blob: f789387e5b41b41bf049fee742e0a00527caf0cc [file] [log] [blame]
/*
* 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 "JSGlobalObjectFunctions.h"
#include "JSObject.h"
#include "Operations.h"
#include "StringObject.h"
#include "StringPrototype.h"
namespace JSC {
static const unsigned substringFromRopeCutoff = 4;
const ClassInfo JSString::s_info = { "string", 0, 0, 0, CREATE_METHOD_TABLE(JSString) };
const ClassInfo* JSString::s_classinfo() { return &s_info; }
void JSRopeString::RopeBuilder::expand()
{
ASSERT(m_index == JSRopeString::s_maxInternalRopeLength);
JSString* jsString = m_jsString;
m_jsString = jsStringBuilder(&m_globalData);
m_index = 0;
append(jsString);
}
void JSString::destroy(JSCell* cell)
{
JSString* thisObject = static_cast<JSString*>(cell);
thisObject->JSString::~JSString();
}
void JSString::visitChildren(JSCell* cell, SlotVisitor& visitor)
{
JSString* thisObject = jsCast<JSString*>(cell);
Base::visitChildren(thisObject, visitor);
MARK_LOG_MESSAGE1("[%u]: ", thisObject->length());
#if ENABLE(OBJECT_MARK_LOGGING)
if (!thisObject->isRope()) {
WTF::StringImpl* ourImpl = thisObject->m_value.impl();
if (ourImpl->is8Bit())
MARK_LOG_MESSAGE1("[8 %p]", ourImpl->characters8());
else
MARK_LOG_MESSAGE1("[16 %p]", ourImpl->characters16());
} else
MARK_LOG_MESSAGE0("[rope]: ");
#endif
if (thisObject->isRope())
static_cast<JSRopeString*>(thisObject)->visitFibers(visitor);
}
void JSRopeString::visitFibers(SlotVisitor& visitor)
{
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i)
visitor.append(&m_fibers[i]);
}
void JSRopeString::resolveRope(ExecState* exec) const
{
ASSERT(isRope());
if (is8Bit()) {
LChar* buffer;
if (RefPtr<StringImpl> newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) {
Heap::heap(this)->reportExtraMemoryCost(newImpl->cost());
m_value = newImpl.release();
} else {
outOfMemory(exec);
return;
}
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
if (m_fibers[i]->isRope())
return resolveRopeSlowCase8(buffer);
}
LChar* position = buffer;
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
StringImpl* string = m_fibers[i]->m_value.impl();
unsigned length = string->length();
StringImpl::copyChars(position, string->characters8(), length);
position += length;
m_fibers[i].clear();
}
ASSERT((buffer + m_length) == position);
ASSERT(!isRope());
return;
}
UChar* buffer;
if (RefPtr<StringImpl> newImpl = StringImpl::tryCreateUninitialized(m_length, buffer)) {
Heap::heap(this)->reportExtraMemoryCost(newImpl->cost());
m_value = newImpl.release();
} else {
outOfMemory(exec);
return;
}
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
if (m_fibers[i]->isRope())
return resolveRopeSlowCase(buffer);
}
UChar* position = buffer;
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
StringImpl* string = m_fibers[i]->m_value.impl();
unsigned length = string->length();
if (string->is8Bit())
StringImpl::copyChars(position, string->characters8(), length);
else
StringImpl::copyChars(position, string->characters16(), length);
position += length;
m_fibers[i].clear();
}
ASSERT((buffer + m_length) == position);
ASSERT(!isRope());
}
// Overview: These functions convert a JSString from holding a string in rope form
// down to a simple String 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 StringImpls 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 JSRopeString::resolveRopeSlowCase8(LChar* buffer) const
{
LChar* position = buffer + m_length; // We will be working backwards over the rope.
Vector<JSString*, 32> workQueue; // Putting strings into a Vector is only OK because there are no GC points in this method.
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i) {
workQueue.append(m_fibers[i].get());
// Clearing here works only because there are no GC points in this method.
m_fibers[i].clear();
}
while (!workQueue.isEmpty()) {
JSString* currentFiber = workQueue.last();
workQueue.removeLast();
if (currentFiber->isRope()) {
JSRopeString* currentFiberAsRope = static_cast<JSRopeString*>(currentFiber);
for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->m_fibers[i]; ++i)
workQueue.append(currentFiberAsRope->m_fibers[i].get());
continue;
}
StringImpl* string = static_cast<StringImpl*>(currentFiber->m_value.impl());
unsigned length = string->length();
position -= length;
StringImpl::copyChars(position, string->characters8(), length);
}
ASSERT(buffer == position);
ASSERT(!isRope());
}
void JSRopeString::resolveRopeSlowCase(UChar* buffer) const
{
UChar* position = buffer + m_length; // We will be working backwards over the rope.
Vector<JSString*, 32> workQueue; // These strings are kept alive by the parent rope, so using a Vector is OK.
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i)
workQueue.append(m_fibers[i].get());
while (!workQueue.isEmpty()) {
JSString* currentFiber = workQueue.last();
workQueue.removeLast();
if (currentFiber->isRope()) {
JSRopeString* currentFiberAsRope = static_cast<JSRopeString*>(currentFiber);
for (size_t i = 0; i < s_maxInternalRopeLength && currentFiberAsRope->m_fibers[i]; ++i)
workQueue.append(currentFiberAsRope->m_fibers[i].get());
continue;
}
StringImpl* string = static_cast<StringImpl*>(currentFiber->m_value.impl());
unsigned length = string->length();
position -= length;
if (string->is8Bit())
StringImpl::copyChars(position, string->characters8(), length);
else
StringImpl::copyChars(position, string->characters16(), length);
}
ASSERT(buffer == position);
ASSERT(!isRope());
}
void JSRopeString::outOfMemory(ExecState* exec) const
{
for (size_t i = 0; i < s_maxInternalRopeLength && m_fibers[i]; ++i)
m_fibers[i].clear();
ASSERT(isRope());
ASSERT(m_value.isNull());
if (exec)
throwOutOfMemoryError(exec);
}
JSString* JSRopeString::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 jsEmptyString(exec);
ASSERT(!isRope());
ASSERT(i < m_value.length());
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) const
{
result = this;
number = jsToNumber(value(exec));
return false;
}
bool JSString::toBoolean() const
{
return m_length;
}
double JSString::toNumber(ExecState* exec) const
{
return jsToNumber(value(exec));
}
inline StringObject* StringObject::create(ExecState* exec, JSGlobalObject* globalObject, JSString* string)
{
StringObject* object = new (NotNull, allocateCell<StringObject>(*exec->heap())) StringObject(exec->globalData(), globalObject->stringObjectStructure());
object->finishCreation(exec->globalData(), string);
return object;
}
JSObject* JSString::toObject(ExecState* exec, JSGlobalObject* globalObject) const
{
return StringObject::create(exec, globalObject, const_cast<JSString*>(this));
}
JSObject* JSString::toThisObject(JSCell* cell, ExecState* exec)
{
return StringObject::create(exec, exec->lexicalGlobalObject(), jsCast<JSString*>(cell));
}
bool JSString::getOwnPropertySlot(JSCell* cell, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
{
JSString* thisObject = jsCast<JSString*>(cell);
// The semantics here are really getPropertySlot, not getOwnPropertySlot.
// This function should only be called by JSValue::get.
if (thisObject->getStringPropertySlot(exec, propertyName, slot))
return true;
slot.setBase(thisObject);
JSObject* object;
for (JSValue prototype = exec->lexicalGlobalObject()->stringPrototype(); !prototype.isNull(); prototype = object->prototype()) {
object = asObject(prototype);
if (object->methodTable()->getOwnPropertySlot(object, exec, propertyName, slot))
return true;
}
slot.setUndefined();
return true;
}
bool JSString::getStringPropertyDescriptor(ExecState* exec, PropertyName propertyName, PropertyDescriptor& descriptor)
{
if (propertyName == exec->propertyNames().length) {
descriptor.setDescriptor(jsNumber(m_length), DontEnum | DontDelete | ReadOnly);
return true;
}
unsigned i = propertyName.asIndex();
if (i < m_length) {
ASSERT(i != PropertyName::NotAnIndex); // No need for an explicit check, the above test would always fail!
descriptor.setDescriptor(getIndex(exec, i), DontDelete | ReadOnly);
return true;
}
return false;
}
bool JSString::getOwnPropertySlotByIndex(JSCell* cell, ExecState* exec, unsigned propertyName, PropertySlot& slot)
{
JSString* thisObject = jsCast<JSString*>(cell);
// The semantics here are really getPropertySlot, not getOwnPropertySlot.
// This function should only be called by JSValue::get.
if (thisObject->getStringPropertySlot(exec, propertyName, slot))
return true;
return JSString::getOwnPropertySlot(thisObject, exec, Identifier::from(exec, propertyName), slot);
}
} // namespace JSC