 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 { | |
// 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 UStringImpls 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_length, buffer)) | |
m_value = newImpl; | |
else { | |
for (unsigned i = 0; i < m_fiberCount; ++i) { | |
m_other.m_fibers[i]->deref(); | |
m_other.m_fibers[i] = 0; | |
} | |
m_fiberCount = 0; | |
ASSERT(!isRope()); | |
ASSERT(m_value == UString()); | |
throwOutOfMemoryError(exec); | |
return; | |
} | |
UChar* position = buffer + m_length; | |
// Start with the current Rope. | |
Vector<Rope::Fiber, 32> workQueue; | |
Rope::Fiber currentFiber; | |
for (unsigned i = 0; i < (m_fiberCount - 1); ++i) | |
workQueue.append(m_other.m_fibers[i]); | |
currentFiber = m_other.m_fibers[m_fiberCount - 1]; | |
while (true) { | |
if (currentFiber->isRope()) { | |
Rope* rope = static_cast<URopeImpl*>(currentFiber); | |
// 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 fiberCountMinusOne = rope->fiberCount() - 1; | |
for (unsigned i = 0; i < fiberCountMinusOne; ++i) | |
workQueue.append(rope->fibers(i)); | |
currentFiber = rope->fibers(fiberCountMinusOne); | |
} else { | |
UStringImpl* string = static_cast<UStringImpl*>(currentFiber); | |
unsigned length = string->length(); | |
position -= length; | |
UStringImpl::copyChars(position, string->characters(), 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_fiberCount; ++i) { | |
m_other.m_fibers[i]->deref(); | |
m_other.m_fibers[i] = 0; | |
} | |
m_fiberCount = 0; | |
ASSERT(!isRope()); | |
return; | |
} | |
// No! - set the next item up to process. | |
currentFiber = workQueue.last(); | |
workQueue.removeLast(); | |
} | |
} | |
} | |
JSString* JSString::getIndexSlowCase(ExecState* exec, unsigned i) | |
{ | |
ASSERT(isRope()); | |
resolveRope(exec); | |
// Return a safe no-value result, this should never be used, since the excetion will be thrown. | |
if (exec->exception()) | |
return jsString(exec, ""); | |
ASSERT(!isRope()); | |
ASSERT(i < m_value.size()); | |
return jsSingleCharacterSubstring(exec, m_value, i); | |
} | |
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_length; | |
} | |
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_length), DontEnum | DontDelete | ReadOnly); | |
return true; | |
} | |
bool isStrictUInt32; | |
unsigned i = propertyName.toStrictUInt32(&isStrictUInt32); | |
if (isStrictUInt32 && i < m_length) { | |
descriptor.setDescriptor(getIndex(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 |